Abstract:The applied core collection is the set of elite germplasm constructed to solve breeding problems， which also greatly embody the tight connections between germplasm research and crop breeding. Considering the present research status of core collection， we clarified the basic category and characteristics of maize applied core collection， and proposed that on the basis of core collection， the construction of maize applied core collection by integrating elite alleles of important breeding traits will be the focus of maize germplasm research. The constructed applied core collection would be suitable for the maize breeding of various ecological regions， with clear heterosis groups， clear elite alleles， but without obvious genetic burden. At last， the key issues of the construction of maize applied core collection are discussed， by which to promote the development of maize applied core collection and also to provide permanent supports for the research of breeding in China.

Abstract:MYB is one of the more abundant classes of transcription factors in plants. Its family members play important regulatory roles in all stages of rice reproduction and in a wide range of adversity stresses. For example， it is involved in the regulation of processes such as root development， cell development， secondary cell wall synthesis， tiller development and elongation， floral organ differentiation and development， spike morphogenesis， seed development， the metabolism of various hormones， the synthesis and metabolism of secondary metabolites and biotic and abiotic stress responses. This review describes the classification of the MYB transcription factor family and the protein structures of the different subgroups， and summarizes the recent research progress of MYB family members in growth and development and hormone signalling in the subsurface and aboveground parts of rice. The regulatory roles of MYB family members on rice under abiotic stress conditions such as drought， high temperature， low temperature， high salt and UV damage were highlighted， and the defence role played by MYB genes against biotic stresses such as fungi and pathogens was explored. Finally， throughout the recent progress of research on the MYB transcription factor in rice，we summarized three shortcomings of the latest research progress on MYB transcription factors in rice and proposed three directions for future research on MYB transcription factors.

Abstract:Leaves are important vegetative organs in plants， and the leaf margin serration （lobe） has many advantages in production practice. Disclosing the regulation of leaf margin serration has important guiding significance for plant breeding. This article reviews the regulation mechanism of leaf margin serration formation. Several factors such as plant hormones， gene expression， and miRNAs， are involved with roles in shaping leaf margins. Auxin unbalanced accumulation at the leaf margin can promote serration. Auxin-dependent cytokinins （CK） accumulation at leaf margin might result in the leaf shape complexity， while gibberellin （GA） negatively regulates leaf shape complexity. This review further summarizes three main pathways of plant hormones and genes involved in leaf margin serration formation： TCP-CUC-PIN1-Auxin， KNOX-GA/CK， LMI1-CK. The miR164， miR319， polycomb group （PcG） epigenetic modification and alpha-1，2-glucosyltransferase are known to be involved in leaf margin serration formation. The ambient temperature and light intensity regulate the leaf margin development through the KNOX-GA pathway. For instance， high temperature and low light intensity might decrease the complexity of leaf shape. The different genetic mechanisms on the regulation of leaf margin serration in plants are revealed. The genes that modulate or associate with the leaf margin serration are often reported in cash crops. In addition to fruit quality and resistance， ornamental character is one task with significant interest in future breeding of fruit trees.

Abstract:The Three Parallel Rivers of Yunnan Protected Areas refers to the longitudinal valley of the Hengduan Mountains where the Nu River， Jinsha River and Lancang River flow in parallel in Yunnan province， and has rich plant resources. In order to find out the distribution of buckwheat germplasm resources in this area， the wild buckwheat expedition team of the Institute of Crop Science of the Chinese Academy of Agricultural Sciences conducted a 15-day wild buckwheat survey in the area from 2020 to 2022， collected a total of 60 materials from 8 species of the genus Fagopyrum Miller. The survey results show that the Jinsha River basin has the most species of wild buckwheat in the Three Parallel Rivers of Yunnan Protected Areas. Fagopyrum cymosum and F. gracilipes have the widest distribution range， and the distribution of other wild buckwheat had obvious regional characteristics. Four kinds of special wild buckwheat resources were found， which were F. gracilipes with strong regenerative ability， F. gracilipes with multi-flowered and multi-branched characteristics， F. gilesii with multi-flowered and multi-branched phenotype， F. cymosum with pink flowers. The survey results laid a solid foundation for the targeted conservation and utilization of buckwheat germplasm resources in this region， and provided certain reference value for the study of the origin and domestication of buckwheat.

