Abstract:Rice （Oryza sativa L.） is one of the most important food crops in the world， low temperature destabilizes the growth and development of rice， and causes lower yield or harvestless in worse cases， has becoming one of the major environmental stresses that decrease rice yield and quality. The use of agricultural protection technologies to reduce cold damage were not only time-consuming and laborious， but also ineffective. Therefore， the cultivation of rice varieties showing cold tolerance in practice is the optimal way to solve this problem. In breeding of cold-tolerant varieties， precise identification and evaluation of cold tolerance rice in conjugation with the exploitation and utilization of important cold-tolerant genes become of significance. In recent years，several cold tolerant QTLs or genes had been identified by map-based cloning， GWAS and QTL analysis，and their functional mechanisms have been investigated. This article reviews the cold resistance of rice， from the aspects of identification methods and periods， evaluation systems and the molecular research basis， and suggested that different evaluation systems should be used to evaluate the cold tolerance of rice at different growth stages. At the same time， it is proposed to pyramid important cold tolerance genes/QTLs in excellent rice germplasm resources for further innovative utilization， which could provide reference for exploring the mechanism of cold tolerance and breeding new varieties of cold tolerance in rice.

Abstract:Rice is the largest crop food in China， possessing a principal strategic position in agricultural production. With the rapid growth of population and the acceleration of urbanization process， the limited yield increase makes rice production is facing severe challenges. Breeding high-yield rice varieties is of great significance to ensure food security and realize sustainable agricultural development. The ideal plant architecture is a considerable strategy of variety improvement and directly affects rice yield. The tiller angle， which affects rice yield by regulating the light energy utilization efficiency of the population， is a core element of plant architecture characteristics. The production practice shows that the varieties with reasonable tiller angle show better lodging resistance and stable yield potential. With the rapid development of functional genomics， researchers have made many important progresses in mining of the rice tiller angle regulatory genes and the molecular mechanism analysis in recent years. In this review， we systematically summarized the functional genes and genetic metabolic networks regulating rice tiller angle. And then， the domestication process and the genetic mechanism of gravitropism in regulating rice tiller angle were mainly elucidated， as well as the regulation mechanism of plant hormones and environmental factors. Even further， we prospected the potential further research directions under the existing theoretical framework. The purpose of this paper is to provide a theoretical reference for the genetic improvement and molecular design breeding of high-yield and ideal plant architecture varieties.

Abstract:The crucifer Orychophragmus violaceus （L.） O. E. Schulz （syn. Moricandia sonchifoli （Bunge） Hook. f.） is an ornamental plant native to China and serves as the germplasm resource in the genetic improvement of the Brassica L. crops. In this paper， the research progress and status of its cytogenetics， cytological behavior of its intergeneric hybrids with the Brassica L. crops， the chromosomal localization of some traits， and the discovery of the dihydroxylated fatty acids are summarized. O. violaceus （L.） O. E. Schulz （2n=24） has the large genome size of about 1.3 Gb and the long chromosomes with the homogenous staining. The meiotic pairing patterns of O. violaceus （L.） O. E. Schulz and its haploid reveal the polyploidy nature of its genome. The latest results from the genome sequencing revealed that the ancestral diploid of this species should likely have the tPCK karyotype with x=7， and experienced one specific tetraploidization event occurring at 600-800 million years ago， which gave rise to the extant genome of n=12 by chromosomal rearrangements and the inactivation of centromeres. With O. violaceus （L.） O. E. Schulz as the male parent， the intergeneric hybrids with six cultivated Brassica L. species give the cytogenetical behaviors specific to each Brassica L. parent， which are likely associated with the genome structures and inherent cytological patterns of two parents. The chromosomes from O. violaceus （L.） O. E. Schulz are clarified easily from those of Brassica L. species in these hybrids， as they are of larger size and more deeply stained. The traits of the serrated leaves， the basal clustering stems， purple petals and dihydroxylated fatty acids are localized on different chromosomes via the development of the Brassica napus L.- O. violaceus （L.） O. E. Schulz additional lines. The dihydroxy fatty acids with high content are discovered in its seed oil and present the better lubricant effect than the castor oil. O. violaceus （L.） O. E. Schulz has also potential medicinal value. Finally， the future research area and utilization for Orychophragmus Bunge species are discussed.

