This study aims to select several new papaya varieties with better comprehensive agronomic traits and suitable for large-scale cultivating in Guangdong Province. A comparative analysis of the plant growth, yield, resistance, fruiting characteristics, fruit commercialization and quality were performed with new papaya varieties ‘Zihui’, ‘Huanghuayou’, and ‘Zhufeng’ in three different regions, ‘Thai Red’ as the control. The plants of four varieties grew luxuriantly with better comprehensive agronomic traits in all pilot sites. Furthermore, ‘Zihui’ and ‘Huanghuayou’ exhibited low fruiting parts, medium inflorescence main axis length, high fruit consistency and node fruit setting rate, stable yield, smooth fruit surface with good color. Besides, the fruits of ‘Zhufeng’ had high sugar content, high and stable yield, and endurable storage. The above new varieties showed excellent quality, and could be used as non-transgenic high-quality and high-yield new varieties. ‘Huanghuayou’ and ‘Zhufeng’ papaya were suitable for fresh food, while ‘Zihui’ was good for both fresh food and processing. All the three new papaya varieties are suitable for promotion in Guangdong or similar climate producing areas.

In order to investigate the role of gibberellin insensitive dwarf gene (GID1) in potato growth, the gene was cloned and transformed to record the expression differences. StGID1 was cloned from ‘Chuanyu 21’ tissue culture seedlings by using the primers designed from PGSC (Potato Genomics Resource). By transformation into potato ‘E Malingshu 3’, overexpressing transgenic plants and RNAi plants were obtained, and the differences in expression were recorded. Phylogenetic analysis showed that the amino acid sequence of StGID1 protein had the highest homology with SlGID1b-1 in tomato. The comparison of overexpression transgenic plants and suppressed expression transgenic plants showed that in the tissue culture seedlings, the average stem diameter of suppressed expression transgenic plants was twice that of overexpression plants. In the mature plants, the relative height of the suppressed expression plants was only 62.8% of that in the overexpressed plants, significantly lower than the blank control and overexpressed plants. When treated with gibberellin, it showed an increase in stem height and a decrease in stem diameter in overexpression plants, suppressed expression plants, and control, with increasing of gibberellin concentration. This study verified that StGID1 was a homologous gene of GID1 gene family in potato and was a part of the gibberellin regulation pathway in potato.

In order to screen out the maize varieties with low-nitrogen tolerance, and provide the technologies for identifying and screening low-nitrogen-resistant corn varieties, 36 corn cross combinations were used as test materials, the phenotypic value of genotypic agronomic traits was determined under the condition that the amount of nitrogen used was reduced by 70% compared to the normal amount of nitrogen applied. Based on the phenotypic value, the comprehensive coefficient of low nitrogen stress was calculated, and then the genotype's ability to low nitrogen resistance was evaluated. The results showed that there were significant or very significant differences in the performance of most agronomic traits among different genotypes under low nitrogen stress. The comprehensive coefficient of low nitrogen stress varied greatly among 36 genotypes, with a maximum value of 1.0319, a minimum value of -0.1139, and an average of 0.4506. There were 6 and 4 genotypes with very significantly and significantly greater coefficients than the average, respectively; 16 genotypes had no significantly different from the average; there were 2 and 8 genotypes with significantly and very significantly smaller coefficients than the average, respectively. Genotypes with extremely significant and significantly greater coefficients than the average were rated as varieties with strong and stronger low-nitrogen resistances. Vigorous growth, higher plants, and wide ear leaves could be used as important characteristics for selecting low-nitrogen-resistant varieties under low-nitrogen stress.

The physiological changes and the expression of EjICE1 gene related to cold resistance embryos of two young loquat fruit under low temperature stress were studied to provide theoretical basis for the screening of new cold-resistant materials and the analysis of cold-resistant molecular mechanism of loquat. Using Dongting loquat (yellow-flesh) and its mutant type (white-flesh) that were growing in pots with fruits (DTM) as materials, the effects of simulated low temperature stress on the relative electrical conductivity, malondialdehyde (MDA) content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activity and the expression of EjICE1 gene were studied. The results showed that the relative electrical conductivity (REC) of embryos of two young loquat fruits presented an ‘S’ type curve change pattern, and the Logistic equation showed that the semi-lethal temperature of Dongting loquat and its mutant type was -4.759 and -2.811℃, respectively. The cold resistance of DTM was stronger than Dongting loquat. The SOD, POD and CAT activities of the two loquats and the MDA contents of Dongting loquat showed a trend of increasing first and then decreasing change pattern with the different time point of reaching the peak, while the MDA contents of Dongting loquat showed a slowly increased trend. SOD activity of Dongting loquat reached the peak at 1℃, and the content of MDA, POD, CAT activity reached peak at -1℃. The SOD, POD and CAT activity of DTM reached the peak at -3℃, while the content of MDA reached the peak at -5℃. The expression level of EjICE1 gene of DTM was higher than that of Dongting loquat at the same time. The expression of EjICE1 gene in DTM was the highest at -3℃, and that in Dongting loquat was the highest at -1℃. The expression level of EjICE1 gene was strongly inhibited in the two loquats under low temperature stress at -5℃. The cold resistance of DTM was stronger than Dongting loquat, under low temperature stress, DTM could rapidly activate higher protective enzyme activity and the expression of genes related to cold resistance, activate the low temperature response mechanism to resist and adapt to low temperature injury.

