ABSTRACT
Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, "XinLuZao1" (XLZ1), a susceptible cultivar Gossypium hirsutum L. and "Hai7124" (H7124), a resistant line G. barbadense, and their F(2:3) families were used to map and study the disease index induced by verticillium wilt. A total of 430 SSR loci were mapped into 41 linkage groups; the map spanned 3,745.9 cM and the average distance between adjacent loci was 8.71 cM. Four and five quantitative trait loci (QTLs) were detected based on the disease index investigated on July 22 and August 24 in 2004, respectively. These nine QTLs explained 10.63-28.83% of the phenotypic variance, six of them were located on the D sub-genome. Two QTLs located in the same marker intervals may partly explain the significant correlation of the two traits. QTLs explaining large phenotypic variation were identified in this study, which may be quite useful in cotton anti-disease breeding.
Subject(s)
Chromosome Mapping , Gossypium/genetics , Gossypium/microbiology , Plant Diseases/immunology , Plant Diseases/microbiology , Quantitative Trait Loci/genetics , Verticillium/physiology , Chromosome Segregation/genetics , Crosses, Genetic , Genes, Plant , Genetic Linkage , Gossypium/immunology , Immunity, Innate/genetics , Minisatellite Repeats/genetics , Plant Diseases/genetics , Polyploidy , Quantitative Trait, HeritableABSTRACT
SRAP (Sequence-related Amplified Polymorphism), a new marker system, was applied in cotton genome analysis. We developed an efficient PCR reaction system for detecting SRAP that showed reliable, effective and reproductive. SRAP marker was used to detect the polymorphisms between 'Pima90' (G. barbodense) and ' Handan208' (G. hirsutum) and showed comparatively high polymorphism. Among the 30 primer pairs, 29 pairs generated 149 polymorphic bands with an average of 5.14 polymorphic bands per primer pair. The primer pair showing most polymorphism was the combination of me3 and em2, which produced 13 polymorphic bands. The SRAP marker was also tested among 11 upland cotton cultivars, 15 of the tested 30 primer pairs showed polymorphism yielding 22 polymorphic genetic loci, which is relatively high among upland cotton cultivars. The results showed that SRAP marker could be widely used in molecular genetic map construction and germplasm evaluation of cotton.
