云南薏苡种质资源农艺性状的主成分和聚类分析

为了揭示云南薏苡种质资源多样性,发掘薏苡资源中的有益基因,利用主成分分析和聚类分析,对收集的65个薏苡种质资源的13个农艺性状进行多样性评价。结果表明,云南薏苡资源存在丰富的遗传多样性,其中栽培种的分枝数和分蘖数的遗传变异系数分别达到57.4%和47.5%,野生种百粒重的遗传变异系数达到60.4%。应用主成分分析将云南薏苡13个性状简化为7个主成分,其累积贡献率为85.67%,以叶片宽因子贡献率最高,为49%。采用系统聚类分析,将65份供试材料在遗传距离16.21水平上聚为5个大类,可区分为株高较矮叶片较短型、株高较高叶片较长型以及3个特殊型。     

15份多花黑麦草优良引进种质的表型变异分析

多花黑麦草(Lolium multiflorum Lam.)是世界栽培牧草中的优良禾本科牧草。为更好地利用多花黑麦草种质资源,本研究对引自国外的15份多花黑麦草种质的15个形态性状和农艺性状进行了变异系数、相关性分析、主成分分析和聚类分析。结果表明:15份材料间存在较大变异,除单株干重外,其余性状在供试材料间均表现出显著性差异,变异系数范围为10.28%~39.15%,变异系数平均值为19.49%,从小到大依次为小穗数小穗长株高分蘖数千粒重花序长倒二叶长小花数茎粗第一节间长倒二叶宽旗叶宽旗叶长单株干重单株鲜重。主成分结果表明,前5个主成分累积贡献率达到84.51%,第1主成分以株高为主要特征;第2主成分以旗叶和倒二叶长、宽为主要特征;第3主成分以花序长和小花数为主要特征;第4主成分以千粒重为主要特征;第5主成分以产草量为主要特征。15份种质材料经基于欧氏距离的UPGMA聚类分析被划分为3大类,类别间存在较显著的差异,其中第2类因其植株高大、叶片宽大的特点,具备选育高产种质的潜力。     

基于表型性状的孔雀草种质遗传多样性分析

为了了解孔雀草种质间的亲缘关系,提高孔雀草种质的利用效率,从18个形态特征对40份孔雀草种质进行了遗传变异分析、主成分分析及聚类分析。结果表明,孔雀草表型多样性丰富,种质间表型性状变异程度高,变异系数(CV值)范围3.92%~46.25%,以花朵数最大,其次是冠幅和株高;Shannon-Weaver多样性指数则以叶片性状及花性状较高,平均2.0以上。国内种质比国外种质多样性更丰富。通过主成分分析,筛选出对总体方差累计贡献率达78.949%的4个主成分,并筛选出综合性状表现良好的种质10份。参试的40份种质在欧氏距离阈值为7.29处可分为两大类,一类植株生长势较强包含2份种质(水星黄色和橙色);其余38份种质为一类,在欧氏距离阈值为6.0处,又以花色差异可进一步划分为2个类群,说明生长势及花色可作为孔雀草种质依据表型性状分类的重要指标。     

内蒙古78份葱属野生种表型遗传多样性分析

为了揭示内蒙古葱属野生种表型遗传多样性,采用方差分析、主成分分析、聚类分析等方法,对收集的78份野生种的种质资源14个表型性状进行了遗传多样性评价。结果表明:内蒙古葱属野生资源存在丰富的遗传多样性。(1)14个表型性状平均变异系数为43.0%,叶片宽的变异系数最大,为94.7%;种子厚的变异系数最小,为14.6%。14个表型性状在居群间的差异除叶片宽达到显著(P0.05)水平外,其余性状均表现差异不显著;(2)14个表型性状可归成为6个主成分因子,累计贡献率达到80.77%,最大程度上反映了所有78份葱属种质资源的表型特征,在前6个主成分包括的14个农艺性状中的株丛直径、叶片长、叶片宽、单株叶片数、花序长度、花序宽度和种子宽等性状是造成葱属种质资源表型差异的主要因素;(3)14个表型性状间存在显著或极显著的相关性;(4)采用欧氏距离系统聚类法将供试材料分为7大类,78份葱属种质资源基本上按种区分开,并和地理条件有一定的关系,种间和材料间表型差异很明显。本研究为内蒙古葱属资源的利用提供了科学依据。     