Abstract:Agropyron cristatum， as one of the important wild relatives of wheat， contains many excellent genes that are useful in wheat improvement. The wheat-A. cristatum addition line， which contains a complete A. cristatum chromosome， serves as an important bridge to utilize the A. cristatum derived excellent genes. As a perennial tetraploid outcrossing species that carries four haploid sub-genomes， the wheat-A. cristatum additional lines carrying each of different chromosomes from the same homologous group might represent the different agronomic characters. In this study， the heading time， plant type， panicle character， grain character， resistance to powdery mildew and leaf rust were identified and analyzed employing cytological identification， molecular marker detection， agronomic character investigation and disease resistance identification. The wheat-A. cristatum 2P addition line II-9-3 was genetically stable， compact， immune to leaf rust and highly resistant to powdery mildew， which could be used for plant architecture improvement and disease resistance breeding. Wheat-A. cristatum 2P addition line II-3-1b was observed with obvious reduction on plant height， early heading and immune to leaf rust， which could be used for plant height improvement and leaf rust resistance breeding. Wheat-A. cristatum 2P addition line II-23-72 is nearly immune to endemic leaf rust and powdery mildew species， and might be useful in disease-resistance breeding. These three 2P addition lines provided raw materials for further producing 2P translocation and deletion lines. These 2P addition lines with different characteristics on plant type， plant height and disease resistance， might provide a basis for future genetic mapping and effective use of excellent genes applicable in wheat.

Abstract:This study attempted to evaluate the plant height， grain traits， and diseases resistance of wheat resources derived from different wheat regions of China at four major breeding stages that were cultivated in spring wheat region of Ningxia Hui Autonomous region， China， in order to provide the methods and excellent germplasms for local wheat breeding in future. A total of 228 wheat resources at four breeding stages were used. The entropy-weighted DTOPSIS method was used for evaluating the plant height and grain traits in order to select good breeding parents. The diseases resistance and proportion of resistant genes were evaluated by field resistance survey， in combination with 18 molecular markers that associate with main wheat diseases in Ningxia， China. The results showed that， at the breeding stages I to IV， the plant height and index of the protein traits were gradually decreased， while the grain number and grain weight were gradually increased. According to the C_i value， 11 resources （Hongxinglong No.3， Nuomai， Xinjiang wheat， Shanglin wheat， Ningchun No.45， Huining No.19， Ningchun No.32， Ningchun No.58， Ganchun No.25， Yongliang No.15 and Xiaobing No.33） ranking top 5% in popupalation were identified. The resistance survey results showed， there were 181， 220 and 83 in 228 resources that were resistant to stripe rust， leaf rust and powdery mildew， respectively. These 11 resources based on the C_i value showed better resistance to stripe rust and leaf rust， and three of them， namely Hongxinglong No.3， Shanglin wheat， and Xiaobing No. 33， were also resistant to powdery mildew. In addition， 18 molecular markers associated with diseases resistance， showed different proportions of amplification results in 228 resources. Collectively， the DTOPSIS method based on entropy weighting and molecular markers associated with main wheat diseases can be used to evaluate the wheat resources at the different breeding stages.These selected wheat resources with good performance can be used as candidate parents for wheat breeding in Ningxia， China.

Abstract:In order to analyze leaf rust resistance genes present in 40 domestic wheat cultivars， using 16 physiological races of leaf rust fungus to deduce their genes， it is speculated that the composition of the resistance genes to leaf rust disease in the tested material. And combined with 11 specific molecular markers closely linked to known disease resistance genes for validation. And further select 5 highly virulent races to make mixed strains， and conduct plant adult inoculation in the Baoding experimental field to screen wheat varieties that may contain adult slow rust genes. Based on pedigree analysis， gene postulation and molecular marker detection results， six known major leaf rust resistance genes （Lr1， Lr11， Lr20， Lr26， Lr30 and Lr37） were detected. Ten varieties including Yunhei 14207 contain Lr1； Hemei 988 and Bainong 207 contain Lr11； Yumai 49 and Bainong 207 contain Lr20； 23 varieties including Wanfeng 269 contain Lr26； Yunhei 14207 and Zhengmai 103 contain Lr30； four varieties including Luo6073 contain Lr37， and some varieties contain unknown genes for leaf rust resistance. Seven varieties， such as Luo 6073， were identified showing slow rust phenotype. Collectively， this study clarified the genetic composition of these varieties， and obtained elite resistant varieties which can be applied in resistance breeding and resistance gene stacking.

Abstract:A naturally-occurring lesion mimic mutant lm452 was identified in the progeny of the near iso-genetic lines derived from Xinong1376 × Kehan21. This study analyzed the development， physiological-biochemical characteristics， agronomic traits， and inheritance of lesion mimic phenotype in lm452. The lesions were initially visualized in the first leaf， with the color from white to tan， with striped and patchy appearance. With the development of plants， the number of lesions gradually increased from leaf to sheath. The lesions seem temperature/light sensitive， since leaves shaded can avoid or reduce their occurrences， and low temperature and strong light can enhance the occurrence. Gained from the results of physiological and chemical assays， the lesions were associated with burst of reactive oxygen species （ROS）， and reduction on soluble protein content and cellular viability. The 1000-kernel weight of lm452 was significantly lower than that of its sister line g451 under either field or greenhouse conditions. Genetic analysis showed that the lesion mimic trait of lm452 was controlled by a single recessive nuclear gene. Collectively， these results provided the foundation for isolation of the target gene and deciphering its molecular mechanism in future.