Dry direct seeding is an important future direction of rice production with a large area in South Asia and Southeast Asia of Indica rice growing regions. However, Japonica rice planting in tropical and subtropical areas mostly adopts traditional transplanting method. Mesocotyl length (ML) is an important factor affecting the emergence and vigor of rice seedlings in dry direct seeding. Breeding long mesocotyl germplasm based on molecular marker assisted selection (MAS) is the most economical and efficient way to promote the popularization of rice direct seeding. So far, four rice mesocotyl elongation genes have been cloned and reported, namely OsGSK2, GY1, OsPAO5 and OsSMAX1, respectively. In this study, we selected the TROP and TEMP Japonica rice subpopulations originated from the 3K re-sequencing project for analysis, determined the length of mesocotyl and identified superior haplotypes of OsGSK2, GY1, OsPAO5 and OsSMAX1. The results showed that the ML of TROP and TEMP populations presented a typical continuous normal distribution. OsGSK2, GY1, OsPAO5 and OsSMAX1 include 3, 3, 3 and 6 haplotypes, respectively. The frequency of haplotype distribution was different in TROP and TEMP panels for the same gene. OsGSK2-Hap1, GY1-Hap2, OsPAO5-Hap3, OsSMAx1-Hap2 and OsSMAx-Hap3 were identified as superior genes in TROP panel; whereas superior haplotypes OsGSK2-Hap1, OsPAO5-Hap2 and OsSMAX1-Hap2 were identified in TEMP panel. In addition, the seedling height for superior haplotype accessions was higher than that of un-superior haplotype accessions in the TROP and TEMP panels, which was easy to form a growth advantage in growth. The superior haplotypes identified showed significant additive effects in TROP and TEMP panels, which could be used in MAS breeding. This study provides reference for the breeding of direct seeding Japonica rice in different regions, and promotes the rapid popularization of dry direct seeding technology.

In order to explore the biological function of PBP gene in transgenic tobaccos and select the low arsenic (As) accumulation parent tobacco germplasm, taking T₂ generation seeds of transgenic tobacco with PBP gene and wild-type tobacco (Nicotiana tabacum K326) seeds as materials, Real-time PCR was used to study the spatial and temporal expression profile of exogenous PBP in transgenic tobaccos, and the activities of antioxidant enzymes (AOEs) in transgenic tobacco lines under As stress were also determined. AOEs activity showed that SOD and POD activities reached the maximum value of 80.25 U/g and 152.02 U/g in CK plants at 5 d after As stress, which were significantly higher than those in transgenic plants. Also, H₂O₂ and MDA contents in CK plants were significantly higher than those in transgenic plants at the later stage of As stress (3-5 d). Additionally, at 7 d and 14 d after stress, the content of As in transgenic tobacco plants was significantly reduced. Based on the expression profiling of ion transporter genes, the results showed that As stress not only induced significant up-regulation of PBP in transgenic plants, but also caused significant up-regulation of channel protein genes such as HAK1 and PHT4 in transgenic and CK plants, and the average expression levels of HAK1 and PHT4 in CK were 1.5 and 3.75 times of that in transgenic plants. The introduction of exogenous PBP gene can effectively reduce the accumulation of As in transgenic tobaccos.

In order to clarify the resistance of flue-cured tobacco with different genotypes to Fusarium tobacco root, the resistance was identified by crude toxin stress culture, inoculation of grain culture with fungi, and spore suspension culture. The results showed that the test varieties showed significant differences in resistance, ‘Y2001’, ‘Y2002’, ‘Changbohuang’, and ‘664-01’ showed resistance to Fusarium oxysporum, and ‘7710’, ‘7713’, ‘Y2007’, ‘Y2008’, ‘Zhongyan 100’ and ‘Xiaohuangjin 1025’ showed susceptibility to F. oxysporum. The identification results of the three inoculation methods were basically consistent, and a total of 4 resistant varieties (lines) were screened.

In order to clone the gene of hydroxyphenyl pyruvate dioxygenase (HPPD) in Echinochloa crus-galli for exploring its genetic function and better developing herbicide, the homologous cloning and rapid amplification of cDNA ends (RACE) techniques were used to clone the EcHPPD gene sequence using E. crus-galli leaves as materials. The characteristics of EcHPPD were analyzed using bioinformatics software. The coding sequence of EcHPPD gene is 1317 bp in length, encoding a protein consisted of 439 amino acids with a relative molecular weight of 46.659 kD and an isoelectric point of 5.30. E. crus-galli is most evolutionarily close to Dichanthelium oligosanthes (OEL23409.1: 8-249) in the Poaceae family based on HPPD protein. The tertiary protein structure of EcHPPD is composed of two chains, with two Fe²⁺ binding sites, and can interact with the pyrazolide active center skeleton through hydrogen bonds. EcHPPD may interact with 11 proteins such as HGO, HPT1, TAT3, AT5G36160 and TAT7. This study reported the EcHPPD gene sequence and conducted bioinformatics analysis, providing a theoretical basis for creating new HPPD inhibitors.

The objective is to address the issue of Carbon Catabolite Repression (CCR) in Klebsiella pneumoniae during mixed carbon source fermentation for 2,3-butanediol (2,3-BD) production, which leads to a decrease in production efficiency. In this study, a Cm resistance gene was used as a marker, and the ptsG gene deletion strain of K. pneumoniae HD79-N was successfully constructed using the λRed homologous recombination technique. Furthermore, the fermentation results using a mixed carbon source of glucose and xylose (glucose:xylose=2:1) demonstrated that the K. pneumoniae HD79-N strain, with the ptsG gene deletion, significantly alleviated CCR, enabling simultaneous utilization of glucose and xylose for 2,3-BD production with a final yield of 9.81±0.38 g/L. Moreover, the xylose utilization rate of K. pneumoniae HD79-N strain [0.23±0.01 g/(L·h)] was also increased by 57.82% compared to that of K. pneumoniae HD79 strain [0.15±0.00 g/(L·h)]. The findings of this study provide technical insights into alleviating the CCR effect caused by the ptsG gene in K. pneumoniae strains and enhancing the production of 2,3-BD.

