Abstract:Ginger (Zingiber officinale Rosc.) and garlic (Allium sativum L.) are important condiments and vegetables, and both can be used as medicine and food. They are of great value in mediating people's dietary structure, nutritional balance and health care. Ginger and garlic in China are also important vegetables for export. Ginger and garlic germplasm resources are important for the scientific studies and technological innovations that substantially support these breeding and sustainable development of industries. This article reviews the research status of ginger and garlic germplasm resources from the aspects of collection and preservation, identification and evaluation, excellent genes mining, innovation and utilization. Many countries in the world, especially for the developed countries, were found to pay great attention to the collection, preservation and evaluation of ginger and garlic resources. Although China is rich in ginger and garlic germplasm resources, the academic research starts late and remains preliminary if compared to that of developed countries. In addition, this review analyzes the problems in the research of ginger and garlic germplasm resources and provides the corresponding strategies and suggestions addressing to these problems.

Abstract:Carrot (Daucus carota L.), which is one of the top-ten ranking vegetable crops in the world, is an important source of vitamin A in human diets. China is a major producer of carrot and has rich carrot landraces with colors (i.e. orange, red, yellow and purple). The carrot germplasm resources with diverse root colors enabled deciphering the regulation mechanisms of the synthesis and metabolism of carotenoids and anthocyanins, and the origin and domestication of carrot. This article outlined the domestication history and major pigment components of carrot with different root colors, reviewed the research progress of genetic loci and functional genes modulating the accumulation of carotenoids and anthocyanins in carrot roots, introduced the uses and breeding methods of varieties with different root colors, as well as provided prospects in future research of carrot root color traits, thus serving as a basis for understanding the regulation mechanisms of carrot root color and breeding with colorful varieties.

Abstract:Seed germination and dormancy are two complicated and closely related physiological processes involving a series of interactions between external environment conditions and internal factors, which are of great significance to high and stable yield and ecological evolution. These traits are typically controlled by multiple loci and largely influenced by environmental factors. In recent years, several QTL involving in seed germination and dormancy have been identified and their functional mechanisms have been investigated. In this paper, the effects of genetic regulation and external factors on seed germination and dormancy were reviewed, the existing problems were summarized, and the future development areas were prospected.

Abstract:Allium crop germplasm is ephemeral vegetable due to its short-lived seeds. Application of the conventional low-temperature preservation is difficult to achieve long-term preservation. It is therefore of great significance to set up the cryopreservation procedure specific to the allium germplasm. In the present study, through the orthogonal experiment of three factors with four levels, we examined the cryopreservation methods using 30 accessions of four allium vegetables (Allium tuberosum Rottler ex Sprengle, Allium fistulosum L. var. giganteum Makino, Allium porrum L. and Allium cepa L.). These results was evaluated by the germination rate of the seeds after cryopreservation if compared to the germination rate of the seeds without treatments. The results showed significant differences among the ANOVA experiments (P<0.05), while the optimal procedure was the A1B4C1 (without cryoprotectant PVS2 treatment, storage in liquid nitrogen, and rewarming for 4 h at 40°C before testing the germination rate). We also determined the physiological indexes of superoxide dismutase (SOD), peroxidase (POD) activity, catalase (CAT) activity, malondialdehyde (MDA) content of cryopreservation seeds after seed rewarming. The MDA content of the seeds decreased after ultra-low temperature preservation of liquid nitrogen, while the SOD activity was higher than that of the control after the liquid nitrogen treatment. A decrease on the POD activity of A. tuberosum Rottler ex Sprengle, after liquid nitrogen treatment and an increase on the POD activity of A. porrum L., A. fistulosum L. var. giganteum Makino and A. cepa L. were detected. Collectively, these results provided optimal cryopreservation procedure for Allium vegetable germplasm resources.

Abstract:To provide theoretical and practical guidance for rootstock breeding, 19 botanical traits of 70 eggplant germplasm resources for rootstock were investigated in this study, followed by the genetic diversity, principal component and cluster analysis. Moreover, tests for resistance to three soil-borne diseases (bacterial wilt, root-knot nematode and Verticillium wilt) were conducted. The coefficient of variation was variable from 15.9%-73.05% with an average of 46.11%. The genetic diversity index ranged from 0.325-2.008 with an average of 1.145. The coefficient of variation of weight per fruit was the highest (73.05%), and the genetic diversity of main stem diameter was the richest with an index of 2.0083. The component analysis revealed seven principal components (eigenvalues >1) with a cumulative rate of 76.55%. The 4th and 5th principal components were related to the convenience of grafting and the growth of grafted plant. The cluster analysis suggested three groups in this collection, including Group Ⅰ and Group Ⅲ were cultivated species, which showed no obvious differences in main stem color, leaf margin, fruit color and fruit size; Group Ⅱ contained four cultivated species and 20 wild germplasms, with the highest main stem diameter (20.42 mm) and the smallest fruit (the average length of 3.79 cm and diameter of 4.60 cm and weight of 73.38 g). 22 eggplant germplasms were detected with high resistance to bacterial wilt, 11 eggplant germplasms with high resistance to root-knot nematode and 7 eggplant germplasms with high resistance to Verticillium wilt. Three eggplant germplasms (BW9, LJ-7, Ng1-052) were highly resistant against bacterial wilt and root-knot nematode, and four eggplant germplasms (Ng1-003, Solanum khasianum C. B. Clarke, Solanum sisymbriifolium Lam., Solanum torvum Swartz) were highly resistant against root-knot nematode and Verticillium wilt. These eggplant germplasms can be used as resistance sources for disease resistance breeding. Based on the identification of botanical traits and disease resistance, three cultivars (LJ-18, Ng1-015 and Ng1-013) showing resistant against multiple diseases and vigorous growth and convenient graft were obtained, which laid a foundation for excellent multi-resistant eggplant rootstock breeding.

