Abstract:Shaanxi province has a long history of agronomical cultivation culture and hosts abundant germplasm resources. Twice actions of China national-wide germplasm survey and several rounds of the regional resource investigation have unlocked ca. 18000 germplasm accessions including 13828 which are registered and persevered in National Crop Genebank of China including food crops (11341), economic crops (1473), vegetables (687), fruit (191) and forage crops (136). Through research and practices in agriculture germplasm, there have been significant progresses in breeding for crops like wheat, rapeseed, corn, apple, tomato, etc., along with noticeable economic benefits in exploiting values from the local characteristic and wild resources like black rice, pepper, walnut, tea and kiwi. However, problems on protection and utilization of germplasm resource in Shaanxi remain, such as inadequacy in the germplasm resources protection system, which fails to address the continued disappearance of some germplasms. In particular, the current system does not have appropriate incentive and management mechanisms to fully support the entire cycles of crop resources management, including search & collection, protection, utilization and management of the germplasm resources, which has hindered the realization of the full value of germplasm resources. We suggest to establish a long-term system valuable for the collection, characterization, protection, innovation and application of germplasm resources. Moreover, we suggest to explore the commercial value of precious or unique germplasm resources, thus serving the breeding for new varieties in Shaanxi.

Abstract:total of 825 sweet potato germplasm accessions are preserved until October of 2020 in Guangxi province of China, including 549 landraces, 266 cultivars, 69 breeding lines, two wild relatives as well as ten accessions without passport information. Out of them, 586 accessions have been registered into germplasm resource nursery in Guangxi. The characterization of the agronomic characters, dry matter content and yield in the whole panel, as well as the quality-related traits and disease resistance in a sub-panel lead to the identification of 126 elite accessions. The preservation and Renewal Technology of Sweet Potato Germplasm Resources has been improved. The data management system containing 5107 and 10202 data points regarding to the qualitative and quantitative traits, respectively, has been established. Based on the genetic diversity analysis of 486 sweet potatoes, we established a core germplasm collection with 122 accessions. Thirty-three new sweet potato varieties have been released by taking use of these germplasm accessions. The application of new varieties in agriculture resulted in remarkable economic, social and ecological benefits.

Abstract:The freezing caused by low-temperature in spring seriously destabilizes the yield production and grain quality of the common wheat. However，such currently techniques show some limitations including laborious-and timeconsuming as well as less effective reduction of the cold damage. It is of great significance to establish a simple，scientific，rapid and systematic evaluation methods and indices system of wheat tolerance to late spring coldness for avoiding the impairment of the late spring coldness on wheat. In this paper，the methods， periods，indicators and evaluation criteria to identify wheat late spring coldness resistance were summarized， which of the molecular biological basis were parsed，and proposed that it is necessary to perform systematical evaluation of the late spring coldness resistance at jointing，booting and flowering stage，respectively，screening of allelic variation and analysis of underlying molecular mechanism for further utilization in wheat breeding program to develop wheat cultivars with high and stable yield in China.

Abstract:Pear is one of the major fruit in China and favorite by domestic and foreign consumers due to its nutritional value and health efficacy. Pear flower is corymb inflorescence and belongs to the multi-flowered type. Fruit setting rate of inflorescence has significant influence on the yield of fruit trees. Artificial control of flowers and fruits is a measure to regulate the amount of fruit set in the tree, to ensure the yield and fruit quality maximizing the commercial profile. Understanding the mechanism of inflorescence formation is of interest to increase fruit yield and improve fruit quality. This paper reviews the evolution of inflorescence, the process of inflorescence development, fruit setting position of inflorescence, effects of endogenous hormones on floral formation, and regulation of related genes on floral formation, etc. Moreover, the future prospective is proposed, in order to provide ideas for the research on pear inflorescence formation.

Abstract:The genus Polygonatum represents a wide geographical distribution, abundant resources, complex taxa and a long cultivation history, and they are considered to be important with the medicinal, economic, ornamental and cultural value. By taking advantage of the improvement of molecular biology, a variety of DNA-based molecular techniques have been developed valuable to the research in related fields of the genus Polygonatum. In this paper, we review the current status and progress of the genus Polygonatum using DNA-based technologies (such as molecular marker and DNA barcode), and propose future prospects in order to provide references for efficient protection and utilization of plant resources.