Using the independently innovative grape variety ‘Yanniang No.1’ as the material, the FRO (ferric reduction oxidase) family genes were screened and cloned, and their bioinformatics identification and expression characteristics were analyzed. This study provides a theoretical basis for studying iron nutrition and the mechanism of absorption and utilization in fruit trees. In total, 6 FRO family genes were isolated from ‘Yanniang No.1’ by homologous cloning method, entitled by VvFRO1-VvFRO6, which belonged to the classic plant ferric reduction oxidase. The amino acid sequences of FRO proteins from 10 plants shared an overall identity of 43.66%, which were classified into 2 major groups (Groups I and II). VvFRO1-VvFRO3 belonged to Group I, while VvFRO4-VvFRO6 belonged to Group II. Phylogenetic tree analysis showed that VvFRO proteins were prone to be closely clustered with homologs form Citrus junos ‘Ziyang xiangcheng’ and Malus xiaojinensis, respectively. All VvFRO proteins were majorly localized in plasma membrane and contained 10-11 transmembrane domains (TMs). Quantitative real-time PCR (qRT-PCR) analysis showed that VvFRO3 was the most abundant expressed gene during different parts of ‘Yanniang No.1’ grape on the whole. VvFRO3 and VvFRO2 were highly expressed in leaves of both mature trees and seedlings, and VvFRO5 was highly expressed in fruits of hard core stage and veraison stage, while genes of VvFRO1, VvFRO4 and VvFRO6 were relatively lowly expressed. In addition, expression of FRO family genes in grape roots were easily induced by iron depletion, 200 mmol/L NaCl stress and 10% PEG6000 (w/v) stress, respectively, but changed little under low temperature (4℃) and heat (45℃) stresses. In particular, VvFRO3 in roots was upregulated under 200 μmol/L ABA treatment but down-regulated under 500 μmol/L iron toxicity stress. This study laid a molecular foundation for revealing iron absorption and transport mechanisms in grape.

In order to cultivate dwarf maize varieties, six generations of population were obtained by crossing the cultivated material DN132610 and the mutant material DN132610-1 to explore the genetic characteristics of the mutant plant height. Six generation populations of P₁, P₂, F₁, B₁, B₂, and F₂ were selected as test materials and joint analysis was conducted using plant quantitative trait segregation analysis software. The results revealed that the optimal genetic model for the dwarf mutant was E-1, which was a mixed genetic model with 2 pairs of additive-dominant-epistasis master genes + additive-dominant polygenes. The additive effect values of both 2 pairs of master genes were -11.205 and dominant effect values were -28.303 and -15.840, respectively. The main gene heritability was 57.26% for B₁, 30.06% for B₂, 76.85% for F₂, and 0%, 28.06% and 0% for polygenic heritability, respectively. The variation caused by environmental factors accounted for 42.74 %, 41.88 % and 23.15 %, respectively. The above experiments showed that the two pairs of genes controlling maize plant height were dominated by dominant effects with high heritability of the main gene. The heritability of B₁ and F₂ polygenes was 0% and maize plant height was influenced by the environment. There was a genetic and environmental interaction effect, which could be combined with environmental identification for early selection on plant height traits.

In order to realize heterologous expression of mannanase and verify its functions, the mannanase-producing Lactobacillus casei HDS-01 was used as the test strain in this study. The M1 predicted to be mannosidase was expressed in Escherichia coli. M1 gene engineering strains were constructed using pET-28a as the vector and E. coli BL21 (DE3) as the host. The recombinant protein was purified and the degradation function of mannan was verified. The results indicated that the recombinant protein M1 existed as inclusion body during expression. After purification by Ni affinity chromatography, the size of the protein was 98 kDa. After renaturation, mannanase activity and protein concentration were 19.24±0.55 U/mL and 0.51±0.01 mg/mL, respectively. High pressure liquid chromatography (HPLC) was used to detect the degradation product of Konjac powder. The concentration of mannotriose or tetrasaccharide was significantly higher in the first 3 hours, and mannose and mannobiose gradually increased as the reaction progressing. This study laid the foundation for the direct application of mannanase-producing lactic acid bacteria in food-grade field and provided the basis for the selective modification of mannanase in lactic acid bacteria.

Zinc (Zn) is an essential micronutrient for animals and plants. Zinc deficiency or excess can seriously affect the growth and development of rice. Maintaining zinc content in rice at a certain level is helpful to improve the yield and quality of rice, increase the zinc content in grain, and solve the current problem of zinc deficiency in human body to a certain extent. Therefore, it is important to understand Zn uptake, transport, distribution, and other molecular mechanisms regulating Zn homeostasis in rice. In this review, we briefly summarized the importance of zinc in plants, especially the ion transporters in rice and the molecular mechanisms. The roles of these ion transporters in the uptake of Zn from soil, the transport from root to shoot, and the distribution of Zn to various parts of rice were summarized. Some molecular mechanisms related to ion transporters were also summarized. This study provides reference for the mining of zinc homeostasis regulatory genes in rice, the study of molecular mechanism, and the creation of high zinc rice germplasm.

Sucrose non-fermenting 1-related protein kinase 2(SnRK2) is a ubiquitous protein kinase in plants. It belongs to the Ser/Thr class of protein kinases, and can play a role in various signal transductions. In order to study the role of SnRK2 protein kinase in plant stress resistance, this study analyzed the characteristics and research process of SnRK2 gene family, summarized the functions of SnRK2 gene in regulating stomatal size of plant leaf, responding to drought stress and salt stress, and responding to seed germination and development. It was pointed out that SnRK2 gene played a role in various signal transductions, which could effectively improve plant stress resistance. It is of great significance for ABA response, plant growth and development, and it provides a reference basis for future research on the molecular mechanism of SnRK2 and plant variety cultivation.