内蒙古扁蓿豆野生资源形态学特性研究

对产自内蒙古不同分布区12份扁蓿豆种质资源的12个形态性状进行主成分和聚类分析。结果表明,除荚果形状和种子宽外,其余形态性状在材料间都表现显著差异,扁蓿豆种质资源遗传变异丰富;通过多变量的主成分分析,第一主成分和第二主成分代表了扁蓿豆形态多样性的62.30%,枝条长、叶面积、荚果宽、种子长和千粒重等5个性状是造成扁蓿豆表型差异的主要因素;基于形态性状的聚类分析把12份材料聚为4类,其中第 1类MR-12扁蓿豆资源的株高、枝条长和株丛直径明显高于其他类,叶片大且叶量丰富,营养性状表现良好;结实性状中荚果长和千粒重较大,综合性状表现较好,可以作为合适的材料作为引种驯化和育种的试验材料。     

东北地区野生百合数量分类研究

对中国东北地区6种3变种30份野生百合的23个形态性状进行了研究。结果表明,我国东北地区野生百合种质资源的主要数量性状均有明显差异,其中花柱长和叶宽的变异系数较大,分别为59.49%和54.03%。基于形态性状,把30份野生百合聚类并划分为两大类:第1类为茎粗壮、花朵较大的种类,包括卷丹和毛百合;第2类为花朵相对较小的种类,包括有斑百合、大花百合、细叶百合、垂花百合、大花卷丹、东北百合和朝鲜百合。通过主成分分析,前4个主成分代表了形态分化的82.51%,即叶长和宽、外轮花瓣宽、内轮花瓣长和宽、花蕾长、花柱长、花药长8个性状是其形态分化的主要指标。     

麻楝种子形态和营养特征遗传变异分析

为系统揭示麻楝种源间种子形态和营养成分的变异程度和变异规律,以8个国家26个种源麻楝种子为试验材料,对不同种源麻楝种子的形态特征和营养成分进行比较分析。多重比较结果表明,麻楝种源间种子的长、宽、厚、长宽比、百粒重以及可溶性蛋白质、可溶性糖和淀粉含量差异极显著;相关分析表明,种子百粒重与种子长、种子宽呈极显著正相关,可溶性蛋白质、可溶性糖和淀粉含量与百粒重均呈极显著正相关;主成分分析结果显示,影响麻楝种子品质的第1主成分主要是种子形态性状,即种子长、百粒重和种子宽,第2主成分是种子营养成分;通过分析麻楝种子形态特征及营养成分变异系数可知,麻楝种子形态变异系数大于营养成分变异系数,表明种子形态受外界环境影响较大。通过主成分聚类分析,将26个种源分为2个集群,第1集群包括澳大利亚和马来西亚2个种源,其特点是种子形态较大、百粒较重、养分含量较高;第2集群包括其余24个种源。结合聚类分析和种子形态与地理气候因子相关分析结果可知,麻楝种子形态变异具有一定的地理区域特征,与分布区的自然地理因素有一定的相关性,麻楝分布区南部种子较大而北部种子较小。     

橡胶草及其同域近缘种表型多样性研究

对蒲公英属橡胶草及其同域10个近缘种共13份材料的59个表型性状(数量性状24个,质量性状35个)进行了观测,通过方差分析、因子分析和聚类分析对其形态性状多样性和种间亲缘关系进行研究,以明确各表型性状对种质分类的重要性及其贡献,为橡胶草品种选育及蒲公英属植物的分类和种质资源保存利用提供依据。结果显示:(1)13份蒲公英属种质资源在数量性状上变异系数在7.50%~55.00%之间,平均为28.25%,多样性指数在1.157~2.032之间,平均为1.663,具有丰富的表型多样性。(2)质量性状方面,变异系数的变化范围在20.40%~67.44%之间,多样性指数变化范围在0.271~1.672之间,平均为1.136,总体上是数量性状形态多样性指数大于质量性状。(3)59个性状的主成分分析中前7个主成分的累计贡献率为84.767%,花部形态变异是蒲公英属植物表型分化的主要因素。(4)利用欧氏距离进行的Ward’s聚类分析结果表明,13份材料可分为4大类群,同一地区的大部分种聚在一起,呈现出一定的地域性,亲缘关系较近;但来源于3个居群的橡胶草却被划分在2个类群中,表现出较远的亲缘关系。研究表明,蒲公英属植物种质材料具有丰富的质量和数量性状变异,表型多样性丰富。     

福建省多叶重楼资源调查与分析

目的：探清福建省多叶重楼野生资源及栽培现状，研究其形态遗传多样性，为重楼优良种质筛选提供基础数据。方法：通过文献查阅、访查和野外实地调查等方法，考察福建省多叶重楼资源分布、生态环境及栽培现状。对9个多叶重楼资源的13个形态性状进行变异系数分析、主成分分析及聚类分析。结论：调查发现福建省多叶重楼野生资源稀少，多分布于湿润且隐蔽度较大、通风性好的地带；多叶重楼原始生境伴生喜阴植物。形态多样性分析表明不同资源间变异系数从10.14%～48.05%，综合结果显示花瓣宽等性状是造成表型差异的主要因素。福建省野生重楼资源蕴藏量下降严重，相关部门应加强重楼野生资源保护和大力推广人工种植。     