Abstract:Grain size and morphology is one of the main factors that determine the wheat yield. It is of great significance to mine the associated loci of grain size and morphology related traits and screen related candidate genes for improving wheat yield. In this study， 300 representative natural populations of winter wheat were used to identify the phenotype at nine grain traits， including 1000-grain weight， grain length， grain width， grain thickness， grain length-width ratio， grain area， grain perimeter， grain shape and grain plumpness. This collection was genotyped by 90K SNP chip， followed by genome-wide association study using mixed linear model （MLM+Q+K）. The results showed that these traits showed rich phenotypic variation， with the coefficient of variation ranged from 3.80%~26.06% and the broad heritability from 56.25% to 91.98%. Sixty-six loci （P≤0.001） were detected by GWAS on 18 chromosomes except 3D， 4D and 5D， explaining 3.74%~14.34% of phenotypic variation at each locus. Thirty-seven pleiotropic loci were found associating with two or more grain traits. Especially， the BS00022512_51 marker on chromosome 3B was simultaneously correlated with 4 grain traits （grain length， grain width， grain thickness and grain length-width ratio）?， with the largest apparent contribution rate （7.06%~14.34%）. The wsnp_Ex_c4480_8055475 markers on chromosome 6D were simultaneously associated with six grain traits except grain thickness， grain shape and grain plumpness， and the phenotypic contribution rate was 3.81%~8.25%. Haplotype analysis of BS00022512_51 and wsnp_Ex_c4480_8055475 markers showed that there were three haplotypes of GC-Hap1， AT-Hap2 and AC-Hap3 in wsnp_Ex_c4480_8055475 loucs on chromosome 6D， and Haplotype GC-Hap1 is a haplotype with large grains and high 1000-grain weight. The three haplotypes accounted for 65.58% and 32.25% and 2.17% in population， respectively. Haplotype GC-Hap1 was predominant in four winter wheat regions in China. Nine candidate genes were proposed based on 37 significantly-associated multiple effect SNPs.

Abstract:To evaluate the resistance of hulless barley to barley yellow dwarf virus （BYDV）， 245 hulless barley genotypes were tested by inoculation with viruliferous aphids under field conditions in three calendar years. The results showed that the genotype 08-1280 was highly resistant to BYDV， and six genotypes （ZYM1289， Beiqing 6， ZDM4409， Ganqing 2， Zangqing 3000， ZYM1853） were resistant. 47， 173 and 18 genotypes showed moderately resistance， susceptibility and highly susceptibility to BYDV， respectively. The genotype 08-1280 was found carrying the resistance gene Yd2 based on genotyping using molecular marker. Moreover， to gain a better understanding of physiological mechanism of hulless barley against BYDV infection， the differences in total phenol， proline， soluble sugar and soluble protein content between resistant genotype 08-1280 and susceptible genotype Kangqing 3 were investigated. At 10 days after inoculation， the contents of total phenol and proline were elevated in 08-1280， higher than that of Kangqing 3. At 30 days after inoculation， a higher increase of total phenol in resistant genotype， if compared to that of susceptible genotype， was detected， while an opposite result for the soluble sugar was observed； the soluble protein decreased dramatically in 08-1280， whereas increased in Kangqing 3. Collectively， this study provided elite germplasm resources and theoretical reference in breeding of resistant varieties and analysis of resistant mechanisms in hulless barley.

Abstract:In order to provide the basis for the genetic improvement of density-tolerant varieties， the characteristics of ear traits were investigated in maize hybrids under different planting density conditions. Twelve maize hybrids that were popularized in China from four different eras since the 1980s were used in this study. From 2017 to 2018， these hybrids were cultivated in Shenyang city， Liaoning province and Gongzhuling city， Jilin province， with the two planting densities of 60，000 plants/hm² and 120，000 plants/hm²， using split plot experiment design （four row plots， three replicates each）. Ear length， ear diameter， bald tip length， rows per ear， kernels per row， and 100-kernel weight were investigated after harvest. These maize varieties showed extensively significant differences on rows per ear， kernels per row and 100-kernel weight. Ear diameter， bald tip length and 100-kernel weight decreased under different planting densities with the decades， while ear length， rows per ear， and kernels per row did not change significantly. The bald tip length was observed with especially significant difference， for example， with the average decrease of 0.24 cm （high planting density） and 0.19 cm （low planting density） every 10 years from 1980s to 2010s. Under higher planting density condition， shorter and thinner ear， longer bald tip and reduction on kernels per row were observed. New varieties released since 2000s became tolerant under higher planting density condition. For example， the ear length of 2000s new varieties and ear diameter of the 2010s new varieties decreased the lest， while the bald tip increase of the 2010s new varieties was the least with the value of 1.04%. In the future breeding for new high-yield varieties that are applicable under higher plant density， it is necessary to synergistically improve the ear length， ear diameter and bald tip， without a reduction on higher 100-kernel weight.

