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1.
光温敏二系杂交小麦恢复系遗传多样性和群体结构分析   总被引:2,自引:0,他引:2  
为揭示光温敏雄性不育小麦恢复系资源的遗传基础,选用49个Genomic-SSR和40个EST-SSR标记位点对100份冬性光温敏雄性不育小麦恢复系进行遗传多样性和群体结构分析.结果表明:89个位点共扩增出531个等位变异,平均每个位点5.96个; 平均基因多样性和多态性信息量(PIC)分别为0.63和0.57,说明本研究所选用的恢复系的遗传多样性比较丰富;利用NJ法聚类和Structure群体结构分析均将100份恢复系划分为6大类群,且聚类结果基本吻合,同时揭示出北方冬麦区和黄淮海冬麦区恢复系间存在较广泛的基因交流;群体结构分析阐明了各恢复系的遗传组成,推测58%的恢复系血缘相对比较单一,42%的恢复系拥有混合来源.研究结果为新恢复系的选育和现有恢复系的利用提供了理论依据,并为重要农艺性状数量性状位点的关联分析奠定了基础.  相似文献   

2.
胡杨(Populus euphratica)是极端干旱荒漠区的珍稀乔木树种。为了确定天然胡杨群体遗传多样性保护单元并挖掘优异的种质资源, 本研究以中国西北地区新疆、青海、甘肃、宁夏、内蒙古的58个天然胡杨群体为研究对象, 利用120个位点的SNPs标记对这些胡杨群体进行群体遗传结构和遗传多样性分析, 并根据不同群体间Nei’s遗传相似度, 采用逐步聚类优先取样法对初始群体、遗传多样性保护单元和剩余群体进行t检验。群体结构和主成分分析表明, 胡杨群体可分为新疆南疆(SX)、新疆北疆(NX)、青海(QH)和混合群(甘肃、宁夏和内蒙古混合群, GNM) 4个分支, 遗传多样性分析表明新疆南疆(SX)遗传多样性高于其他群体。分子方差分析(AMOVA)表明天然胡杨群体的遗传变异主要分布在各个群体内。构建了天然胡杨群体一级核心保护单元3个群体(CU3), 二级核心保护单元33个群体(CU33)。南疆存在较多优异抗逆的天然胡杨古树资源, 南疆分布区的平均遗传多样性水平最高。综上所述, 南疆地区胡杨古树遗传多样性整体高于北疆及疆外地区, 结合新疆地区干旱严重指数等生境信息, 建议加大对南疆胡杨古树群体的保护力度, 重视北疆胡杨林的更新换代。  相似文献   

3.
新疆于田流水墓地青铜时代人类颅骨非连续性特征研究   总被引:1,自引:0,他引:1  
新疆是欧亚大陆东西方人群交流的关键地带,新疆人群是研究东西交流史的主要对象.本文对昆仑山北麓青铜时代的新疆于田流水墓地出土的20具颅骨进行了61项非连续性特征的观察,对其中的20项非连续性特征与世界范围近代和现代人群进行频率数据的主成分分析,计算样本间的史密斯生物学距离,根据距离系数作邻接法聚类分析和多维尺度分析.结果...  相似文献   

4.
Commercial varieties of upland cotton(Gossypium hirsutum) have undergone extensive breeding for agronomic traits, such as fiber quality, disease resistance,and yield. Cotton breeding programs have widely used Chinese upland cotton source germplasm(CUCSG) with excellent agronomic traits. A better understanding of the genetic diversity and genomic characteristics of these accessions could accelerate the identification of desirable alleles. Here, we analyzed 10,522 high-quality singlenucleotide polymorphisms(SNP) with the CottonSNP63 K microarray in 137 cotton accessions(including 12 hybrids of upland cotton). These data were used to investigate the genetic diversity, population structure,and genomic characteristics of each population and the contribution of these loci to heterosis. Three subgroups were identified, in agreement with their knownpedigrees, geographical distributions, and times since introduction. For each group, we identified lineagespecific genomic divergence regions, which potentially harbor key alleles that determine the characteristics of each group, such as early maturity-related loci. Investigation of the distribution of heterozygous loci, among 12 commercial cotton hybrids, revealed a potential role for these regions in heterosis. Our study provides insight into the population structure of upland cotton germplasm. Furthermore, the overlap between lineagespecific regions and heterozygous loci, in the high-yield hybrids, suggests a role for these regions in cotton heterosis.  相似文献   