160份外引鹰嘴豆种质主要农艺性状的遗传多样性分析

对引自国际半干旱热带作物研究中心的160份鹰嘴豆种质资源的13个农艺性状进行了评价鉴定,并筛选了特异种质,为我国鹰嘴豆种质资源创新和品种选育提供参考。结果表明,该批鹰嘴豆种质资源具有较为丰富的遗传多样性,7个数量性状的变异系数由大到小分别为主茎分枝数单株荚数百粒重产量株高单荚粒数生育期,6个质量性状的Shannon多样性指数由大到小分别为粒色株型花色种子表面粒形复叶叶型;产量与粒形、单株荚数极显著正相关,与百粒重显著正相关;前4个主成分的累计贡献率为63.417%,其中第1主成分与产量性状和产量有关,第2主成分与生育期有关,第3主成分与形态性状有关,第4主成分与株高和粒形有关;聚类分析在遗传距离为5时将160份资源分为3个类群,其中第Ⅰ类群的株高较高,第Ⅱ类群的产量较高,第Ⅲ类群的籽粒较大;筛选出63份早熟、矮秆、无分枝、多荚、荚粒数多、大粒、高产的特异种质资源。     

Assessment of the Genetic Diversity of Different Job's Tears (Coix lacryma-jobi L.) Accessions and the Active Composition and Anticancer Effect of Its Seed Oil

Job’s tears (Coix lachryma-jobi L.) is an important crop used as food and herbal medicine in Asian countries. A drug made of Job’s tears seed oil has been clinically applied to treat multiple cancers. In this study, the genetic diversity of Job’s tears accessions and the fatty acid composition, triglyceride composition, and anti-proliferative effect of Job’s tears seed oil were analyzed using morphological characteristics and ISSR markers, GC-MS, HPLC-ELSD, and the MTT method. ISSR analysis demonstrated low genetic diversity of Job’s tears at the species level (h = 0.21, I = 0.33) and the accession level (h = 0.07, I = 0.10), and strong genetic differentiation (G_ST = 0.6702) among all accessions. It also clustered the 11 accessions into three cultivated clades corresponding with geographical locations and two evidently divergent wild clades. The grouping patterns based on morphological characteristics and chemical profiles were in accordance with those clustered by ISSR analysis. Significant differences in morphological characteristics, fatty acid composition, triglyceride composition, and inhibition rates of seed oil were detected among different accessions, which showed a highly significant positive correlation with genetic variation. These results suggest that the seed morphological characteristics, fatty acid composition, and triglyceride composition may be mainly attributed to genetic factors. The proportion of palmitic acid and linoleic acid to oleic acid displayed a highly significant positive correlation with the inhibition rates of Job’s tears seed oil for T24 cells, and thus can be an important indicator for quality control for Job’s tears.     

Morphological characterization of Prunus scoparia using multivariate analysis

In this research, morphological characterization of wild Prunus scoparia species, naturally growing in Iran, was investigated. Twenty-one variables along flowering and ripening date were recorded in 150 accessions of this species to detect their phenotypic variation. All studied characteristics were showing a high degree of variability, but it was highly pronounced for secondary shoot number, leaf area and shape, growth habit, fruit exocarp color, nut shape, pubescence on fruit, canopy size and trunk diameter. The majority of significant correlation coefficients were found in the characteristics representing tree and nut sizes with leaf size. Principal component analysis was performed for phenotypical diversity determination and grouping of species. Characters with high discriminating values were those related to tree height, growth habit, canopy size and kernel weight. Based on the UPGMA cluster analysis, accessions were placed in two main clusters. The first main cluster was divided into five subclusters with high variability within and between populations, while the second cluster contained 11 accessions of Estahban region. Current findings supported these opportunities since the phenotypic variability in Iranian wild P. scoparia species has been found to be very high, suggesting an extensive genetic diversity available to almond cultivar and rootstock development programs. The wide adaptation of this species indicates its potential as resources for resistance to abiotic and biotic stresses such as drought and spring frost. The conservation of the highly diverse native populations of Iranian wild P. scoparia species is recommended.     

