Selección de genotipos de maíz con resistencia múltiple a achaparramiento, cogollero y barrenador

Abstract

This study it was realized with the objective of select genotypes of maize with multiple resistance to corn stunt, army worm and corn borer damage, in two localitys in México, Úrsulo Galván and Poza Rica, Veracruz and one locality in Nicaragua. It used 288 maize line from the Entomology Program of CIMMYT, with multiple resistance to corn stunt, army worm damage and corn borer damage, two lines from Nicaragua with resistance to corn stunt and one open pollination population from the Mexican Institute of Maize. With the genotypes from CIMMYT we used North Caroline I Design, using a male with four female. We obtained 120 crosses, which were evaluated in the three localitys before mentioned. In the three localitys we took harvest data, corn stunt, army worm damage and corn borer damage data. The found results show that the best 20 treatments yielded betwen 5.49 and 4.34 t/h across localitys and betwen 8.77 and 2.69 t/h in each locality. The genotypes that showed the heigest yield they showed too, the lowest damage of corn stunt, army worm and corn borer; between 0% and 22.7%, 1 and 2 and 1 and 4 respectively. Also, they expressed different yield through localitys; the males with a variance of -0.017, were more stable that females, wich show a variance of 0.48, the dominant variance was 1.85 mayor that the additive variance with a value of -0.068, the wide heredability was 2.60 and the narrow heredability was -0.09, the coefficient of variation was 21.26%. In the case of corn stun damage, the resistance of the genotypes showed mayor variance of males, 1.32, that the females, 0.33, the addi tive variance with a value of 5.28, was mayor that dominant variance with a value of - 3.96, the wide heredability was 0.39 and the narrow heredability was 1.44. In the case of army worm damage, the resistance of the genotypes showed male variance of -0.00075 similar to the female 0.0015, the additive variance was 0.003 and the dominant variance was 0.009, the wide heredability was 0.25 and the narrow heredability was -0.16. In the case of corn borer damage, the resistance of the genotypes showed male variance of - 0.00213 similar to the female 0.0075, the additive variance was -0.00852 and the dominant variance was 0.032, the wide heredability was 0.33 and the narrow heredability was -0.08.