The aim was to clarify the expression pattern and the physicochemical characteristics of the encoded protein of polysaccharide monooxygenase gene (CfCel61A), a pathogenic gene of Ceratocystis fimbriata infecting sweet potato. Eleven strains from different regions were used as materials, CfCel61A was cloned, and the physicochemical properties of CfCel61A were determined by bioinformatics analysis software. The gene expression was analyzed by qRT-PCR. The results showed that the coding region of CfCel61A was 1155 bp with a concordance rate of 99.5%-100%, and it encoded 384 amino acids with the concordance rate of 98.4%-100%. The predicted molecular weight was 34.49 kDa, the isoelectric point was 5.59, the hydrophilicity coefficient was -0.195，and it was a stable hydrophilic protein. There was a signal peptide at the N-terminal, and the subcellular localization was in the nucleus without transmembrane structure. There were 58 phosphorylation sites and 2 potential glycosylation sites. The irregular curl of protein secondary structure accounted for 69.01%, which was the highest. The expression of CfCel61A was significantly up-regulated during the infection of C. fimbriata, while the up-regulation ranges were varied at different stages of infection, and it reached the highest level at 12 h and 6 h after the infection in 'Nanjing 92' and 'Xushu 37', respectively. In short, CfCel61A in C. fimbriata may play an important role in the infection of sweet potato and the result will provide a new target for drug development.

The aim of this study was to provide reference for the functional study of early nodulation protein ENOD93 in non-legumes. In this study, bioinformatics method was used to identify rice ENOD93 gene family. The physical and chemical properties, chromosome location, gene structure, protein structure, expression spectrum and evolutionary relationship of the members were analyzed. The results showed that there were 7 members of rice ENOD93 gene family, which were distributed on chromosomes 2 and 6, and the gene structure was relatively simple. Moreover, most ENOD93 genes are highly similar in the distribution and arrangement of conserved domain and motif. The results of RNA-Seq data analysis showed that ENOD93 gene family was highly expressed in pistils, seeds and embryos, and the expression level of some gene was induced by stress. Based on the phylogenetic analysis of nine monocotyledonous and dicotyledonous species, 31 ENOD93 gene family members were divided into four distinct groups. The expression of ENOD93 gene in rice was different in different tissues and at different developmental stages, and some genes were induced by stress, suggesting that ENOD93gene family was involved in the development process of many plant tissues and played an important role in the response to stress.

The purpose of this study was to explore the structure and function of mannanase gene by gene cloning and bioinformatics. The mannanase gene M1 was obtained from genome of Lactobacillus casei HDS-01 through local BLAST. The differential expression of M1 in MRS medium and KGM medium was determined by qRT-PCR, indicating that Konjac powder in KGM medium was better in inducing M1 expression. Gene M1 was cloned from genomic DNA of L. casei HDS-01, and its sequence was predicted and analyzed by bioinformatics method. The sequence was 2640 bp and could be translated into 879 amino acids, including a 2640 bp open reading frame. The molecular weight of M1 protein was 98723.55 Da and the isoelectric point was 5.58. The secondary structure of the stable M1 protein consisted of α-helix, β-folding, β-turning and random curling. The results not only provide theoretical basis for the molecular modification of mannanase, but also help to understand the metabolic pathway of mannan in lactic acid bacteria.

In order to clarify the composition of avirulent genes of Magnaporthe oryzae strains isolated from four populations of Oryza rufipogon in Yuanjiang of Yunnan, pathogenicity of 52 single spore strains from O. rufipogon of Yuanjiang were determined on rice blast 24 monogenic lines, and the avirulent genes of these strains were identified by spraying inoculation method at seedling stage. The results showed that among 52 strains of M. oryzae, the proportion of medium, weak and non-pathogenic strains was 34.69%, 65.39% and 1.92% respectively, and the weak-pathogenic strains were dominant. The 52 strains showed the strong or moderate pathogenicity to only five resistant monogenic lines carrying Pi19, Pii, Pi3, Pib and Pish, respectively, and weak or non-pathogenicity to the remaining 19 monogenic lines. On the basis of pathogenicity determination of M. oryzae strains on 24 monogenic lines, the composition of avirulent genes could be divided into 10 types. M. oryzae strains from O. rufipogon in Yuanjiang of Yunan generally showed weak pathogenicity to 24 monogenic lines, but they still appeared pathogenicity differentiations.

The study aims to explore the effects of three phytohormones GA₃, ABA and 6-BA on fruit quality of wax gourd and further explore their mechanism of action. Taking wax gourd (B481) as the test material, the changes of fruit appearance, flavor and nutritional quality, and the expression of related genes after treatments of the three phytohormones were measured. The fruit length and diameter of wax gourd treated with ABA were significantly decreased, and the expression of auxin-responsive gene BhSAUR related to fruit type was significantly down-regulated. The content of fructose and glucose increased significantly and the content of sucrose decreased significantly in wax gourd fruits under GA₃ treatment. The expression of alkaline α-galactosidase BhAGA1 and BhAGA2, acid invertase BhSAI1 and sucrose synthase BhSUS2 in sugar metabolic pathway were significantly up-regulated, while the expression of sucrose synthase BhSUS4 and sucrose phosphate synthase BhSPS1 were significantly down-regulated. The content of AsA in wax gourd fruits treated with GA₃, ABA and 6-BA decreased significantly, and the expression of dehydroascorbate reductase BhDHAR2 in ascorbic acid metabolism pathway was significantly up-regulated. In summary, phytohormones affect wax gourd fruit length, monosaccharide content, sucrose content and ascorbic acid content by regulating the expression of key genes. The study can provide a theoretical basis for using phytohormones to improve the fruit quality of wax gourd.

To further promote the application of intelligent management technology in vegetable production and management, this paper puts forward the overall framework of vegetable production intelligent technology, analyzes the vegetable data sources and acquisition means under the background of big data age, summarizes the latest research technology of vegetable disease diagnosis, environment and water and fertilizer regulation, cultivation management decision, intelligent production operation, and the intelligent information service. Then, by analyzing the challenges of vegetable intelligent management technology, the development suggestions for vegetable intelligent management technology are put forward. Intelligentization is an essential factor of modern agricultural development. And the use of intelligent information technology to improve the comprehensive productivity and benefit of the vegetable industry is the ultimate goal. It is necessary to dig into the actual demand, integrate the data of the whole vegetable industry chain, promote the deep integration of intelligent information technology and the vegetable industry, and support the transformation and upgrading of the vegetable industry.

