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陆地棉杂种优势及相关性状的遗传分析

Genetic Analysis of Heterosis and Other Traits in Uplang Cotton

【作者】 郝俊杰

【导师】 喻树迅;

【作者基本信息】 华中农业大学 , 作物遗传育种, 2008, 博士

【摘要】 棉花是重要的经济作物,近年来,杂交棉在长江流域、黄河流域已大面积种植。因此,有必要摸索一套杂交棉育种的组配方法,为骨干亲本的构建和应用提供理论依据。本研究选择9个适合黄河流域种植的陆地棉品种(系)作亲本,交配了一套半双列杂交,应用Gardner and Eberhart模型,从群体的角度,分析了多环境下陆地棉杂种优势和配合力反映;并进一步比较了亲本的分子和表型遗传距离与Gardnerand Eberhart模型所估算的多个遗传效应值及F1表现间的关系,探索杂种优势预测的效果。此外,还分析了个别杂交种后代的开花期、叶形、叶片衰老的遗传变异及后代选择效果等,主要结果和结论如下:1.首次应用Gardner and Eberhart模型,分析了陆地棉的杂种优势和配合力反映,结果表明大多数经济和品质性状的品种、杂种优势、杂交组合效应显著,平均杂种优势和品种杂种优势效应不显著,说明加性效应是陆地棉大多数性状杂种优势的遗传基础。通过比较9个亲本产量和产量组成因素的品种、一般配合力(GCA)和品种杂种优势的效应值,表明中棉所41、邯郸109、鲁研棉28是杂种优势利用中比较好的亲本。F1的大多数性状表现群体平均优势,但群体超亲优势的比例偏低。此外,通过比较亲本和杂交种的遗传和表型相关,发现亲本杂交后部分性状间的遗传关系发生了变化。以上结果表明,可以利用杂种优势改良或提高棉花的大多数性状,在选育杂交棉时,应着重提高结铃数,保持适当的铃重和衣分,协同提高纤维品质。2.通过比较分析9个陆地棉品种(系)的分子和表型遗传距离与杂种优势的关系,表明分子和表型遗传距离达极显著的正相关;分别与F1的单株结铃数、籽棉产量、皮棉产量以及纤维比强度达极显著的负相关,与杂交组合12个农艺性状的SCA效应值均不显著;9亲本的分子和表型平均遗传距离与大多数性状的品种和GCA效应值为显著的负相关,与大多性状的品种杂种优势效应值不显著。3.利用主基因和多基因混合模型控制分析了抗3×超鸡463和邯郸109×鸡叶98两个杂交组合的多个世代的开花期遗传。两个杂交组合的F2群体在两年试验中开花期均表现连续分布,但偏离正态分布。应用联合世代分析法对开花期进行主基因-多基因混合遗传模型分析,证明陆地棉开花期的遗传受一对加性效应的主基因和加性-显性效应的多基因控制;一介和二介模型的遗传参数的结果表明,组合间主基因的加性效应和多基因的显性效应有正、负的差别;结果还表明很难确定开花期与叶形的关系。4.应用联合尺度检验法分析了抗3×超鸡463和邯郸109×鸡叶98两个杂交组合的多个世代的叶形性状的数量遗传。对于叶面积、叶裂宽度、叶柄长度及叶裂的长/宽比性状的遗传,六参数模型比三参数模型(加-显模型)更合适,说明上位性效应在叶形变异中的重要性;而叶周长的遗传选择了不同的模型。控制叶形单个性状的最小基因数在0—2之间,控制叶形最小基因数的总和分别为6(抗3×超鸡463)和2(邯郸109×鸡叶98)。结果表明叶形变异在后代的选择是有效的。5.通过对9个棉花品种(系)开花前后相对叶绿素含量(SPAD值)的变化,确定开花后35天的叶片SPAD值,最好是和开花当天的差值,可用来预测棉花早衰的程度。利用SPAD差值和衰老分级两种方法调查了杂交组合抗3×超鸡463构建的6个世代群体的叶片早衰,应用联合尺度检验法进行世代均值分析,结果表明两种方法的分析结果比较一致,叶片的早衰主要由加性效应控制,不存在显性和上位性效应遗传,早代选择是有效的。

