To investigate the characteristics of the dynamic changes of root morphology of silage maize in different periods under the conditions of nitrogen and phosphorus rationing in the wind and sand area of Yulin, silage maize (Zea mays) ‘Dajingjiu 23’ was used as the research object. A two-factor test was set up for nitrogen and phosphorus fertilizers, with the nitrogen application of no nitrogen (N0, 0 kg/hm2), low nitrogen (N90, 90 kg/hm2), medium nitrogen (N180, 180 kg/hm2), medium-high nitrogen (N270, 270 kg/hm2) and high nitrogen (N360, 360 kg/hm2); and phosphorus was applied as no phosphorus (P0, 0 kg/hm2), low phosphorus (P90, 90 kg/hm2) and high phosphorus (P180, 180 kg/hm2). The biomass and root morphology of silage maize were measured at the trumpet stage, silking stage and harvesting stage. The results showed that the nitrogen-phosphorus rationing significantly promoted the longitudinal development of the root system at the trumpet stage, and the fresh weight, root length and surface area of the root system in the 10-20 cm soil layer increased by 73.9%-169.5%, 52.0%-136.4% and 75.1%-124.4%, respectively. Nitrogen-phosphorus rationing had a significant effect on the expansion of the shallow root system during the silking stage, with the fresh weight, dry weight and volume of the root system in the 0-10 cm soil layer increasing by 5.5%-69.3%, 3.9%-62.1% and 3.0%-91.4%, respectively. Nitrogen-phosphorus rationing effectively delayed root senescence at harvest, with increases of 28.5%-190.3% in fresh weight in the 10-20 cm soil layer, and increases of 50.0%-202.3% and 40.2%-158.8% in dry weight and volume in the 20-30 cm soil layer, respectively. The root indexes of each fertility stage showed that the fresh weight, dry weight, root length, surface area and volume of roots in the 0-20 cm soil layer were significantly better than those in the 20-40 cm layer. Through the comprehensive evaluation of the affiliation function, the optimal performance of the N180P180 program was observed, with the above-ground fresh and dry weights increasing by 24.7% and 44.7%, respectively, and the root development indexes showing a sustained gain. The fresh weights increased by 54.5%-91.1%, the dry weight increased by 28.5%-70.6%, the root length increased by 23.8%-70.8%, the total area increased by 52.1%-79.3%, and the total volume increased by 32.6%-98.9%, and a significant increase in the efficiency of nutrient uptake by the plant. In conclusion, the N180P180 dosage was favorable to promote the synergistic growth of maize above-ground and below-ground.
To investigate the regulatory effects of polycarbonate enzyme application on dry matter accumulation and distribution in flue-cured tobacco and to optimize its application techniques for coordinated improvement of yield and quality in central Henan tobacco production, this study utilized the flue-cured tobacco cultivar ‘Yu Nongxiang 201’ and conducted field experiments in 2022 in Weidu District of Xuchang City and Ziyun Town of Xiangcheng County, within the central Henan tobacco-growing region. Three treatments were established: foliar spray (T1), root irrigation (T2), combined foliar spray+ root irrigation (T3), with water as control (CK). The study systematically examined their effects on agronomic traits, photosynthetic characteristics, dry matter allocation, and yield-quality parameters. Results indicated that polycarbonate enzyme application significantly promoted plant development, enhanced dry matter accumulation and rootward allocation, improved leaf photosynthetic rate, and increased yield and economic value of cured leaves compared to CK. T1 treatment achieved the greatest improvements in sugar-to-nicotine ratio and potassium-to-chloride ratio, enhancing the coordination of chemical components and elevating appearance quality indicators such as structure, texture, oil content, color intensity, and hue. T2 treatment maximized the proportion of upper-middle grade leaves, optimizing the grade structure of cured tobacco. T3 treatment increased tobacco yield by over 10% but reduced the proportion of upper-middle grade leaves, with declines observed in leaf structure and sugar-to-nicotine ratio, indicating a potential yield-quality trade-off. In conclusion, sole foliar application (T1) effectively balanced yield maintenance with improvements in photosynthetic carbon assimilation efficiency and rational dry matter distribution, achieving simultaneous optimization of chemical coordination and appearance quality. This approach aligns with the practical requirements for high-quality tobacco production in the central Henan region.