Abstract:Fluorescence in situ hybridization （FISH， fluorescence in situ hybridization） is a powerful tool for molecular cytogenetics studies and is able to authentically allocate particular DNA or RNA sequences on chromosomes. With the development of the genome sequencing technology， the reduction of sequencing cost and the publishment of a large number of species genome information， Oligonucleotide （Oligo） probes based on high-throughput sequencing and reference genome were developed showing the advantages in FISH. In comparison with the traditional probes， Oligo-FISH can further reveal the evolution， inheritance and variation of chromosomes more precisely and deeply in plant evolution.This paper reviews the types and applications of target DNA and fluorescent probes in the development of fluorescence labeling， as well as the types and preparation techniques of oligonucleotide probes， mainly focusing on the origin and development of Oligo-FISH and its application in plants， which plays an important role in the identification of plant chromosomes and plant homologous chromosomes. Since the karyotype of species and genera can be constructed by Oligo-FISH technology， the results of Oligo-FISH can provide guidance for genome assembly of crops in this genus which have no complete genomes. Oligo painting can also solve the problem of fusion and exchange between chromosomes of heteropolyploid species and accurately detect whether there is translocation and heterologous recombination between chromosomes. Therefore， the development of Oligo-FISH technology provides strong support for the assembly of the genome at chromosome level. In the future， Oligo-FISH technology combined with signal amplification technology can overcome the challenge of low Oligo probes with high concentration of repeat sequences in regions， and visualize limited gene regions， such as the detection of promoters or enhancers or the localization of gene segments in transgenes. These studies will make better use of the research results of species genetics and evolution to further ensure， assist and innovate the improvement and development of crop genetics and breeding.

Abstract:As a very valuable germplasm resource， the wheat materials showing male sterile is of significance in the study of wheat hybrid breeding and heterosis utilization. In this study， we identified a male sterility mutant 4167ms from a wheat high generation line 4167， followed by the phenotype classification， genetic analysis and molecular marker mapping. The anthers of the mutant were shriveled and not exposed. The pollens were irregular in shape and failed to be stained with 1% I₂-KI， indicating complete sterility of the pollens. Gained from the outcome of field trials over several years， the male sterility were stable without affects due to light and temperature conditions. The F₁ plants derived from crosses between 4167ms and a number of varieties were completely fertile. The segregation ratio （fertile vs. sterile plants） in F₂ populations fitted to 3∶1. The F₁ plants （KD342//4167ms/4167）， which were derived from reciprocal cross， were fertile， and the segregation ratio （fertile vs. sterile plants） in derived F₂ population of segregation was 3∶1. These results indicated that the sterility was controlled by a single recessive nuclear male sterile gene， temporarily designated ms1t. By taking use of a 4167ms/Chinese spring F₂ mapping population， together with bulked segregant analysis （BSA） and mapping with SSR molecular markers， the ms1t was delimited with five markers （Xwmc617-Xkd661-Xkd696-ms1t-Xkd495-Xkd393） on chromosome 4BS. The genetic distance of the closest flanking markers Xkd696 and Xkd495 to ms1t were 3.9 cM and 1.9 cM， respectively. The comparative analysis based on the physical map of Chinese Spring suggested that ms1t was allocated to the same genetic interval of the former classified ms1 locus， implying ms1t in mutant 4167ms as a novel recessive allele of the MS1gene.

Abstract:In order to analyze the quality characteristics of sesame seed with different colors， 13 nutritional quality traits of 157 sesame germplasm resources with different seed coat colors （white， yellow， brown， and black） were tested and analyzed in Wuhan and Zhumadian. The results showed that average oil content of 157 sesame germplasm was 52.96%， and the average contents of oleic acid， linoleic acid， sesamin， sesamolin， campesterol， and β-sitosterol were 40.65%， 44.32%， 2.67 mg/g， 1.61 mg/g， 1.22 mg/g and 2.96 mg/g， respectively. The average oil content decreased gradually with the deepening of seed coat color. The total sterol content was the highest in black sesame. The content of sesamin and sesamin was the highest in white sesame and the lowest in black sesame. Oleic acid content of yellow sesame and linoleic acid content of brown sesame were the highest. Oil content， oleic acid content， sesamin and sesamolin content of black sesame were significantly lower than those in white sesame， but no significant differences in contents of stearic acid， linoleic acid， arachidic acid， campesterol and β-sitosterol in sesame seeds with different colors were observed. Among the 13 nutritional quality traits， there were significant positive correlations between β-sitosterol and stigmasterol， Δ5-avenasterol and stigmasterol， sesamin and sesamolin， sesamin and oil content， sesamolin and campesterol， and significant negative correlations between oleic acid and linoleic acid. The correlation coefficients between Δ5-avenasterol and stigmasterol， sesamin and sesamolin were higher in black sesame than in sesame with other colors. The 157 sesame genotypes were divided into four subgroups by cluster analysis. The first and second subgroups were mainly brown black and yellow white sesame， respectively. The third subgroup contained high sesame materials， and the fourth subgroup contained high linoleic acid materials and high oil content materials. Collectively， this study explored the quality characteristics of sesame seed with different colors， which provided reference and excellent germplasm for utilization and genetic improvement of sesame germplasm resources.

