RESISTANCE TO MAGNAPORTHE GRISEA AMONG BRAZILIAN WHEAT GENOTYPES

摘要

Magnaporthe grisea, the causal organism of wheat head blast may induce importantyield losses in wheat and barley crops in Brazil. Chemical control besides been expensiveis not effective on highly susceptible varieties. Thus, the use of wheat genotypes withreasonable level of resistance associated with fungicides appears as the most effectivemeans of control of the disease. The research carried out has the objective of evaluatingthe resistance of Brazilian wheat genotypes to wheat blast under controlled environmentconditions. A great variability in reaction to head blast of wheat was observed amongBrazilian varieties and advanced breeding lines tested. The range of head infection variedfrom 10 % to 86 % in average, but none among hundred varieties tested displayed highlevel of resistance to M. grisea. Nevertheless, some varieties and advanced breedinglines showed moderate resistance and eighteen of them displayed average infectionslower than the control BR 18, a known moderately resistant variety under field condition.