Abstract:Phytophthora fruit rot is an important disease in eggplant. Identification of the disease-causing pathogens and the resistant germplasm accessions against these pathogens is useful in breeding of resistant varieties. In this study, the pathogens were isolated from the diseased eggplant fruit from Xuzhou city and Nanjing city of Jiangsu province, followed by tests for disease resistances in 146 globally-collected eggplant germplasm accessions. One strain was obtained from each of the samples in the two regions. Two strains (named NJ1 and XZ1) had typical characteristics of the phytophthora capsici, and both were P. capsici as revealed by rDNA-ITS sequence analysis. The eggplants post inoculation showed typical disease symptoms of phytophthora fruit rot. A variation on resistance among germplasm accessions was observed, and only several genotypes represented ideal resistance. Three germplasm accessions with ideal resistance to both strains could be used as a source of resistance for breeding eggplant against phytophthora fruit rot. Especially, G42 and G114 were resistant to both strains, while G135 was resistant to strain XZ1 and moderate resistant to strain NJ1. Collectively, this study has laid an important foundation for genetic breeding research on phytophthora fruit rot in eggplant.

Abstract:In order to investigate the genetic basis of crops germplasm resources, Ministry of Agriculture & Rural Affairs of PRC and the government of Guangxi Autonomous Region of China launched the projects ‘The Third National Survey and Collection on Crop Germplasm Resources’ and ‘Collection, Identification and Preservation of Crop Germplasm Resources in Guangxi’, respectively. We have collected systematically the resources of Cucurbita in Guangxi, followed by the identification and evaluation of pant morphology, fruit characters, flowering habits, taste quality and resistance to powdery mildew and virus. 261 samples of Cucurbita resources were obtained throughout the whole province, especially in which northern, western and eastern regions represented a higher number of germplasm resources, with better quality and higher resistance than those of genotypes in other areas. These genotypes were classified belonging to C. moschata D. cultivars, with its typical characteristics such as palm-shaped leaves and pentagonal fruit stalks. They showed rich genetic variations, i.e. the coefficient of variation of leaf size and main stem diameter ranging from 10% to 11%, fruit shape index ranging from 0.516 to 3.190, the coefficient of variation of fruit weight ranging from 0.89 kg to 11.40 kg (mean = 38.1%). However, there were defects such as poor genetic stability, overall quality differential and unsatisfactory complex characters. Fifty-three resources showing earlier maturity, 32 genotypes with high-quality, 61 high resistance resources to powdery mildew and 5 high resistance resources to virus were identified. Collectively, this study provided solid foundation for the conservation and efficient use of pant local germplasm resources.

Abstract:In recent years, facility cultivation in watermelon has become one of the main ways in China, and dwarf germplasm resources have been of interest considering their application for their unique advantages in facility cultivation. Dwarf is one important agronomic trait in modulating plant architecture, and dwarf watermelon varieties are adaptable for high-density planting, mechanizing management and pest control, which can effectively reduce costs and meet the current needs of simplified watermelon cultivation. In this study, 14 dwarf germplasms, which were collected from domestic and foreign countries, were subjected for self-pollination with several generations to obtain homozygous inbred lines. Fourteen dwarf germplasms were subjected for diallel crosses, and F1 hybrids and derived F2 populations were analyzed for plant architecture related agronomic traits. Based on allelic tests for 14 dwarf germplasms, two types (class-I and class-II) on the dwarf phenotype were observed. The dwarf trait in class-I mutants d1, d2, d3 and d6 was controlled by the same recessive gene Cldw1, while the dwarf trait in class-mutants was controlled by another recessive gene Cldf. The F1 hybrid derived from inter-crosses between two classes were observed with long vine, and the segregation ratio of the vine type in F2 population was 9:3:3:1, thus confirming that the dwarf trait in two types of mutants were controlled by two different recessive genes. The analysis of different dwarf germplasm mutants in this study provided better understanding of watermelon dwarf resources, which has implication in breeding for new watermelon dwarf varieties.