Morphological variation and evolutionary significance of <Emphasis Type="Italic">Coccinia grandis</Emphasis> (L.) Voigt: an under-exploited cucurbitaceous vegetable crop

Morphological variation was analyzed in wild accessions and cultivars of the vegetatively propagated dioecious Coccinia grandis. Variations of 43 morphological characters, 19 qualitative and 23 quantitative traits, were analyzed among 40 female accessions, including 25 cultivars and 15 wild accessions. Multivariate statistical analyses were used to group accessions according to their morphological similarity. Principal component (PC) analysis revealed that the first three PCs accounted for 50% of the total variance, and differences among the accessions were evidenced principally in relation to fruit characteristics such as fruit weight, fruit length and the number of seeds in each fruit. Analysis of variance carried out in the entire germplasm revealed significant differences within the germplasm, whereas ANOVA carried out between the wild accessions and the cultivars proved the null hypothesis that there are no significant differences between the two groups, and differences were observed only in fruit characters that are targets of human selection. Principal component analysis, UPGMA cluster analysis and discriminant factor analysis revealed strong overlaps between the two groups indicating the ongoing process of evolution and selection in the species.     

Variability in reproductive traits in Jatropha curcas L. accessions during early developmental stages under warm subtropical conditions

Variability in floral, fruit, and seed characteristics, and oil content of 15 accession of Jatropha curcas during early development were assessed during two flowering periods in south Florida subtropical climate. The two flowering periods had leaf flushing in March. Field evaluation using 18 quantitative traits showed significant variation among accessions. The number of female flowers and female : male flower ratio ranged from 1 to 15 and 1 : 8.8 to 1 : 67.8, respectively. Fruit set by natural pollination was 89 and 66% during the first (1st) and second (2nd) flowering periods, respectively. A higher number of female‐type inflorescences were observed during summer. There were significant differences in seed traits, except for number of seeds per fruit. Accession TREC 31 had the highest individual seed dry weight and 100‐seed weight (0.83 g and 79.7 g, respectively). The oil content varied from 19.30% to 35.62%. Seed dry weight had positive correlation with seed fresh weight, seed length, seed thickness, seed width, and 100‐seed weight, but negative correlation with oil content. Based on the cluster analysis using 15 morphological traits, jatropha accessions were grouped into five main clusters and accessions from different geographic regions grouped together in a cluster. Principal component analyses (PCA) revealed morphological variation. The first three components explained 73.5% of the total variation and seed dry weight, 100‐seed weight, total flowers per inflorescence, male flowers per inflorescence and fruit set can be used to distinguish accessions. The PCA also indicated that flowering traits were more influenced by seed origin while seed traits were affected by flowering spans. Although evaluations were performed in plants during the juvenile phase, accessions TREC 31 and TREC 55 had superior averages for almost all characters evaluated. These results provide a preliminary assessment of the high variability in jatropha accessions evaluated and their potential for use in breeding and genetic improvement programs.     

Farmers without borders—genetic structuring in century old barley (Hordeum vulgare)

The geographic distribution of genetic diversity can reveal the evolutionary history of a species. For crop plants, phylogeographic patterns also indicate how seed has been exchanged and spread in agrarian communities. Such patterns are, however, easily blurred by the intense seed trade, plant improvement and even genebank conservation during the twentieth century, and discerning fine-scale phylogeographic patterns is thus particularly challenging. Using historical crop specimens, these problems are circumvented and we show here how high-throughput genotyping of historical nineteenth century crop specimens can reveal detailed geographic population structure. Thirty-one historical and nine extant accessions of North European landrace barley (Hordeum vulgare L.), in total 231 individuals, were genotyped on a 384 single nucleotide polymorphism assay. The historical material shows constant high levels of within-accession diversity, whereas the extant accessions show more varying levels of diversity and a higher degree of total genotype sharing. Structure, discriminant analysis of principal components and principal component analysis cluster the accessions in latitudinal groups across country borders in Finland, Norway and Sweden. F_ST statistics indicate strong differentiation between accessions from southern Fennoscandia and accessions from central or northern Fennoscandia, and less differentiation between central and northern accessions. These findings are discussed in the context of contrasting historical records on intense within-country south to north seed movement. Our results suggest that although seeds were traded long distances, long-term cultivation has instead been of locally available, possibly better adapted, genotypes.     

