硬粒小麦苗期性状遗传多样性及其与SNP的关联分析

发布时间：2018-11-11 01:01

【摘要】：小麦(Triticum spp.)是世界上广泛种植的主要谷类作物之一。硬粒小麦(Triticum durum Desf.)广泛栽培于地中海降水相对较少的地区。小麦的苗期特性及其最佳形态建成对产量有很重要的作用。常规育种和相关生物技术促进了小麦品种的可持续发展。利用关联分析可以分析、了解作物的遗传基础,从而进一步确定其候选基因。单核苷酸多态性(SNP)在小麦品种间的多态性分析中,可以为小麦的多样性分析提供一种前所未有的资源,因而具有十分重要的价值。本研究的目的是在染色体区域,锚定与硬粒小麦苗期性状关联的SNP标记,评估其遗传变异,并进行基于硬粒小麦幼苗形态和农艺性状的关联分析,主要结果如下:1.硬粒小麦苗期性状与基于SNP标记的关联分析关联分析是揭示表型变异和遗传多态性之间的关系的有效方法。在本研究中,对来自全世界的150份硬粒小麦种质主要幼苗性状及其生长情况进行了考察。在水培条件下,分别在硬粒小麦发芽后的第13、20、27和34天对其根长,主根数,幼苗高度,叶数,叶面积,鲜重,性状的生长速率,和性状的生长增量进行了考察。在发芽后第34天对硬粒小麦材料生物叶绿素含量和生物量性状,包括根干重,地上部干重和总苗干重进行了考察。对每个幼苗性状进行了方差分析。对考察的幼苗性状和连续四年三个田间性状,株高,粒重和千粒重中进行了相关分析。利用混合线性模型(MLM)对SNP标记和考察的幼苗性状进行了关联分析。结果表明,硬粒小麦苗期性状具有显著的遗传变异和较高的遗传率。苗期性状及其与成熟后的田间性状间都存在显著的相关性。总之,在所有的性状和四个生长阶段中共检测到763显著关联。一些SNP标记(140)与多个性状相关联,表明硬粒小麦的苗期一些基因具有多效性。关联标记非随机的分布在硬粒小麦基因组,B基因组上的关联标记多于A基因组,主要分布在6、1和7染色体上。相关联的SNP标记对苗期性状的遗传分析,以及对选育具有较强幼苗活力的小麦新品种有裨益。2.硬粒小麦种质产量及产量构成的遗传多样性和遗传率的评估对150份来自全世界硬粒小麦材料的10个农艺性状进行了4年连续的田间试验鉴定,并对其遗传变异进行了评估。结果显示,主穗的穗颈节间长(厘米)的遗传变异在四年的数据中表现最高。株高、主穗的穗茎节间长、主穗长、主穗的剑叶鞘到穗颈节长度和主穗小穗数等性状都表现较高的遗传率(87%以上)。株高和粒重在四年的数据中都表现较高的遗传率。在所有的性状上,基因型间都表现出显著的差异。单株产量分别与单株粒数(r=0.86)、有效穗(r=0.59)、主穗的剑叶鞘到穗颈节长度(r=0.59)、单株小穗数(r=0.53)、千粒重(r=0.51)、主穗穗茎节间长(r=0.35)和主穗小穗数(r=0.27)呈显著的正相关。千粒重与单株小穗数(r=-0.22)呈显著相关负相关。主成分分析表明,单株粒数(r=0.868)和千粒重(r=0.495)对籽粒产量有直接贡献。因此,这些性状可以被考虑作为小麦产量改良的选择标准。本研究显示,开发和利用硬粒小麦丰富的遗传变异的可以拓展普通小麦的种质资源,并使其应用于小麦育种中。
[Abstract]:Triticum spp.) It is one of the main cereal crops widely cultivated in the world. Hard-grained wheat (Triticum durum Desf)) widely cultivated in relatively small areas of the Mediterranean. The seedling stage and the best form of the wheat have a very important effect on the yield. The conventional breeding and related biotechnology have promoted the sustainable development of the wheat variety. By using the correlation analysis, the genetic basis of the crops can be analyzed, and the candidate genes of the crops can be further determined. The single nucleotide polymorphism (SNP) can provide an unprecedented resource for the analysis of the diversity of wheat, which is of great value. The purpose of this study is to evaluate the genetic variation of the SNP marker associated with the seedling traits of the hard-grain wheat in the chromosome region, and to carry out the association analysis based on the morphology and agronomic characters of the hard-grained wheat. The main results are as follows: 1. The relationship between the characteristics of the seedling stage of the hard-grain wheat and the association analysis based on the SNP marker is an effective method to reveal the relationship between the phenotypic variation and the genetic polymorphism. In this study, the main seedling characters and their growth of 150 hard-grain wheat germplasms from the whole world were investigated. The growth rate of the root, the number of the root, the height of the seedling, the number of leaves, the leaf area, the fresh weight, the growth rate of the character and the growth increment of the character were studied under the condition of water culture. The content of chlorophyll and biomass of the hard-grained wheat material, including the dry weight of the root, the dry weight of the ground and the dry weight of the total seedling, were studied on the 34-day post-germination. An analysis of variance was performed on each of the seedling traits. The correlation analysis of three field characters, plant height, grain weight and 1000-grain weight of the three-year field characters, the plant height, the grain weight and the 1000-grain weight of the study was carried out. The characteristics of the seedlings were analyzed by using the mixed linear model (MLM). The results showed that the characters of the wheat at the seedling stage had significant genetic variation and higher genetic rate. There was a significant correlation between the traits of the seedling stage and the field characters after maturity. In summary, 763 significant associations were detected in all of the traits and four growth stages. Some SNP markers (140) are associated with multiple traits, indicating that some of the genes at the seedling stage of the hard-grained wheat have multiple effects. The association marker is not randomly distributed on the genome of the hard-grain wheat, and the association mark on the B-genome is more than that of the A-genome, and is mainly distributed on the chromosome 6, 1 and 7. the associated SNP markers are useful for the genetic analysis of the traits of the seedling stage, as well as to the selection of a new variety of wheat varieties having a stronger seedling activity. The genetic diversity and the genetic ratio of the yield and yield of the hard-grain wheat germplasm were evaluated in a 4-year field trial of the 10 agronomic characters from the hard-grain wheat material in the world, and the genetic variation was evaluated. The results showed that the genetic variation of the internode length (cm) in the ear of the main ear was the highest in the four-year data. The height of the plant, the internode length of the stem of the main ear, the length of the main ear, the length of the blade of the main ear, the length of the spikelet and the number of the spikelet of the main ear showed a higher genetic rate (more than 87%). The high and grain weight of the plant showed a high genetic rate in the four-year data. In all the traits, there was a significant difference between the genotypes. The yield of the single plant was correlated with the number of the single plant (r = 0.86), the effective ear (r = 0.59), the length of the blade of the main ear (r = 0.59), the number of spikelet number of the single plant (r = 0.53), the 1000-grain weight (r = 0.51), the internode length (r = 0.35) of the main ear and the number of spikelet number (r = 0.27) of the main ear. The 1000-grain weight was negatively correlated with the number of spikelet number (r =-0.22). The principal component analysis showed that the number of grain per plant (r = 0.868) and 1000-grain weight (r = 0.495) had a direct contribution to grain yield. Thus, these traits can be considered as a selection criterion for wheat yield improvement. The research shows that the development and utilization of the abundant genetic variation of the hard-grain wheat can expand the germplasm resources of the common wheat, and can be applied to the wheat breeding.
【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S512.1

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