To achieve high-accuracy inversion of potato leaf area index (LAI) in the complex terrain of Southwest China and explain factors potentially affecting retrieval accuracy from the perspectives of surface spatial heterogeneity and model parameters, this study focused on potato cultivation areas in Zhaojue and Butuo Counties, Liangshan Prefecture, Sichuan Province. Based on Sentinel-2 imagery, an LAI inversion algorithm integrating the PROSAIL model and a neural network (NN) within SNAP was employed to achieve simple, efficient, and small-sample 10-meter LAI inversion with field validation. A comparison with the 500-m MODIS LAI product was further conducted to assess the advantages of high-resolution LAI in revealing spatial heterogeneity. The results showed that: (1) the 10-meter LAI retrieved using the PROSAIL+NN algorithm exhibited high overall accuracy, with a coefficient of determination (R²) of 0.86 and a root mean square error (RMSE) of 0.28 when compared with field measurements. Regional differences were evident—the retrieval accuracy in Butuo County sample area (RMSE=0.15) exceeded that in Zhaojue County sample area (RMSE=0.38), primarily associated with more complex topography (slopes 1°-14°) and higher surface heterogeneity. (2) Within 500-m pixels, the 10-meter LAI revealed an average within-pixel LAI variance of 2.17, which was 1.6 times the mean LAI of the study area. Furthermore, the maximum and minimum values of the MODIS LAI product were lower by 0.1 and 0.47, respectively, than the corresponding values from this study, and partial null pixels were present. This confirmed that the 10-meter LAI significantly surpasses the traditional 500-meter MODIS LAI product in quantifying spatial heterogeneity and ensuring data completeness. (3) Retrieval accuracy was also constrained by model input parameters: the SNAP default LAI range significantly exceeded the actual potato LAI range, resulting in some anomalous values. Additionally, insufficient representativeness of soil reflectance (ρ_soil) and overestimation of the Band 12 reflectance after atmospheric correction (maximum value 0.7, exceeding the model's valid input range of 0.5) increased uncertainty. The PROSAIL+NN inversion method used in this study enables simple and efficient acquisition of 10-meter LAI products, allowing for precise characterization of the spatial heterogeneity in potato growth across the complex topography of Southwest China. With minimal ground measurements, strong mechanistic underpinnings and transferability, this approach can serve as an effective pathway for crop information acquisition in the mountainous regions of Southwest China, supporting digital agriculture, crop monitoring, and agricultural management.

To optimize the drip irrigation scheme and explore the effect of drip irrigation amount on the yield and quality of edible sweet potato under medium fertility conditions in Beijing, a field experiment was carried out in Taishizhuang Village Experimental Station of Taishitun Town in Miyun from 2021 to 2022. The conventional flood irrigation was used as the control (CK), 'Yanshu 25' variety was selected as test material, and six drip irrigation treatments with varying water volumes were set. The results showed that drip irrigation applied before transplanting, during root-establishing and seedling-slowdown stage, and branching and tuber-setting stage, with water volumes of 375-450 m³/hm², saved 25%-38% water compared to conventional irrigation. Within this irrigation range, the ratio of above-ground fresh weight to underground fresh weight (T/R) per plant was 0.6-0.7, the sweet potato yield reached 46881.5-47699.4 kg/hm² (54.0%-56.7% higher than that of conventional irrigation), and the commercial tuber yield was 42214.0-43271.6 kg/hm². Different treatments had minor effects on crude protein content, fresh fiber content and soluble sugar content of sweet potato, but relatively greater impacts on dry matter weight. The results approve that under the condition of medium fertility in Beijing, the drip irrigation amount of 375-450 m³/hm² in the key growth period of 'Yanshu 25' is a suitable irrigation scheme to achieve high yield and high efficiency. This scheme can significantly save water resources while ensuring yield and quality, and provide scientific basis for precise irrigation of sweet potato.

【Objective】The potato is a nutrient-rich and widespread non-grain crop that can be eaten as a staple food or vegetable. To reveal the influence of high temperature stress on the growth and development of potato seedlings, this study screened and identified small RNAs (miRNAs) and potential target genes that specifically respond to heat stress, providing a theoretical basis for research on the thermotolerance mechanism in potatoes. 【Method】The experimental material used in this study was 1-month-old tissue-cultured seedlings of Longshu 7, a potato variety independently bred by the Potato Research Institute, Gansu Academy of Agricultural Sciences. After incubation in plant growth chamber under normal temperature (17 ℃) and high temperature (28 ℃) for 10 days, samples were collected and subjected to small RNA sequencing (sRNA-seq) and transcriptome sequencing (RNA-seq). Based on high-quality sequencing data, we used bioinformatics methods to analyze and screen candidate miRNA-target gene pairs exhibiting negative regulatory relationships. In addition, real-time quantitative PCR (RT-qPCR) and dual luciferase assays (DLR) were used to validate some miRNA-target pairs. 【Result】Under high temperature stress, the abundance of 21 and 24 nt miRNAs in potato seedlings increased significantly, and the overall variation of all miRNA expression levels was 27.0% for PC1, while PC1 and PC2 accounted for 39.4% of the overall variation. According to miRNAs differential expression analysis, a total of 100 miRNAs were obtained, including 62 upregulated and 38 downregulated. Among the upregulated miRNAs, the fold change ranged from 1.02 to 6.94; while the fold change ranged from 1.01 to 7.11 in the downregulated miRNAs list. Transcriptome analysis showed that 579 differentially expressed genes were upregulated and 958 differentially expressed genes were downregulated in potato seedlings under high temperature stress. These genes were mainly involved in responding to biotic stress, external stress stimuli, and other cellular components and developmental processes. Integration of sRNA-seq and RNA-seq analyses revealed that a total of 13 miRNA-target pairs were obtained in the up-regulated miRNAs, while 5 miRNA-target gene pairs were obtained in the down-regulated miRNAs. Then, we selected three pairs of differentially expressed regulatory relationships (miRNA8051-Soltu.DM.10G026540, miRNA8051- Soltu.DM.10G026560, and miR5072-Soltu.DM.04G010170) for RT-qPCR. The results revealed that miRNAs showed opposite expression trends with their potential target genes, consistent with the results of bioinformatics analysis. In addition, we analyzed the regulatory pair of miRNA8051-Soltu.DM.10G026540 or Soltu.DM.10G026560 using DLR assay, confirming that miRNA8051 has a negative regulatory effect on both Soltu.DM.10G026540 and Soltu.DM.10G026560. 【Conclusion】It was revealed that potato seedlings under high temperature stress would regulate the target genes expression in a post-transcriptional regulatory manner, thus producing certain adaptations to the adverse environment. These candidate genes may be involved in biological processes such as transcription factors, wax synthesis and epigenetic regulation of methylation.