Abstract:In order to explore the regulation mechanism of genome-wide DNA methylation at rice seedlings upon low temperature stress treatment， three rice genotypes showing levels of cold tolerance were treated at 3-4 ℃， followed by determination of the genome-wide DNA methylation using whole genome bisulfite sequencing （WGBS）. By analyzing the distribution of methylation-related genes in the promoter and genic body region of the three samples， it was found that the related genes were mainly distributed in the promoter region. The genotype P427 was found anchoring the highest number of genes， including 9223 genes in the promoter region， and 2906 genes in the body region. The genotype 9311 was found anchoring the fewest genes. GO and KEGG enrichment analysis revealed that the differentially methylated genes were mainly involved in metabolic pathways such as those of diterpene biosynthesis， starch and sucrose metabolism， β-alanine metabolism， and phenylpropane biosynthesis. These results indicated that the methylation in the promoters was important in the regulation of low temperature stress-responsive genes， and the transcriptional regulation was associated with the degree of methylation and the methylation types. The genotype P427 may affect the cold tolerance of rice through modulating the genes in metabolic pathways such as diterpene biosynthesis， starch and sucrose metabolism， and hormone signal transduction pathways. Collectively， these results provided better understanding of the methylation-based response mechanism of cold tolerance in rice

Abstract:Leaf color mutants are often accompanied by changes in chlorophyll content and abnormal chloroplast structure. They are important materials to decipher the functions of genes in chloroplast development and photosynthesis. In this study， a naturally occurring mutant 74101 showing etiolated leaves was identified in maize. The mutant showed etiolation throughout the growth period. Compared with the wild type， the total chlorophyll content decreased by 53.38%， and the net photosynthetic rate decreased by 25.63%. Transmission electron microscopy revealed the disordered chloroplast thylakoid structure， with loose matrix lamella and no grana structure. Genetic analysis and fine mapping results showed that the 74101 mutant phenotype was controlled by a pair of recessive nuclear gene， which was delimited in the 76.05 kb physical interval between the markers K-138 and K-27 on the long arm of maize chromosome 5. By sequencing and analyzing four candidate genes in this interval， a C to T mutation at 1126 site of the gene ZmNPPR5 （Zm00001eb252430） encoding PPR protein was identified. Tests for allelism with EMS mutants approved the ZmNPPR5 gene as the causal agent of leaf etiolation phenotype. The subcellular localization suggested that it was expressed in the nucleus. Collectively， this study revealed that ZmNPPR5 has an important function affecting chlorophyll synthesis， which laid a foundation for deciphering the nuclear-localized PPR protein on the regulation of chloroplast development and chlorophyll synthesis.

Abstract:Wheat （Triticum aestivum） is one of important food crops in many countries， whereas drought seriously destabilizes its growth and yield production. In this study， the genome-wide association study （GWAS） was conducted to mine SNP loci and candidate genes that associate with drought resistance of wheat root traits at seedling stage. 183 Xinjiang spring wheat varieties （lines） were examined under 20% PEG-6000 or normal nutrient solution treatment conditions， to simulate drought stress at seedling stage. The measurement of root traits were statistically analyzed， and the correlation analysis of drought resistance coefficient was carried out. Genome-wide association analysis of drought resistance coefficients of eight traits including total root length， root surface area， root volume， root mean diameter， root fresh weight， root dry weight， root tip number and maximum root length was performed using a hybrid linear model MLM （Q+K） using 55K SNPs， and candidate genes were identified for significant inherited association loci. The results showed that the variation coefficient of eight root traits were 17.81%~70.71% and 20.01%~61.62% under normal and PEG stress conditions， respectively. Correlation analysis results showed that the drought resistance coefficient of average root diameter was significantly negatively correlated with those of total root length， number of root tips and maximum root length. The drought resistance coefficient of total root length and root surface area had the largest correlation coefficient of 0.74. Genome-wide association scanning enabled identification of 54 SNPs associated to root drought resistance （P≤0.001）， distributed on 16 chromosomes except 3B， 3D， 5D， 6D and 7D. Each single locus could explain the phenotypic variation ranging from 6.18% to 18.74%. In addition， six pleiotropic loci were detected， which were located on chromosomes 1A， 5A， 7A， 1B， 5B and 2D， each explaining the phenotypic variation ranging from 6.55% to 18.74%. The locus AX-110482078-AX-110400975 was significantly associated with the number of root tips， root volume and maximum root length on chromosome 5A， with the contribution rate ranging from 8.74% to 15.44%. Nine candidate genes were proposed based on 54 significantly-associated SNPs. With gene annotation information， three genes TraesCS4A01G424000， TraesCS6A01G047200 and TraesCS5B01G056600 were proposed to be involved in physiological regulation of wheat stress by regulating translipoprotein， peroxidase and MYB transcription factors， respectively.

