عکس العمل ارقام امیدبخش پنبه به بیماری پژمردگی ناشی از Verticillium dahliae

Verticillium wilt disease of cotton with the fungal agent Verticillium dahliae is one of the most important factors limiting the planting of high-yielding cultivars sensitive to this disease. This disease is prevalent in all cotton growing areas. Using tolerant cultivars is the most economical way to combat it. This research was conducted in two consecutive years 1399-1400 and with 5 selected cotton genotypes (including 5 precocious and relatively high-yielding genotypes including T2, N2G80, NSK 871, NSK B23 and M13) along with the sensitive control cultivar Varamin in the form of a block design. Complete random plots were evaluated in 4 replicates at Kashmir Cotton Research Station in terms of verticillium wilt disease index, number of shoot shoots, early maturity percentage, boll weight and total yield. The studied treatments were cultivated in four 6-meter lines with a planting pattern of 70*20. Notes were taken four months after planting by removing two side lines and half a meter from the beginning and end of each line as a margin (five meters between the two middle lines).To determine the disease index of verticillium wilt of cotton, depending on the intensity of infection of each plant, different degrees of the disease were given in terms of appearance (0-4).Then the disease index (DS) was calculated according to the method of Zhang etal.(2005).Data analysis was analyzed using SAS 9.1 statistical software and averages were evaluated by Duncan's test. The statistical results of mean comparison showed that in the grouping of genotypes in terms of verticillium wilt disease index, Varamin variety had the highest disease index (1.71) and was placed in group a, and genotype M13 had the lowest disease index (1.00).Genotype M13 had higher vegetative and reproductive traits, number of dream branches, weight of 30 bolls, precocity index and total yield among these 5 precocious genotypes at the statistical level of 1%.Considering the higher yield and the lower Verticillium wilt disease index, M13 genotype was recognized as the superior and tolerant genotype in two years of testing and can be used in the cotton breeding program.