【Objective】This study aimed to elucidate the mechanisms by which exogenous brassinolide (BR) alleviates the inhibitory effects of sweet potato virus disease (SPVD) complex on storage roots germination in sweet potato, so as to provide the theoretical insights for mitigating SPVD impacts on sweet potato seedling production. 【Method】SPVD-infected ‘Jishu 25’ storage roots were subjected to seed soaking treatments with varying BR concentrations (0.1, 0.5 and 1.0 μmol·L^-1) or brassinazole (BRZ, 0.1 μmol·L^-1). Germination kinetics, soluble sugar content, antioxidant enzyme activities (SOD, POD and CAT), reactive oxygen species (ROS) accumulation, malondialdehyde (MDA) content, and expression levels of BR biosynthesis genes (CYP85A1 and CYP90D1) were quantified to characterize BR/BRZ-induced alterations in cellular redox homeostasis and transcriptional regulation. 【Result】SPVD significantly suppressed storage roots germination. 7 d, 14 d, and 28 d after seedling cultivation, the storage roots of sweet potato infected with SPVD germinate later, and the number and quality of seedlings were reduced. During germination initiation stage (7-14 d): Lower BR concentrations (0.1-0.5 μmol·L^-1) enhanced quality of germination, elevated soluble sugar content, upregulated antioxidant enzyme activities, reduced ROS and MDA accumulation, and stimulated CYP85A1 and CYP90D1 expression. BRZ treatment exacerbated germination inhibition, suppressed antioxidant defenses, and increased oxidative damage. During the period of rapid germination (21-28 d), 0.1 μmol·L^-1 BR sustained germination promotion, reduced soluble sugar content, maintained high antioxidant activity, minimized oxidative stress, and further amplified BR biosynthetic genes expression. BRZ consistently impaired germination, antioxidant capacity, and BR genes expression. 【Conclusion】The germination of sweet potato storage roots infected with SPVD was significantly inhibited. The appropriate concentration of BR (0.1 μmol·L^-1) significantly alleviated the inhibition of SPVD on sweet potato storage roots germination by activating the antioxidant defense system, optimizing the dynamic balance of sugar metabolism, and enhancing the expression of endogenous BR synthesis genes.

In order to enrich the germplasm resources of color potato breeding in Fujian Province, 14 color potato varieties were used as the test materials. Firstly, the yield and nutritional quality performance of the varieties were analyzed, and then SSR molecular markers were used for genetic diversity analysis. The results showed that among all varieties, the anthocyanin content of 'Hei Meiren' was the highest at 41.83 mg/kg, while the protein content, yield and commercial potato rate of 'Fucaishu No.2' were the highest, which were 2.34 mg/g, 31,030.75 kg/hm² and 89.54% respectively. The highest Vc content of 'Jiu En Hong' was 26.27 mg/kg, and the highest dry matter content of 'Minshu No.11' was 23.91%. The genetic distances of the 14 varieties ranged from 0.162 to 0.603, with an average of 0.425. Among them, varieties such as 'Fucaishu No.2', 'Ziyun No. 1', and 'Huasong 66' have performed well comprehensively in Fujian Province. They can provide parent materials for the selection and breeding of new varieties in Fujian Province, and at the same time offer references for theoretical research on potato breeding in Fujian Province.

The virus-free tissue culture technology using potato stem tips is able to restore variety characteristics and improve potato yield and quality, making it one of the key biotechnologies in seed potato production. The entire process of virus-free tissue culture technology using potato stem tips was systematically elaborated, and its common problems along with control strategies were summarized. The technical procedure involved pretreatment of explants, shoot tip dissection, primary culture of plantlets, virus detection, and in vitro propagation of plantlets. During the primary culture stage, the explants were sterilized and pretreated, and then cultured in a specific medium to induce the differentiation of apical meristems into plantlets. The obtained primary plantlets were subjected to virus detection using serological and molecular biological methods. After confirming the absence of viruses, the plantlets were transferred to propagation and strengthening media for multiplication. 3 major issues encountered during the tissue culture process were contamination, vitrification, and browning. Contamination, caused by bacteria, fungi, or endophytes, was prevented through strict aseptic techniques, environmental sterilization, and the addition of antibiotics or bacteriostatic agents to the culture medium. Vitrified plantlets, characterized by a translucent and fragile appearance, were primarily induced by unsuitable culture conditions or excessive subculturing, and could be mitigated by adjusting light and temperature conditions, regulating hormone concentrations, and incorporating dark culture periods. Browning, a phenomenon where wounded explants secreted brown substances leading to death, was commonly suppressed by adding anti-browning agents such as sodium thiosulfate. This article provides a reference for the production of virus-free seed potatoes

To investigate the effects of different irrigation methods on the growth of sweet potato, a field experiment was conducted using the variety Luoshu 17 as test material. Three irrigation treatments were set up: ridge irrigation without mulch (P0), drip irrigation without mulch (P1), and drip irrigation with mulch (P2). Agronomic traits such as the longest vine length, and fresh stems and leaf weight, as well as yield per plant and total yield, were measured. The results showed that, in terms of agronomic traits, at 120 days after planting, the P2 treatment had lower values for the longest vine length, fresh leaf weight, root dry matter rate, and number of tubers per plant compared to the P1 treatment, while it had higher T/R ratio and number of basal branches. The P0 treatment exhibited lower values than P1 in the fresh leaf weight, T/R ratio, number of basal branches, and number of tubers per plant. Regarding yield, at 120 days after planting, both the yield per plant and total harvest yield of the P2 treatment were lower than those of P1. The P0 treatment showed a higher yield per plant but a lower total yield compared to P1. Overall, under the conditions of this experiment, the mulching treatment had a certain inhibitory effect on the growth and yield formation of sweet potato. Compared with ridge irrigation, drip irrigation was more conducive to the growth of sweet potato.

【Objective】The purpose of this study was to analyze the quantitative trait loci (QTLs) related to stem nematode resistance in sweetpotato (Ipomoea batatas (L.) Lam.), lay a foundation for the fine mapping, cloning, and functional analysis of stem nematode resistance genes in sweetpotato. It also aimed to provide support for the study of the genetic mechanisms of stem nematode resistance, as well as the breeding of resistant varieties in sweetpotato.【Method】An F₁ population of 212 progenies derived from a cross between the highly resistant cultivar Yushu 10 and the susceptible line Xin 24 was used. In this study, field-based natural infection assays were conducted to evaluate stem nematode resistance. QTL mapping was performed using composite interval mapping (CIM), and candidate genes within QTL confidence intervals were predicted. Additionally, genome-wide association studies (GWAS) were carried out using the rMVP software (a memory-efficient, visualization-enhanced, and parallel-accelerated R package). For further validation, the resistant cultivar Zhenghong 22 was artificially inoculated with D. destructor, and samples were collected at different post-inoculation time points. The expression patterns of five candidate genes (itf02g19880, itf02g20080, itf02g20100, itf13g18480 and itf13g18550) were analyzed via qRT-PCR.【Result】Three QTLs (qSNR02-1, qSNR02-2, and qSNR13-1) were identified, distributed on chromosomes 2 and 13. The phenotypic contribution rate of the individual QTL related to stem nematode resistance ranged from 9.6% to 11.7%. GWAS revealed one significantly associated locus with stem nematode resistance on chromosome 6. Based on the genomic annotation information, 36 candidate genes related to stem nematode resistance were predicted within the QTL confidence intervals, including members of the ABC transporter family, multidrug and toxic compound extrusion (MATE) efflux proteins, E3 ubiquitin ligases, and glutathione S-transferases, which are involved in defense mechanisms, post-translational modification, and stress response. qRT-PCR results showed that the expression patterns of the five candidate genes were significantly different. The expression level of itf02g20100 reached a peak at 3 days after inoculation, which was 6.2 times that of the control; the expression level of itf02g19880 increased sharply and reached the highest level at 0.5 days after inoculation, which was 43.2 times that of the control; the expression patterns of itf13g18480 and itf13g18550 were similar, and both reached a peak at 7 days after inoculation. This indicates that different candidate genes may play different regulatory roles in the defense response after Ditylenchus destructor infection.【Conclusion】Three QTLs related to stem nematode resistance in sweetpotato were identified, and 36 related candidate genes were screened out, which can be used for the subsequent cloning and functional study of genes related to stem nematode resistance in sweetpotato.