Zinc (Zn) insufficient is one of the limiting factors for the normal growth and development of summer maize in the calcarious soil in the Huang-Huai-Hai region. Zn fertilization is very important for high and stable yield in maize production. To screen high Zn efficiency genotypes in this region, a field experiment was conducted using 10 main cultivated maize genotypes. Four foliar spraying Zn stages were set to analyze the variation of bare tip length, grain yield and Zn content, and screen the high Zn efficiency genotypes according to the Zn responsivity. The results indicated that foliar spraying of 4.5 kg ZnSO₄·7H₂O/hm² could decrease the bare tip length significantly. The grain yield and Zn content under the foliar spraying Zn at the jointing and flaring stage by 1:1 could be increased by 7.5% and 34.3%, reaching 8.73 t/hm² and 43.94 mg/kg, respectively. Compared with no Zn addition, under the foliar spraying Zn at the jointing and flaring stage by 1:1, the reduced margin of bare tip length of ‘DK653’ and ‘LP638’, the yield growth margin of ‘GSY66’ and ‘ZD958’ and the grain Zn content of ‘ZD958’ were the maximum, respectively. The result of cluster analysis of Zn responsivity showed that ‘GSY66’ and ‘ZD958’ were high Zn efficiency genotypes, and they could be planted in the Zn insufficient soil of Huang-Huai-Hai region, and the treatment of foliar spraying of 4.5 kg ZnSO₄·7H₂O/hm² at the jointing and flaring stage by 1:1 could increase grain yield and Zn content in this region.

Bolting and flowering days are the two critical quantitative traits of flowering Chinese cabbage, at the same time, these traits are also affected by various environmental factors (temperature, light, soil, hormones, etc.), so clarifying the molecular genetic mechanism of the bolting and flowering process of flowering Chinese cabbage is quite difficult. In this experiment, two plant materials with significant differences in bolting and flowering days were selected as parents for crossbreeding. A total of 150 lines were selected from the F₂ population for genetic map construction. The map constructed contained 4253 loci, representing 10940 single nucleotide polymorphism (SNP) markers spanning 1030.04 centi Morgans (cM) over 10 linkage groups (LGs). A total of 4 QTLs for bolting time and flowering time were obtained. Mixed linear composite interval mapping method was used to conduct QTL analysis for bolting and flowering traits of flowering Chinese cabbage, and bioinformatics was applied to identify some candidate genes. Three candidate genes (Bra004125, Bra004162 and Bra004165) were identified in the main QTL regions, which could control the formation of floral organs and interact with multiple signaling pathways that induce early flowering in plants.

This study aims to systematically understand the research trends and hotspots of plant disease resistance genes in China. Taking CiteSpace as the tool, the core journals of CNKI databases were used to carry out quantitative and visual analysis of literature related to plant disease resistance genes published from 1991 to 2021. The results showed that the number of publications on plant disease resistance genes increased year by year on the whole. The Institute of Plant Protection of the Chinese Academy of Agricultural Sciences had the highest number of publications among all research institutes, with a total of 86. It was the the journal of Scientia Agricultura Sinica that published the most literature, with 87 publications. With 38 articles, Liu Daqun, from Hebei Agricultural University, published the most. Based on the co-occurrence keyword analysis, the highest frequency keyword was “disease resistance genes”, which appeared 226 times in total. In the analysis of emergent words, the keyword with the highest intensity was “avirulence genes” (9.707). There are several hotspots for plant disease resistance genes, including the prevention and control of crop diseases, the technical means of disease resistance gene research, and the chemical components related to disease resistance.

In order to analyze the effect of orf5 gene on lovastatin content in Monascus and to enrich the regulatory mechanisms of lovastatin metabolism, the over-expressing vector with the gus-orf5 fusion gene was transformed into M. purpureus by ATMT and REMI methods. The co-culture conditions of ATMT and the endonuclease of REMI were optimized. The transformed strains were identified by GUS staining and PCR, and the lovastatin content in positive strains was detected. The results showed that the culture medium supplemented with 20 μg/mL hygromycin could be used as the screening concentration for transgenic Monascus strain. The co-culture medium of Co-IM appended with 1/10 LB was optimal for ATMT, and XbaI-mediated transformation was better in REMI method. Hygromycin resistant colonies were then obtained by both ATMT and REMI. PCR showed that orf5 and hyg genes had been transferred into the Monascus, and GUS staining was blue. The content of lovastatin in the overexpressed strain was significantly higher than that in the control, up to 36.89%. Over-expression of orf5 in Monascus can increase the accumulation of lovastatin, which provides reference for further study of the function of orf5 gene in Monascus.

In order to develop a suitable breeding strategy, the characteristics and genotypes of the indica rice photo-thermo-sensitive genic male sterile (PTGMS) line ‘7-163S’ were analyzed. ‘7-163S’ and its combinations or varieties were used to investigate the key agronomic characteristics. The genotypes of ‘7-163S’ were also determined using genome sequencing and the RiceNavi database. The results show that ‘7-163S’ has excellent agronomic characteristics, good fecundity, low beginning temperature of fertility alteration, and medium resistance to rice blast and bacterial blight. Four hybrid combinations or varieties were bred, showing moderate growth periods, good quality and high yield. Genotype analysis reveals that ‘7-163S’ contains resistance alleles to rice blast, bacterial blight and brown planthopper, as well as excellent alleles of low chalkiness, high nitrogen utilization efficiency and cold tolerance. However, the broad-spectrum blast resistance genes Pi2, Pi9 and Pigm, broad-spectrum bacterial blight resistance gene Xa23, fragrance gene fgr, and cadmium low accumulation genes OsCd1 and OsNRAMP5 are absent in ‘7-163S’. Combining genotypes with phenotypes can provide theoretical support for gene aggregation to enhance ‘7-163S’ resistance and breeding of new varieties.