5.
Gossypium hirsutum L. represents the largest source of textile fibre, and China is one of the largest cotton‐producing and cotton‐consuming countries in the world. To investigate the genetic architecture of the agronomic traits of upland cotton in China, a diverse and nationwide population containing 503 G. hirsutum accessions was collected for a genome‐wide association study (GWAS) on 16 agronomic traits. The accessions were planted in four places from 2012 to 2013 for phenotyping. The CottonSNP63K array and a published high‐density map based on this array were used for genotyping. The 503 G. hirsutum accessions were divided into three subpopulations based on 11 975 quantified polymorphic single‐nucleotide polymorphisms (SNPs). By comparing the genetic structure and phenotypic variation among three genetic subpopulations, seven geographic distributions and four breeding periods, we found that geographic distribution and breeding period were not the determinants of genetic structure. In addition, no obvious phenotypic differentiations were found among the three subpopulations, even though they had different genetic backgrounds. A total of 324 SNPs and 160 candidate quantitative trait loci (QTL) regions were identified as significantly associated with the 16 agronomic traits. A network was established for multieffects in QTLs and interassociations among traits. Thirty‐eight associated regions had pleiotropic effects controlling more than one trait. One candidate gene, Gh_D08G2376, was speculated to control the lint percentage (LP). This GWAS is the first report using high‐resolution SNPs in upland cotton in China to comprehensively investigate agronomic traits, and it provides a fundamental resource for cotton genetic research and breeding.  相似文献   

6.
以中国新疆伊犁地区的巩留县莫合镇库尔德宁、新源县交吾托海、霍城县大西沟和塔城地区的裕民县巴尔鲁克山4个种下居群的109个新疆野苹果实生株系为材料,利用8对苹果SSR引物进行群体遗传结构的研究。结果表明:8对SSR引物在4个居群中可平均扩增出16条带,其中巩留县居群多态性带数百分比最高为89.06%,各位点平均Nei基因多样度为0.257;4个群体共扩增出128个位点,在种级水平及巩留县、新源县、霍城县和裕民县4个居群水平多态性位点百分比分别为100%、88.28%、84.38%、87.50%、78.12%,种级水平Nei基因多样度(H=0.2619)和香农信息指数(I=0.4082)大于种下居群,4个种下居群Nei基因多样度和香农信息指数比较巩留县>霍城县>新源县>裕民县;巩留县居群和新源县居群遗传一致度最大,遗传距离最近;根据基因分化系数(GST=0.064)值,测得的基因流Nm为7.265。UPGMA聚类分析结果表明,巩留县和新源县居群遗传关系最近,霍城县居群次之,裕民县居群远离其他3个居群,巩留县、新源县、霍城县和裕民县4个居群是相对独立的群体,但同时存在部分基因交流。所有参数分析表明,巩留县遗传多样性最丰富,故在制定原位种质保护计划时应优先考虑巩留县居群。  相似文献   

7.
唐如玉  徐鹏  余迪求 《广西植物》2020,40(2):159-172
该研究基于4个陆稻群体及172个水稻品种或杂交组合,构建了水稻多亲本隐性核不育轮回选择群体XTBG-HP1,并经过4次轮回重组,采用16个表型性状对其进行了遗传多样性分析。结果表明:(1)该群体14个数量性状符合正态分布,各表型均存在极端性状个体。(2)数量性状变异系数范围为0.08~0.41,均值为0.20; Shannon-Wiener多样性指数范围为0.72~1.92,均值为1.50。(3)群体在株型与产量构成因子性状方面有显著的相关性,对株型的选择可以实现产量性状的改良。(4)剑叶长、每穗粒总数、千粒重、穗长、粒长、一次枝梗数、有效穗数、剑叶宽、二次枝梗数、抽穗期10个性状可作为群体综合评价指标。(5)剑叶长、二次枝梗数、每穗粒总数3个表型性状具有较高的遗传变异、丰富的遗传多样性及与综合得分F值相关系数较高。综合以上结果发现,后期群体进行基因挖掘、品种改良以及优良育种材料的选育可以基于剑叶长、二次枝梗数及每穗粒总数3个表型性状,同时要充分利用群体株型与产量构成因子性状间的显著相关性。此外,该研究群体中极端单性状或综合得分F值较高的个体,可进一步用于品种选育。  相似文献   

