Determination of Susceptibility of Some Cotton Genotypes (Gossypium Spp.) Against Verticillium Dahliae KLEB

Abstract

Verticillium wilt (Verticillium dahliae Kleb.) is one of the important factors limiting production in cotton areas. It is recommended to use resistant cotton varieties in the control of the disease, which does not have any economical chemical control. For this reason, it is necessary to know the resistance of genotypes against the disease that will participate in a variety of development breeding programs as parents. The aim of the study was to determine the resistance of some cotton genotypes (Gossypium spp.) against the defoliating and non-defoliating pathotypes of V. dahliae Kleb. Total 38 cotton genotypes including three control cultivars (Giza-70, a resistant; Acala Maxxa, a tolerant and Cukurova 1518, a susceptible) were inoculated with conidy suspension technique into crown. Randomized plot design with four replications was set up in the growth chamber conditions. Genotypes were significant at (P <= 0.01) probability level for disease severity values in pot trial. Disease severity values of the genotypes were determined higher in PYDV6 than Vdl 1 isolate. Using PYDV6 isolate, resistant-control Giza-70 (0.75) had the lowest disease severity, and followed by Giza-45 (1.12), Pima S-2 (1.18), Maydos Yerlisi (1.25), and tolerant-control Acala Maxxa (1.25) genotypes. On the other hand, susceptible-control Cukurova 1518 showed the highest disease severity (3.00). Using Vd 11 isolate, resistant-control Giza-70, Giza-45, and Pima S-2 (1.00) had the lowest disease severity, and followed by Maydos Yerlisi (1.12). Pima S-4, Pima S-5, and PI 5299532 showed the highest disease severity (2.37).