转基因抗虫棉产量性状的遗传效应及其杂种优势分析

采用加性-显性与环境互作的遗传模型,分析了9个亲本和36个F1的皮棉产量、单株铃数、铃重和衣分的两年资料,估算了转基因抗虫棉各项遗传方差和成对性状间各项遗传效应的相关性.结果表明,转基因抗虫棉的产量性状受加性和显性效应共同控制,皮棉产量、铃重和衣分都以基因的显性效应为主,而单株铃数是以加性效应为主,单株铃数和衣分还具有基因与环境互作效应.遗传相关分析表明,转基因抗虫棉的皮棉产量与单株铃数的基因型和表现型相关系数都比较大而且比较接近;皮棉产量与单株铃数、铃重和衣分的加性相关系数都达到极显著水平,而且皮棉产量与单株铃数、衣分的数值比较大.利用亲本和F1的资料预测了F2基因型值和杂种优势,结果表明,转基因抗虫棉F2的皮棉产量、单株铃数、铃重和衣分的群体平均优势分别为4.0%、5.1%、-1.3%和3.2%,群体超亲优势分别为-7.3%、-6.0%、-4.2%和-0.5%.     

陆地棉主要农艺与纤维品质性状的双列杂交分析

本文利用加性-显性与环境互作的遗传模型(ADE模型),分析8个陆地棉亲本及其F1在不同环境下的农艺和纤维品质性状,在估算遗传方差分量、遗传效应的基础上,分析各类性状间的遗传相关性,并预测F1和F2的杂种优势,为棉花杂种优势利用和新品种选育提供了较有价值的信息。研究表明,农艺与纤维品质性状的遗传主要受加性、显性和加性与环境互作效应控制。遗传相关分析表明,皮棉产量与纤维品质性状的显性相关系数值较大,利用杂种优势在早期世代可以得到协同改良,纤维品质性状间易实现协同改良。杂种优势分析表明,F1和F2的皮棉产量均具有显著的超亲优势,纤维品质性状的杂种优势不明显。     

陆地棉产量性状的遗传分析

采用加性-显性与环境互作的遗传模型,分析陆地棉8个杂交亲本和F128个组合的7个产量性状的两年试验资料,估算各项遗传方并非分量和F1、F2的杂种优势.结果表明,产量性状受加性效应和显性效应共同控制,加性×环境各产量性状均极显著,铃重、衣分、籽指还受显性×环境的极显著影响,7项产量性状的广义和狭义遗传率均达到极显著水准.     

陆地棉主要农艺与纤维品质性状的双列杂交分 析简

 本文利用加性-显性与环境互作的遗传模型（ADE模型）,分析8个陆地棉亲本及其F1在不同环境下的农艺和纤维品质性状,在估算遗传方差分量、遗传效应的基础上,分析各类性状间的遗传相关性,并预测F1和F2的杂种优势,为棉花杂种优势利用和新品种选育提供了较有价值的信息。研究表明,农艺与纤维品质性状的遗传主要受加性、显性和加性与环境互作效应控制。遗传相关分析表明,皮棉产量与纤维品质性状的显性相关系数值较大,利用杂种优势在早期世代可以得到协同改良,纤维品质性状间易实现协同改良。杂种优势分析表明,F₁和F₂的皮棉产量均具有显著的超亲优势,纤维品质性状的杂种优势不明显。     

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。     

QTL遗传效应正反交差异研究

应用改良AD模型对转基因棉花QTL突变体系进行遗传效应的正反交比较分析,结果表明,农艺性状的主要遗传方差组分分解正反交表现一致,除铃重存在显著的遗传背景加性效应(A2)外,子棉产量、皮棉产量、衣分和铃数均存在显著或极显著的 dQTL加性效应(A1)和显性效应(D1),农艺性状均有显著或极显著的遗传背景显性效应(D2);棉花纤维性状的主要遗传效应正反交之间无显著差异.铃重的dQTL的加性和显性效应与环境的互作存在显著差异.对转基因系、受体及三个品系的dQTL加性效应分解结果也表明,正反交对不同材料各性状的加性效应估计也是一致的.本文还对不同组合正反交时的纯合及杂合显性效应进行预测比较.     

