Preliminary Evaluation for Breeding Advancement of Resistance to Rice Sheath Blight

Sixty four indica cultivars/lines from Guangdong and Jiangsu Province, Lemont and SY63/LH (susceptible checks) and Jasmine 85 and Teqing (moderate resistant checks), were used to analyze the resistance to rice sheath blight (Rhizoctonia solani Kuhn). The results indicated that there were highly dominant differences of resistance among these cultivars. The cultivars should be divided into six groups of highly susceptible, susceptible, moderately susceptible, moderately resistant, resistant and higher resistant, by means of Ward Minimum Variance Cluster Analysis. The cultivars from Guangdong distributed in all of six groups, only a fourteenth of them in resistant and higher resistant groups. There was nearly no cultivar of third type in middle disease reaction group. The forth type cultivars, which bred for accumulation of resistance from the cross of Teqing/91 3, just distributed in moderate resistant to resistant groups, 60% of them in resistant group. The scientists of Lixiahe Agricultural Research Institute put them attention to breeding of resistance to sheath blight in recent years, so cultivars bred by them just distributed among later groups and two of total three higher resistant cultivars bred by them. The results supported that rice resistance to sheath blight was a hereditable character and selection to resistance was effective.