Molecular Assortment of Lens Species with Different Adaptations to Drought Conditions Using SSR Markers

The success of drought tolerance breeding programs can be enhanced through molecular assortment of germplasm. This study was designed to characterize molecular diversity within and between Lens species with different adaptations to drought stress conditions using SSR markers. Drought stress was applied at seedling stage to study the effects on morpho-physiological traits under controlled condition, where tolerant cultivars and wilds showed 12.8–27.6% and 9.5–23.2% reduction in seed yield per plant respectively. When juxtaposed to field conditions, the tolerant cultivars (PDL-1 and PDL-2) and wild (ILWL-314 and ILWL-436) accessions showed 10.5–26.5% and 7.5%–15.6% reduction in seed yield per plant, respectively under rain-fed conditions. The reductions in seed yield in the two tolerant cultivars and wilds under severe drought condition were 48–49% and 30.5–45.3% respectively. A set of 258 alleles were identified among 278 genotypes using 35 SSR markers. Genetic diversity and polymorphism information contents varied between 0.321–0.854 and 0.299–0.836, with mean value of 0.682 and 0.643, respectively. All the genotypes were clustered into 11 groups based on SSR markers. Tolerant genotypes were grouped in cluster 6 while sensitive ones were mainly grouped into cluster 7. Wild accessions were separated from cultivars on the basis of both population structure and cluster analysis. Cluster analysis has further grouped the wild accessions on the basis of species and sub-species into 5 clusters. Physiological and morphological characters under drought stress were significantly (P = 0.05) different among microsatellite clusters. These findings suggest that drought adaptation is variable among wild and cultivated genotypes. Also, genotypes from contrasting clusters can be selected for hybridization which could help in evolution of better segregants for improving drought tolerance in lentil.     

重庆大豆地方资源多样性评价及群体表型特点研究

对收集于重庆市的103份大豆地方品种进行了表型遗传多样性分析,并利用主成分分析和聚类分析对其进行了群体表型特点的研究,研究结果表明,重庆地区大豆地方种质资源以灰色茸毛、黄粒、褐色脐居多,个体之间数量性状上存在较大变异。主成分分析以3个主成分反映了10个农艺性状的大部分信息,将主要农艺性状归纳成产量因子、生长势因子及籽粒因子。聚类分析将103份地方种质资源聚为6个类群, 同一地区的大部分地方品种表现较为相似,少部分地方品种差异大,品种类群间的表型分化与地理分布既有一定的联系又不绝对相关。利用这些种质选配育种亲本应关注各类群间性状差异作选择,而不能仅关注地理来源选择。     

Variation in the Agronomic and Morphological Traits of Iranian Chickpea Accessions

Landraces of chickpea (Cicer arietinum L.) in Iran have not been adequately characterized for their agronomic and morphological traits. Such characterization would be helpful in the development of improved cultivars, so in this study 362 chickpea accessions, collected from the major chickpea growing areas of Iran, were evaluated to determine their phenotypic diversity. High coefficients of variation (CVs)were recorded in pods/branch, seeds/pod, yield/plant, seeds/plant, pods/plant and branches/plant. Using principal component (PC) analysis, the first four PCs with eigenvalues more than 1 contributed 84.10% of the variability among accessions, whereas PC5 to PC10 were less than unity. PC1 was positively related to days to first maturity, days to 50% flowering and days to 50% maturity. The characters with the greatest weight on PC2 were seeds/plant and yield/plant, whereas PC3 was mainly related to pods/plant, seeds/pod and 100-seed weight, and PC4 was positively related to pods/branch and negatively to branches/plant. The germplasm was grouped into four clusters using cluster analysis. Each cluster had some specific characteristics of its own and the cluster I was clearly separated from clusters Ⅱ, Ⅲ and Ⅳ. These accessions are an important resource for the establishment of a core collection of chickpeas in the world.     

Grafting versus seed propagated apricot populations: two main gene pools in Tunisia evidenced by SSR markers and model-based Bayesian clustering

Apricot was introduced into the Mediterranean Basin from China and Asian mountains through the Middle-East and the Central Europe. Traditionally present in Tunisia, we were interested in accessing the origin of apricot species in the country, and in particular in the number and the location of its introductions. A set of 82 representative apricot accessions including 49 grafted cultivars and 33 seed propagated ‘Bargougs’ were genotyped using 24 microsatellite loci revealing a total of 135 alleles. The model-based Bayesian clustering analysis using both Structure and InStruct programs as well as the multivariate method revealed five distinct genetic clusters. The genetic differentiation among clusters showed that cluster 1, with only four cultivars, was the most differentiated from the four remaining genetic clusters, which constituted the largest part of the studied germplasm. According to their geographic origin, the five identified groups (north, centre, south, Gafsa oasis and other oases groups) enclosed a similar variation within group, with a low level of differentiation. Overall results highlighted the distinction of two apricot gene pools in Tunisia related to the different mode of propagation of the cultivars: grafted and seed propagated apricot, which enclosed a narrow genetic basis. Our findings support the assumption that grafting and seed propagated apricots shared the same origin.