棉花产量和纤维品质性状的遗传研究

 采用8×8不完全双列杂交分析法,对棉花产量因素、纤维品质性状的遗传效应及其遗传相关进行了研究分析,并将遗传相关分解为加性相关和显性相关。结果表明,在棉花产量因素中,皮棉产量和单株结铃数的遗传分别以加性效应、显性效应为主,而加性效应、显性效应对铃重和衣分的控制同等重要。其中,衣分受环境变异的影响最小。所以,在F₂～F₃代进行选择的效果较好;在品质性状中,纤维长度、比强度及麦克隆值的遗传均以加性效应为主,受环境变异影响均较大。棉花产量因素与品质性状之间的相关普遍表现为遗传相关大于表型相关,各性状之间的表型相关、遗传相关及加性相关类似,而显性相关则不同。遗传相关特别是加性相关可以指导选择育种,而显性相关对杂种优势的利用至关重要。     

陆地棉配合力与杂种优势、遗传距离的相关性分析

 用10个陆地棉亲本进行不完全双列杂交,共配置了45个组合,计算亲本的一般配合力（GCA）、特殊配合力(SCA)、杂种优势,并结合SSR标记研究了陆地棉亲本配合力与杂种优势、遗传距离之间的相关关系。配合力分析发现,10个亲本的一般配合力和特殊配合力存在显著或极显著差异。分析亲本配合力、杂种优势和遗传距离的相关性发现,子棉产量、皮棉产量、衣分的一般配合力和杂种优势呈显著或极显著相关,纤维长度、比强度、麦克隆值、株高、果枝数、单株铃数、铃重、子棉产量、皮棉产量、衣分的特殊配合力和杂种优势均呈极显著正相关,而与遗传距离相关均不显著。单株铃数、铃重、子棉产量、皮棉产量、衣分的杂种优势与遗传距离均为正向显著或极显著相关。在育种实践中这些显著或极显著相关的性状可能具有较高的改良潜力。     

海岛棉产量性状的遗传效应分析

采用加性-显性的遗传模型，研究海岛稀11个亲本和30个F1杂交组合8个产量性状的各项遗传方差分量和遗传相关。结果表明：单株有效铃数、单株无效铃数、铃重、籽棉产量的加性方差比率分别达到显著和极显著水平，而显性方差比率均不显著，表明这4个产量性状的遗传以加性效应为主，皮棉产量、衣分、衣指则不显著，且普通次义遗传率较低。遗传分析表明：新海14号和99-1111籽棉产量有显著的加性效应，可作为杂交育种的优良亲本。     

转Bt基因杂交棉主要性状优势率分布研究

分析了 73个转 Bt基因抗虫杂交组合 F1主要性状的杂种优势及优势率分布 ,认为 :1杂种一代的霜前皮棉产量、株高、铃重、衣分、霜前花率等性状具有明显的正向优势。 2 5 6%的组合霜前皮棉产量竞争优势 ( CH% )集中在 1 0 .1 %～ 35 %之间 ;子棉总产则以 0 .1～ 2 0 %居多 ;铃重、衣分、子指、霜前花率的 CH%主要分布在 0 .1 %～ 1 5 %之间 ;生育期、2 .5 %跨长为负优势 ,多在 - 5 %～ - 0 .1 %之间。 3与 F1相比 ,除子指、2 .5 %跨长外 ,F2主要性状杂种优势均不同程度下降 ,以子棉总产、霜前皮棉产量、霜前花率、单株铃数降幅较大 ;生育期变化较小 ;铃重、衣分、子指虽比 F1有所下降 ,但仍呈现较强的正向优势     