Abstract:Clubroot disease is one of the most important diseases of Chinese cabbage and other cruciferous crops. Identification of new clubroot resistant resources is of importance in breeding for resistant varieties to effectively prevent the occurrence. In this study, two resistant and two susceptible inbred lines of Chinese cabbage, respectively, were used to identify the polymorphic markers that are closely linked to the CR genes of the resistant inbred lines. Sixty-three turnip germplasms were tested for resistance at the seedling stage by inoculation using the bacterium Plasmodiophora brassicae isolates from Wulong district of Chongqing municipality and Tangshan city of Hebei province. The turnip germplasms showing resistant or tolerant were genotyped using molecular markers linked to CR genes. Based on 20 tested markers, two were found to be linked to the resistance gene CRa, one marker linked to CRb, five markers linked to CRbkato and one marker linked to CRd. Six turnip germplasms showing good resistance simultaneously to isolates were collected from Centre for Genetic Resources (CGN), Netherlands, including three forage turnips and three vegetable turnips originally from European countries. The genotyping results also suggested a heterozygous status in the genetic background of these turnips. The germplasms CGN1, CGN10 and CGN11 were found harboring four CR loci (CRa, CRbkato, CRb and CRd), CGN23 and CGN36 were detected harboring three loci (CRa, CRbkato and CRd), and CGN30 carried two CR loci (CRa and CRbkato). Whether these turnip germplasms host additional CR loci still remains to be further investigated. Collectively, these results provided materials for mining new CR genes and breeding new CR varieties of Chinese cabbage and other cruciferous crops.

Abstract:Glucosinolates and their degradation products are important secondary metabolite of cruciferous vegetables with the anti-cancer function. The Methylthioalkylmalate synthases encoded by various MAM genes are involved in glucosinolate side-chain elongation. MAM1 catalyzes the aliphatic glucosinolate synthesis with short-chain, while MAM3 catalyzes that with long-chain. In this study, the glucosinolate content and the expression of MAM genes were analyzed in Chinese cabbage and cabbage inbred lines during seedling and rosette stages, in order to associate MAM gene expression with the accumulation of beneficial glucosinolates. The results showed that the average glucosinolate content in cabbage was higher than that of Chinese cabbage from seedling to rosette stage. The content of 5C and 4C aliphatic glucosinolates (GBN and NAP) were predominant in Chinese cabbage, whereas the main glucosinolates in cabbage were 3C and 4C aliphatic glucosinolates (IBE, SIN and GRA). The anti-cancer components SIN and GRA were significantly higher in cabbage than those of Chinese cabbage. The genome annotations of Chinese cabbage and cabbage revealed seven MAM paralogous genes respectively. By analyzing the expression levels of MAMs, a significant difference in the relative expression level of MAM1 and MAM3 between Chinese cabbage and cabbage was detected. The expression level of BraMAM1.1 and BraMAM1.2 in Chinese cabbage was significantly lower than that of BoMAM1.1 and BoMAM1.2 in cabbage, while the expression level of BraMAM3.2 and BraMAM3.3 was significantly higher than that of BoMAM3.1. Moreover, the content of 3C aliphatic glucosinolates in cabbage was positively correlated with the expression of BoMAM1.1, and the content of 5C aliphatic glucosinolates in Chinese cabbage was positively correlated with the expression of BraMAM3.2. Collectively we speculated that the low expression of BraMAM1.1 and the high expression of BraMAM3.2 may respond to the low accumulation of 3C aliphatic glucosinolates (SIN) and the high accumulation of 5C aliphatic glucosinolates (GBN) in Chinese cabbage.

Abstract:Tomato is a globally popular vegetable with special flavor and rich nutrition. Along with the increasing need of the customers on the fruit quality, people have paid attention on the sepals, as an important part of fruits. In this study, the genetic populations (P1, P2, F1, F1' and F2) were generated by using tomato genotypes with sepal envelopment and upward curl as parents, respectively. The F2 population was genotyped using 130 polymorphic SSR markers to obtain the genetic linkage map, which contained twelve linkage groups, with a genetic map length of 4682.22 cM and an average genetic interval of 36.02 between markers. The QTL mapping of six sepal-related morphological traits (sepal length, sepal width, sepal thickness, sepal area, sepal upward curl, and sepal upward curl) enabled identifying 20 QTL, of which two were associated with sepal length, three with sepal thickness, 11 with sepal area, four with sepal crimpness. These high-confident QTL at each trait were further analyzed, and might lay a foundation for deciphering the regulation and improvement mechanisms of tomato sepal morphology.

Abstract:To illustrate the regulation mechanism of parthenocarpy and the genes controlling this process, as well as provide basic materials in eggplant parthenocarpy breeding, the parthenocarpy/non parthenocarpy near isogenic lines were constructed in this study. Two groups of near isogenic lines (NILs) JDX1 and JDX8 were generated by hybridization, backcross and selfing, in combination with parthenocarpy identification and agronomic traits investigation. 219 pairs of SSR primers covering eggplant genome were used to genotype eggplant NILs and their parents. JDX1 and JDX8 showed 97.14% and 88.23% on the genetic similarity with respective reincarnation parents, respectively. The parthenocarpy identification showed that, in difference with recurrent parents, JDX1 and JDX8 had been completely transformed into non parthenocarpic lines. There were no significant differences in plant height, first flower height, node spacing, leaf length and width, fruit length and thickness between NILs and their recurrent parents. By considering the agronomic characteristics such as fruit color and strain type, JDX1 and JDX8 showed higher similarity/identity with the reincarnation parent. Collectively, the success on creation of eggplant parthenocarpy lines laid a foundation for the basic research of single solidity.

