大豆杂种产量的主-微位点组遗传分析

选用来源于中国黄淮和美国的熟期组II~IV的8个大豆品种,按Griffing方法II设计,配成36个双列杂交组合(28个杂种组合+8个亲本)于2003-2005年进行田间试验。应用基于数量性状主基因+多基因遗传模型的主-微位点组分析法,解析8个大豆亲本产量的主、微位点组遗传构成及其效应,估计主、微位点组对产量杂种优势的贡献。结果表明,8个大豆亲本间产量由6个主位点组加微位点组控制,主位点组、微位点组分别解释表型变异的75.98%和10.81%。6个主位点组加性效应(a_J)分别为140.10、259.65、1.95、151.35、–32.70和45.00 kg hm^–2,显性效应(d_J)分别为177.15、314.25、105.75、75.90、242.85和171.00 kg hm^–2。杂种遗传构成包括主位点组杂合显性效应、主位点组纯合加性效应、微位点组杂合显性效应和微位点组纯合加性效应4部分,相对重要性依次递减,以显性效应为主,加性效应为辅。亲本间主、微位点组及其遗传效应的解析阐释了各杂种组合的遗传特点,还提供了进一步挖掘遗传潜力进行优势改良的基础。     

棉花霜前皮棉产量主位点组遗传分析

选用不同来源的6个棉花品种作亲本, 按照Griffing P(P–1)/2不完全双列杂交方法配制15个杂交组合。应用QTL检测体系的主位点组基因型和基因效应, 估计主位点组霜前皮棉产量杂种优势并分析有利位点组与杂种优势的关系。结果表明, 霜前皮棉产量主位点组解释的变异占表型变异的36.79%, 主位点组与环境互作解释的变异占表型变异的33.46%, 环境解释的变异占表型变异的10.37%, 微位点组解释的变异很低, 占表型变异的3.27%。6个棉花品种的霜前皮棉产量的遗传受5个主位点组基因控制, 其加性效应(a_J)分别为5.99^{**、-1.26**、-0.92**、-0.75和3.01, 显性效应(d_J)分别为2.55**、4.16**、7.95**、5.32**和-7.71**各主位点组基因的效应方向、大小不等。主位点组中亲优势变幅15.55%~133.56%, 平均63.34%, 高亲优势变幅15.39%~93.82%, 平均44.56%。棉花霜前皮棉产量杂种优势主要取决于主位点组基因的杂合性。在棉花育种实践中, 通过分析亲本及组合的主位点组基因型, 能够得到有价值信息。配制早熟、高产杂交组合的同时, 结合分子聚合设计育种, 把优质、抗病虫、抗逆等性状集于一体, 可培育出综合性状优良的常规品种, 从而提高育种效率。,}      

质量-数量性状的遗传分析 Ⅰ.遗传组成和主基因基因型鉴别

质量-数量性状是指具有主基因效应的数量性状,它在作物的许多重要经济性状中均有存在。这种性状可能同时受主基因和多基因控制,但迄今尚缺乏相应的遗传分析方法。本文分析了主基因为一个位点时质量-数量性状的世代遗传组成。结果表明,如果能够区别分离世代中的各种主基因基因型,就能对这种性状是否存在主基因和/或多基因效应作出有效的测验;而主基因基因型(如果存在的话),则可通过其后裔株系的平均数和方差的分类或聚类进行鉴别。因此,质量-数量性状的遗传也可以应用生统遗传学方法作出分析。     

质量-数量性状的遗传分析 I.遗传组成和主基因基因型鉴别

质量-数量性状是指具有主基因效应的数量性状,它在作物的许多重要经济性状中均有存在.这种性状可能同时受主基因和多基因控制,但迄今相应的遗传分析方法.本文分析了主基因为一个位点时质量-数量性状的世代遗传组成.结果表明,如果能够区别分离世代中的各种主基因基因型,就能对这种性状是否存在主基因和/或多基因效应作出有效的     

重组自交家系群体4对主基因加多基因混合遗传模型分离分析方法的建立

主基因加多基因混合遗传模型分离分析方法是基于数量性状表型数据的统计遗传分析方法,该方法适于育种工作者利用杂种分离世代的数据对育种性状的遗传组成做出初步判断,制订相应的育种策略,也可用以校验QTL定位所揭示的性状遗传组成。重组自交家系群体(RIL)是一种永久性群体,可以进行有重复的比较试验,适合于环境影响较大的复杂性状的遗传研究。本研究以RIL群体为对象,将遗传模型拓展到4对主基因,建立相应的分离分析方法。新构建的模型共包括4对主基因和4对主基因加多基因两类共15个遗传模型,通过极大似然法和IECM算法估算各种模型的分布参数,由AIC值和一组适合性测验选取最佳遗传模型,再由最小二乘法估计模型的遗传参数。通过模拟实验对所建立的模型进行验证,模拟群体中一阶遗传参数的估计值与设定值之间有很好一致性。以大豆科丰1号×南农1138-2构成的RIL群体及其亲本棕榈酸含量的遗传(I-1模型,即4对加性-上位性主基因和加性-上位性多基因遗传模型)为例,说明该方法的应用效果。     

