Construction Of Genetic Linkage Map In BC₁F₁Population From Gossypium Hirsutum×G. Barbadense And QTL Analysis Of Fiber Yield And Quality Traits

Fiber yield and quality have played key roles in cotton breeding. Based on the molecular linkage maps, quantitative trait locus (QTL) associated with fiber yield and quality could be mapped. That is useful for the MAS (marker-assisted selection or marker assisted selection) and even gene clone. A backcross population from a cross between Gossypium hirsutum CCRI36as recurrent parent and G. barbadense Hai1was used to construct genetic linkage map, and more two backcross populations were used to identify quantitative trait loci (QTL) for fiber yield and quality traits.Total469pairs of polymorphic primers were obtained, which accounted for8.26percent of all screened primer. There were440loci out of532polymorphic markers can be got to construct a linkage map of33linkage groups with a total genetic distance of3180.29cM and an average genetic distance of7.23cM. The linkage map was covering71.47percent of total cotton genome.41QTLs associated with fiber yield were detected by the composite interval mapping in the BC1F1, BC2F1, and BC1S1generations, which can explain5.79%～22.43%of phenotype variation. The number of which efficiency gene comes from CCRI36is22, and the rest is coming from Hai1.13QTLs were related to fiber length,10QTLs were related to fiber micronaire,7QTLs were related to fiber strength,8QTLs were related to fiber elongation, and3QTLs were related to fiber uniformity. These QTLs clustered on Chr.10, Chr.13, Chr.16, Chr.19, and Chr.25. Among the41QTLs, one QTL for fiber length and one QTL for fiber elongation can be detected in two generations, and two QTLs for fiber micronaire can be detected in two generations.18QTLs associated with fiber quality were detected, which can explain5.90%～16.42%of phenotype variation.4QTLs were related to boll weight,6QTLs were related to Lint Percentage,8QTLs were related to Seed Index, The number of which efficiency gene comes from CCRI36is11, and the rest is coming from Hai1. Among the18QTLs, one QTL for lint percentage can be detected in three generations. The QTLs existing in many environments can be used of MAS.