Assessments of genetic diversity and anthracnose disease response among Zimbabwe sorghum germplasm

The USDA‐ARS National Plant Germplasm System maintains a Zimbabwe sorghum collection of 1235 accessions from different provinces. This germplasm has not been extensively employed in US breeding programmes due to the lack of phenotypic and genetic characterization. Therefore, 68 accessions from Zimbabwe were phenotyped, and evaluated for their anthracnose response for two consecutive years, and genetically characterized with 21 simple sequence repeat markers. Phenotypic analysis showed significant differences among accessions with plant height and panicle length being the most variable traits. Likewise, 25 accessions were anthracnose resistant, nine showed variable responses and 34 were susceptible. Genetic analysis identified 174 alleles with an average of 8.3 alleles and 11.8 genotypes per locus and a polymorphic information content of 0.60. These results reflect a moderate genetically diverse germplasm. Neighbour‐joining clustering analysis revealed that the majority of anthracnose‐resistant accessions showed high genetic relatedness; therefore, this germplasm might represent one to six new sources of resistances. Results presented herein show that the Zimbabwe collection contains valuable germplasm for breeding programmes and is an important source of anthracnose resistance.     

普通菜豆抗炭疽病基因SCAR标记鉴定

利用12个菜豆品种（鉴别寄主）评价了7个抗炭疽病基因SCAR标记的可靠性和实用性,其中SBB14_1150/1050标记引物扩增没有特异性,SAS13₉₅₀没有扩增带。用5个可靠的菜豆抗炭疽病基因SCAR标记（SCAreoli₁₀₀₀、SH18₁₁₀₀、SAB3₄₀₀、SB12₃₅₀ 和SCF10₁₀₇₂）,对127份普通菜豆抗炭疽病品种进行抗炭疽病基因分子标记鉴定,82份未检测到SCAR标记,45份分别含有1~3个SCAR标记;检测到SCAR标记的资源中,13份含有SCAreoli₁₀₀₀标记,13份含有SH18₁₁₀₀标记,5份含有SAB3₄₀₀标记,9份含有SB12₃₅₀标记,11份含有SCF10₁₀₇₂标记。分析表明抗病品种含有的抗病基因标记与品种来源存在相关性。     

Identification of quantitative trait loci associated with resistance to foliar diseases in sorghum [<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench]

Forage sorghum cultivars grown in India are susceptible to various foliar diseases, of which anthracnose, rust, zonate leaf spot, drechslera leaf blight and target leaf spot cause severe damage. We report here the quantitative trait loci (QTLs) conferring resistance to these foliar diseases. QTL analysis was undertaken using 168 F₇ recombinant inbred lines (RILs) of a cross between a female parental line 296B (resistant) and a germplasm accession IS18551 (susceptible). RILs and parents were evaluated in replicated field trials in two environments. A total of twelve QTLs for five foliar diseases on three sorghum linkage groups (SBI-03, SBI-04 and SBI-06) were detected, accounting for 6.9–44.9% phenotypic variance. The morphological marker Plant color (Plcor) was associated with most of the QTL across years and locations. The QTL information generated in this study will aid in the transfer of foliar disease resistance into elite susceptible sorghum breeding lines through marker-assisted selection.     

Unveilingsources of stripe rust resistance in diverse wheat (<Emphasis Type="Italic">Triticum Aestivum</Emphasis> L.) germplasm using narrow down methodology: a proof of concept

Stripe rust of wheat caused by the fungal pathogen is a destructive foliar disease of wheat. Thus, it is crucial step to characterize the resistant germplasm for stripe rust in a diverse germplasm pool for their ultimate utilization in efficient crop rust resistance breeding. In the present study, we followed two pronged strategies involving integrated phenotypic and molecular characterization of 440 diverse wheat germplasm lines for rust resistance. The germplasm panel was extensively evaluated in field epiphytotic conditions during two consecutive years. After rigorous screening, 72 accessions were successfully revealed as resistant to moderately resistant to stripe rust. Subsequently, entries were then evaluated for their field agronomicperformances, considering prerequisites for serving as a donor germplasm,particularly for yield and 33 potential rust-resistant accessions were identified. Furthermore, to detect the sources of resistance, accessions were molecular characterized for potential race-specific resistance genes Yr5, Yr10,Yr15, and effective adult plant resistance (APR) gene Lr34/Yr18/pm38. We identified the 22 accessions possessing one or more single resistance genes and two accessions were observed with at least three of them. Moreover, Lr34/Yr18/pm38 was determined to confer resistance when observed along with any of the race-specific genes. Thus, the study not only provides proof of concept methodology to identify candidate resistant sources from large germplasm collections but simultaneouslyconfirmed the contribution of combining race-specific andnon-specific APR genes. The finding could further assist in the potential deployment of resistant genes directly into the stripe rust breeding program by involving marker-assisted approaches.     