质量-数量性状的遗传分析——Ⅱ.世代平均数和遗传方差

本文阐述由自花授粉作物的两个纯系杂交而衍生的各种世代群体的质量-数量性状的遗传表达。根据遗传组成和加性-显性遗传模型下的基因效应,给出了各有关群体质量-数量性状的平均数和遗传方差的分量。在此基础上,论述了主、微基因遗传变异的统计测验和主、微基因加性、显性变异分量的样本估计方法。     

质量-数量性状的遗传分析

本文阐述由自花授粉作物的两个纯系杂交而衍生的各种世代群体的质量-数量性状的遗传表达,根据遗传组成和加性-显性遗传模型下的基因效应,给出了各有关群体质量-数量性状的平均数和遗传方差的分量.在此基础上,论述了主、微基因遗传变异的统计测验和主、微基因加性、显性变异分量的样本估计方法。     

不同遗传来源甘蓝型油菜开花期的基因型差异和遗传效应分析

应用作物数量性状QTL体系检测的主位点组方法对不同地理来源的甘蓝型油菜(Brassica napus L.)12个品种双列杂交组合的开花期(播种-初花日数)性状的遗传差异进行了研究. 结果表明, 12个甘蓝型油菜品种开花期的遗传受4个主基因控制, 其加性效应分别为-17.22**, 2.71*, 6.09**和-1.05, 显性效应分别为-3.67*, 1.07*, 4.52*和-2.7     

色素万寿菊W217橙红色花色遗传性状研究

采用W217×W203组合的P1、P2、F1、B1、B2和F2共6个世代的花色色调值,利用主基因+多基因混合遗传模型多世代联合分析方法进行遗传分析.结果表明,色素万寿菊橙红色花性状最优遗传模型为两对加性-显性-上位性主基因+加性-显性-上位性多基因遗传模型,以主基因遗传效应为主,多基因效应为辅.主基因加性效应、显性效应和上位性效应作用很大,主基因遗传力受环境影响较小.在F2群体中主基因遗传率为49.13％,多基因遗传率为48.25％；在B1群体中主基因遗传率为84.23％；在B2群体中主基因遗传率为74.41％,多基因遗传率为18.24％.     

甜玉米品质性状的主基因+多基因遗传分析

对甜玉米品质性状进行主基因+多基因遗传分析,为甜玉米品质改良提供理论依据。用果糖含量、膳食纤维含量和维生素C含量差异显著的甜玉米自交系配制杂交组合T77（高值亲本）×T15（低值亲本）。以该组合F2代群体为试验材料,对其果糖含量、膳食纤维含量和维生素C含量等3个品质性状进行测定,利用主基因+多基因混合遗传模型分析3个性状的最适遗传模型及相关遗传参数。试验表明,果糖含量的最适模型为A-1,是受1对主基因控制的加性-显性遗传模型,主基因遗传率为76.4%;膳食纤维含量和维生素C含量的最适模型同为B-1,表明这2个性状符合2对主基因控制的加性-显性-上位性混合遗传模型,主基因遗传率分别为63.6%和64.7%。在育种实践中,对甜玉米果糖含量、膳食纤维含量和维生素C含量的遗传改良和选择,可在早期世代进行,同时要注意一定的环境因素,采用聚合回交或轮回选择的方法来积累微效基因以提高育种效率。     