Prochloraz is an endocrine disruptor pesticide, and its environmental residues have a great impact on human health. Through the study of the effects of different doses of prochloraz on the reproductive system of offspring mice, we can evaluate the effects of its residues on human health. The results showed that the heat map of gene expression cluster analysis of high concentration group (MD), low concentration group (MB) and control group (MA) had good inter-group difference and high intra-group repeatability, which laid a foundation for further analysis. The subsequent analysis of gene ontology (GO) and metabolic pathway showed that prochloraz mainly involves the functions and pathways related to the reproductive system (such as neuropeptide hormone regulatory signal pathway, immune response, antigen processing and presentation, prostaglandin biosynthesis, etc.). In conclusion, it can be seen that prochloraz has a certain reproductive toxicological effect on offspring male mice.

With the development of plant molecular biology, there is a growing demand for DNA extraction from large-scale samples in plant molecular experiments. In the study, we aim to develop a rapid, simple and high-throughput DNA extraction method. Tomato leaves as test materials were freeze-dried and crushed in a 96-hole box. To simplify the extraction steps and achieve high-throughput DNA extraction, we used the improved SDS-DNA extraction method by “two-step sampling and one-step extraction”. The average concentration of DNA sample extracted by this method was about 138.6 ng/mL, which met the need of PCR amplification. Agarose gel electrophoresis showed that most of the samples had clear and complete DNA bands without obvious degradation, but accompanied by some RNA. A total of 192 samples were detected by using 3 allele-specific quantitative PCR (AQP) markers. The results showed that the overall detection results of the 3 markers were good, and all of them could effectively distinguish different allelic loci between the samples. The effective fluorescence value of samples detected ranged from 97% to 99%, such DNA samples could satisfy molecular marker detection and genetic population genotyping. In this study, a simple, rapid and high-throughput method for DNA extraction from tomato was developed, which was also suitable for DNA extraction from other plant leaf tissues. This method could be successfully applied to AQP and other similar fluorescent molecular marker detection, and provide reference for large-scale molecular marker detection and other experimental DNA sample preparation.

In order to study the effect of intercropping of different maize genotypes, six maize varieties of different genotypes were used as experimental materials to set 3 combinations and 9 treatments. The monoculture and intercropping effect were analyzed comprehensively and compared by using DTOPSIS method (dynamic technique for order preference by similarity to ideal solution) based on entropy weight. Through exploring new methods of comparative analysis, a new dominant pattern of maize intercropping with different genotypes was obtained. The results showed that the C_i value of treatment 4 was the highest (C₄=0.9829), and that of treatment 5 was the lowest (C₅=0.0330). The C_i value of the other two combinations of intercropping were all greater than the C_i value of monoculture. The intercropping pattern of ‘DH605’ with ‘WK702’, and ‘DH618’ with ‘DH371’ had the effect of increasing yield and efficiency, which could be applied in production.

As an important part of modern agricultural production development, intelligent agricultural machinery equipment plays an crucial role in improving resource allocation and ecological environment, enhancing economic development, promoting rural revitalization and ensuring food security, while accelerating the development of agricultural modernization. Shandong Province, as a large province of agricultural machinery equipment manufacturing and application, still has problems such as unbalanced development of agricultural machinery equipment industry, low level of intelligent equipment, insufficient integration of agricultural machinery and agronomy, and backward construction of basic conditions for mechanization. This study analyzes the status quo of the intelligent agricultural machinery equipment. In view of the problems of the development of intelligent agricultural machinery industry in Shandong Province, we deeply dissect the domestic and foreign cutting-edge technologies and the industrial developing trends. In combination with the urgent needs of the modern agricultural and rural development, we put forward future research and application targets of intelligent agricultural machinery equipment in Shandong Province, and further clarify the innovation and support fields of government, enterprises and scientific research institutes, and the key technology research direction in line with the national strategic needs and the requirements of agricultural modernization.

In order to screen the salt tolerance genes of Medicago polymorpha L. and Medicago sativa L., the plantlets of Medicago polymorpha L. (JHC) and Medicago sativa L. (ZHMX) under salt stress were used for transcriptome analysis. The results showed that the number of differential genes between JHC group and ZHMX group was 26722. 15850 genes were down regulated and 10872 genes were up regulated in JHC group vs ZHMX group. Pathways with significant enrichment of KEGG gene in JHC group and ZHMX group included ribosome, photosynthesis antenna protein, glycolysis/gluconeogenesis, photosynthesis, phenylpropanoid biosynthesis, etc. Salt tolerance genes in JHC group included basic leucine zipper 43, NAC transcription factor 47, ABC transporter A family member 7, late embryogenesis abundant protein 2, ethylene responsive transcription factor ERF110, etc. The salt tolerance genes in ZHMX group included WRKY transcription factor, protein TIFY 8, transcription factor MYB13, nuclear transport factor 2A, low temperature and salt responsive protein, etc. The results of this experiment could provide a theoretical basis for understanding the molecular mechanism of salt tolerance of Medicago polymorpha L. and Medicago sativa L. and breeding new salt tolerant varieties of Medicago polymorpha L. and Medicago sativa L..