This study aims to reveal the stability characteristics and spatial distribution patterns of potassium (K), chloride (Cl-) content, and potassium-chloride ratio (K/Cl) in flue-cured tobacco leaves of the main cultivated variety ‘K326’ in the Chuxiong tobacco-growing areas, so as to provide a scientific basis for the precise regulation of tobacco leaves quality. Based on the detection data of 6627 tobacco samples from the raw material bases of Chuxiong Cigarette Factory from 2018 to 2022, the stability of chemical quality was determined by the stability factor and critical value, the coefficient of variation (CV) was used to evaluate annual fluctuations, and township-level zoning analysis was carried out with ArcGIS technology. The results showed that the mean potassium content in upper, middle and lower leaves met the high-quality standard (1.60%-2.50%), but the overall level was low (5-year average: 2.09%-2.82%). The stability of lower leaves was poor (CV≥15%). The compliance rate in 2022 was close to 100%, which showed the optimization effect of cultivation techniques. The mean chloride content (0.44%-0.57%) met high-quality requirements, but annual fluctuations were significant (CV>50%). The proportion of lower leaves exceeding the target chlorine level reached 22.15%, and the chloride ion in the middle and lower leaves exceeded the standard in certain townships (e.g., Yipinglang Town in Lufeng City, Wande Town in Wuding County). The mean potassium-chloride (K/Cl) ratio (6.25-8.70) met the standard, but the compliance rate of sample points were only around 50%. The middle leaves had the worst stability, mainly due to higher and more variable chlorine content. The potassium-chlorine ratio consistently fell below the premium quality target in some regions such as Bajiao Town of Chuxiong City and Yipinglang Town of Lufeng City. In production practices, it is necessary to select tobacco varieties with low chloride content, weak chloride absorption capacity, high industrial acceptance, which can replace ‘K326’. The measures, such as appropriately increasing soil pH, applying organic fertilizer, using special fertilizer formulas, chloride ion inhibitors, and reasonable crop rotation, could also effectively reduce the chloride content in tobacco leaves, thereby increase the potassium chloride ratio of tobacco leaves. The potassium content of tobacco leaves in the Chuxiong area generally met the high-quality target requirements. However, the overall potassium content in tobacco leaves is still low and need further improvement. Precise attention should be given to regulating the potassium content in the upper and middle leaves at sampling points that fall below the target requirements for high-quality tobacco leaves. The strategies, such as using efficient potassium fertilizers, root-zone top-dressing of potassium fertilizer, application of bio-char or microbial fertilizers, and spraying dihydrogen phosphate or ethephon, could effectively increase the potassium content of tobacco leaves.
Adenosine diphosphate glucose pyrophosphorylase (AGPase) is the rate-limiting enzyme in the starch synthesis pathway of plants. Cloning the homologous gene of AGPase in Lilium lancifolium and analyzing its expression characteristics are helpful to understand the law of starch synthesis during the growth and development of bulbils, and provide a basis for the development and utilization of bulbils as a seed resource or dietary ingredient. In this study, a gene encoding a small subunit of adenosine diphosphate glucose pyrophosphorylase (LlAGPS1) was cloned from Lilium lancifolium by homologous cloning technology. The expression of LlAGPS1 in leaves and bulbils was analyzed by fluorescence quantitative PCR. The results showed that the protein encoded by LlAGPS1 gene had PLN02241, GlgC conserved domain and belonged to cl33437 super family protein. Protein multiple sequence alignment showed that it had high homology with AGPase small subunit sequences of other crops. The qPCR analysis showed that LlAGPS1 gene was mainly expressed in bulbils, which was significantly higher than that in leaves. The flower bud removal treatment could up-regulate the expression of LlAGPS1 in leaves, and the diurnal variation of the gene expression in leaves and bulbils showed a decreasing trend. The protein encoded by LlAGPS1 gene has PLN02241 and GlgC conserved domains unique to cl33437 family. It is a homologous gene encoding AGPase protein with obvious tissue expression specificity and high expression in the growth and development of bulbils. The results provide a reference for the follow-up study of the effect of LlAGPS1 gene expression regulation technology on the starch synthesis, growth and development of Lilium lancifolium bulbils, and the development of bulbil value.