Abstract:Vicia sativa L. is one of the legume crops that can be used both as grain and vegetable， as well as green fertilizer and high quality forage， which has important economic value and significant ecological advantages. However， the seed traits and germination characteristics in Vicia sativa wild germplasm resources from southwest China remains investigated. In order to better protect and utilize these endangered wild germplasm resources， this study investigated wild populations of Vicia sativa from Guizhou， Sichuan and Yunnan provinces in southwest China. A total of 106 wild germplasm accessions showing levels of variations on morphology and abiotic stress response were collected from 20 counties （districts）. In addition， eight seed traits， such as 100-seed weight， seed length and seed width were measured. The coefficient of variation on 100-seed weight was the largest （92%）， and these germplasms with highest （9.18 g） and lowest （0.31 g） 100-seed weight were collected from Yunnan and Guizhou， respectively. Vicia sativa accessions from Yunnan exhibited significant differences at eight traits， if compared to those of the accessions from either Guizhou or Sichuan. Through analyzing the germination characteristics of three representative genotypes from three regions， we found that both mechanical peeling and concentrated sulfuric acid treatment for 30 minutes can effectively break down the seed dormancy， thus resulting in significant improvement on the seed germination rate. Collectively， these results provided an important theoretical basis and technical guarantee for the protection and utilization of the endangered wild germplasm resources of Vicia sativa.

Abstract:In order to identify elite germplasm resource of asparagus bean applicable for genetic improvement， 243 representative asparagus bean varieties were cultivated following the split area （variety + year） test design method， followed by quantifying 28 quality characters of the pods. The heritability of the characters， correlation analysis， cluster analysis and principal component analysis were further performed. The results showed that the variation coefficients of 28 quality traits ranged from 10.34% to 66.41%. The analysis of variance illustrated that there were significant differences among varieties at most traits. Based on their characteristic data， the composition of main nutrient components in asparagus bean was listed. The broad heritability of 16 traits such as vitamin C and dry matter content was more than 80%， while that of leucine， methionine content was less than 40%. There were 98 significant correlation coefficients in a manner of pairwise comparisons， and there was a strong correlation between all amino acid components. 243 varieties were classified into five groups by cluster analysis. 42% of the varieties were clustered in group II， representing the benchmark level of asparagus bean. Group I， III and Ⅴ showed high content of sugar， amino acid and flavonoid， respectively. The varieties with extreme individual traits were scattered in group IV. Principal component analysis demonstrated that 28 traits could be transformed into nine principal components， with a cumulative contribution rate of 65%. Twenty-four elite germplasms were identified according to the comprehensive score. Collectively， this study enriched our understanding of the nutrient quality characteristics of asparagus valuable for its genetic improvement in future.

Abstract:The main incidence site and symptom phenotype of anthrax disease for 479 common persimmon germplasms were observed and recorded in National Field Genebank for Persimmon. The results showed that the anthrax pathogen mainly infected twigs， fruits， and leaves of persimmon. Based on the disease symptoms of persimmon branches and fruit in the field， 479 accessions were divided into five resistance levels， including highly resistant， resistant， moderate resistant， susceptible， and highly susceptible. Sixty-six germplasms （13.8% of this collection） were highly resistant （representative varieties， e.g. Yunyang Huoshi）； 35 germplasms （e.g. Huangbian Xiaojixin） were resistant to anthracnose （7.3%）； 119 germplasms （e.g. Fuyu and Jiro） showed moderate resistance （24.8%）； 209 germplasms （e.g. Fuping Jianshi） were susceptible （43.6%）； 50 accessions （e.g. Suruga） were highly susceptible （10.4%）. Pathogenic bacteria were isolated from leaves， branches and fruits. According to the morphological characteristics of colonies， mycelia and spores and the sequence alignment of multiple genes， all of them were identified as Colletotrichum horii.

Abstract:In order to explore the phenotypic diversity of wild Hippophae rhamnoides subsp. sinensis resources in Qinghai province， 150 wild seabuckthorn resources from 10 regions in Qinghai province were collected and 12 phenotypic traits were analyzed. The results showed that seabuckthorn represented rich phenotypic diversity， with the coefficient of variation of 12 phenotypic characters ranged from 16.49% to 58.76%. Especially， three trait including ground diameter， tree height and thorn length were observed with great variations， showing the coefficient of variation over 50%. Correlation analysis revealed significant or extremely significant correlations among all characters except tree height， branch， ground diameter and leaf width. The phenotypic traits were observed correlating with latitude and altitude. The different traits were affected by different geographical factors， among which the leaf traits were largely affected. Four principal components with eigenvalues greater than 1 were revealed by principal component analysis， showing the cumulative contribution rate of 86.35%. Hundred fruit weight was detected with the greatest effect on phenotypic traits diversity. These results indicate abundant phenotypic diversity in population of seabuckthorn resources in Qinghai， with great potential for exploitation and utilization. This study provided a scientific basis for the breeding and preservation of excellent germplasm resources of Hippophae rhamnoides subsp. sinensis.