衣分不同陆地棉品种的产量及产量构成因素的遗传分析

选用衣分不同的陆地棉品种配置组合,率先将主基因-多基因联合世代分析与双列杂交试验分析相结合,分别从单个和整体基因水平上对棉花产量及产量构成因素进行了遗传研究。对2个高×低衣分组合的主基因-多基因6世代联合分析结果表明,各产量性状至少在1个组合中检测到主基因的存在,说明产量性状主基因存在的普遍性。由2个组合各产量性状的主基因、多基因遗传率比较得出,产量性状的主基因遗传率比多基因遗传率在不同组合间趋势变化相对较稳定;各性状在2个组合中的主基因、多基因遗传率分量不完全相同。衣分、铃重和籽指在2个组合中分别以主基因遗传为主和以多基因遗传为主;子棉产量和皮棉产量在2个组合中均以主基因遗传为主;衣指在组合I中以多基因遗传为主,在组合II中属于典型的多基因遗传;单株铃数在组合I中属于典型的主基因遗传,在组合II中以多基因遗传为主。双列杂交结果表明,陆地棉产量及产量构成因素都有较高的遗传主效应方差,产量性状受加性效应和显性效应共同控制,其中,衣分、衣指以加性效应为主;子棉产量、铃重和籽指以显性效应为主;皮棉产量和单株铃数以加性和显性效应为主。衣分和衣指的普通广义遗传率和普通狭义遗传率均最高,与联合世代分析两性状的总遗传率平均值结果趋势一致。相关和通径分析一致表明,产量构成因素中单株铃数对皮棉产量的贡献最大,衣分次之,铃重最小。     

Genetic analysis of pungency and soluble solids in long-storage onions

Summary Pungency and soluble solids are important quality attributes of onion. An eight-parent diallel over two years indicated a preponderance of additive genetic variation for both attributes. Variation among years was significant for pungency but not solids. No reciprocal cross differences were noted for pungency or solids. Generatio means analysis for four crosses over two years had a good fit with a simple additive-dominance model to explain the inheritance of both traits in most cases. Both diallel and generation means analyses demonstrated some dominance for low pungency. Broad sense heritability estimates averaged 0.64 for pungency and 0.83 for soluble solids. Selection was effective for increasing and decreasing pungency in derivatives of five crosses. Pungency and soluble solids were correlated among parental inbreds and hybrids but not within F₃'s. The additive control and heritability suggest that onion pungency and soluble solids can be effectively and independently selected.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

Genetic studies of selection criteria for productive and stable peas

In this study we investigated the genetic determinism of criteria suitable for breeding for seed yield and yield stability in dry pea (Pisum sativumL.) using a diallel cross involving eight genotypes. Seven criteria related to plant and seed development were evaluated including: onset of flowering, node of first flower, leaf appearance rate, rate of progression of flowering, number of podded nodes on the main stem, mean dry seed weight per podded node and number of basal branches per plant. Most of these traits measured are related to timing of seed set and are thought to be critical in determining yield stability. We combined different diallel analyses (Hayman,1954; Griffing, 1956) with a Principal Component Analysis, to divide the parental lines into groups sharing similar genetic control for the traits studied. We found that the two main groups, defined according to their genetic control of node of first flower, also differed for all the others characters and, in particular, did not reach the same levels of productivity. These results indicated that crosses within the group with the highest productivity, but between lines with differing development and architectural features, could be a good starting point for breeding high-yield pure lines. This revised version was published online in August 2006 with corrections to the Cover Date.     

大豆杂种产量相关的位点及等位变异分析

选用来源于中国黄淮和美国的熟期组II~IV的8个大豆品种, 按Griffing方法II设计, 配成28个双列杂交组合, 包括8个亲本共计36份材料。选用300个SSR标记, 对8个大豆亲本进行全基因组扫描, 利用基于回归的单标记分析法, 对大豆杂种产量和分子标记进行相关性分析, 估计等位变异的效应和位点的基因型值, 剖析杂种组合的等位变异。结果表明, 300个SSR标记中有38个与杂种产量显著相关, 分布于17个连锁群上, 其中D1a和M等连锁群上较多, 有8个位于连锁定位的QTL区段内(±5 cM)。单个位点可分别解释杂种产量表型变异的11.95%~30.20%。杂种的位点构成中包括有增效显性杂合位点、增效加性纯合位点、减效加性纯合位点和减效显性杂合位点4部分, 其相对重要性依次递减。从38个显著相关的SSR标记位点中, 遴选出Satt449、Satt233和Satt631等9个优异标记基因位点, Satt449~A311、Satt233~A217和Satt631~A152等9个优异等位变异, 以及Satt449~A291/311、Satt233~A202/207和Satt631~A152/180等9个优异杂合基因型位点。这些结果为理解杂种优势的遗传构成和大豆杂种产量聚合育种提供了依据。     

Evidence suggests that Mycosphaerella pinodes infection of Pisum sativum is inherited as a quantitative trait

Before likely sources of resistance in pea to Mycosphaerella pinodes can be exploited in a breeding program, the inheritance of genetic mechanisms governing the variation in resistance need to be understood. Disease responses were first examined in a diallel cross of nine Pisum sativum genotypes. An analysis of variance of parental and F₁ data detected significant additive and dominance variation but no reciprocal effects. Gene interactions were not significant in leaves with the exception of the line JI 252 and there was no association detected between the frequencies of dominant or recessive alleles and parental disease response. In stems, the slope of the regression line of the covariance if array members with their non recurrent parent on the variance of an array was significantly different from one and the additive-dominance model was therefore rejected. The non-significance of interactions among genes determining disease response in leaves was supported by the triple test cross analyses. These analyses showed that the narrow-sense heritability of disease response was higher in crosses involving SA 1160 than in the cross Wirrega × Austrian Winter. These crosses are likely to generate inbred lines more resistant to M. pinodes infection than either parent. This revised version was published online in July 2006 with corrections to the Cover Date.     