Abstract:Effective long-term conservation of rice germplasm resources is crucial to world food security, and cryopreservation is the best way to achieve this goal. In this study, a method with rice embryogenic callus high sugar preculture and direct liquid nitrogen cryopreservation was established, and the callus regeneration rate and the differentiation rate of regenerated calli were used to evaluate the cryopreservation efficiency directly. The results showed that the callus regeneration rates of japonica rice ‘Nipponbare’ and indica rice ‘Hanhui 3’ with sizes of 1.6-3.0 mm and >3.0mm was significantly higher than those of <1.6mm after cryopreservation. The callus regeneration rates of ‘Hanhui 3’ after preculture with 100 g/L sucrose and 170 g/L sucrose were significantly higher than those after preculture with 240 g/L sucrose. The callus regeneration rates of japonica rice ‘WDR48’, japonica rice ‘Nihonbare’ and indica rice ‘Hanhui 3’ treated only with high sugar preculture were significantly higher than those treated with vitrification. Simple Sequence Length Polymorphism (SSLP) identification indicated that seedlings regenerated from calli either with or without cryopreservation were genetically stable. The study indicated that callus preculture with high glucose and direct cryopreservation is an easy, high-throughput, stable and reliable method for long-term preservation of rice germplasm resources.

Abstract:Dahegu rice resources in Jiangxi Province are rich and are favorable for their special quality. No genetic study and quality improvement of Dahegu rice have been reported, and the plant stature is in need of improvement. In this study, SNP (single nucleotide polymorphism) markers were used to analyze the genetic characteristics of Dahegu rice varieties from Yiyang, and RVA (Rapid Visco Analyser) was used for quality determination. The results showed that 40 pairs of SNP primers detected 82 alleles in 20 materials, among which Dahegu rice varieties had indica frequency between 0.025 and 0.100, and were determined to be of japonica rice type. The viscosity of Dahegu rice grain was an accumulation process through grain maturation, whereas the amylose content was fixed before grain maturation. RVA parameters were closely related to physicochemical properties, and especially the rice grain length was negatively correlated with breakdown value. Pure milled rice grain rate and amylose content were the major gene traits. Compared with soft cultivated rice, the peak time was a key parameter to judge Dahegu rice. Through the screening analysis of the SNP and the viscosity, excellent japonica parents with similar quality and complementary traits were selected, such as brown-chaffed Nongju Ⅲ with the softest grain texture, brown-chaffed Mianhuada with the most stable quality, long-grained Nongkesuo Baikeda as a favorable breeding resource, and Wanyunjing 11036 as a choice breeding material for improving plant stature of Dahegu rice. These results would provide a guidance for the genetic improvement of Dahegu rice.

Abstract:In this study, the genetic diversity of 1287 common buckwheat germplasm resources was evaluated by using the geographical information, 6 phenotypic traits and 7 pairs of SSR markers. The analysis of six phenotypic traits revealed great variation in different germplasm resources. The coefficient of variation ranged from 17.13% to 33.87%, with an average of 24.25%. The coefficient of variation of stem diameter was the largest, which was the main factor causing phenotypic variation. The1287 accessions were divided into five groups, most of which were clustered in the fifth subgroup, and the others showed regional specificity. The analysis of SSR indicated the index of similarity coefficient ranged from 0.0477 to 0.9486 with an average of 0.4289. Clustering analysis based on SSR molecular markers showed that there was a certain correlation between germplasm resources and their geographical distribution. The results of phenotypic traits and SSR molecular markers showed that there was abundant genetic diversity in common buckwheat germplasm resources and 530 accessions of primary core collection were constructed.

Abstract:From 2015 to 2019, through the general survey and collection of germplasm resources in 75 county-level administrative districts in 14 prefecture-level cities in Guangxi Zhuang Autonomous Region of China, and through organized systematic investigation and rescue collection in 50 counties (districts, cities) in 13 prefecture-level cities by our professional investigation teams, a total of 1836 vegetable resources belonging to 19 families, 51 genera and 81 species were solicited and collected. The results showed that the vegetable germplasm resources in Guangxi were mainly distributed in northern and western areas, among which 44.28% came from altitudes of 100-300 m and from the ethnic groups of Han, Zhuang, Yao, Miao, Dong and Maonan, of which again 56.97% came from ethnic minorities. Through the identification and evaluation of the various vegetable resources, 511 elite resources were selected, with cucurbits, alliums, and gingers in the majority. The excellent characteristics are mainly reflected in high quality and resistance to pests and diseases. This study provides scientific evidence for the conservation of vegetable resources and the breeding of new varieties in Guangxi.