Abstract:Glucosinolates (GSLs) are a type of important secondary metabolites in cruciferous plants. GSLs and their degradation products are known with important roles in plant flavor, insect resistance and anti-cancer. Sulforaphane, the degradation product of glucoraphanin (GRA), is one of the most important anti-cancer substances. The BrAOP2 gene is a key factor that modulates the GRA content. To analyze if the GSLs content between the Chinese Cabbage-Cabbage Translocation Line A-4 was different with that of their parent Chinese Cabbage 85-1, 84 selfing progenies plants of A-4 and 85-1 were subjected to measure by High Performance Liquid Chromatography the GSLs content in rosette leaves and heading leaves at rosette, early heading and harvest head stage. The genomic and transcriptional diversity of the BrAOP2 gene were analyzed. The results showed that the average contents of total GSLs, aliphatic GSLs, PRO, GBN, GRA, NAP and GBC of A-4 selfing progenies plants were always higher than those of 85-1 in heading leaves and rosette leaves at all stages. Especially, the highest value on contents were observed in heading leaves at early heading stages. Except the content of NEO, the contents of total GSLs and other GSLs components in heading leaves were higher than those in rosette leaves. The lower expression and SNP/Indels of the BrAOP2 gene in A-4 selfing progenies plants if compared to 85-1 were observed. With these results, it is speculated that the increase on GRA content in A-4 selfing progenies plants associates with the expression of BrAOP2. Collectively, these results provided insights for further analyzing the GRA content in 85-1 and Chinese cabbage-cabbage translocation lines.

Abstract:Apocynum venetum is a crop species with important medicinal value and ecological application potential. However, its breeding and commercial marketing were strictly limited due to the lack of systematic research on its biological characteristics. In order to investigate the geographic distribution of Apocynum venetum resources in the Ili River Valley, and to evaluate the variations on flavonoid content among germplasms and their in vitro antioxidant activity, the germplasm resources in six districts and counties along the Valley were surveyed, and their antioxidant activity of their total flavonoids were evaluated. Apocynum venetum resources were found at 12 sites, with an altitude of 605 to 1376 m. The germplasms showed 75 to 220 cm on plant height, with stem total flavonoid content of 15.92 to 42.31 mg/g (DW), and leaf total flavonoid content of 34.33 to 56.06 mg/g (DW). The total flavonoid content in leaves was higher than that in the stems, while total flavonoid content showed no correlation with either the collection site altitude or plant height (p<0.05). Especially, the samples collected from Apocynum venetum resources in Qapqal Xibe Autonomous County showed that the total flavonoids scavenged 92.97% and 97.40% of DPPH and ABTS radicals with IC50 values of 0.077 mg/mL and 0.143 mg/mL, respectively, and the total antioxidant capacity of T-AOC reached 10.48 μmol/mL. As a result, this study reported the rich genetic diversity on flavonoid content of Apocynum venetum resources in the Ili River Valley, suggesting a potential of their germplasm on genetic improvement and commercial marketing.

Abstract:Increasing yield is one of the major tasks in crop breeding. Evaluation of the yield-related traits of barley cultivars released from the different breeding periods might provide insights in high-yield breeding. In this study, 155 Chinese barley cultivars which include Qingke (hulless barley), malting, and feed barley were evaluated for the phenotypic variations at eight yield-related traits in two environmental conditions. The significant positive correlation among the traits plant height, spike length, and rachis node per spike were observed for malting barley. Spike density significantly negatively correlated with thousand kernel weight in Qingke and malting barley. Overall, the thousand kernel weight of Chinese barley cultivars in the past 30 years showed a gradual increase trend, while the plant height and spike density constantly decreased during the breeding period. Cluster analysis suggested four categories of these cultivars, including high-stalk multi-grain group, mid/dwarf-stalk group, long-spike high-thousand kernel weight group, and long-grain lax-spike group, being coincidence with the breeding targets in production areas. Collectively, the valuation of phenotype changes during barley breeding history and its potential avenues of applications can provide insights for high-yield breeding in different ecological regions in China.