Abstract:Rice is one of the most important food crops in Hainan province， China. However， Hainan has a small cultivated area and low total rice yield， which results in great pressure of food self-sufficiency. Breeding elite rice varieties and improving rice yield are important to ensure food security. Based on the panel data of rice varieties that are officially approved in Hainan province from 2003 to 2021， the datasets at fourteen traits including rice yield， disease resistance and rice quality were analyzed. Out of 384 rice varieties that were approved in Hainan province in the past 19 years， hybrid rice varieties accounted for approximately 71.3%. The yield production of the varieties in regional trials and production trials in Hainan was relatively low. In terms of specific traits， these varieties were mainly with 110-160 grains per panicle， which might be characteristic due to local climate. A large proportion of the varieties were susceptible to blast or bacterial blight， while less than 0.5% varieties are simultaneously resistant to both diseases. The amylose content of the varieties was relatively high， but a slowly decreasing trend was observed in the varieties approved in recent years. Only about 24% of the rice varieties reached the third grade （or above） of the indica rice quality， implying an overall poor quality. Therefore， breeding for new elite rice varieties via germplasm innovation to improve the yield， pathogenic resistance and quality is required in Hainan province. In addition， improving industrial rice production in Hainan province might benefit from actions such as revising registration standard for rice variety， strengthening researches on rice cultivation and extension of elite rice varieties.

Abstract:Functional rice with high resistant starch content improves human health considering the risk of diet-related chronic diseases. Exploring the resistant starch-related genes is of great significance to reveal the genetic mechanism of rice grain resistant starch synthesis， which has implication in breeding rice varieties with high resistant starch. In this study， 126 F₇ recombinant inbred lines （RILs） from cross between Ningxia local high-yield japonica rice variety Ningjing 28 and imported japonica rice variety JTD were used. A genetic linkage map containing 1，856 Bin markers was constructed by whole genome resequencing technology， showing a length of 1973.86 cM， and the average genetic distance of 1.06 cM between markers. Using CIM interval mapping method to map the QTL of resistant starch traits in rice populations， one QTL controlling resistant starch was detected on chromosome 7， with a LOD value of 4.2 and a contribution rate of 9.7%. Through in-depth analysis， two candidate genes Os07g0444000 （predicted as rice glucosylceramidase） and Os07g0443500 （DNA binding protein containing MYB domain） were obtained. The study found that the genotype frequencies of SNP_15740179 and SNP_15740207 on Os07g0444400 were significantly different between the high resistant starch group and the low resistant starch group in the RIL population. During the grain filling process， the expression levels of Os07g0443500 and Os07g0444000 in the male parent JTD（high resistant starch parent） were higher than those of the female parent Ningjing 28. These results implied that both candidate genes may be involved in forming resistant starch during rice grain filling. Collectively， this study provides new genetic resources for the breeding of new rice varieties with high resistant starch by mining the QTL loci and related genes of rice grain-resistant starch.

Abstract:To investigate the effects of Na⁺ and K⁺ content and distribution of the seedling shoot and root on the biomass accumulation and salt tolerance in rice， 51 rice germplasm accessions were analyzed under salt stress treatment by using Yoshida culture solution containing 125 mmol/L NaCl. Five morphological parameters including salt tolerance score （STS）， relative root length （RRL）， relative shoot dry weight （RSDW）， relative root dry weight （RRDW）， shoot water content （SWC）， and six ion indexes， namely shoot Na⁺ content （SNC）， root Na⁺ content （RNC）， shoot K⁺ content （SKC）， root K⁺ content （RKC）， shoot Na⁺/K⁺ ratio （SNa⁺/K⁺） and root Na⁺/K⁺ ratio （RNa⁺/K⁺） were measured. On the basis of principal component analysis （PCA）， with membership functions and weighted standard deviation coefficient method， a comprehensive evaluation D value for each rice germplasm accession was obtained. Specific primers for amplifying the coding region of SKC1 were applied for sequencing， alignment and haplotype analysis. SNC was significantly negatively correlated with other morphologic indexes except RRL， and STS was found to be significantly negatively correlated with SNC， RNC and SNa⁺/K⁺. Meanwhile， significant positive correlations among STS， RSDW， RRDW and SWC were revealed by correlation analysis. PCA with 11 indexes suggested four major components， with a cumulative contribution rate of 82.093%. Six key indexes， including RSDW， STS， RRDW， SNC， SNa⁺/K⁺ and RNC， were selected based on the loadings of 11 indexes in PC1. Combined with the linear regression analysis between the D value and these six indexes， it was found that STS and SNa⁺/K⁺ may be the key factors affecting salt tolerance by maintaining growth and ion balance in rice seedlings respectively， with a great regression coefficient. The diversity analysis of SKC1 coding sequence suggested nine different haplotypes of 51 rice germplasm accessions. The Hap1 detected in Koshihikari was dominant in japonica rice accessions， and the Hap7 detected in Nona Bokra was dominant in indica and Aus rice accessions. Collectively， the results gained from this study provided a theoretical foundation for identifying the salt-tolerant rice germplasm accessions in ion homeostasis.