In order to study the effects of hypoxic stress [(0.8±0.1) mg/L] and reoxygenation [(7.3±0.5 mg/L] on oxygen sensing, respiratory metabolism, oxidative stress, tissue structure, and apoptosis in the gill of L. longirostris, by using qRT-PCR, enzyme activity measurement, H&E staining and TUNEL slice detection, the experiments of hypoxic stress (0, 2, 4, 6 h) and reoxygenation (2, 4, 6 h) on L. longirostris were conducted and the changes of hypoxic response genes, and physiological and biochemical indexes in the gill of L. longirostris were analyzed. The results showed that: the expressions of genes related to oxygen sensors (HIF-1α, HIF-2α, PHDs and Vhl) were upregulated in the gill of L. longirostris during hypoxia, after reoxygenation, there was still a significant difference compared with the control (P<0.05). Expression activities and contents of glycolysis related enzymes (PFK, HK and PK), anaerobic respiration enzymes (LDH), antioxidant enzymes (GSH-Px, CAT and SOD) and oxidative stress indicators (MDA and LPO) significantly increased. The activities of TCA cycle-related enzymes (SDH and MDH) decreased significantly during hypoxia, but most physiological indexes gradually recovered to the level of the control upon reoxygenation. H&E staining showed that under hypoxic stress, the epithelium of the gill was uplifted, and some blood cells gathered in large numbers to make the gill small pieces have rod-like tips, and tissue changes such as swelling and proliferation of mitochondria-rich cells occurred, but these changes in tissue morphology caused by hypoxia were not improved after the recovery of dissolved oxygen. TUNEL sections showed that the number of apoptotic cells in the gill of L. longirostris increased with the prolongation of hypoxia time, the mRNA levels of apoptosis-related genes (Bax, Caspase 3, p53 and Apaf-1) increased significantly and Bcl-2 decreased significantly during hypoxia, and the apoptosis still existed compared with control upon reoxygenation. Hypoxic stress and reoxygenation can significantly affect the gill oxygen sensors, respiratory metabolism, oxidative stress, tissue structure, and apoptosis of L. longirostris. The results lay a theoretical foundation for exploring the molecular regulation mechanism of fish under hypoxic stress, and provide basic data for future development of new hypoxia tolerant varieties of L. longirostris.

For cultivating the herbicide-resistant rice cultivars with excellent agronomic traits, 3 derived herbicide-resistant restorer lines (Hua 84EP-1, 2 and 3) harboring EPSPS gene were mated with 5 sterile lines (Hongxiang2A, Y58S, Guangzhan63-4S, Hua1015S and Tianyuan6S). The herbicide resistance of parents and mated hybrids and the combining ability of 10 main agronomic traits of those mated hybrids, including YP (yield per plant), SSR (seed setting ratio), TGW (1000-grain weight), GP (growth period), PH (plant height), EP (effective panicles per plant), GD (grain density), NG (number of grains per panicle), NFG (number of filled grains per panicle) and PL (panicle length), were analyzed. The results showed that the herbicide resistance of 3 restorer lines was nearly complete (>96%), and it was very effective for improving the purity of rice hybrids to spray herbicide Roundup at seedling stage; the general combining ability of restorer lines and sterile lines reached significant differences in 5 traits (SSR, GP, etc.) and 7 traits (SSR, TGW, etc.) respectively; and the special combining ability of the mated hybrids only reached significant difference in GP. Among these hybrids, Tianyuan6S/Hua84EP-1, Hongxiang2A/Hua84EP-3 and Hua1015S/Hua84EP-1 had the highest yield increase compared with the control. Therefore, using herbicide-resistant restorer lines as male parent can not only improve the purity of hybrids, but also cultivate strong-heterosis combinations.

The purpose of this experiment is to investigate the effect of adding Pennisetum giganteum in diet on growth indexes, slaughter performance, and fat-related genes of heart-type fatty acid-binding protein (H-FABP) and adipocyte fatty acid-binding protein (A-FABP) gene in Phasianus colchicus. The experiment selected 150 healthy P. colchicus (4 weeks old) in the same batch and randomly divided them into 4 experimental groups and 1 control group, 10 in each group, 3 replicates. The addition amount for the experimental groups was 4%, 8%, 12%, and 16%, respectively. The control group was fed with basal diet, and the feeding period was 16 weeks. Compared with that of the control group, the difference of the average body weight of the 8% P. giganteum adding group was significantly increased (P<0.05); the average daily feed intake increased, but the difference was not significant (P>0.05); the average daily weight increase of each experiment group was significantly greater than that of the control group (P<0.05), among which the 8% P. giganteum adding group had the most significant improvement effect. The 4%, 8%, and 12% P. giganteum adding groups had a decrease in the ratio of feed to weight; and compared with those of the control group, the slaughter rate, half evisceration rate and complete evisceration rate of the 8% P. giganteum adding group significantly increased (P<0.05). The breast muscle rate of P. colchicus in the P. giganteum adding groups increased, but the difference was not significant compared with that of the control group (P>0.05); the leg muscle rate in the 8% P. giganteum adding group was significantly higher than that in the control group (P<0.05). The differential expression of H-FABP and A-FABP genes were determined by real-time fluorescence quantitative PCR after the addition of P. giganteum diet, and were significantly increased in the 8% P. giganteum adding group. Therefore, adding 8% of P. giganteum to the diet can significantly improve the growth index, slaughter performance and the expression of fat-related genes in P. colchicus.

The effects of high temperature environment on antioxidant enzyme activity and gene expression in hemolymph of silkworm were explored, which may provide reference for revealing the physiological and molecular adaptation mechanism of silkworm to high temperature environmental stress. The tolerant variety to high temperature 932G and sensitive variety HY were taken as the studied objects, and the changes of antioxidant enzyme activities and enzyme gene expression levels in the hemolymph of the 5th instar larvae under high temperature stress were measured by real-time fluorescence quantitative PCR. The results showed that under 35℃ high temperature stress, the change trend of relative activities of SOD, CAT and GST in tolerant variety and sensitive variety were similar. The change ranges were all small in the early stage of stress, then increased significantly in the middle and late stages, and decreased significantly in the final stage of stress. The overall change trend was first increase then decrease. The relative expression levels of enzyme genes increased in varying degrees in the middle and late stages of stress, and decreased in the final stage of stress, which were basically consistent with the change trend of enzyme activities, but the change ranges among the varieties were different. The relative expression levels of BmSOD and most of BmGSTs genes increased significantly in tolerant variety, while that of BmCAT increased significantly in sensitive variety. In conclusion, the high temperature response trend of antioxidant enzymes SOD, CAT and GST in silkworm hemolymph are relatively consistent, and there are only differences in the change ranges among the varieties.