To investigate nutritional quality changes law of dual-purpose sweet potato varieties during storage and provide theoretical guidance for further utilization (processing, consumption, etc.), this experiment used three varieties 'Shangshu No.19', 'Luoshu No.11' and 'Luoshu No.16' as test materials. Statistical trait data were collected during storage, and nutritional quality data were obtained using colorimetric methods. Statistical software was employed for data analysis. The results showed that a significant negative correlation existed between marketable tuber rate and dry matter consumption rate (coefficient of determination: 0.99874). Moisture consumption rate showed significant annual variations (P<0.01). Trends in nutritional quality indices varied complexly among varieties during storage. Ash content and crude protein content exhibited a highly significant positive correlation (coefficient of determination: 0.9819), while no unified correlations were observed among other quality indices. Dry matter consumption rate serves as a relatively precise indicator for evaluating sweet potato storability. For industrial starch extraction, targeted cultivar selection is required based on specific storage duration requirements. The complex dynamics of nutritional quality in dual-purpose sweet potatoes during storage warrant further investigation.

To investigate the influence of different plastic film mulching on sweet potato growth, three cultivars, ‘Yanshu 25’, ‘Hami’, and ‘Long 9’, were used as test subjects. The effects of black film mulching, white film mulching, and black and white film mulching on the main agronomic traits and yield of sweet potatoes were studied. The results demonstrated that plastic film mulching improved all measured agronomic traits and yield to varying degrees, with the most significant enhancements observed under black-white composite film and black film mulching. Compared to the non-mulching control (P<0.05), black-white film mulching treatment increased the yield of ‘Yanshu 25’ and ‘Hami’ by approximately 20%. Across the three cultivars, the yield improvement followed this order: black-white film > black film > white film > no mulching. Correlation analysis between agronomic traits, quality, and yield revealed that branch number per plant, marketable rate, and dry matter content showed significant correlations with aboveground fresh weight, while yield was significantly correlated with underground fresh weight. The response to different mulching treatments varied among sweet potato cultivars, which may be attributed to intrinsic crop characteristics and their adaptability to environmental conditions. This study shows that black and white plastic film mulching significantly improves the yield and quality of sweet potato, and has important application prospects.

马铃薯中的龙葵素（α-茄碱和α-卡茄碱）是一类具有生物活性的甾体糖苷生物碱（Steroidal glycoalkaloids, SGAs），属于植物次生代谢产物。这类化合物由疏水的甾体骨架（茄啶醇）和亲水的寡糖链组成，主要分布在马铃薯的块茎、芽眼和表皮组织中。龙葵素在植物防御系统中发挥重要作用，能够抵抗病原微生物和害虫侵袭，但当其含量超过200 mg/100 g鲜重时，会对人体产生毒性作用，引起胃肠道不适和神经系统症状。其生物合成途径起始于胆固醇，经过一系列氧化、转氨和糖基化反应，最终由糖基转移酶催化完成。光照、机械损伤和贮藏条件等因素均可诱导龙葵素含量升高，这既是马铃薯重要的品质安全指标，也是育种研究中需要重点调控的目标性状。该研究以二倍体马铃薯自交系E4-63为材料，将E4-63各组织中龙葵素含量与龙葵素合成基因的表达量进行相关性分析，发现SGT3基因表达量与龙葵素含量呈极显著正相关（r = 0.894），其编码的糖基转移酶催化了龙葵素生物合成的最后一步。深入研究发现，在SGT3基因启动子区存在TATA-box重复序列的自然变异，形成 (TA)₁₀和 (TA)₁₃两种单倍型。通过双荧光素酶报告系统等实验证实，pro::SGT3(TA)₁₀的启动子活性显著高于pro::SGT3(TA)₁₃单倍型的，从而导致SGT3基因表达量增加和SGAs积累升高。通过对137份马铃薯种质的基因型-薯块龙葵素含量关联分析，发现pro::SGT3(TA)10单倍型在高SGAs材料中出现频率达92%，显著高于低SGAs材料中的68%。基于这一发现，研究团队开发了可区分SGT3启动子单倍型的分子标记，为马铃薯低毒品种选育提供了重要工具。该研究首次将启动子变异与薯块SGAs含量建立直接关联，相比基因编辑等人工干预手段，利用自然存在的pro::SGT3(TA)13单倍型降低SGAs含量，既避免了中间代谢产物积累的风险，又符合食品安全要求。研究成果不仅深化了对植物次生代谢调控的理解，也为马铃薯分子设计育种提供了新思路。通过分子标记辅助选择，可以实现对薯块SGAs含量的精准调控，对培育兼具抗病性和食用安全性的马铃薯新品种具有重要意义。

In order to breed a new dual-purpose sweet potato variety with high yield and quality, which can be used for both fresh food and starch processing, ‘Rongshu 910’ was bred by group hybridization with ‘Rongshu 756’ as female parent. The variety was involved in the regional test and production test of new sweet potato varieties in Fujian Province from 2014 to 2016. The results of multi-point test showed that the fresh potato yield, dry potato yield and starch yield of the variety were significantly higher than those of the control variety ‘Jinshan 57’; and the variety had high yield stability, good taste quality, moderately resistance to fusarium wilt and good storage performance. ‘Rongshu 910’ passed the national registration of non-major crop varieties in 2019 [GPD sweet potato (2019) 350022], obtained the right of new plant varieties in 2022 (CNA20193211.5), and was listed as the leading variety in Fujian Province in 2024.

To prevent and control the spread of potato cyst nematode, a research on field control methods for this pest was carried out. In the experiment, dazomet fumigation and fosthiazate hole application were adopted. The effects of these measures on potato production were analyzed through various indicators, such as the SPAD value and nitrogen content of the leaves, plant height, plant weight, yield at maturity, and the number of potato cyst nematodes at the pre-sowing, flowering, and maturity stages of the potatoes, and the control effect of potato cyst nematode. The results revealed that both of the treatments significantly improved the plant height and enhanced photosynthesis of leaves. At the same time, the control measures reduced the infection of potato roots by cyst nematode. The average control efficacy of dazomet fumigation for potato new cysts nematode was 91.07%, which was significantly higher than that of fosthiazate hole application and control treatment. Compared with the control, dazomet fumigation and fosthiazate hole application increased the average yield by 20.13% and 9.69%, respectively. Dazomet fumigation was notably more effective in suppressing the potato’s infection of potato cyst nematode than fosthiazate hole application, and it also substantially increased the rate of big tuber and potato yield.

Potatoes represent the primary crop in Ningxia, serving as a pivotal industry for rural revitalization in the region. Leveraging agricultural meteorological data and daily weather records from potato planting areas in Ningxia, this paper employs a climate suitability assessment model. A spatiotemporal analysis of the climate suitability characteristics for potatoes in Ningxia is conducted. The findings reveal that, examining the comprehensive suitability index ratios for different decades during various developmental stages, the past decade demonstrates a relatively balanced average suitability index across different growth stages, followed by the 1970s. In contrast, other decades exhibit significant variations in suitability index ratios during different growth stages, with one or more stages showing lower suitability. Poor coordination of light, temperature, and water is identified as a climatic factor contributing to the pronounced inter-decadal fluctuations in potato yields. Under the backdrop of climate change, with increased heat resources, early-maturing plastic-mulched potatoes can be sown slightly later. Later flowering helps avoid high-temperature drought during flowering while coinciding with increased precipitation. Provided that the heat resources are sufficient to ensure maturity, sowing slightly later can also be beneficial for increasing yield. Spatially, the extremely suitable areas for potato cultivation include the entire territories of Haiyuan County and Xiji County, as well as most regions of Longde County, Jingyuan County, and Yuanzhou District, except for the high-altitude Liupan Mountain ridge, and the western part of Pengyang County. These regions have relatively favorable precipitation conditions, and although the sunshine is slightly less, it can still meet the growth requirements of potatoes. The suitable areas are in the majority of Tongxin County and the eastern part of Pengyang County. However, Tongxin County has less precipitation, which restricts the growth of potatoes and makes its climatic resources inferior to the previous region. The relatively suitable area is in the southern part of Yanchi County, where precipitation is scarce and droughts are common. The northern part of Yanchi County is an unsuitable area. The research results have scientific guiding significance for actual potato production and can provide scientific support for the layout and quality improvement of the potato industry.