To establish an environmentally friendly seedling substrate system, this study employed a mixture experimental design to systematically evaluate the growth-regulating effects of Lyophyllum decastes residue (LDR)-based composite substrates with varying ratios on processing pepper seedlings. By analyzing changes in substrate physicochemical properties, seedling growth metrics, biomass accumulation, and root morphology, LDR exhibited significantly superior nutrient content and pore structure compared to traditional peat. At the optimal ratio of peat: LDR: perlite=6:3:1, seedling leaf area, strong seedling index, and root activity increased by 17.32%, 13.11%, and 7.58%, respectively, compared with the control CK (peat: perlite=8:2). Fresh and dry weights of aboveground biomass rose by 26.44% and 14.47%, while total root length and root surface area expanded by 10.05% and 12.76%. Substituting 30% peat with LDR reduces costs while enhancing pepper seedling growth through root-shoot synergy.
The demand for plant hormones varies in different stages of asexual rapid propagation of Dendrobium officinale. The paper aims to further explore the relationship between exogenous hormone ratio and tissue culture seedling growth. The segmented stem segments of D. officinale from Tianmushan of Zhejiang were used as explants to conduct experiments on induction, proliferation, and rooting of clustered buds of D. officinale. The effects of different hormone ratios on the growth of D. officinale at different stages were compared, and the optimal hormone conditions for rapid propagation of D. officinale stem segments were selected to establish an asexual rapid propagation system of D. officinale stem segments. The results showed that the optimal hormone conditions for inducing clustered buds were 1.0 mg/L NAA+ 2.0 mg/L 6-BA, with a germination rate of 97.8% and robust buds. The optimal hormone conditions for the proliferation of clustered buds of D. officinale were 0.5 mg/L NAA+ 2.0 mg/L 6-BA, with a proliferation rate of 86.9% and good growth. The optimal hormone conditions for the rooting of clustered buds of D. officinale were 1.0 mg/L NAA+ 1.0 mg/L IBA, with a rooting rate of 83.4% and a robust and developed root system. The study confirmed that hormone ratio and medium salt concentration synergistically regulated the morphogenesis of D. officinale, and the 7-8 leaf stage was the key node of physiological response. The hormone combinations screened in this study can provide theoretical basis and technical reference for large-scale tissue culture of orchid medicinal plants.
The novelty of floral organ morphology serves as one of the critical indicators for the ornamental value of flowering plants. This article summarized the influences of relevant floral developmental genes, temperature, hormones, and other external factors on the floral organ variation of Rosa chinensis ‘Viridiflora’. Analysis indicated that the formation of unique floral organ traits in R. chinensis ‘Viridiflora’ was associated with the inherent characteristics of floral organs, external factors, and molecular mechanisms. Finally, suggestions were made for future research directions. (1) Conducting physiological and anatomical studies on the leaf-like structures of R. chinensis ‘Viridiflora’ to determine their evolutionary orientation. (2) Performing functional verification of the screened related genes to determine whether this gene can cause flower type variation. (3) Constructing interaction network diagrams illustrating relationships between genes. (4) Utilizing rose plant regeneration and genetic transformation systems to cultivate novel floral cultivars.