Abstract:To identify elite soybean germplasm resources showing cold tolerance at the seedling stage in the northern part of China’s Heilongjiang Province, in this study 158 soybean germplasm resources from China and Europe were evaluated through a comprehensive analysis of seedling emergence rate, final seedling emergence rate, relative seedling emergence rate, and seedling emergence index under artificial low-temperature stress treatment conditions and early low-temperature stress treatment conditions in the field. With the preliminary results, the relative seedling emergence rate might be deployed as an index for evaluating artificial cold tolerance with an efficiency up to 60%. We suggested four grades with variations on cold tolerance: grade I (high cold tolerance) containing 10 accessions, with a relative seedling emergence rate of 75–100%; grade II (moderate cold tolerance) containing 22 accessions, with a relative seedling emergence rate of 45–75%; grade III (moderate cold sensitivity) containing 33 accessions, with a relative seedling emergence rate of 20–45%; and grade IV (high cold sensitivity) containing 93 accessions, with a relative seedling emergence rate of 0–20%. A highly significant linear positive correlation between the final emergence rate and relative emergence rate in artificial cold tolerance identification experiment was observed, and a significant positive correlation between relative emergence rate and emergence index (EI) in the Heihe experimental site was observed. The European germplasms showed cold tolerance better that of Chinese germplasms. Except one Chinese germplasm (C63, Heihe 5), in six cold-tolerant germplasms five were from Europe (A28, ESSenator; A54, Tajfun; A65, AUGUSTA; A75, GLHermine; A76, Josefine). These cold-tolerant soybean germplasms may provide a material basis for cold-tolerant soybean varieties breeding and mining the functional genes with cold tolerance in the early-maturing cultivation areas of China.

Abstract:To understand the genus Fragaria resources distributed in the south of Qinling Mountain in Hanzhong City, Shaanxi Province of China, the wild strawberries were surveyed during 2019-2021 (latitude, 32°49′46″ to 33°19′38″; longitude, 106°09′23″ to 106°40′23″). The investigation sites include eight villages of three counties (Mengjiahe Village and Wangjiazhuang Village in Lueyang County; Erliba Village and Dashuya Village in Ningqiang County; Liziba Village, Lijiagou Village, Qiuqiya Village and Toudaohe Village in Mi'an County). A total of 57 wild strawberry accessions were collected in this survey. These accessions were identified and classified into three Fragaria species including Fragaria nilgerrensis Schlect., F. chinensis Lozinsk. and F. pentaphylla Lozinsk. (white-fruited), and two types including F. pentaphylla pink-fruited genotype and F. pentaphylla red-fruited genotype through botanical character observation and ploidy identification. Among them, F. pentaphylla was found to be predominant in population. These wild strawberries were found in the vertical space of 849 - 1352 m above sea level, such as mountains, forests, streams, roadsides, barren fields and rock walls. We provided the characters of the collected Fragaria species in detail, and proposed the suggestions on the protection and utilization of local wild strawberry resources.

Abstract:In order to disclose the phylogeny and genetic diversity of wild wolfberry germplasm resources in Ningxia and Shaanxi Province, as well as the mechanism on taste of mature fresh fruits (i.e., bitter and sweet), the substances of wild bitter Lycium, several methods including systematic investigation, SLAF sequencing technology, ultra-high performance liquid chromatography quadrupole time-of-flight high-resolution mass spectrometry (uplc-q / TOF-MS) and ultraviolet wavelength identification were used in this study. The results showed that from Qishan County and Fufeng County in Shaanxi Province to the mountainous area in Southern Ningxia, the Yellow River Ningxia Basin and the eastern foot of Helan, the mature fresh fruits showed a general trend from bitter to half bitter, bitter after sweet (or hemp bitter after sweet), sweet, slightly bitter after sweet and whole bitter then. The phylogenetic tree analysis revealed five groups, consisting of Group I, group II, group III and group IV that were different types of wild bitter wolfberry. Group V was a large number of wild germplasm with a mixture of germplasm showing bitter to sweet taste. There is a genetic diversity in the wild bitter wolfberry ceollection. By analyzing the liquid total ion flow diagram from the four samples (Ningxia sweet wolfberry cultivar ‘Ningqi 7’, ‘Haiyuan wild bitter wolfberry’, ‘Xiji wild bitter wolfberry’ and ‘Shaanxi Qishan wild bitter wolfberry’), we observed an absent signal in the 30-50min region in ‘Ningqi 7’ if compared to other samples. These chemical components mainly were steroidal alkaloids, namely Solanine, and 5,6-dihydrosolanine, which might be causal agents resulting in bitter taste in wild bitter wolfberry. Collectively, these results of this study provided a theoretical basis for in-depth study and utilization of wild bitter wolfberry germplasm and new cultivar breeding for medicine.

Abstract:Conyza blinii H.Lév. (C. blinii) is a plant species with natural wild distribution in Yunnan, Guizhou and Sichuan in China. It’s considered as genuine traditional Chinese medicine, since it has good anti-inflammatory, cough relieving and asthma relieving effects. In order to explore the diversity among wild C. blinii populations, nine samples collected from different regions were analyzed for karyotype, chloroplast genome and phylogeographic structure. The results showed that blinin content, a secondary metabolite of wild C. blinii, was higher in Panzhihua area than that in other areas. C. blinii tenuifolia was identified as diploid species (2n = 2x = 20 = 18m + 2st), and no significant difference in karyotype between populations was detected. Phylogenetic analysis of chloroplast genome showed a close relation with Aster spathulifolius. The cpDNA phylogeographic analysis revealed that Hap1 was an ancestral type. The population expansion in C. blinii was detected, and the genetic diversity was largely contributed by intra-population variations. Collectively, the intra-population variation and environmental factors may lead to the differentiation between populations of C. blinii, thus providing insights for future development and utilization of wild C. blinii resources.