Identification of resistance to rust (Uromyces appendiculatus) and powdery mildew (Erysiphe diffusa) in Portuguese common bean germplasm

Portugal has a diverse common bean germplasm, which is still grown in farmers' fields. In this work, we searched for resistance to rust (Uromyces appendiculatus) and powdery mildew (Erysiphe diffusa) in a representative collection of the Portuguese common bean germplasm. Despite many accessions depicting intermediate levels of resistance when compared to the susceptible check, 24 and 13 accessions showed low levels of infection, in spite of a compatible interaction (disease severity (DS) values lower than 5% and infection type (IT) of 4), to rust and powdery mildew, respectively, indicative of partial resistance. Moreover, a resistant reaction was observed in 11 accessions when inoculated with powdery mildew (IT = 0–1) and in additional 11 accessions (one in common) when inoculated with rust (IT = 0–2). The levels of resistance found in this report anticipate great potential of the Portuguese national germplasm, recently reported as genetically closer to the Andean common bean gene pool, for disease resistance breeding of this important crop.     

Genetic Diversity of Farmers’Preferred Sorghum Accessions and Improved Lines from ICRISAT Reveal a Disconnect Between Innovation and Technology Transfer

The genetic diversity of 65 accessions of sorghum [Sorghum bicolor (L.) Moench] collected from various farmers and germplasm lines from ICRISAT-Kenya were analyzed. Simple sequence repeats (SSR) markers were used in order to determine the extent and distribution of its genetic diversity. Twenty-nine (29) SSRs markers were polymorphic and a total of 192 alleles were detected which showed diversity. The number of alleles per primer ranged from 2 to 17, with an average of 6.62. The range of polymorphism information content (PIC) ranged from 0.03 to 0.86, with total average of 0.82. According to the results analyzed, estimates of the mean allelic pattern across the two populations was generated; expected heterozygosity (He; 0.45, 0.54), average observed alleles (Na; 3.40, 6.20), number of private allele (0.23, 3.03), and Shannon information index (I; 0.85, 1.13) for farmer and ICRISAT-Kenya germplasm, respectively. The expected heterozygosity (He) varied from 0 to 0.26 with an average of 0.05. The Neighbor-joining phenogram based on Nei’s genetic distance grouped the 65 accessions into three main groups. The analysis of molecular variance (AMOVA) revealed that 99% of the total genetic variation was within accessions in a population whereas the genetic variation among populations in accessions accounted for 1% of the total genetic variation. Genetic diversity in ICRISAT sorghum material compared to the farmer’s collection suggested little infiltration of improved germplasm to the farmers.     

Analysis of the molecular diversity of Kenyan sorghum germplasm using microsatellites

The aim of this study was to estimate the extent of the genetic diversity present in sorghum germplasm grown in Kenya using simple sequence repeat markers. A total of 139 accessions were genotyped using 11 microsatellite markers or simple sequence repeats (SSRs) and the genetic diversity was estimated. The markers showed a wide range of differences in quality index from 0.005 to 0.39. The average Polymorphic Information Content value observed was 0.6241 indicating a high level of diversity. The gene diversity index ranged between 0.2419 and 0.9313 with a mean of 0.6627 per locus. A total of 105 alleles were observed with an average of 10.4 alleles per locus. The average heterozygosity level per locus was low at 0.1717. The variability within accessions among the populations was 74.85% and within individual accessions was 18.67%. The results showed that genetic diversity within Kenyan sorghum germplasm accessions is higher than that between the different populations. It is implied that such genetic diversity can be exploited as such or in hybridization programs to improve sorghum varieties currently grown by subsistence farmers in Kenya.     

