Identifying cotton genotypes resistant to Meloidogyne incognita race 3 using Blup

Abstract

Few genetic resistance sources to root-knot nematodes are known for cotton, and there are no cultivars combining both resistance and good agronomic attributes in Brazil. Techniques that allow an efficient selection of promising sources of genetic resistance are needed. This study aimed to identify cotton genotypes resistant to Meloidogyne incognita race 3 via REML/Blup. The experiment was completely randomized, with 32 genotypes and seven replicates, in a protected environment. The statistical model 83 was used. The root weight, final population, reproduction factor and reproduction index were estimated. The final population and reproduction index presented the highest values for genotypic variance and genetic variation coefficients, indicating a favorable situation for the selection of cotton genotypes resistant to the nematode. The mean heritability (h2mg) of the genotype was higher than 85 % for the final population, reproduction factor and reproduction index, opening a possibility of selection success based on genotype means. The genotypes CS8601, SA2572, Coodetec 404 and BJ 3128 are promising for crosses aiming the selection of genotypes resistant to the nematode.

Keywords

• gossypium spp.
• genetic resistance
• root-knot nematode