Abstract:The purpose of this study is to identify the QTL associating with low temperature germination（LTG）in rice and screen germplasm resources showing strong cold tolerance during germination, laying a foundation for cold-tolerant germination-related molecular marker-assisted breeding. Fifty-seven rice varieties with strong cold tolerance during germination were obtained by counting the LTG rate of 309 rice core germplasm resources from Guangdong province, China. Using the LTG rate in conjugation with high-density SNP markers, eleven QTL were identified by genome-wide association scanning (GWAS), of which qLTG2-1, qLTG7-1, qLTG7-2 and qLTG10-1 were resided with previously-identified QTL. qLTG11-1, as the most significant newly-identified QTL, was subjected for RNA-seq and qRT-PCR, in order to predict its candidate genes. LOC_Os11g07020, which is found surrounding qLTG11-1, showed different expression patterns in varieties with high and low germination rates during LTG. This gene encodes for a fructose-1,6-bisphosphate aldolase isozyme, which may regulate glycolysis reaction to affect cold tolerance during germination. Collectively, this study identied 57 rice varieties with strong cold tolerance during germination as well as 11 QTL for LTG, which laid a theoretical foundation for molecular marker-assisted breeding of cold tolerance at germination stage.

Abstract:Kernel weight is one of the three elements contributing to the wheat yield, and kernel size is highly correlated with kernel weight. Therefore, the study of kernel size has a great significance to improve the wheat yield. The TaGS2 gene positively regulates kernel size and kernel weight in wheat. In order to further explore allelic variation of TaGS2 gene in wheat, specific primers were designed to amplify the genomic DNA sequence of three TaGS2 homoeologues and identify the polymorphisms in 12 samples of 268 wheat cultivars from the Yellow and Huai wheat regions. A deletion of three nucleotides (CTT) at position 3,002 bp in the fourth exon of TaGS2-2B genomic DNA sequence was detected in some cultivars, resulting in a deletion of one phenylalanine (F) at the 306 position. Both alleles without and with the 3 bp deletion was designated as TaGS2-2B-a and TaGS2-2B-b, respectively. In wheat cultivars carrying TaGS2-2B-a allele, thousand-kernel weight, kernel length, kernel width, kernel area, and kernel circumference were significantly higher than those of wheat cultivars harboring TaGS2-2B-b allele. Collectively, this study provided a relatively superior allele (TaGS2-2B-a) with positive effects in increasing kernel weight in wheat cultivars.

Abstract:Plant height as the main plant architecture trait is closely related with lodging resistance and yield in flax. In order to analyze the genetic mechanism of plant height, in this study, several populations derived from the cross of P.I.250089×Heiya15 were constructed, followed by the genetic analysis using the method of mixed inheritance separation analysis of major gene plus polygene of plant quantitative traits. The quantitative trait (QTL) mapping of flax plant height was performed using RIL population together with BSA method based on the next-generation sequencing technology. The results showed that the plant height of flax was controlled by two pairs of major genes with additive-dominate-epistatic effects plus poly-genes with additive-dominate-epistatic effects. The heritability of the major genes in B1, B2 and F2 generations was 7.68%, 0.0% and 13.86%, and that of polygenes was 70.88%, 0.0% and 0.0% respectively. The inheritance of flax plant height is dominated by epistatic effect of two major genes, followed by additive effect and dominant effect. QTL mapping revealed two candidate gene loci which were on chromosome 14, 5770000 bp-6100000 bp and 6920000 bp-9400000 bp, with interval sizes of 0.33 Mb and 2.48 Mb, respectively, harboring 176 candidate genes. Collectively, our results provided insight for revealing the genetic mechanism of plant height in flax breeding.

Abstract:In order to explore the genetic loci underlying rice appearance quality-related traits , QTL mapping of chalky grain rate, chalkiness degree and grain type phenotypes in recombinant inbred lines were carried out based on the three-year phenotypic datasets (2019-2021). Twelve QTL related to appearance quality traits were identified. Four QTL to chalkiness percentage were located on chromosome 5 and 6 with the contribution rates of 3.53%, 18.32%, 13.97% and 5.62%, respectively. Three chalkiness-related QTL on chromosome 5 and 6 contributed to 15.64%, 12.29% and 6.27% of phenotypic variation. Five QTL were identifed on chromosome 5 and 12 with the contribution rates of 42.56%, 46.75%, 55.50%, 3.86% and 4.30%, respectively. The genetic interval (0.833 cM) between the markers Marker49932 and Marker160033, where three QTL qCGP-5-2, qCGP-5-3 and qCGG-5-1 of chalkiness rate and chalkiness degree were resided, contributes >10% of phenotypic variation. The locus in Marker49932-Marker160033 interval is a new QTL for chalky grain rate and chalkiness, which can be further delimited in a higher resolution and might be of great significance in rice quality breeding.