To optimize and promote the techniques of potato planting and field management, based on the production practice of potato planting, the technical key points were summarized in the process of its planting and field management from four aspects: variety selection, soil improvement, sowing and fertilization, and field management. Including giving priority to the selection of high quality, high yield and disease resistant varieties; implement in-depth cultivation and carry out reasonable crop rotation; determine the sowing time based on climatic conditions, and determine the sowing density and depth based on the characteristics of the variety; apply fertilizers scientifically and appropriately increase the application of nitrogen, phosphorus and potassium fertilizers; strengthen hoeing, soil mounding and water management, and appropriate microbial preparations, chemical agents, etc. are adopted to control diseases and pests such as late blight, cutworms and aphids. The above measures have increased the yield and quality of potatoes and improved the economic benefits of growers. This article provides a reference for the scientific planting and field management of potatoes.

To explore the effects of different degrees of fertilizer reduction and compost application on potato yield and quality in semi-arid areas of Ningxia, the potato cultivar ‘Qingshu 9’ was used as the test material, and a single factor randomized block design was used to set up six fertilizer reduction treatments, namely CK (single application of chemical fertilizer), T1 (chemical fertilizer reduction 10%+ composting 30000 kg/hm²), T2 (chemical fertilizer reduction 20%+ composting 30000 kg/hm²), T3 (chemical fertilizer reduction 30%+ composting 30000 kg/hm²), T4 (chemical fertilizer reduction 40%+ composting 30000 kg/hm²) and T5 (composting 30000 kg/hm²). The results showed that the yield of T4 treatment was significantly higher than that of other treatments, and the highest yield was 30434.85 kg/hm², which was 106% higher than that of CK treatment. In terms of quality, with the increase of chemical fertilizer reduction, the contents of potato starch, Vitamin C and soluble sugar decreased first, then increased and then decreased. Among them, the quality of T4 treatment was the best, and the contents of starch, Vitamin C and soluble sugar were 23.33 g/100 g, 24.73 mg/100 g and 1.00%, respectively. Through principal component analysis of yield and quality indicators, T4 treatment with 40% reduction of chemical fertilizer was the optimal treatment. Under the condition of semi-arid area in Ningxia, the goal of high yield and high quality can be achieved when the chemical fertilizer is reduced by 40%.

To investigate the effects of liquid mulch on potato yield composition and soil physicochemical structure, considering the arid and semi-arid climatic characteristics of Inner Mongolia, liquid mulch was selected as the mulching material in this study with a view to increasing potato yield and reducing pollution to the environment. The experiment was conducted in Wuchuan County, Hohhot City, Inner Mongolia Autonomous Region, and three treatment plots were set up, namely, basic liquid mulch (A), functional liquid mulch (B) and open field cultivation (CK). The results showed that through comparative analysis, the potato yield of the functional liquid mulch (B) treatment was the highest, reaching 1.98 kg/plant, with an increase of 0.26 kg per plant over the bare-ground (CK) treatment, with a yield increase of 15.12%. In addition, the commercial potato yield and commercial potato rate of the functional liquid mulch treatment were higher than those of the other treatments, indicating its superiority in improving the economic traits of potato. The results of soil nutrient analysis showed that there were significant differences in organic carbon, total phosphorus, pH and effective phosphorus content of soil under different mulching film treatments. Among them, the organic matter content was higher in the soil treated with functional liquid mulch. The economic benefit analysis showed that the functional liquid mulch film cover had higher profit and reduces the environmental problems of plastic mulch film at the same time. In terms of ecological benefits, the use of biodegradable liquid mulch was of great benefit to the alleviation of “white pollution” and the promotion of sustainable green development of agriculture. In summary, functional liquid mulch shows significant advantages in improving potato yield and quality and reducing environmental pollution, and it is an agricultural technology with good economic and ecological benefits.

To investigate the effects of the potato-legume intercropping system on soil enzyme activity and potato yield in the arid region of southern Ningxia, a field positioning experiment with three different planting patterns, including potato monoculture (P), potato-soybean intercropping (PS), potato-broad bean intercropping (PB) were conducted for two consecutive years from 2020 to 2021 to explore the differences of soil enzyme activity and potato yield in different intercropping patterns. The results revealed that intercropping significantly enhanced the activities of catalase, urease, sucrase and acid phosphatase in 0-60 cm soil. The enzyme activities of each treatment were basically manifested as PS>PB>P, which increased first and then decreased during the whole growth period, and gradually decreased with the deepening of soil layer. In 2020, the activities of catalase, urease, sucrase and acid phosphatase of PS were 0.51%-4.69%, 7.96%-152.23%, 3.22%-192.00%, 5.75%-175.80% and 1.28%-9.10%, 4.11%-53.99%, 3.61%-140.27%, 4.27%-133.7% higher than those of PB and P, respectively. In 2021, the activities of catalase, urease, sucrase and acid phosphatase of PS were 0.20%-4.63%, 0.84%-93.93%, 4.26%-143.26%, 4.85%-50.41% and 0.13%-8.83%, 0.05%-94.53%, 1.13%-334.33%, 7.15%-99.34% higher than those of PB and P, respectively. The potato yield showed PS>PB>P in both years. In 2020, PS and PB significantly increased by 13.96% and 5.33% compared with P, respectively. In 2021, PS and PB significantly increased by 33.85% and 14.31% compared with P, respectively (P<0.05). Through principal component analysis, the comprehensive scores of P, PS and PB in 2020 and 2021 were -0.79, 2.55, -1.75 and -2.69, 3.36, -0.68, respectively, and PS was the highest in both years. The intercropping of potato and leguminous crops promoted the increase of soil catalase, urease, sucrase and acid phosphatase activities, which provided a certain basis for soil formation and soil fertility improvement, and provided a better environment for potato growth and development, thus increasing the yield of potato. In this study, potato-soybean intercropping had the advantage of intercropping and could significantly increase potato yield.

【Objective】 This study aimed to explore the effects of straw and green manure mulching on soil fertility and crop yield on the dryland in southwest China, so as to provide the theoretical basis and practical guidance for exploring reasonable, efficient and ecologically healthy conservation tillage measures in southwest China. 【Method】 The sweet potato field in the "broad bean/maize/sweet potato" dry three-crop intercropping mode in southwest China was selected as the research object, and four treatments were set up: no mulching (CK), straw mulching (S), straw and milk vetch mulching (S+M), and milk vetch mulching (M). The effects of different treatments on soil characteristics and soil fertility, sweet potato dry matter content in the sweet potato field were studied. 【Result】(1) Compared with no-mulching treatment, straw and milk vetch mulching could improve the physical and chemical properties and biological characteristics of soil in sweet potato field. Among them, straw and milk vetch mulching had the best effect. (2) The comprehensive evaluation of soil fertility based on principal component analysis showed that soil fertility under straw and milk vetch mulching treatment was higher than that under no mulching treatment, and the comprehensive scores of straw and milk vetch mulching treatment were the highest in both rhizosphere and non-rhizosphere soil. (3) S+M treatment significantly improved the dry matter quality of various organs of sweet potato and sweet potato yield, the yield of sweet potato under S+M, S and M treatment was 34.53%, 14.60% and 11.55% higher than that under CK treatment, respectively.【Conclusion】Straw and milk vetch mulching in the dryland, triple cropping systems of southwest China, could effectively improve the physical and chemical properties and biological characteristics of soil, enhance soil fertility, and improve dry matter quality and yield.