In order to obtain Streptomyces strains with antagonistic effect on Fusarium oxysporum causing pepper root rot and clarify their antagonistic effect and classification, F. oxysporum was used as the indicator strain to screen by plate confrontation method. The inhibition rate was determined by mycelial growth rate method. Phylogenetic analysis was conducted based on 16S rRNA gene sequence. In this study, eight antagonistic Streptomyces strains were obtained by primary screening. The results of confrontation culture showed that the inhibition rate against F. oxysporum was 45.18%-62.81%, and the inhibition rate against the other four root rot fungi was 28.51%-60.00%. Among them, the strain ZY12.53b showed the best antagonistic effect with more than 50% inhibition rate against five root rot fungi. The fermentation filtrates of strains MDI2.4 and ZY12.23a had the highest antagonistic effect on F. tricinctum, and the inhibition rates were both more than 60%. In the phylogenetic tree of 16S rRNA gene sequence, the eight antagonistic Streptomyces strains clustered into five different branches, and two of them were likely to be potential new species. In this study, eight antagonistic Streptomyces strains belonging to at least five species were obtained, among which three strains showed satisfied antagonistic effect with the value of potential exploration.

The major gene + polygene genetic analysis of quality traits in sweet corn was carried out to provide a theoretical basis for quality improvement of sweet corn. In this experiment, the hybrid combination T77 (high-value parent) ×T15 (low-value parent) was prepared from sweet corn inbred lines with significantly different fructose content, dietary fiber content and vitamin C content. Three quality traits, namely fructose content, dietary fiber content and vitamin C content, were measured in the F₂ generation population of this combination. The optimal genetic model and related genetic parameters of the three traits were analyzed by using the major gene + polygene genetic model. The experiment showed that the optimal genetic model for fructose content was A-1, which was a mixed one additive-dominant major gene genetic model, and the heritability of major gene was 76.4%. The optimal models for dietary fiber content and vitamin C content were both B-1, which indicated that these two traits conformed to the genetic model of two additive-dominant-epistatic major genes, and the heritability of major genes was 63.6% and 64.7%, respectively. In breeding practice, the genetic improvement and selection of fructose content, dietary fiber content and vitamin C content of sweet corn could be carried out in the early generation, and at the same time, certain environmental factors should be highlighted, and the method of polymerization backcross or recurrent selection should be adopted to accumulate minor genes to improve breeding efficiency.

Bacterial blight severely restricts the production of rice. The discovery and utilization of disease-resistant genes is currently the most environment-friendly and effective way to control the disease. In order to efficiently discover, study and utilize bacterial blight resistance genes, this paper summarized the interaction mechanism between bacterial blight and rice, concluded the location and cloning status of bacterial blight resistance genes, and classified their functional types. Research progress on disease resistance-related factors was reviewed. In view of the current situation that the research progress of bacterial blight resistance genes is slow and the overview research reports are relatively lagging behind, we put forward the research prospect, and believe that more in-depth research should be done on the location cloning and utilization of rice bacterial blight resistance genes, and the synergistic relationship between genes and disease resistance-related factors should be explored.

In order to construct an overexpression vector of HMOX1 gene in Hezuo pigs and analyze its tissue expression characteristics, the complete CDS region sequences of HMOX1 gene were obtained by PCR amplification, and then were inserted into pcDNA3.1 (+) blank vector to construct pcDNA3.1-HMOX1 overexpression vector. At the same time, the expression of HMOX1 gene in the heart, liver, spleen, lung, kidney, stomach, duodenum and longissimus dorsi muscle of Hezuo pigs were detected by real-time quantitative PCR. The results showed that the completed CDS region of 924 bp of HMOX1 gene was successfully amplified and identified by double enzyme digestion and sequencing, which was successfully linked to the pcDNA3.1(+) overexpression vector. Results of tissue expression analysis showed that HMOX1 gene expression was the highest in Hezuo pig spleen tissue, followed by liver, lung, kidney and heart, and the lowest was in duodenum. These results can provide reference for further research on the function of HMOX1 gene in the process of adaptation of Hezuo pigs to high altitude and hypoxia.

Strain ZX67 belonging to Pectobacterium carotovorum subsp. carotovorum is the pathogen of konjac soft rot disease. In order to further understand the characteristics of the pathogen and effectively control and prevent konjac soft rot disease, the whole genome of the strain was sequenced and analyzed. The results showed that its total genome length was 4,909,724 bp and GC-content was 51.27%. It contained 4,977 coding genes, and the sequence accounted for 85.25% of the total genome. The predicted non-coding RNA (ncRNA) mainly included tRNA (74), rRNA (22) and sRNA (100). There were 10 gene islands, and 6 transposons. Two prophages were predicted, the average length of each prophage was 26,258 bp. Five CRISPR sequences were predicted, with the average length of each sequence of 621 bp. In the coding genes, the pectate lyases and other enzymes related to degradation of host plant cells were analyzed. There were five protein secretory systems related to the infected plants. The results provided a new and comprehensive idea for further understanding the characteristics of the pathogen, and studying its prevention and control measures.

This study aims to improve the quality of citrus fruits. Function of a CsaccA gene, which is suspected to be related to citrus fruit quality, was systematically investigated through overexpression in Micro-Tom tomato, identification by PCR and GUS staining, plant phenotype observation and physiological and biochemical determinations. The results showed that the CsaccA gene significantly promoted plant biomass, and the biomass of the root, stem and leaf of transgenic plants were all significantly higher than that of control. The plant growth rate of transgenic plants was significantly faster than that of control as well. The transgenic fruit colored and ripened earlier than that of control. Quality analysis showed that the main sugar components of tomato fruit, glucose and fructose, had a significant increase in content. However, the main acid component citrate had a decrease in content significantly. In summary, transgenic studies have verified that the CsaccA gene functions in increasing fruit sugar-to-acid ratio, which can lay a foundation for fruit quality improvement in the future.