Abstract:Under the frame of “the Third National Campaign of Crop Germplasm Census and Collection”, 87 hyacinth bean landraces were collected from 29 counties in Jiangsu province from 2016 to 2019, followed by the genetic diversity analysis based on the phenotypic variations of 19 traits and the genotyping outcome using 39 SSR markers. The abundant phenotypic diversity was observed showing the diversity index of 12 morphological traits ranged from 0.4773 to 1.3695, and that of 7 agronomic traits ranged from 1.8064 to 2.0260. These landraces were divided into four genetic groups by cluster analysis. Levels of phenotypic variation were revealed in each cluster, and the performance of the yield-related traits in landraces in cluster IV was superior. Twelve elite hyacinth bean landraces showing early maturity, high yield and larger seed were selected. Taken together, this study unlocked the genetic diversity of hyacinth bean landraces in Jiangsu province, which provided insights for the germplasm innovation and breeding for new varieties in hyacinth bean.

Abstract:One wild strawberry accession, which was collected from Linxia city, Gansu Province is conserved in the National Clonal Germplasm Repository in Nanjing, China. In order to identify its taxonomy, the main taxonomical characters such as plant posture, leaflet type, stolon branching, flower sex, fruit shape and chromosome number have been investigated in the natural habitat (Linxia city, Gansu province). Plant (diploid, 2n=2x=14) is slender with trifoliate leaves (rarely quinquefoliolate); inflorescences are in cymes with 3 to 5 bisexual flowers per inflorescence; fruits are red, oval or short cylindrical; achenes are sunken; Calyxes are flat or slightly inversely curving; the runners are monopodial. This wild accession has been identified F.chinensis. In the natural habitat, plants generally germinate in March, bud appears in early May, and fruit ripens in mid-June. The floral bud differentiation has initiated since the middle of July (lasting for 60 days at 10 to 25°C), while 75% of floral bud have differentiated in the first 30 days. The leaves turned yellow in late September, withered in November before the dormancy. Based on the comparative analysis of climatic factors (Linxia and Nanjing), we discussed the environmental factors that associated to the flower bud differentiation of strawberry, as well as the reasons that resulted in a compromised flowering of F.chinensis in Nanjing.

Abstract:In order to clarify the phenological process of flowering and leaf expanding in peach, and the effects of chilling and heat requirement differences between floral and leaf buds on the phenological process, we first evaluated the chilling and heat requirements of floral and leaf buds of 257 peach germplasms, and investigated the full bloom date and leaf expanding date, then according to the chilling requirement of floral buds, the materials were classified into 4 types of very low, low, medium and high chilling requirement, respectively, and finally the phenological process of different types of peach in different years, as well as chilling and heat requirement differences of each phenological process, were systematically discussed. The results showed that peach with very low chilling and low chilling requirements had 3 kinds of phenological process, including “flowering before leaf expanding”, “simultaneous flowering and leaf expanding” and “leaf expanding before flowering”. The phenological process of the same germplasm varied in different years, and the patterns of chilling and heat requirement differences were complex and varied accordingly. Peach with medium chilling and high chilling requirements had only 1 kind of phenological process, which was “flowering before leaf expanding”, and the patterns of chilling and heat requirement differences were simple and unvaried. The phenological process of peach floral and leaf were related to patterns of chilling and heat requirement differences, and mainly depended on the difference of heat requirement. Regardless of the chilling requirement of the floral bud, when the heat requirement of floral bud was less than that of leaf bud, the phenological process was “flowering before leaf expanding”; when the heat requirement of floral and leaf buds was equal, the phenological process was “simultaneous flowering and leaf expanding”; when the heat requirement of floral bud was greater than that of leaf bud, the phenological process was “leaf expanding before flowering”. The results indicated that the heat requirement difference of the floral bud and leaf bud was chiefly responsible for the different and variable phenological process of peach.

Abstract:Autophagy pathway is known to be widely involved in the regulation of growth and development, nutrient recycle, a variety of biotic or abiotic stresses tolerance in plant. However, the functional research in rice is still in its infancy. In this study, OsATG12, a rice autophagy-related gene, was isolated and subjected for producing over-expressing and gene editing plasmids transformed into rice. We identified the transgenic lines over-expressing OsATG12 and atg12s mutant lines. By testing for rice blast resistance using these transgenic lines, OsATG12 was found to negatively regulate the blast resistance of rice. Collectively, this study provided new insights for revealing the functions of rice autophagy pathway and autophagy related genes.