甘蓝型油菜裂角相关性状的遗传与相关分析

抗裂角性是非常重要的油菜性状, 但相关研究报道较少。本研究对11个甘蓝型油菜骨干亲本品系及由其配制的30个不完全双列杂交组合在2个环境下的抗裂角指数及其他7个角果相关性状进行了遗传分析。结果表明, 抗裂角指数遗传变异显著, 遗传上受少数主效基因控制, 效应以加性为主, 显性效应和环境效应影响较小。大部分杂交组合的抗裂角指数杂种优势不显著。抗裂角指数与角果长、果皮重、千粒重和种子直径呈极显著正相关, 与结角密度和角粒数呈极显著负相关。抗裂角性相关性状中, 角果长、千粒重、结角密度和种子直径变异主要由加性方差解释;果皮重和每角粒数主要由显性方差解释。亲本评价分析指出, 作为波里马细胞质雄性不育系统保持系的ZS11B和恢复系的R11其抗裂角性的一般配合力高, 是培育抗裂角杂交油菜品种的首选直接亲本。     

Signatures of divergent selection for cold tolerance in maize

Divergently selected genotypes can be used for detecting the genomic regions affecting the selected trait (selection signature). Moreover, the genetic distances (GDs) among divergently selected lines can be correlated with the agronomic performances of the crosses among them. Using as source the maize F₂ of B73?×?IABO78, we previously conducted four cycles of divergent recurrent selection and three cycles of divergent selection in inbreeding for cold tolerance at germination. We finally obtained 10 lines selected for low (L) and 10 lines selected for high (H) cold tolerance, which exhibited a notable divergence for both the selected and associated traits. Herein, we investigated the 20 lines and the 28 single diallel crosses among eight random lines (four L and four H); the main objectives were to identify the putative regions controlling the selected and associated traits and to study the relationships between crosses performances and GDs among their parental lines. Allele frequencies at 932 recombination blocks based on 19,220 polymorphic SNPs were obtained for the two lines’ groups; the F _ST calculated across sliding windows indicated 18 regions highly divergent between groups. The increasing alleles for cold tolerance were contributed by both parents, consistently with the transgressive segregations previously found. Several regions associated to DG also affected various agronomic traits. The cross performances showed some relationships with the genetic distances among parental lines for traits affected by dominance, provided that all crosses were considered, while these relationships vanished when only L?×?H crosses were examined.     

Genetics of nitrate content of lettuce, 1: Analysis of generation means

Summary The genetics of nitrate content in butterhead lettuce (Lactuca sativa L.) was studied using the mean values of five parental genotypes and several generations obtained from crosses between them. One high nitrate parental genotype was chosen and four low nitrate ones. A diallel analysis showed additive genetic effects to be the major source of variation in generation means. Estimates of additive genetic effects differed significantly between experiments, indicating genotype x experiment interactions. Effects of dominance were relatively small. The size and direction of dominance varied between experiments. Reciprocal differences were of very limited size and also varied between experiments. The inheritance of nitrate content in lettuce fitted the additive-dominance genetic model.     

Combining ability and heterosis under pest epidemics in a broad-based global wheat-breeding population

Wheat breeders rarely apply population improvement schemes or select parental sources according to combining ability and heterotic patterns. They rely on pedigree selection methods for breeding new cultivars. This experiment was undertaken to assess the advantages of using diallel crosses to define combining ability and understand heterosis in a broad‐based wheat‐breeding population across different environments affected by yellow rust. Sixty‐four genotypes derived from a full diallel mating scheme were assessed for grain yield in two contrasting growing seasons at two locations for two consecutive years. Parental genotypes showed significant combining ability for grain yield that was affected by yellow rust and genotype‐by‐environment (GE) interactions, both of which affected heterosis for grain yield. Significant GE interactions suggested that decentralized selection for specific environments could maximize the use of this wheat germplasm. Cultivar effects and specific heterosis were the most important factors influencing grain yield. Some crosses capitalized on additive genetic variation for grain yield. This research shows the power of available quantitative breeding tools to help breeders choose parental sources in a population improvement programme.