In order to screen out new potato varieties suitable for field planting in Ningxia, two varieties of 'Jizhangshu 8' and 'Hutou' were planted by double ridge side hole sowing in the field environment, and 10 treatments such as different film colors and film mulching methods were set up. The results were analyzed by variance and repeated comparison. The results showed that the water content of black film was 5.1% higher than that of 0-20 cm open soil, and 2.3% higher than that of white film. The ground temperature was 0.6℃ higher than that in the open field and 1.5℃ lower than that in the white film field at 0-20 cm of autumn tuber swelling stage. The average yield of black film covered potato was 27000 kg/hm², which was 4500 kg/hm² higher than that of white film covered potato and 10500 kg/hm² higher than that of open field, with the increases of 20% and 63.6% respectively. The yield of black film was significantly higher than that of white film, and the yield of full film significantly higher than that of half film. The yield of 'Jizhang Potato 8' was significantly higher than that of 'Hutou', in which the weight of a single plant with black full film was 488 g higher; the output was 16311 kg/hm² higher, increasing by 306.5%, and the effect of increasing production was very significant. In terms of planting density, under the planting density of 30000 plants /hm², the yield was the highest, and the increase rate reached 27.7%. It is suggested to popularize 'Jizhang Potato 8' in a large area, which increase yield by more than 3 times under black full film cultivation by drip irrigation.

The study aims to select new potato varieties suitable for cultivation in winter in Longhai District, Zhangzhou City, and to promote the green and sustainable development of the potato industry. This study selected nine new potato varieties including ‘Zhongshu 50’, ‘Minshu 12’, ‘Yunshu 109’, ‘Longshu 24’, ‘Shiyan 1’, ‘Funong 4’, ‘Funong 5’, ‘Huasong 3’ and ‘Wotu 5’ as experimental materials for variety screening, the variety ‘Favorita’ was used as the control. The results indicated that the comprehensive characters of tubers of these 9 new varieties were recognized by the market with yellow-skin, yellow-flesh and oval-shape, which were not significantly different from ‘Favorita’. Compared to the control group, the fresh potato yield of ‘Funong 4’, ‘Funong 5’, ‘Zhongshu 50’, ‘Wotu 5’, ‘Huasong 3’, ‘Minshu 12’ and ‘Shiyan 1’ were increased by 42.63%, 39.66%, 29.00%, 25.39%, 20.69%, 10.19%, and 9.56%, respectively. Conversely, ‘Yunshu 109’ and ‘Longshu 24’ showed a decrease of 19.91% and 7.37%, respectively (P<0.01). In terms of overall quality of large and medium-sized potatoes, including yield, dry matter content, and taste, the ranking was as follows: ‘Funong 5’, ‘Funong 4’> ‘Wotu 5’, ‘ Shiyan 1’, ‘Huasong 3’> ‘Favorita’, ‘Zhongshu 50’> ‘Minshu 12’, ‘Yunshu 109’, and ‘Longshu 24’. Regarding field late blight resistance, ‘Longshu 24’ and ‘Huasong 3’ were as susceptible as ‘Favorita’, while the other varieties exhibited moderate susceptibility. The growth period for each variety ranged from 83 to 89 days. Additionally, ‘Minshu 12’, ‘Longshu 24’, and ‘Zhongshu 50’ displayed varying degrees of secondary growth, hollowing, and splitting of potatoes, whereas no such physiological defects were observed in the other varieties. In conclusion, the comprehensive performance of ‘Funong 4’, ‘Funong 5’, ‘Zhongshu 50’, ‘Wotu 5’, ‘Huasong 3’, and ‘ Shiyan 1’ in Longhai District surpasses that of ‘Favorita’. It is recommended that ‘Funong 4’ and ‘Funong 5’ can be used as primary varieties, while ‘Zhongshu 50’, ‘Wotu 5’, ‘Huasong 3’, and ‘Shiyan 1’ serve as alternative varieties for demonstration and promotion in local winter potato production.

In order to reveal the difference between thick root (TR) and storage root (SR) of sweetpotato with difference drought tolerance from transcriptional level, and further explicit the mechanism of roots differentiation and drought tolerance by simulating field drought in dry shed with artificial water control, two varieties including ‘Jishu21’ (‘JS21’ ) with strong drought tolerance and ‘Jizishu1’ (‘JZ1’) with weak drought tolerance were chosen as research materials. Transcriptome analysis of sweet potato thick root and storage root was carried out. The results indicated GO classification of differentially expressed genes (DEGs) of the two varieties was similar to that of KEGG enrichment. Under drought stress, 84 DEGs between SR and TR of ‘JS21’ mainly enriched the accumulation of starch and sucrose metabolic pathway, while 112 DEGs between SR and TR of ‘JZ1’ mainly enriched ribosomal metabolic pathway. Among different varieties, 224 DEGs between ‘JS21’ and ‘JZ1’ were found in SR, but 204 DEGs between ‘JS21’ and ‘JZ1’ were counted in TR, and all mainly enriched ribosomal metabolic pathway. Further analysis by transcription factors and hormones metabolism showed that ARF-like transcription factors in storage root and NAC-like transcription factors in thick root of ‘JS21’ were more differentially expressed than ‘JZ1’ under drought stress. The expression of genes involved in carotenoid biosynthesis pathway was up-regulated, while genes involved in brassinosteroid biosynthesis pathway were down-regulated in both thick root and storage root of ‘JS21’. In the same variety, the gene expression of α-linolenic acid metabolic pathway in ‘JS21’ storage root was up-regulated compared with thick root. In conclusion, sweetpotato with strong drought tolerance can maintain starch and sucrose metabolism under drought conditions by coordinating the expression of drought tolerance genes and growth-related transcription factors, balancing drought tolerance hormones (ABA, JA) and growth related hormones (IAA, BR), so as to improve the drought resistance and ensure the formation of yield.

In order to explore the difference of selenium enrichment ability of different sweet potato strains, 22 excellent sweet potato strains independently selected by Fuzhou Institute of Agricultural Sciences were used as test materials, and ‘Guangshu 87’ with strong selenium enrichment ability was used as the control variety. 22 independently bred sweet potato strains were selected as materials, and ‘Guangshu 87’ was used as the control variety. The comparative experiment of selenium enrichment ability was carried out by spraying exogenous organic selenium fertilizer on the leaves. The results showed that: (1) Cluster analysis of selenium content in sweet potato tubers of different strains treated with selenium fertilizer showed that the strains with high enrichment and medium high enrichment types included nine strains such as ‘Rongshu 2306’, ‘Rongshu 2321’, ‘Rongshu 2310’, ‘Rongshu 2305’, ‘Rongshu 2322’ and so on. ‘Rongshu 2306’, ‘Rongshu 2301’, ‘Guangshu 87’, ‘Rongshu 2315’ and ‘Rongshu 2321’ ranked the top five in the increase rate of selenium content in tubers compared with the control. (2) There were differences in selenium accumulation of sweet potato tubers among different strains treated with selenium fertilizer. The top five strains included ‘Rongshu 2306’, ‘Guangshu 87’, ‘Rongshu 2315’, ‘Rongshu 2301’ and ‘Rongshu 2310’. The selenium absorption and utilization rates of different strains of sweet potato tubers were quite different. The strain with absorption and utilization rates of more than 5% was ‘Rongshu 2306’, and the strains with absorption and utilization rates of more than 3% included ‘Rongshu 2301’, ‘Rongshu 2315’, ‘Guangshu 87’, ‘Rongshu 2321’, ‘Rongshu 2310’ and so on. (3) Cluster analysis of selenium sensitivity of different sweet potato strains showed that ‘Rongshu 2306’, ‘Rongshu 2315’ and ‘Rongshu 2301’ were more sensitive to selenium. The selenium sensitivity index was between 0.89 and 0.91, and the yield increase rate of selenium fertilizer treatment was between 9.82% and 12.48% compared with the control. In conclusion, ‘Rongshu 2306’, ‘Rongshu 2301’ and ‘Rongshu 2315’ had strong selenium enrichment ability and high fresh tuber yield, which were suitable for planting as selenium-enriched sweet potato varieties and parent materials for breeding new selenium-enriched sweet potato varieties.