Abstract:Aberrant degeneration of panicle (ADP) usually occurs during the reproductive growth in rice. It causes yield loss due to the reductions of panicle length, branch number, grain number per panicle and seed setting. However, the ADP phenotype is sensitive to growth environments and regulated by multiple quantitative trait loci, which have complicated the identification of ADP-related function genes.The molecular mechanism underlying ADP occurrence remain largely unknown. The tutou4 is a panicle degeneration mutant derived from a tissue culture, and shows abnormal panicle, reduction of panicle grain number and branch number, as well as single plant yield. Genetic analysis showed that the ADP trait was controlled by a pair of recessive nuclear gene. The candidate gene was finally mapped to the short arm of chromosome 8, flanked by both Indel markers Os8-3-2 and Os8-3-3, with an interval of 39.09 kb, which contained three encoding genes. The sequencing result showed a 4325-bp deletion in the promoter region and one base alternation (A?G, synonymous) of the gene LOC_Os08g06480, which was designated as OsLIS-L1/OsREL2/ASP1. Real-time PCR analysis revealed a reduction on gene expression in mutant to that of the wild type. Considering the expression level decreased in the tutou4, the mutant will be useful germplasm in the study of abnormal panicle degeneration.

Abstract:Pi2 is a rice gene for broad-spectrum resistance to blast pathogens, which has an important application value for rice blast resistance breeding in South China. In order to improve the selection efficiency, a KASP marker specific for Pi2 gene was developed based on the variation GCA GGA / GTG TTA at codon 787 and 788 of Pi2 gene between the highly resistant variety Huangguang Youzhan and the highly susceptible variety Guanglu Ai 4. The developed allele specific marker could accurately distinguish the resistance allele, susceptible allele and heterozygous genotype at Pi2 in 40 rice varieties, which was highly correlated with their resistance/susceptible phenotypes. Further more, this marker was applied in a large F2 segregation population from a cross of Wushan Youzhan and Yujing 91 to select the target genotypes of the individuals or lines that carried the blast resistance Pi2 alleles through marker-assisted selection exhibited intermediate or high resistance to blast in disease nursery. In conclusion, using the developed allele specific marker, 27 Guangdong rice varieties that carry blast resistance gene Pi2 were identified, which has an important application value in improving selection efficiency in the development of blast resistant rice varieties.

Abstract:Mutation induced by irradiation is one of the efficient ways to innovate crop germplasm resources. In this study, a drooping-panicled mutant rice with other variations in the panicle, named JD-1, was derived from ‘Jindao 565’ by carbon ion beam irradiation. Compared with the agronomic traits of the wild type ‘Jindao 565’, JD-1 had a highly significant (P＜0.01) increase in neck-panicle curvature, number and density of main panicle grains by 305.90%, 66.86% and 47.79%, respectively. In addition, panicle length, number of main panicle filled grains and number of main panicle secondary branches increased significantly (P＜0.05) by 12.11%, 63.06% and 74.19%, respectively, but the 1000-grain weight significantly decreased by 11.54%. The whole genome sequence alignment revealed the existence of 18639 single nucleotide polymorphisms (SNPs) with a conversion/transversion ratio of 2.34, and of 3428 insertion-deletions (InDels), between ‘Jindao 565’ and JD-1, which were distributed in clusters and mainly located on chromosomes 5 and 11, accounting for 25.19% and 22.98%, respectively. Through the structural analysis of mutated genes, the mutations occurred in intergenetic regions had the maximum proportion of 45.22%, while those detected in splicing hold the minimum proportion of 0.08%. GO functional analysis of the mutated genes revealed that most of them were involved in cell physiological process. The sixteen genes related to plant height, 1000-grain weight, panicle length and secondary branches were identified from the cloned genes which were mutated in JD-1. The molecular markers for these genes were further designed based on the mutation sites, and the twelve SNP markers and the nine InDel markers were proved to be polymorphic in nine genes between ‘Jindao 565’ and JD-1. This study created a new rice germplasm and explored the allelic variation related to yield trait in rice.