Abstract:This research examined the identification method and genetic traits of low nitrogen resistant soybean at the seedling stage. 260 soybean varieties were used and subjected for pot experiments under normal and low nitrogen treatments， followed by examination of nine traits （such as SPAD， plant high， and shoot fresh weight） at the stage of the fourth compound leaf unfolding. By analyzing the phenotypic difference of soybean varieties under low nitrogen stress condition， as well as the low nitrogen tolerance coefficient， correlation analysis， principal component analysis， affiliation function， and regression analysis， the soybean varieties showing low nitrogen tolerance were identified. The significant differences at all the traits were observed under two different nitrogen-supplying levels， showing levels of variation among the traits and the varieties. The indexes of nine traits were refined using three indexes by principal component analysis. Based the value of the affiliation function and the comprehensive evaluation of low nitrogen tolerance in conjugation with cluster analysis， five categories （strong resistant， resistant， middle resistant， sensitive and most sensitive） were suggested. Seventeen soybean varieties were strong resistant categories， while seven were most sensitive categories. Through stepwise regression analysis， total dry weight， root dry weight， shoot fresh weight， SPAD of the second compound leaf， and SPAD of the first compound leaf， might be deployed as the principal indicators for evaluating low nitrogen tolerance in soybean.

Abstract:Soybean is an important source of plant protein and oil in diets of Chinese residents. Jiangsu province is one of the main soybean producing areas in China. Under the frame of the Third National General Survey and Collection Action of Crop Germplasm Resources， 203 soybean landraces were collected from 35 counties in Jiangsu province from 2016 to 2019. In this study， the genetic diversity based on the phenotypic datasets at 25 traits were investigated. The abundant phenotypic diversity was observed with the diversity index of 12 morphological traits ranging from 0.0311 to 1.3800， and that of 13 quantitative agronomic traits ranging from 1.3850 to 2.0155. The 203 landraces were divided into five groups by cluster analysis. The phenotypic variation at each group was revealed， and the performance of the yield-related traits in IV group was superior. Principal component analysis suggested eight principal components that showed a cumulative contribution rate of 68.361%. The comprehensive scores of 203 soybean resources ranged from 0.140 to 1.385. According to the order of scores， seven elite soybean landraces in Jiangsu province were selected. Collectively， the present study unlocked the genetic diversity of soybean landraces in Jiangsu province， which provided insights for the germplasm innovation and breeding for new soybean varieties.

Abstract:In order to study the effect of sowing in different seasons on the content of nutritional functional components in barley grass powder and grains， and to explore the high-efficient production technology of high-quality dual-purpose barley， 48 barley varieties （lines） from Yunan province were sown in four seasons （spring， summer， autumn and winter） for two consecutive years. The samples harvested were subjected to measure the contents of total flavones， GABA， alkaloids and proteins by spectrophotometry and Kjeldahl method， followed by the correlation analysis on the nutrient function components between barley grass powder and grains. The results showed that samples harvested from different years and seasons showed a significant difference on the accumulation of nutritional functional components in barley grass powder and grains. The average contents of the four nutritional functional components （total flavones， GABA， alkaloids and proteins） in grass powder were autumn sowing > winter sowing > spring sowing > summer sowing. These components in grains from winter sowing season were higher than those in grains from autumn sowing season. In general， the nutritional functional components of grass powder was higher than those of the grains. The nutrient functional components were greatly affected by the sowing season， showing the trend of sowing season > varieties > varieties × sowing season. As a result， excellent dual-purpose barley varieties （Aisi 4， Tengyun 4 and Yunpi 22） were preliminarily selected.