This study investigated the effects of different fertilization treatments on sweet potato growth, nutrient utilization, and soil quality using liquid fertilizers compounded from hydrothermal cracking products of agricultural and forestry residues, to provide a scientific basis for the application of hydrothermal cracking liquid fertilizers in sweet potato cultivation. A randomized block design was conducted with five treatments: no fertilizer (CK), conventional solid water-soluble fertilizer (CF), conventional solid water-soluble fertilizer plus micro-element liquid fertilizer (CFMI), macro-element liquid fertilizer (MA), and macro-element plus micro-element liquid fertilizer (MAMI). Quantitative analyses were conducted to evaluate the impact of these fertilization treatments on sweet potato yield and quality, economic benefits, nutrient absorption and utilization efficiency, and soil physicochemical properties. The results showed that compared to the CK treatment, all fertilization treatments significantly enhanced sweet potato yield, quality and economic benefits. Compared to the CF treatment, the application of hydrothermal cracking liquid fertilizers significantly increased the number of marketable roots per plant, individual root weight, fresh root yield, marketable root yield and the proportion of marketable roots, as well as the content of soluble sugar, vitamin C and carotene. Particularly under the MAMI treatment, the fresh root yield and marketable root yield increased by 13.7% and 19.8%, respectively, and the output/input ratio improved by 16.3%, demonstrating significant enhancement of yield and economic benefits. Additionally, the use of hydrothermal cracking liquid fertilizers did not significantly reduce soil pH nor did it lead to excessive nutrient accumulation. However, it enhanced nutrient (N, P, K) utilization efficiency and agronomic efficiency, thereby reducing resource waste. In summary, liquid fertilizers compounded from hydrothermal cracking products of agricultural and forestry residues are highly efficient, which can promote the yield and quality of sweet potatoes and improve the soil environment. The results support the potential agricultural application of hydrothermal cracking liquid fertilizers in sustainable sweet potato cultivation.

Re-domestication of diploid potato (Solanum tuberosum) into a seed crop is an innovative breeding method to accelerate genetic improvement. Seed propagation would allow hybrid production and mix superior alleles. However, almost all diploid potatoes in nature are self-incompatible (SI). Gametophytic self-incompatible (GSI) is a widespread SI in Solanaceae and is controlled by the S locus that contains a ribonuclease (S-RNase) and multiple F-box (SLFs); however, the genetic diversity of the S locus in potato is unclear. In this study, we identified 21 S-RNase alleles involved in SI from 194 diploid potato accessions by large-scale transcriptome sequencing. The levels of amino acid similarity among different S-RNase proteins varied from 31.3 to 95.8%. S2 alleles is the most widespread in 194 diploid potato and is mainly distributed in the S. tuberosum Group Phureja. Based on genomic annotation and expression analysis, we identified 12 potential functional SI male-determinant genes, S-locus F-box (SLFs), encoding F-box proteins in the S2 locus on a genomic region of approximately 13 Mb. Comparative genomics analysis showed that eight SLF genes are relatively conserved among four homozygous S locus. The Ka and Ks analysis suggested that S-RNase and intra-haplotypic SLF genes have undergone co-evolved. These findings can not only help to select suitable pollinators but also to combine more hybrid combinations and make full use of heterosis to accelerate diploid potato breeding.

The TSJT1 protein belongs to the superfamily of class-II glutamine amidotransferases (GATase). There is little research on the functions and underlying mechanisms of TSJT1 in plants.  In this study, an abscisic acid (ABA)-inducible gene IbTSJT1 was isolated from drought-tolerant sweetpotato line ‘Xushu55-2’.  Its expression was strongly induced by PEG6000 and ABA.  The IbTSJT1 protein was localized in the nucleus and cell membrane.  The IbTSJT1-overexpressing sweetpotato plants exhibited significantly enhanced drought tolerance.  Their ABA and proline contents and superoxide dismutase (SOD) and peroxidase (POD) activities were increased and reactive oxygen species (ROS) scavenging-related genes were upregulated under drought stress.  The stomatal aperture assay confirmed that the IbTSJT1-overexpressing plants increased the sensitivity to ABA.  Yeast one-hybrid (Y1H) assay, electrophoretic mobility shift assay (EMSA), luciferase reporter assay and ChIP-qPCR assay indicated that IbABF2 could directly bind to the cis-acting ABA-responsive element (ABRE) in the IbTSJT1 promoter to activate the expression of IbTSJT1.  These findings suggest that IbTSJT1 mediates ABA-dependent drought stress responses and enhances drought tolerance by inducing stomatal closure and activating ROS scavenging system in transgenic sweetpotato.  Our study provides a novel gene for improving drought tolerance of sweetpotato and other plants. 

To improve the grain and oil yield per unit land area, suitable soybean varieties under the potato, corn and soybean compound planting model in shallow mountain and hilly areas were screened. 2 belt types (1.67 and 2.00 m) of potato, corn, and soybean compound planting models were set up, and comprehensive analysis and evaluation were conducted on the growth period, biological traits, agronomic traits, and yield traits of 9 soybean varieties (Qindou 2018, Qihuang 34, Shankendou 4, Zhonghuang 13, Shandou 125, Yandou 15, Yandou 11, Baodou 12, and Baodou 312). The results showed that there was no significant difference in the maturity and growth stages of various soybean varieties under different belt type compound planting models. Belt types had a certain impact on the growth habits and lodging resistance of soybean plants. As the width of the band increased, the lodging levels of Qihuang 34, Zhonghuang 13 (CK), Yandou 15, and Baodou 312 decreased. The main agronomic traits such as plant height and pod height of various soybean varieties did not show significant changes under different intercropping patterns. Each variety was affected by different degrees of diseases and pests, and attention should be paid to preventing and controlling diseases and pests in production. The yield of Qihuang 34 was higher under the 1.67 and 2.00 m belt type compound planting models, with 886.67 and 1 150.57 kg/hm², respectively. Overall, Qihuang 34 has lodging resistance and performs well in comprehensive agronomic traits, promoting planting the potato, corn and soybean compound planting model in the shallow mountain and hilly areas.

The study aims to investigate the effect of potato starch that is irradiated by γ-ray radiation on the properties of starch film. Starch was irradiated by ⁶⁰Co-γ-ray radiation with different absorbed doses (0-50 kGy) and the starch films were made. The prepared films were characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results showed that γ-ray radiation caused the breakage of glucoside bond and the breakdown of starch long chain molecules. The tensile strength and elongation at break of starch film increased and then decreased with increasing absorbed doses, the light transparent of starch film decreased and then increased. When the absorbed dose was 10 kGy, the mechanical properties of the film was the best, the elongation at break and the tensile strength were 62.37% and 3.73 Mpa respectively, however, the light transmission of the film was the worst, with the opacity value of 1.29. The solubility of film increased with the increase of absorbed dose. Insoluble starch granules decreased and the surface of starch films became more and more smoothed with increasing absorbed does. γ-ray radiation could effectively destroy the molecular structure and break starch molecular chain. The mechanical properties, light transmittance, water solubility and film forming properties of starch film could be significantly changed by irradiation.

