RESISTÊNCIA DE LINHAGENS GENITORAS E HÍBRIDOS SIMPLES DE SORGO A Colletotrichum sublineolum, AGENTE CAUSAL DA ANTRACNOSE

Abstract

The reaction of resistance to ten simple hybrids of sorghum (Sorghum bicolor), as well as of their 14 parents were evaluated to the pathogen Colletotrichum sublineolum, the causal agent of anthracnose. In greenhouse, the genotypes were inoculated separately with 20 monosporic isolates obtained from different sorghum producing areas in the Brazil. Evaluation was carried out ten days after inoculation utilizing methodology proposed by Cardwel et al. (1989). Neither sorghum genotype was resistant to all the isolates inoculated. Line CMSXS657 was resistant to 95%, ATF14 to 90%, ATF08 to 85% and CMSXS210 to 70% of the isolates. The most outstanding hybrids were BRS305 (CMSXS210A X BR012R) resistant to 75% of the isolates, 9920045 (ATF14A X CMSXS180R) to 65% of the isolates, BRS308 (CMSXS233A X BR012R) to 60% of the isolates, and BRS650 (CMSXS222A X CMSXS657R) to 55% of the isolates. Lines BR001 and CMSXS222 were susceptible to 90% of the isolates. The resistance frequency of the hybrids was equal or inferior to that of the parent lines, except for hybrid BRS305 (CMSXS210A X BR012R) which was resistant to a larger number of isolates than its parents. None of the isolates tested were virulent to all the genotypes. The isolates from Campo Novo dos Parecis (MT) were the most virulent while the isolates from Jardinopolis (SP) were the least virulent.