Abstract:The chlorophyll content determines the rate of photosynthesis. To explore the genetic mechanism of the chlorophyll content, this study measured the chlorophyll content of 119 winter wheat varieties (lines) at flowering period and filling stage under watering-drought treatment. The genome-wide association scanning using 50K chips was conducted using the Q+K association hybrid model. The chlorophyll content of wheat under drought treatment was slightly lower than that under water treatment at flowering and grain filling stage. One-hundred nineteen wheat varieties (lines) were divided into three subgroups, each of which accounted for 48.7%, 23.5% and 27.7%. The polymorphic information content (PIC, Polymorphic Information Content) of the 50K chip was 0.091-0.375, and the whole-genome LD decay distance was 4.27Mb. Genome-wide association scanning (P < 0.001) identified a total of 88 loci significantly associated with chlorophyll content under the two treatments. These loci were found on all chromosomes except 4B, 5A and 7A, with a contribution rate of 9.39%- 15.69%. A total of forty-one loci significantly associated with chlorophyll content were detected at the flowering stage, among which 40 loci were identified under water treatment and one locus under drought treatment. A total of 51 loci significantly associated with chlorophyll content were detected at the grain-filling stage, among which forty-three loci were identified under water treatment and nine loci were identified under dry treatment, with a total of four repeat loci in the two stages. A locus located on 4A was detected in the flowering stage at two environments, with the contribution rate of 12.01%-12.26%. A total of 21 candidate genes associating to chlorophyll formation were identified under water treatment condition, including magnesium transporter, transporter, chlorophyllase, phospholipid/glyceryl acyltransferase family protein, GATA transcription factor. Under drought treatment condition, three genes possibly related to stable expression of chlorophyll were obtained, including chlorophyll a-b binding protein, F-box protein and dehydration stress protein, which are involved in chlorophyll synthesis and decomposition and regulate the growth and development of crops. Collectively, this study provided insights for gene cloning and marker development.

Abstract:This study reported a quantitative trait locus (QTL) mapping for identifying the adult-stage powdery mildew resistance genes in a recombinant inbred line (RIL) population of common wheat (Triticum aestivum L.). This population was derived from the highly susceptible variety Ningchun 4 crossing with the highly resistant variety Ningchun 27, and genotyped using genotyping-by-sequencing (GBS) approach. The results showed that the additive-epistatic genetic model using four pairs of major genes was suitable for identifying the powdery mildew resistance loci. Two resistance-conferring loci QPm.naafs-4D and QPm.naafs-7D have been identified from Ningchun 27 and Ningchun 4, respectively. Out of them, QPm.naafs-4D represented a LOD value of 5.9 to 15.4 at multiple environmental conditions (additive effects: -1.1 to -1.2), and contributed to a phenotypic variation of 18.6% to 34.5%. This locus was delimited to a genetic distance of 4 cM harboring the durable poly-resistance gene Pm46/Lr67/Yr46/Sr55. Sequence analysis confirmed that QPm.naafs-4D in Ningchun 27 was identical to Pm46/Lr67/Yr46/Sr55. The resistance-conferring donor line is valuable in marker-assisted breeding for powdery mildew resistance in wheat.

Abstract:In our previous study, CD-3, a novel CS-Dasypyrum villosum 3V (3D) substitution line with high resistance to wheat stripe rust, had been developed, and the stripe rust resistance had been mapped on the 3V chromosome. To explored the transmission character of the 3V chromosome and provide the theoretical basis for the utilization of stripe rust resistance from 3V in wheat breeding, CD-3 was directly and reciprocally crossed with landrace Kaixian Luohan Mai wheat (KL) and commercial variety Chuan Mai 42 wheat (CM42), respectively, in this study. The F1 hybrids were then selfed to obtain F2 plants for estimation of the transmission characters of the 3V chromosome using fluorescent in situ hybridization (FISH). At last, the stripe rust resistance of the F2 plants was investigated. The results showed: (1) The transmission rates of 3V in the 4 crosses (CD-3/KL, KL/CD-3, CD-3/CM42 and CM42/CD-3) ranged from 20.45% to 34.94%, which were significantly lower than the theoretical value (75%), and there was no significant difference among the 4 crosses, indicating that the genetic background had no influence on the transmission of 3V in this study; (2) The chromosomal structural aberration rate of 3V in CD-3/CM42 was significantly higher than that in CD-3/KL and CM42/CD-3, suggesting that the genetic background had influence on the chromosomal structural aberration rate of 3V; (3) The plants with two 3V chromosomes showed high resistance, and the plants carrying one 3V chromosome were susceptible or moderately resistant to stripe rust, which was consistent with the infection type of their parents, CM42 and KL. The result showed that the resistant gene(s) of stripe rust located on the 3V chromosome could express in the genetic background of the landrace KL and the commercial variety CM42. This research provided theoretical foundation for further exploration of the resistant gene(s) of stripe rust originating from the 3V chromosome of D. villosum, as well as valuable genetic materials for wheat improvement.

