Wu Man, Li Longyun, Liu Guoyuan, Li Xihua, Pei Wenfeng, Li Xingli, Zhang Jinfa, Yu Shuxun, Yu Jiwen
State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, 455000, Henan, China.
Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, 880033, USA.
Mol Biol Rep. 2019 Feb;46(1):1199-1212. doi: 10.1007/s11033-019-04589-x. Epub 2019 Jan 18.
Fiber length is one of the most important fiber quality traits in Upland cotton (Gossypium hirsutum L.), the most important fiber crop, and its improvement has been impeded in part by a lack of knowledge regarding its genetic basis. Introgressed backcross inbred lines (BILs) or near isogenic lines (NILs) differing in fiber length in the same genetic background, developed through advanced backcrossing between Upland cotton and extra-long staple cotton (G. barbadense L.), provide an important genomic resource for studying the molecular genetic basis of fiber length. In the present study, a long-fiber group and a short-fiber group, each with five BILs of Upland cotton, were selected from a BIL population between G. hirsutum and G. barbadense. Through a microarray-based comparative transcriptome analysis of developing fibers at 10 days postanthesis from the two groups, 1478 differentially expressed genes (DEGs) were identified. A total of 166 DEGs were then mapped to regions of fiber length quantitative trait loci (QTL), including 12 QTL hotspots and 2 QTL identified previously in the BIL population from which the two sets of BILs were selected. Several candidate genes possibly underlying the genetic control of fiber length differences between G. barbadense and G. hirsutum, including GhACX and GhKIF, were identified in this study. These results provide a list of positional candidate genes for the fine-scale mapping and map-based cloning of fiber length QTL, which will facilitate targeted gene transfer from G. barbadense to Upland cotton to further improve fiber quality.
纤维长度是陆地棉（Gossypium hirsutum L.）这一最重要的纤维作物中最重要的纤维品质性状之一，其改良工作在一定程度上因缺乏对其遗传基础的了解而受阻。通过陆地棉与超长绒棉（G. barbadense L.）之间的高代回交培育出的、在相同遗传背景下纤维长度不同的渗入回交自交系（BILs）或近等基因系（NILs），为研究纤维长度的分子遗传基础提供了重要的基因组资源。在本研究中，从陆地棉和海岛棉的BIL群体中选出了一个长纤维组和一个短纤维组，每组各有五个陆地棉BILs。通过对两组开花后10天发育中的纤维进行基于微阵列的比较转录组分析，鉴定出1478个差异表达基因（DEGs）。然后将总共166个DEGs定位到纤维长度数量性状位点（QTL）区域，包括12个QTL热点以及之前在从中选出这两组BILs的BIL群体中鉴定出的2个QTL。本研究鉴定出了几个可能是海岛棉和陆地棉之间纤维长度差异遗传控制基础的候选基因，包括GhACX和GhKIF。这些结果为纤维长度QTL的精细定位和图位克隆提供了一系列位置候选基因，这将有助于从海岛棉向陆地棉进行有针对性的基因转移，以进一步提高纤维品质。
