Leaf blast resistance of rice different genotypes in blast nursery

ABSTRACT: Rice blast disease is a major cause of yield reduction in IRAN, which due to yield reduction in sensitive rice cultivars. In this study 62 genotypes for resistance to rice blast in Sari University of Agricultural Sciences and Natural Resources in 2011 were evaluated. Means comparison of infected leaf area percent to leaf blast in rice genotypes shows that 9 genotypes (IR 04A325, IR 05A103, IR 70213-10-CPA 4-2-3-2, IR 57514-PMI 5-B -1-2, CT 19561-3-20-2-3-2-2-M, CT 18667-6-6-1-5-1, IR 06L138, CT 18615-1-5-1-2-1 , IR 72768-12-1-1) had the lowest percentage of infected leaf area of the blast (Infected leaf range from 0.92 to 2.0 percent). Also these genotypes in clustering according to type of infection and the percentage of leaf traits were in resistant group. Means evaluation of leaf blast infection type in different genotypes of rice showed that 29.03% of genotypes in the resistant group (infection type of 0.0 to 2.0), 45.16% of genotypes included controls of local and international in moderately resistant group (infection type 2.1 to 3.0) and 25.81% of genotypes included local (Binam) and international (B40) susceptible controls with infection type of 3.1 to 5.0, are located in susceptible group.