Survey of the Bru1 gene for brown rust resistance in Brazilian local and basic sugarcane germplasm

Bru1 is currently the major gene conferring brown rust resistance in sugarcane, and diagnostic markers are available. A survey for the presence of this gene was conducted on 391 genotypes including Brazilian cultivars, clones and basic germplasm. The efficiency of these markers for identifying resistant cultivars and artificially inoculated basic germplasm was also evaluated. The Bru1 frequency among cultivars (73.5%) suggests this gene is the prevalent source of brown rust resistance in Brazilian sugarcane breeding programmes. Most of the cultivars known to be resistant were positive for Bru1, although other genes for resistance could be present in lines not having Bru1. Only 17.8% of the basic germplasm accessions were positive for the Bru1 gene, and a low correlation between Bru1 diagnostic markers and brown rust severity was observed for basic germplasm accessions. Overall, Bru1 diagnostic markers proved to be efficient identifying resistant cultivars and clones and have potential to be in screening brown rust resistance in Brazilian breeding programmes.     

Identification and characterization of RAPD and SCAR markers linked to anthracnose resistance gene in sorghum [Sorghum bicolor (L.) Moench]

Anthracnose, one of the destructive foliar diseases of sorghum growing in warm humid regions, is incited by the fungus Colletotrichum graminicola.The inheritance of anthracnose resistance was studied using the parental cultivars of Sorghum bicolor (L.) Moench, HC 136 (susceptible to anthracnose) and G 73 (anthracnose resistant). The F₁ and F₂ plants were inoculated with the local isolates of C. graminicola cultures. The F₂ plants showed a segregation ratio of 3 (susceptible): 1(resistant) indicating that the locus for resistance to anthracnose in sorghum accession G 73 segregates as a recessive trait in a cross to susceptible cultivar HC 136. RAPD (random amplified polymorphic DNA) marker OPJ 01₁₄₃₇ was identified as marker closely linked to anthracnose resistance gene in sorghum by bulked segregant analysis of HC 136 × G73 derived recombinant inbred lines (RILs) of sorghum. A total of 84 random decamer primers were used to screen polymorphism among the parental genotypes. Among these, only 24 primers were polymorphic. On bulked segregant analysis, primer OPJ 01 amplified a 1437 bp fragment only in resistant parent G 73 and resistant bulk. The marker OPJ 01₁₄₃₇ was cloned and sequenced. The sequence of RAPD marker OPJ 01₁₄₃₇ was used to generate specific markers called sequence characterized amplified regions (SCARs). A pair of SCAR markers SCJ 01-1 and SCJ 01-2 was developed using Mac Vector program. SCAR amplification of resistant and susceptible parents along with their respective bulks and RILs confirmed that SCAR marker SCJ 01 is at the same loci as that of RAPD marker OPJ 01₁₄₃₇ and hence, is linked to anthracnose resistance gene. Resistant parent G 73 and resistant bulk amplified single specific band on PCR amplification using SCAR primer pairs. The RAPD marker OPJ 01₁₄₃₇ was mapped at a distance of 3.26 cM apart from the locus governing anthracnose resistance on the sorghum genetic map by the segregation analysis of the RILs. Using BLAST program, it was found that the marker showed 100 per cent alignment with the contig{_}3966 located on the longer arm of chromosome 8 of sorghum genome. Therefore, these identified RAPD and SCAR markers can be used in the resistance-breeding program of sorghum anthracnose by marker-assisted selection.An erratum to this article can be found at     

Genetic Divergence and Molecular Characterization of Sorghum Hybrids and their Parents for Reaction to Atherigona Soccata (Rondani)

Summary Simple sequence repeat (SSR) markers linked to quantitative trait loci (QTL) associated with resistance to sorghum shoot fly, Atherigona soccata resistance were used to characterize the genetic and phenotypic diversity of 12 cytoplasmic male-sterile (CMS) and maintainers, 12 restorer lines, and 144 F₁ hybrids. The genetic diversity was quite high among the shoot fly-susceptible parents and the hybrids based on them, as indicated by high polymorphic information content (PIC) values, while limited genetic diversity was observed among shoot fly-resistant lines. The phenotypic and genotypic dissimilarity analysis indicated that the shoot fly-resistant and -susceptible parents were 73.2 and 38.5% distinct from each other, and the morphological and genetic distances of certain resistant and susceptible cross combinations was more than their resistant or susceptible parents. Genetic variability among the groups was low (10.8%), but high within groups (89.2%). The genetic and morphological distances suggested that the F₁ hybrids were closer to CMS (5 to 12% dissimilar) than the restorer (11 to 87% dissimilar), suggesting that CMS influences the expression of resistance to sorghum shoot fly. The SSR markers can be used to characterize the homologous traits in sorghum germplasm.     