In order to establish the method of aseptic germination and tissue culture of Maianthemum japonicum seeds, the seeds of M. japonicum were used as experimental materials, and the effects of exogenous hormone types, concentrations and soaking time on seed germination were investigated by orthogonal test. At the same time, the stems of Cervus elaphus were used for callus culture to obtain sterile seedlings. Finally, M. japonicum was introduced and cultivated in greenhouse. The results showed that 100 mg/L GA3 and 500 mg/L ethephon could promote the growth process of M. japonicum seeds, and the effect of soaking for 48 h was better than that of soaking for 12 h and 24 h. In the treatment of callus of stem section of M. japonicum, after the sequential exchange of sodium hypochlorite solution disinfection and black material removal, the pollution rate of M. japonicum decreased, and there was no significant difference in browning rate. At a suitable temperature, M. japonicum can quickly break dormancy and grow. This study preliminarily clarified that there was no significant difference in the germination rate of M. japonicum seeds treated with different exogenous hormones, but it had a certain promoting effect on their germination, and the callus induction browning rate of M. japonicum stem segments was higher, which could provide reference for the rapid propagation of M. japonicum in the later stage.
To investigate the soil fertility status under different land use types in a typical arid oasis region, this study focused on five land use types in Kutie reclamation area in the northeastern margin of the Tarim Basin, including cropland, orchard, forestland, grassland and saline-alkali land. Soil indicators such as pH, total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), available potassium (AK) and organic matter (OM) were measured. A fuzzy comprehensive evaluation method was employed to assess soil fertility comprehensively, aiming to provide scientific references for soil resource management and ecological restoration in the region. The results showed that the average soil pH in the study area was pH 8.16, with a variation coefficient (CV) of 0.037, indicating weak variability and predominantly alkaline or strongly alkaline soils. The levels of TP, TK, AP and AK were moderate to high, while OM, TN and AN were deficient. Soil fertility varied significantly among land use types, with cropland having the highest fertility, followed by orchard, while forestland, grassland and saline-alkali land had relatively lower fertility. The contents of OM, TN, AN, TP and AP in orchard and cropland soils were higher than those in forestland, grassland, and saline-alkali land. Overall, the soil fertility in the study area was relatively low, with available nitrogen and organic matter identified as the primary limiting factors. These findings provide a basis for improving soil management practices and promoting ecological restoration in arid oasis regions.
The study aims to investigate the effects of fertilization on yield, quality, fertilizer use efficiency in maize (variety ‘Fuhua 22’) and rapeseed (variety ‘Yunyouza 15’) and discharge amount of fertilizer pollution, providing scientific guidance for optimizing fertilizer management of major crops in the upper reaches of the Chishui River. A field experiment with five treatments was implemented, including control (CK), phosphorus-potassium (PK), nitrogen-potassium (NK), nitrogen-phosphorus (NP), and nitrogen-phosphorus-potassium (NPK), to assess their effects on crop yield, quality at maturity, fertilizer use efficiency, and discharge amount of fertilizer pollution. The results showed that the NPK treatment significantly increased rapeseed yield by 81.73% compared to CK, whereas the yield increases under nutrient-deficient treatments (PK, NK, NP) ranged only from 35.42% to 52.86%. In terms of quality, fertilization significantly increased the contents of fat, protein, oleic acid and erucic acid, but had no significant effects on palmitic acid, stearic acid, linoleic acid or linolenic acid contents. Similarly, maize yield under NPK treatment increased by 90.00% compared to CK, whereas the yield increases under nutrient-deficient treatments (PK, NK, NP) ranged only from 42.74% to 79.24%. In terms of quality, the NPK treatment exhibited the highest maize starch and protein contents, which increased by 4.94% and 60.47%, whereas nutrient-deficient treatments demonstrated comparatively smaller increments. In addition, the study also found that the nitrogen, phosphorus, and potassium utilization efficiencies of maize and rapeseed reached their highest levels under NPK fertilization conditions. Under NPK fertilization conditions, nitrogen and phosphorus pollution from maize and rapeseed fields were minimized, being significantly lower than those under nutrient-deficient treatments. In conclusion, balanced fertilization not only significantly enhanced crop yield and quality along with the fertilizer use efficiency, but also effectively mitigated agricultural non-point source pollution.