Abstract:Peanut is one of the important oilseed crops in China. Breeding for high yield is an important target. Seed size and shelling percentage are the factors effecting of peanut yield. QTL mapping for seed size and analyzing its relationship with shelling percentage will lay a foundation for high yield molecular breeding. In this study, the seed size of a recombinant inbred line (RIL) population (Xuhua 13 × Zhonghua 6) were investigated at three consecutive years. The seed length (SL), seed width (SW), and hundred seed weight (HSW) were variable in RIL population, and a significant positive correlation was detected among them. 52 QTL were detected with 3.09%-17.34% phenotypic variations explained (PVE), of which qSLA05.2 and qHSWA05.2, qSWA07.1 and qHSWA07 are co-localized and they can be repeatedly detected in multiple environments. Favorable alleles of qHSWA05.2 and qHSWA07 were derived from the female and male parents, respectively. A combination of the two favorable alleles using the linked markers was verified to increase hundred seed weight by 33.80±1.19g in the RIL population. In conjugation with the QTL mapping result of shelling percentage, co-localized QTL and specific QTL for either trait were found. Collectively, this study laid a foundation for future fine mapping, molecular marker-assisted breeding and synergistic improvement of high yield in peanut.

Abstract:In order to understand the molecular genetic mechanism of yield-related traits and identify markers/genes in sunflower, QTL mapping and candidate gene identification of yield-related traits were performed using 150 individuals derived from recombinant inbred line (RIL) population of K55×K58 combination. The phenotype data at two environmental conditions in 2019 and 2020 were producted, and the high-density linkage map of SNP molecular markers were deployed. The results showed that nine QTL (LOD≧2) for 8 traits including plant height, stem thickness, number of leaves, number of grains particles, grain weight, number of empty grains particles, 100-seed weight, and seed setting rate were detected, in which QTL loci at stem diameter (Qsd17, Qsd9) and 100-grain weight (Qhgw8 and Qhgw5) were detected at two environmental conditions. A multi-genic effect site (Qsd17, Qngp17) controlling the number of grains and stem thickness was detected. These QTL loci were found on chromosomes 4, 5, 7, 9, 13, 14, 16 and 17, and the contribution rate of phenotypic variation was 0.265%-13.075%. There were two main effect loci (Qngp17 and Qhgw8) with phenotypic contribution over 10% on chromosome 17. Fourteen candidate genes were annotated in QTL loci with stable or main effect (PVE>10%), These genes are involved in carbohydrate processes and cell wall/membrane/envelope biogenesis, and annotated such as NADH dehydrogenase, E3 ubiquitin protein ligase, SAUR family proteins, MADS-box transcription factors, MYB family transcription factors. Collectively, these results might provide theoretical basis for sunflower high-yield breeding.

Abstract:The DUF761 family members contain a domain of unknown function (DUF) protein in plants, and these functions in rice remain un-described. In this study, 33 family members in rice genome have been identified by bioinformatics pipeline. Phylogenetic analysis suggested three subfamilies, while Motif-1, a conserved motif was present in each member of each subfamily. Fifteen types of cis-acting elements related to stress response, hormone response and development were found in the promoters of these OsDUF761 genes. The promoters of 30 OsDUF761 genes contain the ABRE element (abscisic acid response), and the promoter of a member OsDUF761-21 contains 16 ABRE elements. Tissue expression profile analysis showed that OsDUF761 gene members represented similar or distinct tissue expression profile patterns in rice. The transcriptional expression levels of 12, 13, 24, 24 and 18 OsDUF761 genes in rice were significantly changed after ABA, JA, low temperature, drought and rice blast treatments, respectively. Eight genes showed a common significant up- or down-regulation response trend after ABA treatment and drought treatment. Six genes showed a common response trend after JA treatment and M. oryzae treatment. Collectively, by conducting a comprehensive analysis of the rice DUF761 gene family members, this study provided insights for future deciphering their biological functions in rice.

Abstract:The FvC5SD gene from Flammulina velutipes was transformed into soybean cultivar Shennong 9 by Agrobacterium mediated genetic transformation of soybean cotyledon nodes. The transgenic soybean line FvC5SD-L05 showed good drought tolerance and agronomic performance. To clarify the characteristics of the transgenic soybean FvC5SD-L05 material meeting its biosafety evaluation, we analyzed the copy number of FvC5SD gene in T4 generation plant, by Southern hybridization and identified the position and direction of the insert in soybean genome. Meanwhile, by PCR amplification of the flanking sequences of exogenous T-DNA, we established a specific qualitative PCR detection method for FvC5SD-L05. This method represents specificity with high sensitivity, e.g. being able to detect transgenic fragment in the template with FvC5SD-L05 genomic DNA content of 0.1%. The specific detection of FvC5SD-L05 provided technical basis to identify the transgenic soybeans with the target gene.

