Song Weiwu, Wang Mi, Su Wei, Lu Quanwei, Xiao Xianghui, Cai Juan, Zhang Zhen, Li Shaoqi, Li Pengtao, Gong Juwu, Gong Wankui, Shang Haihong, Liu Aiying, Li Junwen, Chen Tingting, Ge Qun, Shi Yuzhen, Yuan Youlu
State Key Laboratory of Cotton Biology, Key Laboratory of Biological and Genetic Breeding of Cotton, The Ministry of Agriculture, Institute of Cotton Research, Chinese Academy of Agricultural Sciences. Anyang, Henan, China.
Enshi Academy of Agricultural Sciences. Enshi, Hubei, China.
PLoS One. 2017 Sep 20;12(9):e0184882. doi: 10.1371/journal.pone.0184882. eCollection 2017.
MBI9915 is an introgression cotton line with excellent fiber quality. It was obtained by advanced backcrossing and continuous inbreeding from an interspecific cross between the upland cotton (Gossypium hirsutum) cultivar CCRI36 as the recurrent parent and the sea island cotton (G. barbadense) cultivar Hai1, as the donor parent. To study the genetic effects of the introgressed chromosome segments in G. hirsutum, an F2 secondary segregating population of 1537 individuals was created by crossing MBI9915 and CCRI36, and an F2:3 population was created by randomly selecting 347 individuals from the F2 generation. Quantitative trait locus (QTL) mapping and interaction for fiber length and strength were identified using IciMapping software. The genotype analysis showed that the recovery rate for MBI9915 was 97.9%, with a total 6 heterozygous segments and 13 homozygous segments. A total of 18 QTLs for fiber quality and 6 QTLs for yield related traits were detected using the two segregating generations. These QTLs were distributed across 7 chromosomes and collectively explained 0.81%-9.51% of the observed phenotypic variations. Six QTLs were consistently detected in two generations and 6 QTLs were identified in previous studies. A total of 13 pairs of interaction for fiber length and 13 pairs of interaction for fiber strength were identified in two generations. Among them, 3 pairs of interaction for fiber length and 3 pairs of interaction for fiber strength could be identified in all generations; 4 pairs of interactions affected fiber length and fiber strength simultaneously. The results clearly showed that 5 chromosome segments (Seg-5-1, Seg-7-1, Seg-8-1, Seg-20-2 and Seg-20-3) have important effects on fiber yield and quality. This study provides the useful information for gene cloning and marker-assisted breeding for excellent fiber related quality.
MBI9915是一个纤维品质优良的渐渗棉系。它是通过以陆地棉（Gossypium hirsutum）品种CCRI36为轮回亲本、海岛棉（G. barbadense）品种海1为供体亲本进行种间杂交，再经过先进的回交和连续自交获得的。为了研究陆地棉中渐渗染色体片段的遗传效应，通过将MBI9915与CCRI36杂交创建了一个由1537个个体组成的F2次级分离群体，并从F2代中随机选择347个个体创建了一个F2:3群体。使用IciMapping软件对纤维长度和强度进行数量性状位点（QTL）定位和互作分析。基因型分析表明，MBI9915的回复率为97.9%，共有6个杂合片段和13个纯合片段。利用这两个分离世代共检测到18个纤维品质QTL和6个产量相关性状QTL。这些QTL分布在7条染色体上，共同解释了0.81%-9.51%的表型变异。在两个世代中一致检测到6个QTL，在先前的研究中鉴定出6个QTL。在两个世代中分别鉴定出13对纤维长度互作和13对纤维强度互作。其中，3对纤维长度互作和3对纤维强度互作在所有世代中均可鉴定到；4对互作同时影响纤维长度和纤维强度。结果清楚地表明，5个染色体片段（Seg-5-1、Seg-7-1、Seg-8-1、Seg-20-2和Seg-20-3）对纤维产量和品质具有重要影响。本研究为优良纤维相关品质的基因克隆和分子标记辅助育种提供了有用信息。