Using humic acid water-soluble fertilizer produced by Zhongcheng Guolian (Henan) Biotechnology Co., Ltd. as the test material, this study investigated the impact of foliar application of humic acid water-soluble fertilizers on the yield and yield factors of wheat and summer maize under different soil texture types in Shangqiu City. The paired test design was used, and the effects on economic benefits were also analyzed. The results showed that with foliar spraying of humic acid water-soluble fertilizer, the number of grains per ear, 1000-grain weight and both yield and economic benefits significantly increased. Statistical analysis revealed a highly significant increase in yield for both wheat and summer maize. The increase in yield and economic benefit varied across different soil texture types. For wheat, the highest yield increase and lowest yield increase rate occurred on silty soil. The highest increase rate and smallest yield increase were found on sandy soil. The order of net increase in economic benefit was silty soil> loamy soil> sandy soil. For summer maize, the yield increase ranking was silty soil> sandy soil> loamy soil, while the orders of increase rate and net increase in economic benefit were loamy soil> silty soil> sandy soil.
The paper aims to investigate the effects of compound application of organic fertilizers with microbial fertilizers on photosynthetic characteristics, antioxidant capacity and yield and quality of organic Lycium barbarum in saline and alkaline land in Ningxia region. In 2023, a fertilizer experiment was carried out at the wolfberry base of Liu Chuanjing Organic Wolfberry Professional Cooperative in Zhenbeibao Unity Village, Yinchuan City, Ningxia. Four fertilizer treatments were set up, namely, single application of organic fertilizers (MD), organic fertilizers and balanced light and photosynthetic fungal fertilizers compost rotting furrow application (MPG), single application of balanced, photosynthetic fungal fertilizers (MP), and no application of any fertilizers (absolute control, CK), and the results were obtained by analyzing the interrelationships between the leaf physiological characteristics and yield quality of wolfberry. The results showed that: the application of microbial fungal fertilizer could significantly improve the photosynthetic parameters of L. barbarum, increase the antioxidant capacity, and inhibit the accumulation of lipid membrane peroxidation products, thus significantly improving its yield and quality, and the overall performance of MPG treatment was the best. Compared with CK, the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and SPAD were increased by 47.83%-122.09%, 32.26%-69.31%, 36.74%-96.94%, and 3.65%-25.52%, respectively, with MD, MPG, and MP treatments; meanwhile, superoxide dismutase (SOD), peroxidase (POD) and catalase activity (CAT) increased by 3.22%-12.30%, 8.59%-28.53% and 2.76%-32.76%, respectively; whereas flavonoids content, Lycium barbarum polysaccharide content, betaine content and total dry fruit yield increased by 7.07%-40.46%, 18.70%-28.43%, 1.22%-35.37% and 23.80%-55.43%. Correlation analysis showed that the L. barbarum yield was positively correlated with Pn, Ci, Tr and SPAD in a highly significant way; flavonoids content, polysaccharide content and betaine content were positively correlated with physiological characteristics such as Pn, Ci, Tr, SPAD, SOD, POD and CAT in a significant or highly significant way; while the quality and yield indicators were negatively correlated with MDA in a significant or highly significant way. The principal component analysis showed that the composite score of each treatment was MPG>MP>MD>CK. Therefore, the compound application of organic fertilizers with microbial fertilizers could consistently improve the SPAD value, Pn, Gs and Tr of L. barbarum leaves; optimize the antioxidant capacity of L. barbarum leaves and inhibit the accumulation of MDA; and then promote the growth of the plant and significantly increase the content of flavonoids, polysaccharide, betaine, and yield.