Abstract:Brown planthopper （BPH， Nilaparvata lugens） is one of the most disaster insects of rice. The most effective measure to prevent its damage is developing BPH resistance lines and cultivating resistant varieties. The indica rice germplasm 47-1 from Guangxi， China， is highly resistant at seedling and adult stage for three consecutive years， thus proving the genetic stability and the significant antibiosis and antixenosis against BPH. In order to enrich the gene diversity of BPH resistance and breed resistant rice varieties， it is meaningful to map its resistance gene and explore its mechanism. In this study， we developed by crossing 47-1 and a susceptible line 9311 a F₂ population containing 91 individuals， followed by identifying the insect weight gain. 61 and 30 individuals， each of which showed the BPH weight increased ≤1.1 and >1.1， respectively， were obtained （Chi-square test： χ²=3.081<χ²_0.01，1=3.84）， suggesting that this locus is genetically controlled by one pair of single dominant gene. This locus was delimited to the region flanked by markers 04M0.453 and 04M3.688 on chromosome 4， where the BPH resistance gene Bph40 is present. Three substitutions in the coding sequence of Bph40（t） differing with that of Bph40 were detected in variety 47-1， which resulted in two amino acid substitutions in the protein. Phylogenetic tree analysis showed that the Bph40（t） haplotype from 47-1 was closely related to the Bph40. Collectively， these results implied that the BPH resistance gene in 47-1 is a novel allele of Bph40.

Abstract:DNA fingerprinting analysis that enables assigning uniform identity information for each rice germplasm is of great significance for identifying the genetic basis of rice germplasm resources， improving their utilization efficiency and protecting the intellectual property rights of the seed industry in China. In this study， using 5374 rice accessions that have been genotyped by the whole-genome resequencing， two sets of genome-wide DNA fingerprinting standards were established through the selection of reference sample resources， analysis of high-quality SNP loci， and selection of the optimal number of SNPs and SNP combinations. Through principal component analysis and phylogenetic tree analysis， SNPs in the collection of fingerprinting standards 1 and 2 could represent 94，197 high-quality population common SNPs applicable for the population genetic diversity. In addition， population genetic similarity analysis verified the effectiveness of fingerprinting standards 1 and 2 to uncover the genetic similarity identification of rice germplasm resources. This study is expected to provide technical support for the conservation and utilization of rice germplasm resources and the protection of intellectual property rights in the seed industry， and to provide reference for the development of DNA fingerprinting standards for other crops.

Abstract:Floral organ is the basis of seed growth， and the development of rice floral organ directly affects the yield and quality. An open-hull mutant （oh） was found in the progenies of rive cultivar Yuanmeisimiao crossed with P704. The oh mutant displayed abnormal floral organ with unclosed lemma and palea， decreased seed setting rate and smaller seeds. Genetic analysis showed that the open-hull phenotype was controlled by a pair of recessive nuclear genes. Using bulked-segregant analysis （BSA） method， the open-hull gene was allocated in the interval 22806614~23000408 on rice chromosome 3， where the OsMADS1 gene （LOC_Os03g11614） is present. Through alignment with the homologous gene in the Shuhui498 reference genome， the nucleotide transversion （aspartic acid to tyrosine） at the 118^th nucleotide of the first exon of OsMADS1 in oh was identified （designated OsMADS1^oh）. OsMADS1^oh was cloned from oh and used to construct overexpression vector. The overexpression vector was introduced into the transformable material （ZH11） by Agrobacterium-mediated transformation. The lines over-expressing OsMADS1^oh showed the open-hull phenotype. In addition， the RNA expression results of real-time quantitative PCR showed that the expression of MADS8 and YABB5 were regulated by OsMADS1. Collectively， this study approved the OsMADS1^oh， as a new allelic variant of OsMADS1， and provided specific resources for elucidating the molecular mechanism of floral organ formation.

Abstract:The aim of this study was to use a high-density genetic map to identify QTL for panicle architecture-related traits in sorghum， which would enable marker-assisted selection and the exploration of the genetic mechanisms of key genes underlying these traits. 205 recombinant inbred lines （RILs） from a cross between BTx623， an American cultivar， and Hongyingzi， a cultivar for brewing liquor， were used to investigate five panicle traits in five environments （Guiyang， Anshun and Ledong） from 2020 to 2021. These traits include panicle length （PL）， panicle handle length （PHL）， number of cob nodes （NCN）， number of primary branches （NPB）， and length of the longest primary branch length （LLPB）. The inclusive composite interval mapping （ICIM） method was used to identify QTL， enabling the identification of 61 QTL at 45 unique loci. Of these， 14、10、8、11 and 18 QTL were related to PL， PHL， NCN， NPB， and LLPB， respectively. Nineteen important QTL were identified across multiple traits or environments and were distributed on chromosome 1（3）， 3 （4）， 4 （2）， 5 （1）， 6 （4）， 7 （1）， 8 （3）， and 9 （1）. In addition， 13 orthologous genes for rice panicle architecture were found in or near 12 of the 19 QTL， including DEP1， RGN1， OsPID， OsSPL7 and WTG1. These findings provided a basis for gene cloning and function verification in future.

