Reaction of High Quality Japonica Varieties to Leaf Blast Reaction through G X E Interaction Analysis in Rice

Abstract

This study was done to understand the G x E interaction of rice blast reaction for Japonica high quality rice varieties and to observe blast pattern for high quality varieties. Twenty one percent of the total sum of squares (SST) in blast reaction data of high quality Japonica varieties is attributed to genotype (G) by environment (E) interaction variation. This portion of blast response is higher than 8～12% of G x E effect in blast severity data obtained from various ecotypes of rice varieties. Blast response scores obtained from high quality Japonica varieties group were more severely affected by environment condition than mixed groups with Japonica and Indica varieties. Interaction Principal Component Analysis (IPCA) scores obtained from AMMI analysis for the leaf blast response implied variation of G x E interaction. Correlation analysis suggested that IPCA1 was associated with latitude, maximum mean temperature, precipitation and mean cloud amount. IPCA2 was associated with mean relative humidity, and IPCA3 was associated with precipitation and minimum relative humidity. Pattern analysis generated nine genotype clusters according to blast reaction over 11 regions. Collectively, the A, B, C, and D groups were susceptible to rice blast, where as the E, F, G, H, and I groups were relatively resistant to rice blast through multi-location blast nursery test. Relationship between the identified genes of high quality varieties and blast scores at each test site in the level of group could be analyzed based on the results from G x E Interaction analysis.