RESULTS AND DISCUSSION
Experiment 1
The rice genotypes varied for qualitative resistance to blast, as measured by lesion type (Table 1). The
mean lesion type ranged from 0.0 to 4.8, with Masuli having the highest rating. Twenty-nine of the 35
genotypes showed R to blast. Three genotypes were MR and the rest were susceptible to blast under the
field conditions.
The 35 genotypes also differed for neck blast resistance, as measured by percentage of neck infected
(Table 1). Neck blast infection varied from 0.0 to 66.45 percent. Radha 7 showed the highest neck blast,
whereas Masuli, Radha 11 and Radha 9 had higher percentage of neck blast. Sabitri, TOX 4004 and CN
836-3-10 were completely free from neck blast. Radha 12 had 7-folds less neck blast than that of
Masuli. Similarly, NR 1558 and NR 601-1-1-5, the two promising rice lines had, respectively, 6 and 10
times less neck blast than that of Masuli. Other genotypes had lower neck damage due to blast (about >
20 times less) as compared to that of Masuli.
Experiment 2
The AUDPC values ranged from 1.6 to 410 and differed significantly among the 11 genotypes (Table
2). Masuli, CO39 and Radha 11 had higher AUDPC, indicating the higher level of susceptibility to leaf
blast. Radha 7 and NR 1558 showed one-third and one-sixth of AUDPC, respectively, in comparison to
CO39. The rest genotypes exhibited the AUDPC even significantly lower than NR 1558 suggesting that
they have higher level of partial resistance to leaf blast.