To investigate the transmission and attenuation of antibiotic resistance factors carried by poultry manure in field application experiments, and to better control the spread of antibiotic resistance risks during the resource utilization of livestock manure, a greenhouse-based farmland simulation experiment was conducted. Soil samples with different fertilization rates were monitored over time for changes in antibiotic resistance genes (ARGs). A total of 90 samples were collected, including untreated soil, fresh chicken manure, organic fertilizer and soil amended with these two types of manure. PCR was used to detect 14 representative ARGs corresponding to common antimicrobial resistance traits in poultry-derived microorganisms. The results showed that genes such as blaNDM, tetM, sul1, sul2, sul3 and aadA were detected in all sample types. The fexA and cfr genes were not detected in untreated soil samples, but were detected in manure, which led to contamination of the fertilized soil. However, the positive detection rate of these genes in soil decreased over time. Additionally, genes including blaTEM, blaCTX-M, ermA, ermB and floR were detected in untreated soil, but subsequent studies found reduced detection rates in soil amended with manure, particularly organic fertilizer. In conclusion, the current field experiments revealed that farmland soil amended with poultry manure carries a high risk of ARGs. While poultry manure introduces short-term ARG contamination to the soil, the application of organic fertilizer helps mitigate ARG pollution in the soil over time.
Land recultivation can increase the area of cultivated land, provide a production basis for food security, reduce the occupation of cultivated land resources by non-agricultural land, and help protect agricultural ecology. Compared with the soil cultivated all year round, the recultivated soil has low soil fertility, poor physical structure and poor micro-ecological environment. It is necessary to improve the quality of recultivated soil through subsequent soil improvement technology and fertilization technology. Through the summary of the current soil improvement and fertilization technology in China, the current situation of sustainable utilization of recultivated soil was discussed, and the problems existing in the sustainable utilization of recultivated soil in China were pointed out and targeted suggestions were put forward, so as to provide guidance for better sustainable utilization of recultivated soil and ensure food security. The research showed that the improvement of recultivated soil should be analyzed according to different soil conditions. Suitable soil improvement methods should be selected for construction land, forest land and economic crop land to improve soil quality and improve soil nutrients. Re-tillage soil improvement mainly includes physical, chemical and biological improvement techniques. At present, combined improvement techniques are mostly used. The compound cultivated land could regulate soil nutrient status, improve soil conditions and create a good soil ecological environment for plant growth through fertilization. The main ways include adding organic fertilizer, trace element fertilizer, formula fertilization and agronomic measures to fertilize. In order to further promote the rational utilization of recultivated soil and clarify the improvement and fertilization mechanism of recultivated soil, it is necessary to improve the following aspects: constructing the conservation technology system of re-cultivated soil, and carrying out multi-angle and multi-level comprehensive management of recultivated soil; establishing the quality evaluation index system of recultivated soil; playing the ecological service function of recultivated land.
To explore the temporal variations of climate suitability during different growth stages of juicy peaches and provide support for the sustainable development of the juicy peach industry in Ningbo, the suitability model of temperature, precipitation, and sunshine was established using the fuzzy mathematics method based on meteorological indices of juicy peaches and daily meteorological data. A climate suitability model was then established using the geometric average method. The results showed that the constructed climate suitability model can better describe and analyze the climate suitability of peaches, based on the climate yield verification. From the ranking results of the suitability of single meteorological elements, the temperature suitability is the highest, followed by the precipitation suitability, and the sunshine suitability is the lowest. The suitability of various climate factors has internal changes and a downward tendency. The sunshine suitability has the most significant downward trend, with a climatic tendency rate of -0.069/10 a. The suitability of temperature and climate is the lowest during the fruit-expansion period, with the highest coefficient of variation. The suitability of precipitation is the lowest and the coefficient of variation is the highest during the period from expansion to maturity. The sunshine suitability is the lowest during the hard core stage and has the highest coefficient of variation during the fruit-expansion stage. Except for the suitability of sunshine, all suitability during the nutritional recovery period is at a high level, with the lowest coefficient of variation. Therefore, there are significant temporal variations in temperature, precipitation, sunshine, and climate suitability at the different growth periods of juicy peaches, with the most significant changes occurring during the fruit-expansion period. Targeted cultivation measures should be developed in production to mitigate the impact of adverse climate conditions on the yield and quality of juicy peaches.