Abstract:Grain size is an important factor affecting yield production in rice. GS3， as the firstly cloned grain size gene in rice， mainly functions in regulation of the grain length and grain weight. GS3 protein contains OSR （Organ size regulation） domain at the N-terminal and Cys-rich domain at the C-terminal. There are four main natural variants of GS3， namely GS3-1 to GS3-4. GS3-1 encodes a full-length GS3 protein， GS3-2 encodes a protein with one amino acid missing， GS3-3 abolishes full-length GS3 protein （associating with longer seeds）， GS3-4 only encodes the N-terminal OSR domain （associating with significantly shorter seeds）. Up to now， the GS3 variant type encoding only the Cys-rich domain remains yet identified in the natural populations， and the consequence on seed size also remains unclear. In this study， by deployment of the CRISPR/Cas9 genome editing technology to delete large DNA fragments by two target sequences flanking the target DNA， we generated a new mutation variant gs3-5 that encodes only the C-terminal Cys-rich domain. The gs3-5 mutant showed increase on seed length and thousand grain weight， thus indicating that the OSR domain is necessary for the GS3 protein to act as a negative regulator of grain size. Collectively， these results provided a reference for further analysis of the regulation of the OSR structural domain on grain size and exploration of new breeding improvement methods.

Abstract:Exploring dwarf genes and analyzing their regulatory mechanisms may provide germplasm resources and theoretical bases for maize dwarf breeding. The differences of dwarfing characteristics between maize dwarf mutant K15d and its wild type K15 were analyzed by morphological observation and paraffin section. Based on the result of allelism test， the functional gene in K15d mutant （designated d15） was cloned by PCR amplification， and the expression pattern of d15 gene in stem internodes were analyzed at three stages. Compared with wild type K15， the plant height， ear height and the internodes number below ear position of mutant K15d significantly decreased by 39.22%， 69.75% and 38.83%， respectively. There was no significant difference in cell size in the transverse section of the stem， and the cells in the longitudinal section became shorter and arranged irregularly. The dwarf gene d15 was allelic to br2， showing a 200 bp deletion （5485-5685 bp） at the fifth exon， with the coding region of 3983 bp. The d15-encoded protein had ten transmembrane domains， two less than that of D15-encoded protein， and a second conserved functional domain responsible for substrate binding and transport functions was missing. Compared to the allele br2， only two SNPs differences were observed in the promoter sequence of d15. There were no significant differences in the expression levels of d15 gene between the mutant and the wild type at the three stages of pre-elongation， elongation and post-elongation. In conclusion， the dwarfing characteristics and expression pattern of dwarf gene d15 are similar to br2， which is a new br2 allele and enriches maize dwarf gene resources.

Abstract:The immature embryos of maize are able to form embryogenic calli through tissue culture， and are usually used as explants in genetic transformation. The molecular mechanism in the process of maize embryonic callus formation remains fully illustrated. To reveal the candidate genes that are involved in the callus formation of maize， two types of calli （type I， well growth； type II， poor growth） from F₃ embryos of maize inbred line CAL28 × Zheng58 were harvested for the RNA-seq analysis. 4419 differentially expressed genes （DEGs） were revealed between two types， including 1571 up regulated genes and 2848 down regulated genes. GO enrichment analysis showed that DEGs were mainly enriched in the pathways such as cellular process， catalytic activity， and cell component. KEGG enrichment analysis showed that the enrichment of DEGs were mainly involved in phenylpropanoid biosynthesis and the plant hormone signal transduction pathway. Among the early auxin responses genes， eight AUX/IAA genes including IAA23， IAA33， IAA41， and four GH3 genes were upregulated in type I callus. A total of 2968 transcription factors belonging to 56 transcription factor families in DEGs were significantly enriched. The expression levels of ZmEREB53， ZmEREB206， ZmEREB184， ZmLBD10， ZmLBD24， ZmLBD31， ZmLBD32， ZmWOX5b and ZmWOX9b， which are from AP2， WOX and LBD transcription factor families， were significantly up-regulated in type I callus. Genetic manipulation of these target genes may possibly promote the formation of maize callus. Collectively， this study identified candidate DEGs with great application potential， which provide theoretical reference for deciphering the molecular mechanism of maize callus formation.