Abstract:The identification and evaluation is an important research subject in the protection and utilization of germplasm resources. Wheat landraces from the western region of Yunnan province， P.R. China， were known with various types and abundant diversity. Analysis of their genetic diversity is of significance to accelerate their breeding utilization rate. In this study， 65 SSR markers were used to analyze the genetic polymorphism of 186 wheat landraces from the western region of Yunnan. A total of 407 alleles were detected， with an average of 6.26. The total of the major allele frequency was 36.1077， with an average of 0.5555. The total of gene diversity index was 37.5473， with an average of 0.5777. The total of polymorphism information content （PIC） was 34.9924， the average was 0.5383， the range were from 0.146 to 0.835， and the polymorphism reached high level （PIC ≥0.5）. Among subgenomes A， B and D， the average value of gene diversity index from high to low were B > A > D. Among the 7 homologous groups， the average value of gene diversity index ranged were from 0.5202 to 0.6508. the fourth homologous groups were the highest， and the seventh homologous groups were the lowest. Cluster analysis had showed two groups， of which in group I five samples expect a hulled hexaploid wheat landrace are tetraploid wheat， and in group Ⅱ 181 samples were hexaploid wheat. In group II， the landraces were clustered into subgroups mainly being coincidence with the geographical sources such as Lincang， Baoshan and Dali. The results of principal component analysis were consistent with those of cluster analysis. These results indicated that wheat landraces from the western region of Yunnan province had possessed high genetic diversity and were valuable gene bank for wheat breeding and improvement in future.

Abstract:Fifty-six color-grained wheat varieties， which were released from different provinces in China in the past 25 years， were investigated in this study. The variation coefficient， principal component analysis and cluster analysis were applied to evaluate their five agronomic and three quality traits， which would provide reference for germplasm resources innovation and new varieties breeding in China. The results showed that the variation coefficient in the growth period， plant height， kernels per spike， 1000-grain weight and grain yield ranged from 8.11% to 21.82%， especially for the yield and growth period both with a higher variation coefficient. The variation coefficient of three quality traits protein content， bulk density and wet gluten content ranged from 3.44% to 15.06%， among which the bulk density was stable and the variation of protein and wet gluten content was abundant. Most of the varieties released by Shanxi Province， Anhui Province and Beijing showed good quality， and wheat varieties from Shandong Province showed better yield performance. There were no significant differences in traits among different color-grained wheat. The correlation analysis showed that the growth period negetively correlated with the plant height. The 1000-grain weight was observed to be positively correlated with the kernels per spike. The protein content positively correlated with the wet gluten content and growth period. The principal component analysis simplified the six traits into three principal components， with a cumulative contribution rate of 67.55%. The first principal component was associated with the bulk density， the second principal component was associated with the yield， and the third principal component was associated with the protein and wet gluten content. Cluster analysis suggested the 56 color-grained wheat resources into four groups at a distance of 12.5， among which the first group had better comprehensive traits. The varieties Shannong Lanmai 1 had the highest F value （1.02）， and Liuzi Heimai 1 had the second highest F value （0.99）. According to the trend of color-grained wheat variety traits， the growth period and yield attended to be increased within years， while the plant height and protein content attended to be decreased. Collectively， in breeding for color-grained wheat varieties the yield performance was the major target， and future improvement on the quality traits， especially the protein content would become of interest.

Abstract:The bio-enhancement breeding for higher folate in food crops is a potential effective way to improve folate deficiency in humans. It is of great significance to study the genetic effects of folate traits in waxy maize F₀ kernels. Two components 5-methyltetrahydrofolate （5-M-thf） and 5-formyltetrahydrofolate （5-F-thf） are the main forms of natural folate. In order to study the content and variants of folate in F₀ kernels， twenty crosses were generated according to Griffing diallel cross using 5 waxy corn inbred lines， followed by the evaluation of the 5-M-thf and 5-F-thf contents of fresh F₀ kernels in this study. The results showed that the content of 5-M-thf was higher than that of 5-F-thf in all crosses， and the content of 5-M-thf in ZN3/J6 was highest， which was 432.85 ug/100 g DW； the content of 5-F-thf in BN2/ZN3 was the highest， which was 115.64 ug/100 g DW. The F₀ heterosis was observed in the 5-M-thf and 5-F-thf. The 5-F-thf showed positive heterosis in all crosses， while the 5-M-thf showed variants on heterosis in different crosses. Further calculation of the heritability and maternal effect of folate traits showed that the heritability of 5-F-thf （0.81） was higher than that of 5-M-thf， while the maternal effect of 5-M-thf （0.16） was higher than that of 5-F-thf. In conclusion， this study revealed the F₀ heterosis and maternal effect of folate trait in waxy maize kernels， and the different performance on forms of folate in maize kernels. The inbred lines such as BN2 and ZN3， which were detected with high folate content， can be applied as female parent to obtain high folate content in maize F₀ kernels.