In order to screen out chemical fungicides to control cherimoya leaf spot, an evaluation of compound fungicides was conducted through field trials in the study. Seven compound fungicides widely used in agricultural production in China, which were 300 g/L difenoconazole·propiconazole suspension concentrate (SC), 275 g/L pydiflumetofen·propiconazole suspo-emulsion (SE), 325 g/L difenoconazole·azoxystrobin SC, 400 g/L mefentrifluconazole·pyraclostrobine SC, 42.4% pyraclostrobine· fluxapyroxad SC, 19% picoxystrobin·propiconazole micro-emulsion (ME) and 17% pyraclostrobine·epoxiconazole ME, were used in the test to confirm the control effects under field conditions. The survey result showed that 17% pyraclostrobine·epoxiconazole ME 170 mg/kg, 19% picoxystrobin·propiconazole ME 126.7 mg/kg, 42.4% pyraclostrobine·fluxapyroxad SC 226.1 mg/kg, 275 g/L pydiflumetofen·propiconazole SE 275 mg/kg had control effects of 83.20%-86.08% after third application, significantly higher than other treatments, as well as the yield increase percentages were higher than 16%. The four aforementioned fungicides were safety and had positive control effects and effectively reduce production losses caused by cherimoya leaf spot, thus it is recommended for consideration of use in production.
To investigate the effects of melatonin on the growth and physiological characteristics of hybrid Pennisetum urpureum ‘Guimu-1’ under drought stress, and to explore the physiological mechanism of melatonin alleviating the growth inhibition of hybrid P. urpureum ‘Guimu-1’ under drought stress, hybrid P. urpureum ‘Guimu-1’ plantlets under 10% PEG6000 drought stress were treated with six concentrations of melatonin solution by plant tissue culture. The differences in the responses of morphological and physiological indicators to different melatonin concentrations were analyzed. The results showed that drought stress significantly inhibited the growth of hybrid P. urpureum ‘Guimu-1’ plantlets, while adding different concentrations of melatonin could alleviate the growth inhibition caused by drought stress, and the most significant relief effect was observed when the melatonin concentration was 100 mg/L. Compared with the treatment of drought stress alone, the addition of 100 mg/L melatonin under drought stress increased the plant height, root length, stem length, leaf length, total fresh mass, aboveground fresh mass, underground fresh mass, and root shoot ratio of hybrid P. urpureum ‘Guimu-1’ plantlets by 74.4%, 69.9%, 110.9%, 75.4%, 97.6%, 80.5%, 118.1% and 20.2%, respectively; increased the relative water content, chlorophyll a, chlorophyll b, carotenoids, total root length, total root surface area, average root diameter, total root volume, root vitality, ascorbic acid (AsA) content, reduced glutathione (GSH) content, soluble sugar (SS) content, soluble protein (SP) content, proline content, CAT activity, SOD activity, POD activity, IAA content, GA3 content, ZR content, and ETH content by 40.2%, 69.2%, 117.3%, 141.3%, 87.8%, 38.3%, 62.5%, 35.9%, 59.2%, 113.6%, 80.8%, 72.2%, 52.5%, 25.7%, 48.7%, 82.5%, 27.5%, 38.5%, 49.8%, 55.4% and 9.1%, respectively; decreased the relative conductivity, ABA content, O2- content, H2O2 content and MDA content by 52.9%, 14.2%, 38.4%, 67.7%, 50.5%, respectively. Plant height, root length, stem length, leaf length, total fresh mass, aboveground fresh mass, underground fresh mass, root shoot ratio had significant or extremely significant positive correlations with relative water content, chlorophyll a, chlorophyll b, carotenoids, total root length, total root surface area, total root volume, root vitality, AsA, GSH, SS, SP, Pro, CAT, SOD, POD, IAA, GA3, ZR, ETH, and had significant or extremely significant negative correlations with relative conductivity, H2O2, ABA. Therefore, melatonin could significantly promote the growth of hybrid P. urpureum ‘Guimu-1’ plantlets under drought stress, enhance their antioxidant capacity, increase their osmoregulatory substance content, inhibit their excessive production of reactive oxygen species, and reduce their membrane peroxidation level, thereby improve the drought tolerance of hybrid P. urpureum ‘Guimu-1’ plantlets.
