陆地棉背景的Pima棉染色体片段置换系创制

Development of Pima Cotton Chromosome Segment Substitution Lines with Gossypium hirsutum Background

染色体片段置换系（CSSLs,chromosome segment substitution lines）基因组内只有1个或少数几个纯合的供体亲本染色体片段,而其余部分与受体亲本相同,是进行QTL分析的理想材料。本研究以陆地棉中棉所8号（CCRI8）为受体亲本,海岛棉Piam90-53为供体亲本在BC3F1-3借助分子标记辅助选择培育了一套182个株系构成的染色体片段置换系。这套置换系置换片段平均长度21.0 c M,总长度19957.8 c M,是棉花基因组总长度4168.7 c M的4.7倍。每个株系内置换片段长度不一,最短为0.7 c M,最长是83.2 c M,导入片段数量为1-11个。CSSLs在纤维品质性状上的分布表现为相对连续的正态分布,部分株系较CCRI8有了明显提高。本研究为进一步开展棉花纤维品质QTL定位以及陆地棉纤维品质育种研究提供了新材料。

Chromosome segment substitution lines（ CSSLs） consist of a battery of near-isogenic lines and cover the entire genome of some crops. With the exception of one or a few homozygous chromosome segment transferred from a donor parent,the remaining genome of each CSSL line is the same as the recipient parent. It is an ideal material for QTL mapping. In the present study,we developed a set of CSSLs that constituted of 182 lines,using G. hirsutum CCRI8 as the recipient parent and G. barbadense Pima90-53 as the donor parent,through molecular assisted-selection in BC3S1-3generations. The genetic length of the substituted segments covered 19957. 8 c M with an average segment of 21. 0 c M,4. 7 times the total genetic length of upland cotton（ 4168. 7 c M）. The substituted segments of each line varied in length,ranging from 0. 7 c M in the shortest segment to 83. 2 c M in the longest. The number of substituted segments ranged from 1 to 11. Fiber quality of the CSSLs was nearly normally distributed,and a part of the lines have been obviously improved in fober properties compared to CCRI8. These materials provide new genetic resources for further QTL mapping,as well as upland cotton fiber quality improvement.