Abstract:

【Objective】 In this paper，the study was conducted to investigate the relationship between phenotype of blast resistance and resistance gene analog polymorphism of rice, and search molecule hereditary basis of broad spectrum and durable resistance. 【Method】 Comparison of clustering analysis was investigated using spectrum of resistance to blast and polymorphism of resistance gene analog (RGA) in 25 varieties for blast resistance identification and 20 varieties (lines). 【Result】 The resistance spectrum clustering analysis showed that the 45 varieties (lines) could be divided into group A and group B with the genetic similarity coefficient of 0.450. Group A and group B could be divided into subclassⅰ, subclass ⅱ, subclass ⅲ, subclass ⅳ, respectively, with 0.618 genetic similarity coefficient. The RGA-PCR clustering analysis showed that proposed the 45 varieties (lines) could be divided into group Ⅰ and group Ⅱ which clearly inclined the Indica-japonica differentiation with 0.620 genetic similarity coefficient. GroupⅠcould be divided into six subclasses and group Ⅱ could be divided into seven subclasses with 0.783 genetic similarity coefficient. The resistance spectrum clustering analysis showed that some varieties with similar resistance spectrum could finely fall into the same group, while the RGA-PCR clustering analysis showed that some varieties with the similar genetic background could fall into the same group. For some varieties with low resistance frequency or high resistance frequency, there was a better corresponding relationship between the resistance spectrum clustering and the RGA-PCR clustering. General comparison of clustering analysis showed that there was no parallelism relationship between group and group in two different types of the clustering 【Conclusion】 It could more accurately reflect their genetic background to test resistance to single strain and analysis on RGA polymorphism for resistance parents, and avoid applying the same source of resistance again and again, and enrich rice resistance germplasm, and breed durable resistance varieties.

Key words: rice varieties, blast resistance phenotypes, resistance gene analog, polymorphism