Abstract:

【Objective】 In this paper, two F2 mapping populations were respectively assembled by using the parents of CRI28 hybrid (CRI12 and 4133, their corresponding population named as Pop1) and the parents of XZM 2 hybrid (CRI12 and 8891, their corresponding population named as Pop2), to construct linkage map with higher genome coverage, to map QTLs related with fiber qualities, and further to provide information for molecular marker-assisted breeding. 【Method】 The linkage map was constructed with SSR markers by JOINMAP 3.0 software. The QTLs for 6 fiber quality properties in F2 and F2:3 populations were mapped by the composite interval mapping method (CIM) using Win QTLCart 2.5. 【Result】 A joinmap was integrated with 245 loci and covered 1 847.81 cM. Based on this, QTLs related with fiber qualities were further detected. In detail, 39 QTLs were identified in three environments in separate analysis and 22 QTLs in the joint analysis in Pop1. Similarly, 51 and 18 QTLs were identified in Pop2, respectively. QTLs were clustered on chromosomes A3, D2 and D9, and some stably heritable QTLs were also discovered by integrating analysis in different environments. Of them, 8 QTLs for the 4 traits could be found simultaneously in the two populations, and more 4 QTLs for fiber strength, micronaire, and fiber elongation were offered by CRI12. 【Conclusion】 These stably heritable QTLs could be used for the molecular breeding of fiber quality traits in upland cotton.

Key words: upland cotton, fiber quality, QTL mapping