渝棉1号优质纤维QTL的标记与定位

QTL Mapping for Fiber Quality Properties in Cotton Cultivar Yumian 1

利用陆地棉遗传标准系TM-1和优质品种渝棉1号组建了（TM-1X渝棉1号）R和R2，3分离群体。通过5544对SSR引物对亲本进行筛选，获得178个多态性标记，用其中138个构建了总长为959．7cM的遗传图谱，覆盖棉花基因组的19％。应用复合区间作图法分析了该组合的R单株和R：，家系纤维品质性状，共检测到12个纤维品质数量性状基因座（QTL），包括1个纤维长度的、4个纤维强度的、3个马克隆值的、3个整齐度的和1个伸长率的，分别解释各性状表型变异的6．1％、5．3l％～14．62％、7．88％～19．17％、7．4％～11．71％和8．26％。研究还发现Chr．23和Chr．24是优质纤维QTL的富集区。

Cotton fiber is one of known natural resources comprising the highest purity cellulose. It plays an important role in the textile industry worldwide. With acceleration of spinning speeds and improvement of people＇ s living level, the demand of improving cotton fiber qualities is getting stronger and stronger. Using molecular marker linked tightly with main QTL of super quality to make marker-assisted selection is the most direct and effective method to improve fiber quality of commercial cuhivars quickly. In this paper, a genetic linkage map was constructed by the F2 segregation population derived from a cross between Yumian 1, a high quality cotton cuhivar, and TM-1, a genetic standard line. We identified 178 polymorphic loci with 5 544 pairs of SSR primers. The genetic map with 138 loci was constructed, which had a whole length of 959.7 cM and covered 19% of the whole cotton genome. Moreover, the fiber characteristics of the F2 plants and the F2：3 family lines were analyzed by composite interval mapping （CIM） and 12 putative quantitative trait loci （QTLs） were detected for 5 traits, 1 for fiber length, 4 for fiber strength, 3 for fiber fineness, 3 for fiber uniformity and 1 for fiber elongation. These QTLs explained their corresponding phenotypic variations with 6.10%, 5.31%-14.62%, 7.88%- 19.17%, 7.40%-11.71 %, and 8.26%, respectively. Many QTLs associate with fiber quality located in Chromosome 23 and Chromosome 24 through chromosome tagging analysis combining with different elite fiber lines in the lab. The result provides references for utilizing reasonably Yumianl in cotton breeding improvement.