利用荧光SSR分析中国糜子遗传多样性

分析糜子种质资源的遗传多样性,有助于了解糜子起源与进化,可为糜子优异种质发掘及资源高效利用提供理论基础。本研究利用15个糜子特异性荧光SSR标记检测来源于中国11个省(区)的132份糜子种质资源,检测到107个等位变异,每个位点等位变异数为2~14个,平均7个;基因多样性指数为0.0936~0.8676,平均0.5298;多态性信息含量为0.0893~0.8538,平均0.4864。采用遗传距离的聚类将试验材料分为4类,类群I来自东北春糜子区,类群II来自黄土高原春、夏糜子区,类群III来自于北方春糜子区,类群IV来自北方春糜子区和黄土高原春、夏糜子区。分析模型的遗传结构表明,中国糜子资源来自4个(东北地区、黄土高原、北方地区和西北地区)基因库,与基于遗传距离的聚类结果基本一致,均与材料的地理起源相关。糜子遗传变异丰富,主要存在于糜子材料间。该结果从分子水平上准确揭示了中国糜子的遗传多样性。     

玉米种质资源大规模多年多点多病害的自然发病抗性鉴定

病害是影响玉米生产的重要因素。利用品种的抗性是控制玉米病害的经济、安全和有效措施。2016—2019年间,在黄淮海和东华北地区,首次对2000份来源广泛且遗传背景丰富的玉米种质资源进行了多年多点多病害的田间自然发生条件下抗病性鉴定,部分材料在西北地区也进行了田间鉴定,重点调查了小斑病、茎腐病、瘤黑粉病、弯孢叶斑病、南方锈病、粗缩病、大斑病、灰斑病和丝黑穗病的抗病性。综合4年共10个不同环境的自然发病下抗性鉴定数据表明,自然发病鉴定的结果受环境因素影响较大,表现为年度间和地域间的差异。在所有鉴定的病害中,小斑病在多个年份和多个鉴定点的发病均比较充分, 11份种质对该病害表现出稳定抗性;茎腐病、大斑病和灰斑病,在不同年份的部分鉴定点发病较为充分,对这3种病害表现抗病的种质分别为440、356和423份,综合抗性鉴定结果具有较大的参考价值;弯孢叶斑病、瘤黑粉病和粗缩病仅在1个鉴定点发病较为充分,南方锈病和丝黑穗病在所有鉴定点均发生较轻,鉴定结果有待进一步验证。本研究筛选出一批在不同环境条件下对多种病害均具有稳定抗性的材料,其中JN15、953、沈977、68122、K21、SC24-1、17...     

Molecular characterization of taro (Colocasia esculenta) using RAPD markers

Forty-four taro (Colocasia esculenta), two tanier (Xanthosoma species) and one Colocasia gigantea accessions were evaluated for genetic diversity using random amplified polymorphic DNA (RAPD) primers. Seventy-three of 112 primers amplified PCR DNA products used to fingerprint the accessions. Thirty-two primers were considered highly informative because they amplified more than 5 bands or amplified one or more polymorphic bands that distinguished between accessions. RAPDs showed high genetic diversity in taro accessions from Indonesia, were capable in distinguishing between Hawaiian accessions, and could separate triploid from diploid accessions. UPGMA cluster analysis of genetic similarity estimates (Jaccard's coefficient), separated the accessions into 3 main groups with C. esculenta divided into 5 subgroups. These primers will be useful for future genetic analysis and provide taro breeders with a genetic basis for selection of parents for crop improvement. Polymorphic markers identified in the DNA fingerprinting study will be useful to screen a segregating population which is being generated in our laboratory aimed at developing a taro genetic linkage map. This revised version was published online in July 2006 with corrections to the Cover Date.     