8.
采用分别保存于长期库及中期库的3个小麦地方品种的6份材料,进行了9项农艺性状及35个与农艺性状相关的微卫星标记检测,每份材料选取30个单株进行遗传多样性与遗传结构分析。结果表明:(1)更新前,3个小麦地方品种均为遗传异质性群体,在SSR位点上的异质度分别为57.14%、48.57%和5.71%。(2)在农艺性状表现上,只有温泉小麦3在株高和穗粒数上更新后比更新前显著增加,其他材料无显著差异。(3)在SSR位点多态性表现上,3个品种在更新后均发生了遗传多样性变化,8个与粒重、产量、生育期性状相关位点存在等位位点丢失现象,其中2个与粒重、生育期相关位点频率变化显著。(4)综合农艺性状调查与SSR分子标记检测结果发现,3个品种更新前后在多样性指数上无显著差异,遗传分化系数Gst分别为0.0269、0.0324和0.0380,即更新前后遗传差异分别为2.69%、3.24%和3.80%。上述结果建议,经繁殖更新的小麦种质资源能够比较完好地保持其遗传多样性和遗传结构。对于遗传异质性小麦地方品种在繁殖更新后存在遗传多样性丢失的危险,为了保证更新前后的遗传完整性,建议在繁殖更新过程中每个品种至少应保持300个单株的群体。  相似文献   

9.

Key message

Four genetic regions associated with water use traits, measured at different levels of plant organization, and with agronomic traits were identified within a previously reported region for terminal water deficit adaptation on linkage group 2. Close linkages between these traits showed the value of phenotyping both for agronomic and secondary traits to better understand plant productive processes.

Abstract

Water saving traits are critical for water stress adaptation of pearl millet, whereas maximizing water use is key to the absence of stress. This research aimed at demonstrating the close relationship between traits measured at different levels of plant organization, some putatively involved in water stress adaptation, and those responsible for agronomic performance. A fine-mapping population of pearl millet, segregating for a previously identified quantitative trait locus (QTL) for adaptation to terminal drought stress on LG02, was phenotyped for traits at different levels of plant organization in different experimental environments (pot culture, high-throughput phenotyping platform, lysimeters, and field). The linkages among traits across the experimental systems were analysed using principal component analysis and QTL co-localization approach. Four regions within the LG02-QTL were found and revealed substantial co-mapping of water use and agronomic traits. These regions, identified across experimental systems, provided genetic evidence of the tight linkages between traits phenotyped at a lower level of plant organization and agronomic traits assessed in the field, therefore deepening our understanding of complex traits and then benefiting both geneticists and breeders. In short: (1) under no/mild stress conditions, increasing biomass and tiller production increased water use and eventually yield; (2) under severe stress conditions, water savings at vegetative stage, from lower plant vigour and fewer tillers in that population, led to more water available during grain filling, expression of stay-green phenotypes, and higher yield.
  相似文献   

10.
Ferula loscosii (Lange) Willk (Apiaceae) is a threatened endemic species native to the Iberian Peninsula. The plant has a narrow and disjunct distribution in three regions, NE, C and SE Spain. Genetic variability within and among 11 populations from its natural distribution was assessed using allozymes. Intermediate levels of genetic diversity were detected in F. loscosii (P(99%) = 36.83; H(E) = 0.125; H(T) = 0.152). However, the highest genetic diversity (58%) corresponded to the threatened populations from SE and C Spain (H(T) = 0.169) rather than the more abundant and larger populations from NE Spain (Ebro valley) (H(T) = 0.122). Low to moderate levels of genetic structure were found among regional ranges (G(ST) = 0.134), and several statistical spatial correlation analyses corroborated substantial genetic differentiation among the three main regional ranges. However, no significant genetic differentiation was found among the NE Spain populations, except for a northernmost population that is geographically isolated. Outcrossing mating and other biological traits of the species could account for the maintenance of the present values of genetic diversity within populations. The existence of an ancestral late Tertiary wider distribution of the species in SE and C Spain, followed by the maintenance of different Quaternary refugia in these warmer areas, together with a more recent and rapid post-glacial expansion towards NE Spain, are arguments that could explain the low genetic variability and structure found in the Ebro valley and the higher levels of diversity in the southern Iberian populations.  相似文献   

