Abstract:

With the development and application of molecular biology technology in recent years, several genetic maps developed from different combinations have been constructed and lots of QTL controlling fiber quality or yield components detected, which makes the breeding procedure more effective, immediate and time-saving. In this paper, both F₂ and F_2:3 populations were constructed using two elite upland cotton (Gossypium hirsutum L.) strains (variety), 7235 and Yumian 1 as parents. Linkage analysis with SSR molecular markers revealed that 80 loci were mapped into 19 linkage groups that covered 1 147.8 cM genetic distance. A total of 36 QTLs were detected by composite interval mapping method, including 6 for fiber length, 8 for fiber strength, 7 for micronaire value, 8 for fiber elongation and 7 for fiber uniformity; and explained 3.4%–14.4%, 5.0%–42.4%, 6.5%–11.7%, 5.1%–19.4%, and 6.9%–14.0% of the corresponding phenotypic variations, respectively. Analysis of QTL distribution indicated that D7, D8, and D9 chromosomes were enriched with QTLs controlling fiber strength in both parents, among them those existed in D7 and D8 chromosomes were closely linked and two QTLs controlling fiber strength located respectively in D7 and D9 chromosomes were in the complete same position, which could be related with that both 7235 and Yumian 1 bear the pedigree of elite fiber accession PD4381. The utilization potential of the QTL of super quality in the pyramiding breeding was also discussed.

Key words: Gossypium hirsutum, Fiber quality, QTL, Source