31份甘蔗野生核心种质资源褐锈病抗性鉴定及Bru1基因的分子检测

为明确甘蔗野生资源对黑顶柄锈菌的抗性水平,了解Bru1基因在甘蔗野生资源中的分布状况,于2013年对中国国家甘蔗种质资源圃保存的31份野生核心种质资源进行苗期抗褐锈病鉴定和抗褐锈病基因Bru1的分子检测。结果表明,31份供试材料中,高抗(1级)至中抗(3级)的有28份,占90.3%。其中19份材料表现高抗(1级),占61.3%,3份材料表现抗病(2级),占9.7%,6份材料表现中抗(3级),占19.4%。31份供试材料中只有贵州78-2-12、云南97-4、E.rockii95-19、E.rockii 95-20、云南83-224、广西79-8、云南95-35和广西89-13含抗褐锈病基因Bru1,占参试材料的25.8%;其余20份抗病材料和3份感病材料均不含抗褐锈病基因Bru1,表明除Bru1外,可能还有其他抗褐锈病基因存在。结果暗示中国国家甘蔗种质资源圃保存的野生核心种质资源中蕴藏着优良的抗褐锈病基因,是选育抗褐锈病甘蔗品种很有利用前景的抗源种质。     

Genetic variation of grain sorghum germplasm for resistance to Pseudomonas andropogonis

Pseudomonas andropogonis is the causal agent of bacterial leaf stripe of sorghum (Sorghum bicolor (L.) Moench). Fifty grain sorghum accessions were evaluated for genetic variation to P. andropogonis over a 2-year period. Plants were inoculated at the 7 to 8 leaf stage of juvenile growth with an Idico filler-plug gun calibrated to deliver one ml of inoculum. Disease severity ratings were noted 2 weeks after inoculation on a 0 to 5 scale. For 1993 and 1994, disease severity ratings were significantly different (P < 0.01) among accessions and groups of resistant, intermediate, and susceptible germplasm. Significant differences (P < 0.05) were also observed between years. Resistant accessions included SC 326-6, SC 414-12E, BTX 378, B35-6, and TX 2862. Susceptible entries included TX 2767, TX 430, TAM 428, BTx 623, R 9117, and 90B2662. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic relationship analysis and molecular fingerprint identification of the tea germplasms from Guangxi Province,China

The tea plant (Camellia sinensis) is an evergreen woody plant with a high economic value. Guangxi Province is adjacent to the origin center of the tea plant in southern China. It has abundant germplasm resources and is a historically important tea-producing province. However, there is little information about the genetic diversity, genetic introgression, and fingerprints of the tea germplasms from Guangxi Province. Here, we constructed a phylogenetic tree of 126 tea accessions from Guangxi Province using 20 SSR markers. This tree classified these tea accessions into three subgroups containing 19, 47, and 60 members, respectively. High genetic similarity was observed among the three subgroups, and the genetic diversity of the populations was ranked as follows: subgroup 3 > subgroup 2 > subgroup 1. Furthermore, we analyzed the genetic relationships among 168 tea accessions from Guangxi Province and neighboring provinces. The results of the population structure analysis were highly consistent with the clustering results, and genetic introgression was observed. We identified six SSRs as the core marker set, because they could sufficiently distinguish between all 126 tea accessions. The results provide a crucial theoretical basis for utilization and protection of tea germplasms from Guangxi Province, and will help improve the breeding and popularization of elite tea cultivars.     

Pre and posthaustorial resistance to rusts in <Emphasis Type="Italic">Lathyrus cicera</Emphasis> L.

Lathyrus cicera has a high potential as fodder crop in dry areas, but can in particular environments be damaged by rust. Little is known on the availability of resistance against rust fungi and the underlying mechanisms in L. cicera germplasm. The present study assessed and characterised macro and microscopically the resistance to rust fungi Uromyces pisi and U. viciae-fabae, in a collection of L. cicera accessions. A wide range of disease reaction was found in the germplasm collection against the different rust species. L. cicera accessions were highly resistant to U. viciae-fabae being hypersensitive response the most frequent reaction. On the contrary, most accessions showed a compatible interaction with U. pisi, with varying levels of partial resistance, although cases of hypersensitivity were also identified. Differences on germination, orientated germ tube growth and appressoria differentiation were observed but were in general of marginal importance to explain the resistance to U. pisi among the L. cicera accessions. Resistance was due, to a combination of pre and post-haustorial mechanisms.     