To select suitable potato varieties with different maturity periods for cultivation in the Western Sichuan Plateau, this study analyzed 12 yield and quality related traits across 18 potato varieties of different maturity periods, and further comprehensively evaluated their performance of yield and quality by combining multiple linear regression and correlation analysis. Our results showed that in early-maturing varieties, the variation coefficients of the number of tubers per plant, average single tuber weight, and vitamin C content were more than 30%, yield was significantly positively correlated with the number of main stems, and commodity potato rate was significantly positively correlated with average single tuber weight. There was a significant negative correlation between the commodity potato rate and both the number of tubers per plant and vitamin C content. In mid-late-maturing varieties, the variation coefficients of the number of main stems, vitamin C, and reducing sugar content were more than 30%, the commodity potato rate was significantly positively correlated with average single tuber weight, while growth period was significantly negatively correlated with plant height, starch, and reducing sugar content. This study clarified that the yield of early-maturing varieties was related to the number of main stems, number of tubers per plant and commodity potato rate, while the yield of mid--late-maturing varieties waas related to the commodity potato rate and number of tubers per plant. These findings provided a reference for screening and breeding of potato varieties in the Western Sichuan Plateau.

To investigate the effects of different organic fertilizers on the yield and quality of purple sweet potatoes, a field experiment was conducted in 2023 at the experimental base of Tai’an Academy of Agricultural Sciences using ‘Taizishu 1’ as the test sweet potato variety. Six treatments were designed, including no fertilization, single chemical fertilizer, and 50% reduced chemical fertilizer combined with pig manure, cow manure, sheep manure, and chicken manure. The study analyzed the impacts of these treatments on agronomic traits, dry matter distribution, yield, and quality of purple sweet potatoes. The results showed that the purple sweet potato stem treated with pig manure had the thickest diameter, at 14.95 cm, an increase of 15.71% compared to the single chemical fertilizer treatment; the aboveground dry weight of sheep manure treatment was the heaviest, at 197.62 g, 30.33% higher than the single chemical fertilizer treatment; the proportion of dry matter distribution in the tubers treated with cow manure was the highest, at 71.82%, which increased by 11.47% compared to the single chemical fertilizer treatment; the yield and commodity rate of purple sweet potato tubers treated with pig manure were the highest, which were 48607.95 kg/hm² and 79.25%, respectively; the soluble sugar content in purple sweet potato tubers treated with pig manure was the highest, at 38.75 mg/g, significantly higher than other treatments. Research has shown that the combination of pig manure and chemical fertilizers can promote the coordinated growth of the aboveground and underground parts of purple sweet potatoes, promote the rational distribution of dry matter, and thereby increase the quantity, rate, weight, yield, and soluble sugar content of commercial sweet potatoes. The effect is superior to the combination of other organic fertilizers and chemical fertilizers. This research provides a theoretical foundation for high-quality and high-yield cultivation techniques of purple sweet potatoes.

Biogenic pesticides have a good control effects on crop diseases and pests, and can effectively replace some chemical pesticides, which is a new research direction in the pesticide industry. 3 biological pesticides, eugenol, carvacrol, and polyoxin, as well as fipronil manganese zinc chemicals, were selected as the research objects to spray potatoes at different periods, and the control effects of the 4 pesticides on potato early blight, late blight, black scurf and scab disease were compared.The experimental results showed that in terms of early blight control efficiency of the crop, the control efficiency of the 4 pesticides was ranked as carvacrol> fipronil manganese zinc> polyoxin> eugenol; in terms of late blight prevention effectiveness, the order was carvacrol> eugenol> fipronil manganese zinc> polyoxin; in terms of black scurf prevention effectiveness, the order was carvacrol> eugenol> polyoxin> fipronil manganese zinc; in terms of scab disease prevention effectiveness, the order was fipronil manganese zinc> carvacrol> eugenol> polyoxin. In conclusion, comparing the comprehensive control effect of three biological pesticides and fipronil manganese zinc on 4 diseases, carvacrol was found to be the best. This article provides references for exploring the application methods of bio-derived pesticides, reduce the dosage of chemical pesticides, and promoting the green integrated control technology of potato.

In order to provide reference for rational fertilization and green disease prevention and control in flue-cured tobacco, the effects of boron and silicon nutrient elements on the diseases prevention and control and the physiological mechanism were discussed. The field experiment was conducted to study the effects of different boron and silicon application levels on the incidence of potato virus Y (PVY) disease and defense enzyme activity of flue-cured tobacco named ‘Yunyan 100’. The results showed that the application of boron and silicon reduced the incidence and disease index of PVY in flue-cured tobacco. Compared with the treatment of spraying water (CK), the incidence and disease index of PVY under 9.0 kg/hm² boron+ 6.0 kg/hm² silicon treatment decreased by 32.5% and 22%, respectively. Meanwhile, reasonable application of boron and silicon fertilizer significantly improved the defense enzymes activities of tobacco leaves, and the phenylalanine degradation enzyme activity and proline content were significantly increased by 121.4%-426.5% and 30.0%-74.3%, respectively. Correlation analysis showed that the incidence of PVY was significantly negatively correlated with proline content, while phenylalanine degradation enzyme activity was significantly positively correlated with proline content. The combined application of 9.0 kg/hm² boron+ 6.0 kg/hm² silicon could reduce the occurrence of diseases and induce the increase of defense enzyme activity.

【Objective】Seeking key indicators and methods for accurately characterize drought tolerance in sweet potato, and screening and identifying drought-tolerant sweet potato germplasm resources, to provide effective methods for the rapid and accurate identification of drought-tolerant sweet potato germplasm resources, and to provide material and theoretical basis for selection and breeding of high quality and drought-tolerant sweet potato varieties. 【Method】Fifty-four sweet potato germplasm resources were used as materials for drought stress experiments. By using two treatments including drought stress and control, and combining with drought pool cultivation experiment and field test, the effects of drought stress on the growth and development, physiological and biochemical characteristics, antioxidant metabolism, photosynthetic characteristics and yield of different sweet potato germplasm resources were investigated, the response characteristics of different sweet potato germplasm resources to drought were analyzed, and the effective indicators for drought tolerance evaluation in sweet potato were selected. The drought tolerance evaluation was preformed using principal component analysis, correlation analysis, direct evaluation of drought resistance coefficient, and calculation of comprehensive drought tolerance measurement value (D value) based on membership function, and the drought-tolerant sweet potato germplasm resources were screened and identified.【Result】The results obtained from the drought pool cultivation experiment showed the influences of drought treatment on the main stem length, aboveground fresh weight, underground dry weight and fresh weight of storage root were extremely significant (P<0.01), and eight drought-tolerant germplasm resources were screened based on cluster analysis of D values. In the field test, the main stem length, stem diameter, number of branches, leaf area index, leaf relative water content, total chlorophyll content, stomatal conductance, net photosynthetic rate, transpiration rate, intercellular carbon dioxide concentration, proline (Pro), malondialdehyde (MAD), peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) showed highly significant differences (P<0.01) under drought stress when compared with control. Through the establishment of regression models, it could be initially determined that eight indicators including the leaf area index, root tip, leaf POD, leaf APX, storage root Pro, storage root SOD, storage root CAT, and yield could be used as indicators for drought tolerance identification in sweet potato. XN18111-1, 20XN18-1, XN1834-11 and XN17104-46 were classified as drought-tolerant germplasm resources according to grading of drought resistance coefficient based on yield. The D values of XN18111-1, 20XN18-1 and XN1862-61 were over 0.6 and showed high drought tolerance based on comprehensive drought tolerance evaluation. 【Conclusion】Based on results of comprehensive drought tolerance evaluation in drought pool cultivation experiment, as well as the comprehensive drought tolerance evaluation and yield evaluation in field test, XN18111-1 and 20XN18-1 were finally identified as drought-tolerant germplasm resources, which can be used as drought-tolerant breeding materials or ideal resource materials for study on drought-tolerance mechanism in sweet potato.