Abstract:Orange wheat blossom midge（OWBM，Sitodiplosis mosellana Géhin） is an important pest insect that seriously threatens wheat production. Cryptic habitat of OWBM lifecycle made pest control very difficult. Therefore，screening for OWBM-resistant wheat germplasm and tightly-linked molecular marker is of great important for pest control. In this study，566 wheat germplasm resources from different wheat regions and different periods，and genomic regions surrounding major OWBM locus were used to identify their resistance to OWBM，and to discover new SSR markers，respectively. The results showed that 27.03% of wheat cultivars were immune or highly resistant to OWBM，of which released in early years were still resistant to OWBM. Meanwhile，565 SSR markers were developed from the genomic region of major OWBM-resistant locus（Qsm. hbau-4A），and their detection efficiency were tested among this panel of wheat accessions. Of these SSR markers， marker Xhs87201bp showed robust PCR amplification and presented an average of 65.37% detection efficiency，and can be used for marker-assisted selection of OWBM resistance.

Abstract:In this study, bm-like1, a natural brown midrib mutant, was found to be steadily inherited after continual self-pollination. Phenotype analysis of the F2 population composed of homozygous bm-like1 mutant and B73 inbred lines indicated that the brown midrib phenotype of bm-like1 was controlled by a single recessive gene. Using BSA-seq and fine mapping, the target region was mapped to the interval of 32-36 Mb on maize chromosome 4, where BM3 was located. BM3 gene encodes a caffeic acid o-methyltransferase, which is an important enzyme in lignin biosynthesis. We crossed bm-like1 mutant with bm3 mutant for allelism testing and found that the F1 plants showed brown midrib phenotype, indicating that BM3 was the causal gene for bm-like1 mutant. Genomic sequence analysis revealed that a 1439-bp insertion at 144 bp upstream of transcription start site of BM3 might cause the brown midrib phenotype of bm-like1, which is different from bm3 mutation of 5452-bp insertion in the second exon of BM3 gene. Real-time quantitative PCR and transcriptomic analysis indicated that the expression of BM3 gene in bm-like1 mutants was significantly decreased compared with the wild type plants, the differentially expressed genes between bm-like1 and wild type plants were mainly enriched in the secondary metabolites biosynthesis and metabolic pathway.

Abstract:In order to understand the genetic basis of silk color in maize, the candidate genes and excellent alleles associating with silk color were explored. The recombinant inbred lines (RIL) crossed from maize cultivars “Zheng 58” and “Chang 7-2” were used for QTL mapping. A fine mapping of the major gene qSC10 causing pink silk was conducted in a F3 population of “Zheng 58” that hybridized with a near isogenic line qSC10-NIL (harboring qSC10), followed by a physical mapping and candidate gene analysis according to the reference genome sequence of B73 (RefGen-v4). Four major QTL were identified on chromosomes 1, 8, 9 and 10 using the RIL families, and each explained 3.34% to 12.28% phenotypic variation. The gene qSC10 on chromosome 10 was delimited to a 374.2 kb interval which contains 14 annotated genes, including the R-S gene (GRMZM5G822829) that was associated with seed coat color. The R-S gene was found to be expressed in silk, root, leaf and tassel, while the expression level of qSC10-NIL in silk was significantly higher than that of Zheng 58. Collectively, these results suggested that the R-S gene, which is a candidate gene for qSC10, may contribute to the accumulation of anthocyanins in maize filament by a positive regulation on the expression of anthocyanin synthesis-related genes.

Abstract:Ear length is one of yield components and shows higher heritability than that of yield trait in maize. Unlocking its genetic basis is important in order to understand the mechanism of maize yield formation. This study analyzed an ear length major QTL q21EL-GZ that was identified in our research group. The secondary segregation population (BC1F2) harboring the desirable target was used for the genotyping by taking use of the Sequenom SNP technology. The ear length was determined using BC1F2 and derived BC1F2:3 families. The target region containing q21EL-GZ was further narrowed by using the group t test analysis method to a 195-kb interval. Based on the transcriptional profiles, three candidate genes MTD1, RSH2 and APK1B of q21EL-GZ were identified, which would be important targets in gene isolation and functional mechanism analysis.