11.
为拓宽本地棉花种质基因库,筛选适于作杂交亲本的种质资源,以134份国外棉花种质为试验材料,研究了其主要品质与农艺性状的变异情况、遗传多样性指数、品质性状间的相关性,并以主要农艺与品质性状为指标,对134份种质进行了聚类分析和主成分分析。结果表明,纤维品质性状中整齐度指数的遗传多样性指数(5.16)最高,马克隆值的变异系数(11.96%)最大,农艺性状中霜前衣分的遗传多样性指数(5.42)最高,不孕籽率的变异系数(49.18%)最大,参试种质的遗传多样性丰富;整齐度指数与上半部平均长度、断裂比强度均呈极显著正相关,断裂比强度与上半部平均长度间也呈极显著正相关;10个农艺性状和5个品质性状的主成分分析结果表明,前6个主成分的累计贡献率达75.277%;Ward法聚类将134份参试种质按品质性状分为5类,其中第Ⅱ类群的35份种质棉纤维品质性状表现最好,按农艺性状分为3类,其中第Ⅰ类群的58份种质产量最高。通过综合35份纤维品质优异的种质与58份农艺性状优异的种质筛选出美1870、美1884、FM1830等14份品质与产量俱佳的优异种质。  相似文献   

12.
Sugarcane (Saccharum spp.) and other members of Saccharum spp. are attractive biofuel feedstocks. One of the two World Collections of Sugarcane and Related Grasses (WCSRG) is in Miami, FL. This WCSRG has 1002 accessions, presumably with valuable alleles for biomass, other important agronomic traits, and stress resistance. However, the WCSRG has not been fully exploited by breeders due to its lack of characterization and unmanageable population. In order to optimize the use of this genetic resource, we aim to 1) genotypically evaluate all the 1002 accessions to understand its genetic diversity and population structure and 2) form a core collection, which captures most of the genetic diversity in the WCSRG. We screened 36 microsatellite markers on 1002 genotypes and recorded 209 alleles. Genetic diversity of the WCSRG ranged from 0 to 0.5 with an average of 0.304. The population structure analysis and principal coordinate analysis revealed three clusters with all S. spontaneum in one cluster, S. officinarum and S. hybrids in the second cluster and mostly non-Saccharum spp. in the third cluster. A core collection of 300 accessions was identified which captured the maximum genetic diversity of the entire WCSRG which can be further exploited for sugarcane and energy cane breeding. Sugarcane and energy cane breeders can effectively utilize this core collection for cultivar improvement. Further, the core collection can provide resources for forming an association panel to evaluate the traits of agronomic and commercial importance.  相似文献   

13.
Habitat fragmentation can lead to a decline of genetic diversity, a potential risk for the survival of natural populations. Fragmented populations can become highly differentiated due to reduced gene flow and genetic drift. A decline in number of individuals can result in lower reproductive fitness due to inbreeding effects. We investigated genetic variation within and between 11 populations of the rare and endangered plant Silene chlorantha in northeastern Germany to support conservation strategies. Genetic diversity was evaluated using AFLP techniques and the results were correlated to fitness traits. Fitness evaluation in nature and in a common garden approach was conducted. Our analysis revealed population differentiation was high and within population genetic diversity was intermediate. A clear population structure was supported by a Bayesian approach, AMOVA and neighbour-joining analysis. No correlation between genetic and geographic distance was found. Our results indicate that patterns of population differentiation were mainly caused by temporal and/or spatial isolation and genetic drift. The fitness evaluation revealed that pollinator limitation and habitat quality seem, at present, to be more important to reproductive fitness than genetic diversity by itself. Populations of S. chlorantha with low genetic diversity have the potential to increase in individual number if habitat conditions improve. This was detected in a single large population in the investigation area, which was formerly affected by bottleneck effects.  相似文献   

