Identification of Quantitative Trait Loci (QTLs) Affecting Yield and Fiber Properties in Chromosome 16 in Cotton Using Substitution Line

利用置换系检测棉花第 1 6染色体的产量、纤维品质QTLs(英文)

Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.

陆地棉 (GossypiumhirsutumL .)和海岛棉 (GossypiumbarbadenseL .)是两个栽培四倍体棉种。前者产量高、适应性广 ,后者纤维品质优良。置换了海岛棉一对染色体的陆地棉置换系是研究海陆杂种此对染色体上基因互作的优异材料。在对第 16染色体的置换系 (简称Sub 16 )进行遗传评价的基础上 ,利用 (TM_1×Sub 16 )F2∶3 家系对位于第16染色体上的重要农艺性状进行遗传分析 ,发现第 16染色体上有铃重、衣分、衣指、纤维长度、第一果枝节位的QTLs各 2个 ,纤维伸长率、开花天数的QTL各 1个 ,没有检测到子指、纤维强度、麦克隆值的QTL。在构建第 16染色体的RAPD、SSR分子标记连锁图基础上 ,利用分子标记对相应重要农艺性状进行区间作图 ,检测到铃重、开花天数、纤维长度、纤维伸长率的QTL各 1个 ,在F2∶3 株系群体中能解释的表型变异分别为 15 .2 %、12 .1%、19.7%和 11.7% ;检测到 2个衣指QTLs,在F2∶3 株系群体中能解释的表型变异分别为 11.6 %和 41.9% ;检测到 3个衣分QTLs,在F2∶3 株系群体中能解释的表型变异分别为 8.7%、9.6 %和 2 9.2 %。单标记检测到铃重、开花天数的QTL各 1个 ,在F2∶3 株系群体中能解释的表型变异分别为 1.6 0 %和 4.6 3%。证明了第 16染色体与铃重、衣分、衣指、纤维长度、纤维伸长?