Abstract:The hulless barley （locally referred qingke） is the staple food crop in the Qinghai-Tibet Plateau in China， and ensuring its sustainable production is crucial to both food and national security. Since the straw of the hulless barley is of importance in yak feeding， breeding for new varieties showing dual-purpose end-use in grain consumption and forage becomes of interest. In order to establish an evaluation system suitable for hulless barley varieties， this study performed the field trials at two locations （Changdu city of Tibet； Haixi city of Qinghai） for two years （2020 and 2021） to record the performance at 15 agronomic and yield-related traits and the responses to five fungal pathogens. The plants including straw and grains at the milk maturity stage were harvested to measure the feeding quality by quantifying 15 parameters. These datasets were further evaluated by clustering analysis， multiple comparisons， principal component analysis， gray relation analysis and the analysis of productivity and stability. An evaluation method was established for selecting the hulless barley varieties for dual-purpose end-use. With the evaluation criteria， the variety Ganqing 9 was identified suitable for both grain consumption and forage. In addition， Kunlun 15 which had high grain yield production were suggested for grain consumption， and Kangqing 7 and Zangqing 22 which had high biomass and feeding quality were qualified for taking as silage.

Abstract:To provide reference on genes exploration in chestnut， this study investigated the genetic diversity of 17 soluble sugar related traits in 121 chestnut germplasm resources collected from ten provinces in P. R. China. The contents were quantified by the HPLC method， followed by genetic variation， Shannon-weaver index diversity analysis， principal component analysis and cluster analysis. The result showed that： （1） The soluble sugar related traits in samples had abundant phenotypic diversity. The average variation coefficient and average diversity index were 20.57% and 1.89， respectively. The differences on genetic variation and genetic diversity in samples from different regions were observed. In samples from Shaanxi province， the variation degree was the highest， with the coefficient of variation of 20.73%， and the samples from Hebei province showed the highest genetic diversity， with the diversity index of 1.88. The genetic variation and diversity level in samples from Anhui province were the lowest， with the coefficient of variation and diversity index of 12.27 % and 0.97， respectively. （2） Except sucrose content， fructose content， mannitol content and the sum of measured sugars（Total content of sucrose， maltose， stachyose， fructose， mannitol and sorbito）， significant differences among populations in remaining traits were observed. The soluble solids content， total soluble sugar content， maltose ratio， stachyose content， stachyose ratio， sorbitol content and sorbitol ratio were extremely significant differences among populations. There were rich variations and high diversity among different regions. （3） The differentiation coefficient of 17 traits between populations was 13.41 %， and that within populations was 86.59 %， indicating that the variations on these traits was mainly attributed by intra-population diversity. （4） Principal component analysis showed that the contribution rate of the first principal component was 30.609%， severing as a comprehensive evaluation index of chestnut fruit sweetness and taste. The main feature vectors were soluble total sugar content （0.708）， sucrose content （0.619）， sucrose / Total soluble sugar （0.921）， maltose / Total soluble sugar （0.623）， stachyose / Total soluble sugar （0.664）， the sum of measured sugars （0.647） and sum of measured sugars/ Total soluble sugar （0.951）.（5） Cluster analysis suggested 2 groups of 121 germplasm resources， being correlated with the geographical collection information.

Abstract:Apart from facilitating the development of the potato processing industry and enriching the diets of people， breeding of potato varieties with good nutritional qualities also contributes to the adjustment of the national-wide planting structure. Protein， vitamin C and potassium （K） are important quality traits in potato. In this study， the genetic variation of protein， vitamin C and K and their interaction relationship in 118 potato breeding lines were assessed by cluster analysis and the two-dimensional quadrant method. The variable coefficient of protein， vitamin C and K content were 16.34%， 26.01% and 14.19%， respectively， and the genetic diversity index were 1.9744， 1.9952 and 2.0411， respectively. These indicated a broad genetic basis for protein， vitamin C and K content in this collection. The protein content was extremely significantly positively correlated with the K content in potatoes. The cluster analysis enabled the classification of 118 potato lines into four groups. The lines in groups I and II had lower protein content； the lines in group II had high vitamin C content； the lines in group III had the highest contents of protein and K； the lines in group IV had the highest vitamin C content. Twenty lines showing multiple high nutritional qualities were identified by two-dimensional quadrant analysis. Gained from these results， it is possible to identify potato varieties with high nutrition and suitable for planting in Fujian province of P. R. China. This study might provide useful materials breeding and deciphering the mechanism of elite potato varieties with high nutritional value.