高品质陆地棉与不同类型品种杂种的遗传及优势分析

 比较分析了高品质棉与高品质棉、常规品质转Bt基因抗虫棉杂交组合主要性状的遗传效应和杂种优势。结果表明,两类杂种的子棉产量存在极显著的加性和显性效应;高×高杂种的株铃数和铃重具有极显著的显性效应,高×常抗杂种受加性和显性效应共同控制;两类杂种的纤维品质性状以加性效应为主,但显性效应对纤维长度也起较大作用。高×高杂种的F₁子棉产量和株铃数具有正向超亲优势,高×常抗杂种表现为负向超亲优势;两类杂种的纤维长度和麦克隆值具有较小的正向平均优势,比强度具有负优势。高×高杂种可以在保持亲本良好品质的基础上,利用产量和产量性状的正向超亲优势来提高产量。     

Genetic effects and heterosis of within-boll yield components in upland cotton (Gossypium hirsutum L.)

Within-boll yield components are the most basic contributors to lint and seed yield of cotton (Gossypium hirsutum L.), which is a major source of natural fiber and edible oil throughout the world. Little information is available on genetic effects and heterosis of these traits in cotton. Three cotton cultivars and six breeding lines differing in within-boll yield components were used for this study. Parents and their F₁ progeny with reciprocals from a 3×6 factorial mating design were grown at Jiangxi Agricultural University experimental farm in 2008 and 2009. Seven within-boll yield components and two boll bur characters were analyzed under an additive-dominance genetic model with genotype and environment interaction. Additive effects were significant for all traits and dominance effects were significant for all traits except seed mass per seed. Genetic variances for lint mass per seed, SM/S and boll bur weight were primarily additive variances ranging from 39.6 to 58.9 %. Lint mass per boll and seed number per boll variances were primarily due to dominance genetic effects ranging from 36.4 to 48.8 %. Dominance and additive effects were equally important for boll weight, seed mass per boll and boll bur percentage. Additive and additive × environment effects were more important than other effects for lint percentage. A802-1 had the best mean performance and additive effects increasing BW, SM/B, S/B and SM/S, but reduced LP and LM/S. A9-1 and Lu40534 had additive effects associated with increasing LP. The two crosses A9-1×Lu40534 and Tezsh×33B were detected with favorable heterozygous dominant effects and heterosis over best parent for BW, LP, LM/B, SM/B and S/B. Favorable genotypic and phenotypic correlations were identified between within-boll lint yield components (LM/B, LM/S) and within-boll seed yield components (SM/B, S/B, SM/S). These results indicate that simultaneous genetic improvement of multiple within-boll yield components can be expected in breeding populations derived from these cotton cultivars and breeding lines.     

光子陆地棉种质资源主要性状的遗传评价

以102份光子陆地棉材料为母本,分别与遗传标准系TM-1杂交,获得102个F₁群体。采用随机区组设计,设置3个重复,对光子陆地棉材料主要性状进行遗传评价。结果表明,调查的11个性状表型差异均较大,材料间产量性状(株高、果枝数、铃数、铃重、衣分和子指)差异大于纤维品质性状(纤维长度、纤维强度、马克隆值、整齐度和伸长率),特别是衣分、铃数等性状差异更明显; 除果枝数、马克隆值、伸长率以外,光子亲本群体其他性状的平均值都小于F₁群体。而亲本群体所有性状的变异系数均大于F₁,不同光子材料的杂种优势有很大差别,中亲优势和超亲优势也有很大的差别,有些种质某些性状的中亲、超亲优势为负值,其后代性状表现劣势; 纤维品质性状的中亲、超亲优势与毛子程度均呈负相关,而产量性状的中亲、超亲优势与毛子程度均呈正相关,说明可利用光子材料杂种优势改良纤维品质,而其后代产量性状的杂种优势利用受到限制; SSR分子标记遗传相似系数与各个性状的中亲、超亲优势的相关都不显著,说明在光子材料的育种中,杂种优势是不能通过亲本之间的遗传背景相似程度来预测的。     