The volatile components and relative contents in different organs of Echinacea purpurea, introduced in Mengzi City, Yunnan Province, were analyzed through experiments, providing experimental data for their comprehensive development and utilization. The volatile components in the organs of E. purpurea were identified by gas chromatography-mass spectrometry (GC-MS) combined with headspace solid-phase microextraction (HS-SPME). The compositions of 92 compounds were identified in total. The identified components in roots, stems, leaves, capitulum and peduncles accounted for 90.034%, 90.143%, 91.411%, 94.279%, and 89.016% of their total volatile components, respectively, mainly terpenes, alcohols, ketones, polycyclic aromatic hydrocarbons, alkanes and aldehydes. The relative content of terpenes was the highest in the roots, stems, leaves, capitulum, and peduncles, with percentages of 66.216%, 69.396%, 63.818%, 58.93%, and 40.62% respectively. The composition of terpenes in different organs was different. The highest terpenes in roots and stems were 1-octadecenyl followed by β-caryophyllene. The highest terpenes in leaves was germacrene D, followed by caryophyllin. The highest terpenes in capitulum was caryophyllin, followed by a-cyclohexene. The highest terpenes in peduncles was caryophyllin, followed by germacrene D. Some of the volatile components identified in this study have antibacterial, anti-inflammatory and anti-cancer pharmacological effects, and some have positive effects on human development and cardiovascular and cerebrovascular health care. The research results provide a reference for the quality evaluation and product development of E. purpurea.
To address the limitations of conventional remote sensing classification methods, such as reliance on manual feature design and poor generalization ability, this study systematically evaluated three backbone architectures (ResNet34, MobileNetV2_100 and TF_MobileNetV3_Small_100) under frozen and non-frozen transfer learning strategies, utilizing Landsat 8 Operational Land Imager (OLI) multispectral imagery and employing a saline-alkali land information extraction method based on U-Net deep learning model. The experimental findings demonstrated that ResNet34 generally showed superior convergence speed, segmentation accuracy and generalization ability in comparison to the lightweight models (MobileNetV2_100, TF_MobileNetV3_Small_100). Specifically, the non-frozen ResNet34 model achieved the optimal overall performance, with a classification precision of 0.880, recall of 0.708, and F1-score of 0.785, all of which exceeded those of other models. The lightweight model demonstrated efficacy in scenarios characterized by limited resources, which could be employed in cases where computational resources were limited and segmentation precision required was low but still necessitates high-performance backbones for complex environments. Notably, non-frozen training consistently exceeded frozen strategies, emphasizing the importance of full-parameter optimization for enhancing accuracy and generalization ability. The research not only validates the effectiveness of deep learning in the remote sensing monitoring of saline-alkali land but also provides a model selection framework for intelligent identification and monitoring of saline and saline-alkali land, offering practical guidance for ecological governance and precision agriculture.
The study aims to understand the content of mineral elements in the edible portion of oriental river prawns (Macrobrachium nipponense) from different cultured and wild origins, to further explore the nutritional quality of oriental river prawns from different origins and the possibilities of mineral elements and stable isotopes for determining the origin of oriental river prawns. This paper selected samples from Yixing, Kunshan, and Shezhu culture origins and the Yangtze River wild oriental river prawns population for the study, and analyzed the content of 21 mineral elements using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that each oriental river prawns contained not only the essential macronutrients Ca, Na, Mg and K, but also the essential trace elements Fe, Zn, Mn, Se and Cu. One-way analysis of variance showed that there were significant differences in the contents of various mineral elements in spring and autumn (P<0.05). The results of stepwise discrimination analysis based on mineral elements showed that the discrimination accuracy could reach 100% and 98.3% for spring and autumn oriental river prawns, respectively, while the C and N stable isotope ratios had the potential to differentiate between wild and farmed oriental river prawns. The results effectively confirmed that the oriental river prawns is a healthy aquatic product with high nutritional value, and that the microchemical ‘fingerprints’ have the potential to be used for origin traceability.