Abstract:Creating dwarfmutant germplasm in Panicum miliaceuml and developing Panicum miliaceuml breeding isof great theoretical significance and valuable on application. A character-stably-heritable dwarfmutant in Panicum miliaceuml was induced from Shi hu qian jin mi (planting number 260) by EMS (ethyl methyl sulfonic acid) mutagenesis. The mutants’ agronomic traits, physiological characteristics and dwarfing mechanism were studied from the perspective of morphology, cytology and molecular biology. The results showed that :The mutant was dwarfed at the seedling stage and it would maintain until maturity, the plant height was only 57.1cm. Compared with the wild type,the mutantinternodes were extremely significantly shortened, internodes number has insignificantdifference, tiller number increased significantlyreaching extremely significant level, the drop of pedicel length, ear length and thousand-grain weight reached extremely significant level, no obvious changes appeared on the stem diameter and leaf length, the increase of leaf widthreached extremely significant level and the mutant leaf greened darkly. The chlorophyll contents in sword leaf and top second leaf at heading stage and the sword leaf at mature stage were higher than these in wild type, of whichthe chlorophyll content difference in top second leaf reached significant level compared with wild type. According to the cytological observation of the main stem profile, it was found that the main cause of dwarfing was the decrease of the number of longitudinal cells in the stem node. The plant height frequency of F2 segregation population constructed by the mutant and the high straw J12 distributed unimodally, indicating that the dwarf mutant 819 belonged to quantitative trait inheritance controlled by multiple genes. The endogenous content of GA₃₊₁ in mutant leaves at maturity stage was significantly higher compared with wild type, and the mutant was insensitive to exogenous GA3, indicating thatthe mutant was a GA signal transduction defect type dwarf mutant. A gibberellic acid insensitive gene (accession number: PM01G30960) was identified by BSA-Seq method, which was assumed to be the key gene for the formation of dwarf mutant 819, which laid a foundation for the development and application of new dwarf varieties in Panicum miliaceuml.

Abstract:In cytoplasmic male sterility (CMS)/restorer-of-fertility (Rf) system, the male sterility might become fertile once the fertility restorer gene(s) is present. However, different restorer genes may represent levels of restorative ability in the three-line hybrid soybean breeding. In this study, the CMS line JLCMS84A and its restorer line JLR1 were used as female and male parents, respectively, to construct F2 population used for genetic mapping. Segregation analysis during R2 stage indicated a typical inheritance pattern of gametophytic CMS with fertility restorer being controlled by a single dominant gene. allocated The restorer gene was allocated using BSA-seq on chromosome 9 between SSR markers BARCSOYSSR_09_1151 and BARCSOYSSR_09_1183 with the distances of 0.6 cM and 0.5 cM, respectively. Based on the soybean reference genome ZH13 v2.0, this physical interval spans 522 kb between 41.152 to 41.674 Mb and hosts a novel restorer gene named Rf3. Out of 51 annotated genes in the target region, three genes (SoyZH13_09G151700, SoyZH13_09G152000 and SoyZH13_09G154200) are encoded for putative pentatricopeptide repeat (PPR) protein. By PCR amplification and Sanger sequencing of their full-length DNA sequences between the CMS line JLCMS84A and its restorer line JLR1, three SNPs and two InDels, which lead to frame-shift mutations in SoyZH13_09G152000, have been identified, while 47 SNPs in SoyZH13_09G154200 have been detected. Therefore, both genes were the strongest candidates for Rf3. These results lay a foundation for fine mapping and function identification, as well as marker-assisted selection of new restorer lines which contained this restorer gene.

Abstract:In order to study the function of HSF transcription factor in Tartary buckwheat, a HSF family gene was cloned from ‘Chuanqiao No.1’ in this study. The open reading frame is 1047 bp in length encoding for 349 amino acids. The analysis of gene structure showed that FtHSFA6b gene is composed of two exons and one intron. The sequence alignment and phylogenetic analysis showed that FtHSFA6b protein was closely related to CQA-2C in Chenopodium quinoa and GHA-7A in Gossypium hirsutum. Cis-acting elements in the promoter of FtHSFA6b were predicted and divided into five categories. Furthermore, tissue-specific expression analysis showed that FtHSFA6b gene was expressed in roots and leaves, with the lowest expression in roots and the highest expression in stems. qRT-PCR showed that the expression of FtHSFA6b was induced under MeJA or NaCl treatments. The analysis of total flavonoids content in transgenic hairy roots showed that the overexpression of FtHSFA6b could increase the tolerance of hairy roots to salt treatment, and the total flavonoids content also increased significantly. In transgenic Arabidopsis thaliana, over-expressing FtHSFA6b can improve the salt tolerance at the germination stage, possibly by decreasing malondialdehyde (MDA) content and increasing the activities of Catalase (CAT) and peroxidase (POD).

