Verticillium wilt resistance evaluation in cotton (G. hirsutum L.) mutants

Research for resistance evaluation of common important disease - Verticillium wilt (Verticillium Dahlae Kleb.) of upland cotton in Uzbekistan have been developed in 2007 cotton crop season in Central Experimental Farm at the Uzbek Research Institute of Cotton breeding and seed production in the frame of IAEA TCP UZB 5004 - 'Development of Mutant Cotton Breeding Lines Tolerant to Diseases, Drought and Salinity'. The research plot is situated near the Tashkent city and Verticillium wilt evaluation conducted on the naturally infected fields. There have been used irradiated cotton seed with a different doses of gamma rays to the both 4 upland (G. hirsutum L.) and 3 long staple cotton(G. barbadense L) variaties in the Gamma Facility of Nuclear Physics Institute of Uzbekistan. If, strong affection in standard of Djarkurgan shows 4,6 %, so in M1 plants where used the irradiation dose of 50Gy wilt resistance was less for 1,6% in comparison than standard, but minimum affection in M1 taken from usage of 150Gy. In some cases the date of evaluation the plants of M1 were not wilt affected. Even there is no overall picture, in general it could be said that the resistance of M1 plants are comparatively higher than standard ones. Taking into account of advantages of using gamma irradiation in cotton breeding programs in getting wide spectrum cotton plant mutants, which are comparatively wilt resistance there are quite important to continuing the studies. (author)