Abstract:In this study, we generated a mutant population of tartary buckwheat cultivar 'Chuanqiao 2' treated by 50 mmol ethyl methanesulfonate (EMS) solution. We recorded the phenotypic variations of M2 to M3 lines, and also measured the content of chlorophyll and anthocyanin in the mutant plants with leaf and stem color variation in the M3 population as well as the transcription level of flavonoid synthesis and metabolite related genes (CHS, F3H, F3'H, FLS and UFGT). 177 mutant plants showing alternations on stem and/or leaf morphology and/or growth stages were found in M2 population with a mutation rate of 10.56%. 665 mutant plants in M3 population were found, including leaves, growth stages, stems, and other types of mutant plants, accounting for 45.86% of the M3 population. We also observed that the shape, color and size of grains in M3 generation changed in varying degrees. We found that the change trend of chlorophyll and anthocyanin content in plants with color variation were almost the same, the content of the red plant at the base of the leaf was higher than that of the normal plant, and the content of the other types of mutant plants were lower than that of the normal plant. Among them, the yellow-green spotted leaf had the lowest content. We also found that CHS and F3H genes had the highest expression level in red stem plants, the FLS genes had the highest expression level in yellow leaf plants, and the expression of F3'H was higher in the two types of plants with red leaf than the other types, and the content was the highest in the plants with the leaf edge turned red. It is speculated that leaf and stem color variations in the M3 population may be contributed by the expression of flavonoid synthesis-related genes. Collectively, these mutants gained from this study provided the basic material for future deciphering the rutin metabolism mechanism.

Abstract:SSI and GSI in self-incompatibility (SI) plant are mainly controlled by S locus. Camellia oleifera belongs to Late-acting self-incompatibility (LSI) plant, and its self-incompatibility has become a limiting factor to the development of Camellia oleifera industry. To investigate the molecular mechanism of LSI in Camellia oleifera, we designed primers for five S-RNase (CoS-RNase) genes sequences derived from the preliminary study of the annotated genome-wide data of elite variety called‘Huashuo’ and the pistil transcriptomic data of camellia oleifera. By PCR amplification of CoS-RNases f exons rom 10 camellia oleifera varieties, in conjugation with the full-length cDNA of pistil -CoS-RNase, 28 CoS-RNase alleles were annotated. The CoS-RNase gene contains 4 exons and 3 introns, with the cDNA complete sequence of 1141 bp which contains an open reading frame of 717 bp encoding for 238 amino acids. Phylogenetic analysis revealled the highest similarity (98.6%-98.8%) between CoS-RNase with CsS-RNase of tea plant. The CoS-RNases possessed two conserved domains and active sites of T2 RNase protein family, and had the same action sites as in S-RNase of apple and pear: a histidine (His, (His, 119 bit)) site that degraded RNA and a proline (Pro, 156’) site that depolymerized actin. In vitro recombinant protein studies indicated that the recombinant protein CoS-RNase had RNase activity and inhibited pollen tube growth. qRT-PCR analysis showed CoS-RNase was rarely expressed in the pollen while expressed in all other tissues. Morever, the expression pattern of CoS-RNase in styles and in ovaries respectively after self-pollination and outcrossing were consistent with pollen tube growth law. These results implied CoS-RNase as an important factor involved in the SI reaction in Camellia moleifera. Collectively, this study provided a theoretical basis for future deciphering the molecular regulation of self-incompatibility in Camellia oleifera.

Abstract:The National Wild Plant Germplasm Resource Center(NWPGRC) is one of the 31 national biological germplasm and experimental materials platforms established by the Ministry of Science and Technology and the Ministry of Finance. At present, 11 domestic research institutes and universities engaged in the collection and preservation of wild plant germplasm resources participate in the construction. In order to realize the collaborative work of all participating units in data exchange, resource sharing and statistical analysis of wild plant germplasm resources, The Germplasm Bank of Wild Species with the Science and Technology Information Center, Kunming Institute of Botany, Chinese Academy of Sciences first analyzed the needs of the shared service platform, and then designed the architecture, functional modules, core business processes and databases of the platform. Based on the ASP.NET MVC framework, the shared service platform of NWPGRC was realized by using data quality assurance technology, interconnection technology, authority control technology and security technology. The platform can effectively control the data quality of germplasm resources, realize the data interaction with relevant platforms such as China Science and technology resources sharing network, meet the more complex requirements of authority allocation, and the security of the platform is high. It not only promoted the cooperative work of the participating units in the collection, treatment, preservation and distribution of wild plant germplasm resources, but also provided a convenient way for the vast number of scientific and technological workers to obtain the material objects and data of wild plant germplasm resources, and promoted the sharing of national scientific and technological resources, especially plant genetic resources represented by seeds. It plays an important role in improving the development and utilization of national strategic biological resources. In addition, the design and implementation method of the platform can also provide reference for the construction of resource sharing service platforms in other fields.