Abstract:C2H2 zinc finger protein transcription factor plays an important role in plant growth and development， stress response and regulation of secondary metabolism synthesis. The previous study found that the flavonoid content in the root of fagopybuckwheat was higher than that of Tartary buckwheat， which may be due to the amplification of gene families related to flavonoid biosynthesis， such as FdCHI， FdF3H and FdDFR. However， it has not been reported how the C2H2 zinc finger protein transcription factor family genes involved in flavonoid biosynthesis regulate rutin synthesis in golden buckwheat. In this study， the whole genome of FdC2H2-ZFP transcription factor was identified and its expression profile was analyzed. A total of 114 FdC2H2-ZFPs were identified. Based on the analysis of RNA-Seq data， the C2H2 zinc finger protein gene FdC2H2-2 was screened and cloned. This gene has three typical C2H2 zinc finger structures， and has high homology with Arabidopsis AtTREE1 and AtDAZ3. qRT-PCR showed that the expression of FdC2H2-2 gene was significantly induced by jasmonic acid. In addition， the content of rutin in the hairy roots of overexpressing FdC2H2-2 was significantly higher than that of the control， and the transcriptional expression of flavonol synthetase （FLS）， phenylalanine aminolyase （PAL） and flavonoid 3'，5'-hydroxylase （F3'5'H）， the key enzyme genes in the rutin synthesis pathway were significantly increased. These results suggest that FdC2H2-2 gene may positively regulate the accumulation of rutin by activating the expressions of the key enzymes in rutin biosynthesis， such as FLS， PAL and F3'5'H. This study provides reference for the future analysis of C2H2 zinc finger protein gene function of golden buckwheat.

Abstract:Inflorescence type is one of the important ornamental traits of Hydrangea macrophylla. To localize the key genes controlling inflorescence types， 125 H. macrophylla individual plants were re-sequenced to obtain the single nucleotide polymorphisms （SNPs）. Genome-wide association study （GWAS） was carried out using general linear model （GLM） and mixed linear model （MLM） of Fastlmm and GEMMA software， to identify the SNPs that strongly associated with inflorescence types. respectively. 285 SNPs significantly associating with floral phenotypes were found （cutoff： -log₁₀（P）>9）， which contributed to the phenotypic variation from 11.80% to 60.54%. Twelve SNPs from 285 loci were further genotyped by Sanger sequencing and kompetitive allele-specific PCR （KASP） in 52 hydrangea cultivars， and 9 hybrid populations. Four SNPs including Hma1.2p1_0060F.1_796640， Hma1.2p1_0060F.1_1540773， Hma1.2p1_0653F.1_868484 and Hma1.2p1_0669F.1_949341 were validated closely associating with inflorescence type， which indicated that the genes controlling hydrangea inflorescence type were probably allocated in three Scaffolds Hma1.2p1_0060F.1， Hma1.2p1_0653F.1 and Hma1.2p1_0669F.1. According to the DNA sequence surrounding the 285 SNPs associating with floral phenotypes， a total of 1287 genes were annotated. In these genes， four genes putatively encoding for transcription factors， including two MYBs， one MADS， and one bHLH， were predicted to be associated with hydrangea inflorescence type. These findings provided a foundation for future gene cloning and molecular marker-assisted breeding for hydrangea.

Abstract:The breeding of hybrid soybean varieties is mainly based on the three-line method （based on cytoplasmic male sterility）. As the male parent of the hybrid， the restorer-of-fertility （Rf ） gene in the restorer line plays a decisive role. In the former study， we mapped the Rf gene GmRf1 for the soybean RN type cytoplasmic male sterile line. This study conducted functional annotation， subcellular location prediction， sequence alignment and differential expression analysis of candidate genes in the physical interval of GmRf1. We identified that the PPR （Pentatricopeptide repeats） gene Glyma.16G161900 encoding for 576 amino acids encoded in male restorer line JLR230 is GmRf1. By crossing Williams82 containing GmRf1 with the female sterile line JLCMS204A， the pollen fertility of F₁ plants was identified demonstrating that GmRf1 could restore the fertility of CMS-RN sterile lines. We further developed functional molecular markers Rf1-dCAPS-2 and Rf1-dCAPS-3 based on the single nucleotide mutation sites of GmRf1 between female and male parents. Collectively， this study laid a theoretical and technical foundation for the future marker-assisted selection of GmRf1， as well as the creation of new restorer lines through genetic engineering.

Abstract:Potato cyst nematode （PCN） is an important quarantine disease and its infection can reduce the potato yield up to 80%. In recent years， the potato golden nematode （Globodera rostochiensis） was reported in several major producing areas in Southwest of China. In order to ensure the safety of potato production in China， it is urgent to identify germplasm resources with cyst resistance and breed for resistant varieties. Using the molecular markers N146， N195， 57R， TG689， Gro1-4-1 and Gpa2-2 from earlier studies， in this study 875 potato germplasm accessions preserved by Yunnan Academy of Agricultural Sciences were genotyped for resistance genes to potato cyst nematode. 211 accessions were detected with H1 molecular markers （N146，? N195， 57R and TG689） amplifying the resistance gene to potato cyst nematodes， of which 114 accessions contained four molecular markers at the same time. Seven accessions were identified carrying the resistance gene Gro1-4， while 237 resources were found with Gpa2-2 resistance gene Gpa2. Collectively， this study provided technical support and material basis for the breeding of potato cyst nematode resistance.