转Bt抗虫棉与常规棉品种间配合力分析及杂种优势研究

 利用6个抗虫棉品种作母本,4个常规品种作父本,按NCⅡ设计,对24个组合的杂种F₁进行了分析。结果表明,杂种F₁具有明显的优势,所研究的13个性状全部具有中亲优势,9个性状具有高亲优势,11个性状具有竞争优势。配合力分析的10个性状中单株铃数、铃重、纤维长度、纤维伸长率和麦克隆值主要受基因的加性效应控制,而子棉产量和皮棉产量主要受基因的非加性效应影响。鲁棉研17是优良的抗虫棉亲本,而冀棉12 是良好的非抗虫棉亲本,组合鲁棉研17×中棉所12在重要农艺性状上优势明显,相对而言纤维品质的改良较难。     

Heterosis,combining ability and genetic effect,and relationship with genetic distance based on a diallel of hybrids from five diverse <Emphasis Type="Italic">Gossypium barbadense</Emphasis> cotton genotypes

The cultivated tetraploid Gossypium barbadense L. cotton produces superior natural fibers for the textile industry in the world. However, the possibility in utilization of heterosis to further increase its lint yield has not been extensively explored. In this study, two commercial US Pima cotton cultivars and three exotic G. barbadense lines, together with all of their possible hybrids in F₁ and F₂ progeny without reciprocals, were tested for lint yield, yield components, and fiber quality traits in four environments in 2005–2007. With a few exceptions, genotype (G), environment (E), and G × E were all significant or highly significant for all the traits studied. General combining ability (GCA) variances for all the traits in both F₁ and F₂ were also significant, while specific combining ability (SCA) variances were detected only for lint yield, fiber length, and micronaire in both generations and boll weight in F₁. GCA × E was also detected for lint percent, seed index, and fiber length in both F₁ and F₂, and boll weight in F₁, but none of the traits had significant SCA × E. As a group, F₁ and F₂ out-yielded the parent group by 20–40% and 6–10%, respectively. Mid-parent heterosis (MPH) for lint yield in F₁ was generally positive, ranging from ?4.7 to 116.4% with an average of 21.2–48.7%, while lint yield MPH in F₂ ranged from ?23.3 to 69.4% with an average of 6.4–12.4%. However, useful heterosis in lint yield was only detected in the hybrid between the two US commercial cultivars Pima S-7 and DP 340. MPH for other traits was low or not detected. MPH in F₂ was lower than that in F₁ but they were generally positively correlated. The genetic distances (GD) of the parents (based on 467 polymorphic RAPD and AFLP markers) between the five parents was not consistently correlated with MPH and SCA of their hybrids and dominant effects for lint yield and other traits. However, significant and positive correlations between GD of parents and the performance of their hybrids were detected for lint yield, lint percentage, and lint index in both F₁ and F₂ in most of the tests. GD of parents was also correlated with their GCA and additive effects in lint yield, lint percent, lint index, micronaire, plant height, and elongation. The results suggest that the close correlation between GD and hybrid performance per se was mainly due to the existence of GCA and additive effects from parents.     

Germplasm for genetic improvement of lint yield in Upland cotton: genetic analysis of lint yield with yield components

Determination of genetic effects for lint yield and yield components in cotton (Gossypium hirsutum L.) germplasm is critical for its utilization in breeding programs. This study was designed to apply the conditional approach and an additive and dominant model to analyze genetic effects for lint yield and yield components. Forty-eight F₂ populations derived from crosses between four existent Upland cotton cultivars as female parents and 12 germplasm lines as male parents were evaluated at two locations in 2008 and 2009. Conditional and unconditional variance components were estimated by the mixed linear model based conditional approach. Lint yield and yield components were mainly controlled by genotypic effects, i.e., additive variance and dominance variance (≥66 % of total phenotypic variation). Lint percentage and lint index had the highest proportions of additive variance component to the total phenotypic variances. SP156 and SP205 had positive additive effects for lint yield and yield components, and were also parents of the most hybrids with positive predicted dominant effects. Therefore, these two lines are good combiners for development of both pure lines and hybrids. Positive additive contribution effects to lint yield from lint percentage, boll number, boll weight, and seed index were detected in different parents. Adding seed index to boll number and lint percentage increased additive contribution effects to lint yield from these two components relative to the contribution effects from either boll number or lint percentage alone. Results in this study suggest that boll number, lint percentage, and seed index should be balanced in pure line development.