Abstract:In order to identify kenaf germplasm resources resistant to root knot nematode， In this study， the root knot nematode population infected with kenaf was identified by SCAR primers， and the root knot nematode resistance of 220 kenaf wild or cultivated germplasm resource materials were identified and evaluated by using the methods of natural field disease and pot inoculation identification. The results showed that the pathogen causing disease in the field was Meloidogyne incognita. The results of field resistance identification showed that there were 133 kenaf resources showed high resistance， accounting for 60.45%， and all the roselle， false roselle and creeping saxifrage showed high resistance， and the high resistance ratio was the highest. The results of pot inoculation showed that there were 7 immune resources， accounting for 3.18% of the total resources. And 98 high resistance resources，accounting for 44.55% of the total resources. All roselle were identified as high resistance grade. There were some differences in the identification of kenaf germplasm resistance between natural field disease and pot test. There were 98 germplasm resources with the same identification results by the two methods.There were 69 high resistance resources ，accounting for 70.41% of the 98 germplasm resources. Among the high-resistance resources， 49 were from cultivated kenaf， 10 were from wild relatives， the rest were from roselle， rose hemp and hibiscus， and 1 high susceptible variety was from wild relatives.These results of this study provided scientific basis for the exploitation and utilization of kenaf germplasm resources against root knot nematode disease.

Abstract:In this study， a total of 222 samples from nine populations of ancient Liquidambar formosana Hance that distributed in Jiangxi province， P.R. China， were genotyped by capillary electrophoresis using 14 pairs of SSR primers， followed by the genetic diversity and cluster analysis using GenAIEx， CERVUS and Structure. The results showed that the average number of observed alleles （Na） of 14 SSR loci was 8.143， with the average number of effective alleles （Ne） of 2.819. The average value of Shannon information index （I） was 1.009， with a mean polymorphism information content （PIC） of 0.513. The average expected heterozygosity （He） and observed heterozygosity （Ho） were 0.504 and 0.470， respectively. The Ningdu （ND） population had the highest genetic diversity （He=0.551）， and the Wanli （WL） population had the lowest genetic diversity （He=0.394）. The South region of Jiangxi province showed the highest genetic diversity （He=0.534） and eight private alleles， followed by the North region of Jiangxi province with He=0.505 and the largest number of 14 private alleles. The lowest genetic diversity and a small number of private alleles were found in the Central region of Jiangxi province （He=0.473， n=2）. The results of AMOVA showed that the intra-population variation （92%） was significantly higher than that of the populations （8%）. This was in line with a coefficient of genetic differentiation （Fst=0.133）， implying higher gene flow （Nm=2.995）. According to principal component analysis （PCoA） and structure analysis， 9 populations could be divided into three groups， and there were different degrees of introgression among populations. Collectively， this study provided insights for the utilization and protection of ancient L. formosana， indicating the importance on the protection of ancient trees vailable in the future breeding program. In order to maximize a long-term genetic gain， the selection of superior trees in the populations in the North and South of Jiangxi province should be strengthened which may contain specific gene type resources.

Abstract:Grape is one of the most widely cultivated fruit trees in the world and is rich in germplasm resources.Germplasm resource nurseries have been collecting and preserving germplasm resources for a long time， accumulating resources such as wild species， local varieties， breeding varieties， breeding materials， rare resources and closely related plants， etc. However， the traditional germplasm resources information based hand-writing or printing is un-friendly on information management， acquisition and communication. Taking advantage of the development of internet technology， online germplasm databases becomes easily accessible in information sharing， trait evaluation， germplasm conservation and utilization. There are many grape-related databases worldwide， which not only provide data information to decision-making departments， variety certification institutions， management personnel， scientific research and teaching units， but also serve germplasm resources and biotechnology researchers， seed bank management， seed introduction and investigation personnel， agricultural technology extension personnel， farmers， students， and seed， feed， wine and other enterprises. In this article， we focused on four databases （The European Vitis Database； Genesys PGR， the International Research Institute for Tropical Agriculture； GRIN， the US Department of Agriculture； China Germplasm Resources Information System） to analyze the datasets of origin， species， fruit color， application， aroma and botanical characteristics of Germplasm. We would like to provide insights on promoting innovative germplasm technology research and development， as well as improving the sharing efficiency of germplasm resources， which has implication for the efficient use of online database and the future construction of Chinese database.