Study of genetic diversity in Indian and exotic sesame (Sesamum indicum L.) germplasm using random amplified polymorphic DNA (RAPD) markers

Fifty-eight accessions of sesame (Sesamum indicum L.), an important oil seed crop of the tropics and subtropics were analysed using random amplified polymorphic DNA (RAPD) technique. The material analysed comprised 36 collections from 18 different states of India and four adjoining countries of the Indian subcontinent, and 22 exotic accessions from 21 sesame growing countries around the world. The results from PCR amplifications with the selected 24 random 10-mer primers were statistically analysed. The value of Jaccard’s similarity coefficients ranged from 0.19 to 0.89. The results indicated the presence of high level of genetic diversity. However, the extent of genetic diversity was greater in the collections from Indian subcontinent as compared to the exotics. Among the Indian accessions, the collections from Rajasthan and North-eastern states were highly diverse. The phenetic analysis grouped 48 out of 58 accessions in six clusters and the remaining highly diverse accessions were placed outside these close-knit clusters. The Bootstrap estimates obtained by Wagner parsimony analysis were significant for seven out of 49 nodes in the majority-rule consensus tree (<95% occurrence). The results of both the analyses were, however, broadly comparable when the constitution of the individual clusters were considered. The principal components analysis indicated that the first two components accounted for only 21% of the total variations and in order to explain <75% of variations 18 components were required. The high level of genetic diversity prevalent among the Indian collections is probably indicative of the nativity of this crop species. Similarly, the relatively lower level of polymorphism in exotic germplasm could be ascribed to the comparatively recent introductions of limited germplasm of this crop into some of the non-traditional sesame growing countries. This revised version was published online in August 2006 with corrections to the Cover Date.     

Bru1 gene and potential alternative sources of resistance to sugarcane brown rust disease

Brown rust, caused by the fungus Puccinia melanocephala, is responsible for important yield losses in sugarcane production globally and it is therefore an important objective to introduce resistance to this disease in breeding programs. A major gene, Bru1, has been shown to confer resistance to P. melanocephala strains from different parts of the world and two molecular markers, R12H16 and 9O20-F4, closely associated to this gene have been previously reported. The usefulness of these molecular diagnostic markers in order to predict a rust resistant phenotype under natural high pressure inoculums conditions was analyzed. A total of 129 sugarcane accessions were evaluated under field infection for resistance or susceptibility to brown rust and subsequently screened for presence or absence of the two Bru1 diagnostic markers. A total of 49 genotypes (38 %) were phenotyped as resistant to brown rust but only eight (16.3 %) of them were harboring the Bru1 gene. To determine overall frequency of the Bru1 in the local sugarcane germplasm collection, 190 additional genotypes were examined. Presence of Bru1, as determined by the diagnostic markers, was detected in only 7 % of the genotypes evaluated. In conclusion, Bru1 diagnostic markers enable positive selection for brown rust resistance in sugarcane and moreover allowed detecting at least one additional source(s) of resistance. Interestingly, whilst only little genetic variability of rust resistance independent of Bru1 has been reported previously, this alternative genetic resource(s) found in our local germplasm constitutes the predominant one and should be helpful in order to amplify the narrow genetic basis for brown rust resistance in sugarcane.     

基于SNP和InDel标记的巴西木薯遗传多样性与群体遗传结构分析

为了对巴西木薯种质资源进行遗传多样性、亲缘关系和群体遗传结构分析,本研究利用了7946个SNPs和1997个InDels分子标记,通过ADMIXTURE软件进行群体结构分析、GCTA软件进行主成分分析。结果显示,巴西木薯被划分为9个亚群。这与利用PHYLIP进行的聚类分析结果大概一致,其中亚群1、亚群2、亚群4、亚群6和亚群8能较好地分别聚在一起,而其他亚群中的样品大致能聚在一起,且样品间有一定的交叉。巴西木薯种质资源遗传多样性指数(0.274)高于中国、尼日利亚等,其中巴西木薯亚群5具有相对较高的遗传多样性水平(0.29)。巴西木薯各亚群的群体遗传分化程度较低(群体分化指数在0.03~0.15之间),但高于中国木薯种质资源的群体分化指数。各木薯材料间的遗传距离变幅为0.084~0.297,平均遗传距离为0.228。本研究结果可为后续关联分析发掘优良等位基因及引种提供依据。