Assessment of Breeding Materials for Resistance to Fusarium Wilt in Cotton under Greenhouse Conditions in 2019

Abstract

The germplasm evaluated in this study was a part of the National Screening Program for Fusarium Wilt Resistance. This program is conducted annually in the glasshouses of (Cotton and Fiber Crops Diseases Research Dept.), PPRI. The current study included 50 of Lower Egypt experimental genotypes, this experimental genotypes and 931families of seven common cultivars. The investigational genotypes were supplied by Cotton Breeding Dept., while the families of the seven common cultivars were supplied by Cotton Research Institute . Healthy survival rate of seedlings of the genotypes was used as a criterion to evaluate their reactions when the genotypes were grown in autoclaved soil highly infested with a mixture of race 3 of Fusarium oxysporum f. sp. vasinfectum isolates. All the lower Egypt genotypes (100%) were very highly resistant. The majority of the Upper Egypt genotypes 68 % were very highly resistant while 4% were very highly susceptible. The other reaction classed ranged from 4 to 16% of the tested genotypes. The distribution of Upper Egypt genotypes to reaction classes in 2017, 2018 and 2019 showed steady and considerable increases in the VHR genotypes, which were 48, 54 and 68% in 2017, 2018 and 2019 respectively. Over the three year period, the majority (56.67%) of the Upper Egypt genotypes were VHR. . All families of the common cultivars were VHR. The present study provides new and useful sources of resistance to Fusarium wilt caused by race 3 isolates