Abstract:NAC (NAM, ATAF1/2, CUC2) gene plays an important role in responses to plant abiotic stresses. In this study, we cloned FtNAC11 from tartary buckwheat cultivar ‘Pinku No.1’. Sequence analysis showed that the full-length coding sequence of FtNAC11 was 774bp encoding for 257 amino acids residues, with a molecular weight of 8954.58 Da and an isoelectric point of 5.91.The sequence alignment and phylogenetic tree analysis showed that FtNAC11 had higher homology with Arabidopsis thaliana AtNAC61. The expression of FtNAC11 gene was induced under PEG or NaCl treatments. Sub-localization by transient expression and yeast transactivation assay indicated that FtNAC11 encoded for a nuclear transcription activator with an activation domain at the region of C-terminal. Moreover, the coding sequence of FtNAC11 was transformed into Arabidopsis thaliana by Agrobacterium-mediated transformation, and the transgenic plants over-expressing this gene resulted in significant enhancement under drought and salt tolerance treatments. Collectively, these results indicated that FtNAC11 is likely involved in abiotic stress adaptation, providing a basis for further investigation of its molecular mechanism responding to drought and salt tolerance in tartary buckwheat.

Abstract:Salt stress is one of the main abiotic stresses affecting plant growth and development. Metalloproteinase FtsH (Filamentation temperature-sensitive H) is a type of ATP and Zn2+ dependent protease in the AAA family of proteases (ATPase associated with various cellular activities), and it plays an important role in plant chloroplast development, photosynthetic system protein synthesis and repair, response and resistance to abiotic stress, leaf noise regulation and other important processes. Although FtsH has been extensively studied in several species such as Arabidopsis thaliana, Brassica napus, Glycine max, its function in Medicago sativa has not been reported. In this study, we cloned and analyzed the expression pattern of MsFtsH8 gene in Medicago sativa, followed by a Bioinformatics analysis of the gene sequence. Over-expression of the gene in A. thaliana significantly increased seed germination rate, root length and fresh weight under salt stress. Collectively, this study provides important candidate genes and theoretical reference for alfalfa molecular breeding regarding to salt tolerance.

Abstract:The sequence analysis of CPP (cysteine-rich polycomb-like protein) gene family in mango (Mangifera indica) was carried out by bioinformatics methods, and the transcription level and tissue-specific expression of the CPP family genes during the infection of Xanthomonas campestris pv. mangiferaeindicae (Xcm) and Colletotrichum gloeosporioides (Cg) were studied using qRT-PCR. Ten members of the CPP gene family were identified from the mango genome, all of which contained conserved CRC domains, and they were all unstable hydrophobic proteins. A phylogenetic tree was built with 69 members of the CPP gene family from mango, Pyrus bretschneideri, periwinkle, Populus euphratica, rice, grape, and Arabidopsis thaliana, which were divided into 7 evolutionary branches. The 10 MiCPPs genes of mango were distributed in 5 of the evolutionary branches, most of which were clustered with members of the CPP gene family of Pyrus bretschneideri. qRT-PCR analysis showed that the relative expression levels of MiPP1 and MiCPP2 were up-regulated at 3 h, 6 h and 12 h after the Xcm infection, while the relative expression level of MiCPP8 was up-regulated and that of MiCPP9 was down-regulated at 0-72 h after the Cg infection. qRT-PCR analysis also showed that the relative expression levels of MiCPP8 were very high in young leaves, flowers and buds infected by Colletotrichum gloeosporioides, while the relative expression levels of MiCPP7 were very low in those parts, the relative expression levels of MiCPP4 and MiCPP9 were high in young leaves and flowers but very low in buds, and the relative expression of MiCPP6 was very low in flowers. These results indicated the expression specificity of the mango MiCPPs gene family members in different tissues. This research would provide a basis for further studies on the response mechanism of mango CPP gene family members to pathogen infection and help breed for disease resistance in mango.