14.
For broadening the narrow genetic base of modern soybean cultivars, 159 accessions were selected from the Chinese soybean collection which contained at least one of seven important agronomic traits: resistance to soybean cyst nematode (SCN) or soybean mosaic virus (SMV), tolerance to salt, cold, or drought, high seed oil content or high protein content. Genetic diversity evaluation using 55 microsatellite loci distributed across the genome indicated that a large amount of genetic diversity (0.806) and allelic variation (781) were conserved in this selected set, which captured 65.6% of the alleles present in Chinese soybean collection (1,863 accessions). On average, 9.4 rare alleles (frequency <5%) per locus were present, which were highly informative. Using model-based Bayesian clustering in STRUCTURE we distinguished four main clusters and a set of accessions with admixed ancestry. The four clusters reflected different geographic regions of origin of the accessions. Since the clusters were also clearly different with respect to the seven agronomic traits, the inferred population structure was introduced when association analysis was conducted. A total of 21 SSR markers on 16 chromosomes were identified as significantly (P < 0.01) associated with high oil content (6), high protein content (1), drought tolerance (5), SCN resistance (6) and SMV resistance (3). Twelve of these markers were located in or near previously identified quantitative trait loci (QTL). The results for both genetic relationship and trait-related markers will be useful for effective conservation and utilization of soybean germplasm.  相似文献   

15.
Yam is an important edible tuber and root plant worldwide; China as one of the native places of yams has many diverse local resources. The goal of this study was to clarify the genetic diversity of the commonly cultivated yam landraces and the genetic relationship between the main yam species in China. In this study, 26 phenotypic traits of 112 yam accessions from 21 provinces in China were evaluated, and 24 simple sequence repeat (SSR) and 29 sequence‐related amplified polymorphism (SRAP) markers were used for the genetic diversity analysis. Phenotypic traits revealed that Dioscorea opposita had the highest genetic diversity, followed by D. alata, D. persimilis, D. fordii, and D. esculenta. Among the 26 phenotypic traits, the Shannon diversity indexes of leaf shape, petiole color, and stem color were high, and the range in the variation of tuber‐related traits in the underground part was higher than that in the aboveground part. All accessions were divided into six groups by phenotypic trait clustering, which was also supported by principal component analysis (PCA). Molecular marker analysis showed that SSR and SRAP markers had good amplification effects and could effectively and accurately evaluate the genetic variation of yam. The unweighted pair‐group method with arithmetic means analysis based on SSR‐SRAP marker data showed that the 112 accessions were also divided into six groups, similar to the phenotypic trait results. The results of PCA and population structure analysis based on SSR‐SRAP data also produced similar results. In addition, the analysis of the origin and genetic relationship of yam indicated that the species D. opposita may have originated from China. These results demonstrate the genetic diversity and distinctness among the widely cultivated species of Chinese yam and provide a theoretical reference for the classification, breeding, germplasm innovation, utilization, and variety protection of Chinese yam resources.  相似文献   

16.
为筛选火龙果(Hylocereus undatus)优良种质资源,对22份种质资源果实的表型性状、农艺性状、品质性状进行遗传多样性分析。结果表明,火龙果种质资源果实的表型性状、农艺性状和品质性状具有丰富的遗传多样性和较高的变异性,表型性状的多样性指数(H′)为0~1.04,品质性状为0.40~2.01;农艺性状的变异系数(CV)为0.06~0.38,品质性状为0.01~0.62。聚类分析表明,在遗传距离为15时,火龙果22份种质资源可分为5类,说明不同资源间亲缘关系较远。这为发掘火龙果的育种潜力,筛选优异基因资源,改良种质奠定了基础。  相似文献   

