Abstract
Cotton (Gossypium hirsutum L.) is the most important natural textile fiber crop grown worldwide. Several biotic and abiotic stress factors affect cotton yield due to lower genetic diversity for the traits of particular interest. Verticillium wilt (VW) is one of the major factors incurring huge cotton yield losses. The most effective management option against VW is the development of resistant cultivars. The resistant cultivars must also have superior fiber quality and yield traits. Therefore, the current study was aimed at screening some of the identified simple sequence repeats (SSR) markers for VW resistance and fiber quality traits of cotton genotypes in Turkey. Fifty different cultivars were screened with 30 SSR markers. Polymerase chain reaction (PCR) was conducted to amplify the SSR markers. The amplified bands were scored as 0 or 1 for absence and presence, respectively. For the molecular data analysis, polymorphism information content (PIC) values of molecular markers were calculated. Among tested SSR markers 13 were found polymorphic, which produced a total of 677 loci. The number of alleles per marker ranged from 1 to 4 and, overall average PIC values of markers ranged from 0.00 to 0.76, respectively. Principal component analysis executed on presence absence data yielded two distinct groups of cultivars screened. Hierarchical clustering revealed low genetic diversity among the tested cultivars. Based on the results TamcotCamdES, Gloria, Natalia, Lydia, Teks, Tamcot SP37H, N87 and BA525 are the promising cultivars for further breeding studies. The results of the current study also revealed that 4 SSR markers (DPL752 and DPL322 for fiber traits, DPL0022 and GH215 for VW resistance) out of 30 could be used for improving VW resistance and fiber quality in cotton through marker assisted selection.
Evaluating Genetic Diversity of Chilling Stress in Cotton Genotypes