Abstract:EIN3/EILs （Ethylene inductive proteins/ethylene inductive 3-like） protein family function as the main members of ethylene signal transduction pathway and play an important regulatory role in plant growth and development and stress response. In this study， ZmEIL2 was isolated from maize inbred line B73 based on sequence homology （GeneBank ID： KJ727458.1）. This gene carries a 1788 bp coding sequence （CDS） that encodes for 595 amino acid residues with a relative molecular mass of 63.81 kD and a theoretical isoelectric point of 6.34. ZmEIL2 contains an EIN3 domain which is specific to EIN3/EILs family. Phylogenetic tree analysis showed that ZmEIL2 protein had the closest evolutionary relationship with SbEIL1 protein in Sorghum bicolor and was relatively distant from EIL proteins in Arabidopsis and soybean. The subcellular localization assay showed that ZmEIL2 protein was localized to the cell membrane and nucleus. Tissue specific expression analysis showed that ZmEIL2 gene was highly expressed in bract， followed by ear， tassel and silks， and the lowest expression was detected in mature leaves. The transcripts of ZmEIL2 gene were inducible under abiotic stresses treatments such as dehydration， PEG， ABA， high salt， heat and cold， particularly under PEG， ABA or high salt treatments. The expression level of ZmEIL2 gene in leaves was significantly higher than that in stems and roots. These results laid a theoretical foundation for further deciphering the molecular mechanism of ZmEIL2 gene in responses to abiotic stresses.

Abstract:In order to explore the dwarf gene and analyze the dwarfing mechanism in maize， the maize dwarf mutant K718d， wild-type K718 and their F₂ segregation population were used for gene mapping by BSA whole genome resequencing （BSA-reseq） and transcriptome sequencing （RNA-seq）. Three candidate regions with a total length of 21.03 Mb hosting 438 annotated genes were detected on chromosome 1. A total of 2374 differentially expressed genes （DEGs） were identified， including 1452 up-regulated genes and 922 down-regulated genes. KEGG analysis showed that DEGs were mainly involved in metabolic pathways including phenylpropane metabolism， fatty acid chain elongation and galactose metabolism. Gene function annotations showed that DEGs were involved in cell growth， cell wall composition， and plant hormone anabolism. BSA-reseq and RNA-seq suggested 26 candidate genes， of which 19 were found with non-synonymous mutations. Two candidate genes Zm00001d032035 and Zm00001d032422， which are annotated with plant hormone metabolism， were obtained based on the homologous gene function annotation， gene expression level and bioinformatics analysis. PCR amplification and qRT-PCR analysis showed that， both genes contained the amino acid substitutions in the coding region in K718d if compared to K718， and both showed decreased transcripts. These results provide reference for further dwarfing gene cloning and application in maize breeding.

Abstract:In plants， erucic acid is synthesized by the catalysis of a multienzyme complex， in which the β- Ketoacyl-CoA synthase encoded by FAE1 （fatty acid elongase 1） is a key rate limiting factor. Erucic acid is mainly stored in seeds in the form of TAG and is an important oleochemical feedstocks. The FAE1 genes in plants are variable on DNA sequence， thus resulting in differences on capability of erucic acid synthesis. To identify and isolate FAE1 genes with the highest capability on erucic acid synthesis， four plant species including Brassica napus， Crambe abyssinica， Tropaeolum majus and Limnanthes douglasii were used and twelve encoded FAE1 sequences were obtained from their genomes by homologous cloning method. Each FAE1 gene was sub-cloned into the yeast expression vector， followed by the analysis of erucic acid content in each recombinant yeast under induction culture conditions. The results showed that the twelve FAE1 genes shared 52.1-99.9% and 49.9-99.8% identity on cDNA and amino acid sequence， respectively， showing species-specific characteristics. By GC-MS analysis of all recombinant yeasts， eight FAE1 genes derived from Mianyou328， Crambe abyssinica and Limnanthes douglasii have been demonstrated with the capability to synthesize very-long-chain fatty acids. CaFAE1-3 had the strongest capability to synthesize erucic acid （4.82%）， followed by GjFAE1-1 （4.53%）， and LdFAE1 that was the weakest one （0.29%）. In addition， 95.39% of the C20∶1 fatty acids were converted by CaFAE1-3， implying great application potential in high erucic acid breeding. The remaining four genes derived from Yangguang80 and Tropaeolum majus were not detected with the capability on erucic acid synthesis. This is possible because of GyFAE1-2， TmFAE1-1 and TmFAE1-2 that contain mutations in the conserved cysteine or （and） histidine sites， and GyFAE1-1 that contains a R395K mutation resulting in loss of enzyme activity. Collectively， this study represented better understanding of the relationship between the structure and function of FAE1 gene， which has implication in higher erucic acid breeding and genetic engineering improvement on erucic acid trait in rapeseed and Crambe abyssinica.