陆海BC_4F_2和BC_4F_3代换系的评价及纤维产量与品质相关QTL的检测

Assessment of Substitution Lines and Identification of QTL Related to Fiber Yield and Quality Traits in BC_4F_2 and BC_4F_3 Populations from Gossypium hirsutum×Gossypium barbadense

【目的】利用SSR标记对陆海BC4F2和BC4F3代换系进行评价并检测纤维产量与品质相关的QTL,为筛选棉花染色体单片段代换系、精细定位纤维品质QTL、实现分子聚合育种奠定基础。【方法】利用GGT32(graphical genotyping)软件分析每个代换系的基因型组成,采用SAS PROC GLM的单向方差分析方法检测影响各性状的QTL。【结果】检测到50个单片段代换系,其中9株含有纯合的海岛棉片段,并筛选出12个代换片段少、纤维品质优良的代换系。共检测到15个控制产量性状和19个控制纤维品质的QTL,集中分布在12个连锁群中,解释的表型变异率在2.80%—14.13%。【结论】4个上半部平均长度QTL在2个世代中稳定遗传,1个上半部平均长度QTL在前人研究论文中检测到,部分标记位点同时控制几个不同的性状,并发现增效基因不全来自高值亲本。

[Objective] A total of 276 SSR makers were used to assess the substitution lines and identify the QTLs related to fiber yield and quality traits in BC4F2 and BCaF3 populations from Gossypium hirsutum xGossypium barbadense with Gossypium hirsutum as recurrent parent, which could lay a foundation for further screening SSSLs （single segment substitution lines）, finely mapping QTL of fiber yield and quality-related traits and realizing molecular assistant breeding. [Method] GGT32 was employed to analyze the genotype of BC4F2 and BCaF3 individuals. Possible QTL were identified by one-way analysis of variance on SAS PROC GLM. [Result] Atotal of 50 SSSLs were detected in BC4F2 and BCaF3 individual populations, in which 9 plants contained the single homozygosis chromosome segment of Gossypium barbadense. Twelve plants were screened out with excellent fiber quality trait and a few chromosome segments from Gossypium barbadense. Fifteen QTLs for fiber yield-related traits and 19 QTLs for fiber quality-related traits were mapped in twelve linkage groups, which accounted for 2.80%-14.13% of phenotypic variance. [ Conclusion] This study indicated that 4 QTLs related to fiber length could be detected in the two populations and 1 QTL for fiber length was reported in previous research, pleiotropism or linked genes existed in some loci that controlled different traits, and not all of additive genes were from the parent with excellent traits.