Among-Population Genetic Diversity of Rice Blast Fungus Based on Fingerprinting of Virulence-related genes. (December 2020) - Lan, Bo
Abstract: In this study, 189 strains of rice blast fungus isolated from rice-growing fields in five counties within the Jiangxi Province, China, were amplified with 16 pairs of virulence gene-specific primers. Fifteen pairs were able to amplify their target bands. The percentage of polymorphic sites was as high as 93.75%, and the frequency of amplification varied greatly. Cluster analysis classified the 189 strains, represented by 108 different haplotypes, into 21 genetic lineages at a genetic similarity level of 0.80. JXH16 was the dominant haplotype. The 21 genetic lineages included 1 dominant, 2 subdominant, 12 secondary, and 6 minor lineages. At the population level, rich genetic diversity was observed among the 189 strains from different geographic regions ( H = 0.2890; I = 0.4398). At a genetic distance of 0.02, the five populations were clustered into three groups that were unrelated to geographical distribution. A certain level of genetic differentiation was found to exist within each blast fungus population ( HT = 0.2842). Within-population genetic diversity was higher than that among populations ( Hs = 0.2210; Dst = 0.0632), with 77.75% of the total genetic variation originates within populations ( Gst = 0.2225). Some within-population gene flow were detected ( Nm = 1.7473). The results of our study, which revealed the genetic structure and diversity of rice blast fungal strains in five major rice cultivation areas of Jiangxi Province and their relationship to geographical distribution, can serve as a basis for rice blast resistance breeding and the selection of suitable varieties for these regions, including Duchang County, Jinggangshan City, Fengcheng City, Wan 'an County and Wuyuan County. Highlights: The result of population structure of Magnaporthe oryzae is inaccurate by the method of pathotypes identification. Genetic diversity based on virulence-related genes of Magnaporthe oryza is correlated with pathotypes of the pathogen. Clarify the genetic variation of Magnaporthe oryzae population in different areas of Jiangxi Province, China.