【Abstract】 Cotton is produced as raw material for the textile industry and is considered to be a high value crop. During the past decades, the hybrid cotton was greatly planted by the Yellow River valley and the Changjiang River valley. Therefore, the method for mating hybrid cotton is necessary for establishing the parental core. In this study, nine parental lines of upland cotton, collected from germplasms of the Yellow River valley, were evaluated byGardner and Eberhart’s diallel analysis for combining ability, heterosis and other genetic parameters for cotton yield, fiber quality et al. Furthermore, genetic distances from molecule and phenotypic data were estimated. Comparison of phenotypic and molecular distances related with heterosis, combining ability from Gardner and Eberhart’s diallel analysis, and F1 performance was analyzed to predict heterosis. Based on the above genetic distances and leaf morphology among the nine parental lines, the present study also reported the quantitative genetic analysis of time of flowering, leaf morphological traits and premature senescence of leaf from the intraspecific crosses using joint segregation analysis or generation mean analysis.1. 45 diallel entries including nine parental lines and their 36 crosses were evaluated by Gardner and Eberhart’s diallel analysisⅡandⅢ. For a majority of traits, variety, heterosis, crosses, general combining ability (GCA) effects were significant, and average heterosis and variety heterosis effects was not significant, indicating additive effects were important for heterosis of upland cotton. Estimates of variety, GCA and variety heterosis effects showed Zhongmiansuo 41, Handan 109 and Luyanmian 28 among nine the parental lines were the relative best for heterosis of yield. According to the results of population midparent heterosis and population high-parent heterosis, a majority of the performances of F1 were between their double parental lines, but proportion of high-parent heterosis, especially positive significance, was relatively less. The genetic relationship among yield and fiber quality had some changes after hybrid occurred among the parental lines. According to the above results, the utilization of heterosis is feasible for several traits, and hybrid cotton cultivars for breeding in upland cotton should increase no. of total bolls, retain suitable boll weight lint%, and cooperatively improved fiber quality.2. This study was also undertaken to determine the relationship between parental distances estimated from phenotypic traits and molecular markers with heterosis and F1 performance. The positive correlation between phenotypic and molecular distances was highly significant. Negative correlations between molecular and phenotypic distances with several traits of F1 were highly significant. Mean phenotypic and molecular distances were significantly correlated with GCA and variety effects for most of traits with negative. According to the results, the corrections were negative between phenotypic or molecular distances with a majority of heterosis traits.3. This paper presents a study of the genetic control for time of flowering in Kang3×Chaoji463 and Handan109×Ji98 crosses obtained from different early-maturity parental lines. In each cross, multiple generations including P1, F1, P2, B1, B2 and F2 were evaluated under two natural field conditions. The data on time to flowering in the F2 populations had a continuous distribution but deviated from normality. A joint segregation analysis (JSA) revealed that time of flowering in upland cotton was controlled by a mixture of an additive major gene and additive-dominant polygenes. The first- and second-order genetic parameters were all calculated based on the mixture of major gene and polygenes inheritance models using JSA. These results suggested that there was considerable genetic diversity and complexity in days to anthesis in upland cotton. This variation can be used to formulate the most efficient breeding strategy and to design cotton for a particular environment.4. Genetic manipulation of leaf architecture may be a useful breeding objective in cotton (Gossypium spp.). The present study firstly reported quantitative genetic analysis of leaf traits from two intraspecific crosses of inbred lines in upland cotton (Gossypium hirsutum L.) viz. Kang3×Chaoji463 and Handan109×Ji98. Six leaf morphological traits (leaf area, leaf perimeter, main lobe length and width, petiole length, and main lobe length/width ratio) were recorded from multiple generations (P1, F1, P2, B1, B2, and F2) in the two crosses. Generation mean analyses were conducted to explain the inheritance of each leaf morphological trait. The six-parameter model showed a better fit to an additive-dominance model for leaf area, main lobe width, petiole length, and main lobe length/width ratio in the two crosses, suggesting the relative importance of epistatic effects controlling leaf morphology. A simple additive-dominance model accounted for the genetic variation of the main lobe length in the Kang3×Chaoji463 cross. Different models were selected as appropriate to explain leaf perimeter in the two crosses. The estimated minimum number of genes controlling each leaf morphological trait ranged from 0-2 for both crosses. Moreover, the sums of the minimum number of genes controlling leaf morphology were 6 and 2 in the Kang3×Chaoji463 and Han109×Ji98 populations. respectively. Most data suggested that there existed a substantial opportunity to breed cottons that transgress the present range of leaf phenotypes found.5. According to the changes of leaf Chlorophyll (SPAD) before and after the flowering time in nine cotton lines, the reductions between leaf Chlorophyll at 35 days after the flowering and at flowering was used as one of the indicators of senescence. Another measurement of stay-green was an independent visual estimation of the retention of the green-area for leaves at 35 days after flowering on a 1 to 5 scale. Generation mean analyses were conducted to explain the inheritance of leaf senescence for multiple generations (P1, F1, P2, B1, B2, and F2) in the Kang3×Chaoji463 cross. The results according to the SPAD and scale were relative consistent, both showing additive effects controlled the genetic of leaf senescence without dominance and epistatic effects.

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