EVALUATION OF Fusarium AND Verticillium WILT TOLERANCE IN UPLAND COTTON CULTIVARS

The article outlines the results of research on the effect of mycotoxins of pathogenic Fusarium fungi on the samples taken from the leaves of upland cotton varieties. According to the study data collected, АN-Boyovut-2, Yulduz, Kelajak, UzFA-705 and UzFA-710 cultivars manifested absolute resistance to Fusarium oxysporum f.sp. vasinfectum. UzFA-713 cultivar had a weak infestation, while in Mekhnat cultivar a strong infestation was observed. Kelajak and UzFA-705 cotton cultivars showed more resistance to adverse effects of Fusarium solani fungi comparing to other varieties, while АN-Boyovut-2, Yulduz, UzFA-707, UzFA-710 and UzFA-713 cultivars had weak infestation on their leaves. Fusarium oxysporum f.sp. vasinfectum, Fusarium solani and Verticillium dahliae Kleb pathogens was strongly infected to Mekhnat cultivar. The effect of Verticillium dahliae Kleb fungus was not observed in the samples of АN-Boyovut-2, Yulduz, Kelajak, UzFA-710 and UzFA-713 cultivars. UzFA-705 and UzFA-707 cultivars were found to have less damage by pathogens, while Mekhnat cultivar had a strong infestation by fungi. Based on the data obtained in the study, it can be said that medium-fiber UzFA-710 cultivar that was studied in the research was found to be resistant to F.oxysporum f.sp. vasinfectum, while the cultivars Yulduz, Kelajak, UzFA-710 and UzFA-713 appeared to be resistant to mycotoxins of Verticillium dahliaekleb, and these cultivars can give effective results when used in genetic selection and breeding practices.