DEVELOPMENT AND BIOCHEMICAL SCREENING OF F1 COTTON HYBRIDS TOLERANT TO VERTICILLIUM DAHLIAE KLEBHAN AS A STRATEGY FOR CLIMATE-RESILIENT AGRICULTURE

UDC: 633:511.631.572:631.521 DEVELOPMENT AND BIOCHEMICAL SCREENING OF F1 COTTON HYBRIDS TOLERANT TO VERTICILLIUM DAHLIAE KLEBHAN AS A STRATEGY FOR CLIMATE-RESILIENT AGRICULTURE Viktor Avtonomov, Zarina Alimova, A`zam Ravshanov, Dilbar Rashidova, Umid Kayumov, Muzaffar Yakubov, Normukhammad Mamedov Research Institute of Cotton Breeding, Seed Production and Agrotechnologies, 111218, Universitetskaya St., Kibray District, Tashkent Region, Uzbekistan https://doi.org/10.5281/zenodo.21776393 Abstract: The abstract is devoted to the analysis of laboratory and field studies aimed at identifying cotton varieties and hybrids tolerant to the pathogen Verticillium dahliae Kleb. through the use of biochemical and field assessments. In the research, several cotton varieties of G. hirsutum with different genetic origins were used as the initial material for hybridization, namely SB-6, C-6541, Namangan-34, C-6545, and Namangan-77. These varieties, along with their F1 hybrids, were carefully evaluated for resistance to V.dahliae under both laboratory and field conditions. The results of the comparative analysis showed that the two applied methods — biochemical and field assessments — provide practically identical information, which confirms their reliability and indicates that there is no urgent need to repeatedly verify the results of field assessments. Based on the evaluations, the most resistant varieties to V.dahliae were classified as Namangan-34, Namangan-77 and C-6541. In addition, among the studied F1 hybrids, several cross combinations demonstrated promising resistance: Namangan-77 × C-6541, Namangan-34 × SB-6, C-6541 × SB-6, C-6541 × C-6545, C-6545 × C-6541, and SB-6 × C-6541. The findings clearly demonstrate that the integration of biochemical and field studies is a reliable approach to identify resistant genotypes, and the resistant varieties and hybrids obtained can serve as valuable breeding material for developing cotton with improved tolerance to V.dahliae. Keywords: cotton, medium-fiber, variety, hybrid, resistance, pathogen, biochemistry, antibodies, polyclonal, evaluation, selection.