The purpose of this study was to investigate the phenotypic and main quality changes of nine yellow-fleshed sweetpotato (YFSP) varieties at different development stages, and to provide a theoretical basis for the breeding of fresh sweetpotato. Nine winter YFSP varieties were used as materials. The diameter, length, weight, flesh color, dry rate, starch, and soluble sugar content of sweetpotato at five development stages were measured and analyzed. The results showed that the diameter, length, weight and dry rate of single potato increased continuously during the development process. The growth rate of sweetpotato length of ‘Guangshu 79’ was the fastest at 45-105 d, and that of ‘Anna’ was the fastest at 135-165 d. The highest rate of increase in diameter and single sweetpotato weight was ‘Mashali’. The dry matter rate of ‘Guangshu 79’ increased the fastest. The soluble sugar content showed a downward trend during development, and ‘Guangshu 79’ showed the fastest decline. With the increase of starch content, ‘Guangshu 79’ increased rapidly in the early growth period of 45-105d, and ‘Anna’ increased fastest in 135-165d. The study found that the length, diameter, single root weight, dry rate and total starch content of YFSP tubers increased gradually with the growth and development period, and the content of soluble sugar decreased gradually. The rapid development and growth periods of different varieties of sweet potato were different.

To evaluate the field control effects of several chemical control agents on potato late blight in Matou Town of Tancheng County, Linyi City, Shandong Province, 687.5 g/L fluopyram-penoxifen wettable powder, 72% mancozeb-manganese zinc, 42.8% fluopyram-iprovalent wettable powder, and 10 billion/g Bacillus subtilis biological preparation were selected, and a control group and treatment groups were set up, and the incidence index, control effect, and yield were monitored. The results showed that the 687.5 g/L fluopyram-penoxifen wettable powder had a significant control effect on the disease. In 2020, the incidence index was 3.21, 5.13, and 6.02 after three applications of the treatment, with an average control effect of over 80% and a maximum of 85.14%, and an increase in yield of 27.9%. In 2021, the incidence index was 2.95, 4.75, and 5.45 after three applications of the treatment, with an average control effect of over 84% and an increase in yield of 26.0%. The 42.8% fluopyram-iprovalent wettable powder had a slightly lower control effect but was better than other pesticides. The importance of selecting control agents based on regional specific conditions was emphasized, and fluopyram-penoxifen wettable powder was recommended as the preferred control agent for late blight of potato in the study area. The research results provide scientific control guidelines for farmers.

In order to explore the effects of cultivation density and nitrogen fertilizer application on potato yield and quality in high-altitude areas, a two factor split plot experimental design was adopted. Three density levels (41700, 50000, 62500 plant/hm², represented as D₁, D₂, D₃ respectively) and four nitrogen application levels (0, 110, 220, 330 kg/hm², represented as N₀, N₁, N₂, and N₃ respectively) were set up to analyze different densities and the effect of nitrogen fertilizer treatment combination on the plant traits, yield, and quality of the late maturing potato variety ‘Zangnongshu 1’, and explore the optimal fertilizer density configuration for this variety. The results showed that density and nitrogen fertilizer had a significant impact on the traits, yield, and quality of potato plants, and the yield and quality were significantly affected by the interaction between density and nitrogen fertilizer. The potato yield and commercial potato yield under low density of 41700 plants/hm² increased with the increase of nitrogen application. The dry matter content, starch content, and protein content showed a trend of first increasing and then decreasing with the increase of nitrogen application. The potato yield and commercial potato yield under high density of 50000 plants and high density of 62500 plants/hm² increased and then decreased with the increase of nitrogen application, while the dry matter content, starch content, and protein content showed an upward trend. The highest potato yield under D₂N₂ treatment was 47884 kg/hm², with a commercial potato yield of 56.03%, and good performance in plant and quality traits. Taking into account plant, yield, and quality traits, based on TOPSIS analysis results, it is more suitable to plant potatoes in Lhasa and its surrounding areas with a density of 50000 plants/hm² and a nitrogen application rate of 220 kg/hm².

In order to explore a new intercropping model that suitable for the flatland and shallow hill in Chongqing and similar ecological areas, increase the yield and economic benefits of crops, and provide reference for research on crop intercropping models, an intercropping experiment with fresh maize, sweet potato, and soybean was conducted. In this experiment, three different row ratios of maize-sweet potato-soybean intercropping models were used, with one fresh waxy maize variety, three fresh sweet potato varieties, and one fresh soybean variety as materials. The results showed that there were no significant differences in the yield components of fresh waxy maize in different row ratio intercropping models, but there was a significant difference in the average fresh ear weight per plant and yield. There were no significant differences in the number of branches, effective pod number per plant, and fresh pod yield of fresh soybean in different row ratio intercropping models. In the intercropping system, sweet potatoes in different row ratio intercropping were affected by the shading of maize, resulting in varying degrees of reduction in storage root yield. The different row ratio intercropping models had inconsistent effects on the number of storage root per plant and commodity rate of different sweet potato varieties. Increasing the intercropping planting density of fresh sweet potato and waxy maize properly is beneficial for achieving high yields. Using the row ratio model of 2:2:3, and intercropping fresh waxy maize and fresh soybean with sweet potato variety ‘Pushu32’ can achieve the highest total economic benefits.

The study aims to solve the lack of high starch processing potato varieties with high yield and good quality in Hulunbuir area. In 2022 to 2023, using ‘Weilasi’ as the control, the phenophase and tuber traits of 8 potato varieties were investigated, and the performance and stability of starch content, tuber yield and starch yield were identified and evaluated. Among the 9 cultivars, the starch content of ‘Zhong Shu 49’ and ‘Long Shu 20’ ranked first and second respectively, and the average values of the two years was 18.27 and 18.10 respectively, which were higher than those of the control, but the difference was not significant. ‘Long Shu 20’and ‘Zhong Shu 28’ had high tuber yield of 55074 kg/hm² and 54607 kg/hm² respectively, which were significantly higher than that of the control, and the stability was good. The highest tuber starch yield of ‘Long Shu 20’ was 9863 kg/hm², which was significantly higher than that of the control and other cultivars, and the performance was stable. ‘Long Shu 20’ had the highest starch yield and stable performance among the nine cultivars, which was suitable for demonstration and promotion as a starch processing variety in this region.

The input-output data of potato in S Province from 2011 to 2022 were selected, and the data envelop analysis method was used to explore their production benefits and efficiency. The results showed that the overall cost of potato production in the study area had been increasing year by year, with significant increases in cost elements such as labor, seed, fertilizer, and land transfer; The profit margin fluctuates greatly, indicating a large potential for improvement in production efficiency and output value; Its overall efficiency fluctuates, and there was significant room for improvement in production efficiency; The overall trend of return to scale coefficient was on the rise, and most of them were increasing returns to scale, indicating the need for moderate development of potato scale operations. Based on the current situation of potato production efficiency in the research area, measures to improve quality and efficiency were proposed, including further construction of agricultural infrastructure, promoting full mechanization, accelerating the construction of the industrial chain, and improving social service capabilities, to provided references for the high-quality development of the potato industry.

Sweet potato is an important food crop and cash crop in China, and it has played an important role in ensuring China’s food security. Plant growth regulators not only increase crop yield, but also enhance stress resistance and improve quality, playing an important role in crop production. At present, there are relatively few researches on the application of plant growth regulators in sweet potato. To explore the effects of different plant growth regulators on the agronomic traits of sweet potato seedlings, three plant growth regulators, 6-benzylaminopurine, gibberellin and naphthalene acetic acid, were selected in this study, and their effects on sweet potato seedlings were studied by the method of bottom application. The results showed that the three plant growth regulators significantly promoted the rooting of sweet potato, and significantly promoted the root length and fresh weight of sweet potato. The research results would provide theoretical basis and technical support for further optimization of sweet potato cultivation management, help to improve sweet potato yield and quality, and promote the sustainable development of sweet potato industry.