17.
鹰嘴豆种质资源农艺性状遗传多样性分析   总被引:12,自引:2,他引:10  
以100份鹰嘴豆种质资源为材料,应用聚类分析和主成分分析方法,对15个主要农艺性状的遗传多样性进行分析。结果表明,参试材料存在广泛的遗传多样性。其中,多样性指数最高的是株高,其次是百粒重;性状变异系数最大的是单株荚数,其次是单株粒重;基于各种质间形态标记的遗传差异,将100份鹰嘴豆种质聚类并划分为4大类群。第Ⅰ类群可作为选育丰产中粒型和株高适中的品种,第Ⅱ类群可作为选育矮秆耐密及特异粒色(型)品种,第Ⅲ类群丰产性较差可作为选育子粒球型、光滑的品种,第Ⅳ类群可作为选育大粒型、适宜机械化收获的品种。9个数量性状的主成分分析结果表明,前4个主成分累计贡献率达73.91%,各主成分性状载荷值反映了主要数量性状的育种选择潜力。综合分析种质资源农艺性状,为鹰嘴豆的有效利用提供一定的科学依据。  相似文献   

18.
Altitudinal gradients in mountain regions are short‐range clines of different environmental parameters such as temperature or radiation. We investigated genomic and phenotypic signatures of adaptation to such gradients in five Arabidopsis thaliana populations from the North Italian Alps that originated from 580 to 2350 m altitude by resequencing pools of 19–29 individuals from each population. The sample includes two pairs of low‐ and high‐altitude populations from two different valleys. High‐altitude populations showed a lower nucleotide diversity and negative Tajima's D values and were more closely related to each other than to low‐altitude populations from the same valley. Despite their close geographic proximity, demographic analysis revealed that low‐ and high‐altitude populations split between 260 000 and 15 000 years before present. Single nucleotide polymorphisms whose allele frequencies were highly differentiated between low‐ and high‐altitude populations identified genomic regions of up to 50 kb length where patterns of genetic diversity are consistent with signatures of local selective sweeps. These regions harbour multiple genes involved in stress response. Variation among populations in two putative adaptive phenotypic traits, frost tolerance and response to light/UV stress was not correlated with altitude. Taken together, the spatial distribution of genetic diversity reflects a potentially adaptive differentiation between low‐ and high‐altitude populations, whereas the phenotypic differentiation in the two traits investigated does not. It may resemble an interaction between adaptation to the local microhabitat and demographic history influenced by historical glaciation cycles, recent seed dispersal and genetic drift in local populations.  相似文献   

19.
The limited knowledge of genomic diversity and functional genes associated with the traits of soybean varieties has resulted in slow progress in breeding.In this study,we sequenced the genomes of 250 soybean landraces and cultivars from China,America,and Europe,and investigated their population structure,genetic diversity and architecture,and the selective sweep regions of these accessions.Five novel agronomically important genes were identified,and the effects of functional mutations in respect...  相似文献   

20.
Euterpe edulis (Arecaceae) Mart has high ecological and economic importance providing food resources for more than 58 species of birds and 20 species of mammals, including humans. E. edulis is the second most exploited nontimber product from Brazilian Atlantic Forest. Due to overexploitation and destruction of habitats, E. edulis is threatened by extinction. Euterpe edulis populations have large morphological variations, with individuals having green, red, or yellow leaf sheath. However, no study has related phenotypic distinctions between populations and their levels of genetic structure. Thus, this study aimed to evaluate the diversity and genetic structure of different E. edulis morphotypes. We sampled 250 adult individuals in eight populations with the different morphotypes. Using 14 microsatellite markers, we access genetic diversity through population genetic parameters calculated in the GenAlex program and the diveRsity package in R. We used the Wilcoxon test to verify population bottlenecks and the genetic distance of Nei and Bayesian analysis for genetic clusters. The eight populations showed low allele richness, low observed heterozygosity, and high inbreeding values (f). In addition, six of the eight populations experienced genetic bottlenecks, which would partly explain the low genetic diversity in populations. Cluster analysis identified two clusters (K = 2), with green morphotype genetically distinguishing from yellow and red morphotypes. Thus, we show, for the first time, a strong genetic structure among E. edulis morphotypes even for geographically close populations.  相似文献   

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