Knowledge of the geographic distribution and frequency of avirulence genes will contribute to the development of strategies to effectively use rice varieties that carry various resistances genes, including combinations of varieties in mixture cropping systems. Here, we analyzed the geographic distribution and frequencies of avirulence genes in rice blast fungus using samples collected from 11 prefectures across Yunnan province, China. A total of 467 single spore isolates were assayed for pathotypes based on their reaction to 20 rice blast resistance monogenic lines. The results revealed that frequencies of avirulence genes among 10 prefectures showed insignificant difference, but frequencies of avirulence genes in Xishuangbanna showed significant differences compared to the remaining 10 prefectures. The avirulence genes Avr-Pi9, Avr-Piz and Avr-Pizt were observed at the highest frequency in blast isolates from the 11 prefectures; their average frequency was greater than 80%. Our results imply that the composition and distribution of rice genetic diversity are more important than climate and other environment conditions for formation and maintenance of rice blast fungus genetic diversity. Using average frequencies, the avirulence genes can be categorized into 4 groups. There were significant differences of frequencies of avirulence genes among different groups, while insignificant differences observed within any group. These results will provide useful information for evaluation of resistance genes and effective management of rice blast disease.
LI Jinbin, YANG Jing, LIU Lin, HE Hanming, HE Xiahong, ZHU Youyong, LI Cheng-yun
. Geographic Distribution of Avirulence Genes in Rice Blast Fungus in Yunnan Province, China[J]. Journal of Resources and Ecology, 2011
, 2(2)
: 181
-185
.
DOI: 10.3969/j.issn.1674-764x.2011.02.012
Bonman J M & D J Mackill. 1988. Durable resistance to rice blast disease. Oryza, 25, 103-110.
Jwa N S, G K Agrawal, S Tamogami, et al. 2006. Role of defense-stressrelated marker genes, proteins and secondary metabolites in defining ricedefense mechanisms. Plant Physiology and Biochemistry, 44: 261-273.
Khush G S and K K Jena. 2009. Current status and future prospects for research on blast resistance in rice (Oryza sativa L.) In: Wang G L and B Valent (eds.). Advances in Genetics, Genomics and Control of Rice Blast Disease. Dordrecht: Springer, 1-10.
Leung L, Zhu Y Y, I Revilla-Molina, et al. 2003. Using genetic diversity to achieve sustainable rice disease management. Plant Disease, 87 (10): 1156-1169.
Li J B, Luo C X, and Li C Y. 2001. Race composition and distribution of Magnaporthe grisea in Yunnan Province in recent years. Plant Protection, 27(2): 12-14. (in Chinese)
Liu B, Zhang S H, Zhu X Y, et al. 2004. Candidate defense genes as predictors of quantitative blast resistance in rice. Mol Plant-Microbe Interact, 17(10): 1146-1152.
Liu J L, Wang X J, T Mitchell. et al. 2010. Recent progress and understanding of the molecular mechanisms of the rice-Magnaporthe oryzae interaction. Molecular Plant Pathology, 11(3): 419-427.
Liu J, Liu X, and Wang G L. 2007. Recent progress in elucidating the structure, function and evolution of disease resistance genes in plants. J. Genet. Genomics, 34 (9): 765-776.
Ou S H. 1977. Breeding rice for blast resistance. A critical review. In Proceeding of a rice blast workshop, pp. 81-137. Los Banos, Philippines, IRRI.
Ou S H. 1980. Pathogen variability and host resistance in rice blast disease. Annu. Rev. Phytopathol., 18: 167-187.
Skamnioti P and S J Gurr. 2009. Against the grain: safeguarding rice from rice blast disease. Trends Biotechnol., 27 (3): 141-150.
Tsunematsu H, M J T Yanoria, L A Ebron, N Hayashi, I Ando, H Kato, et al. 2000. Development of monogenic lines of rice for blast resistance. Breeding Science, 50 (3): 229-234.
Yang Q Z, Lin F, Feng S J, et al. 2009. Recent progress on molecular mapping and cloning of blast resistance genes in rice (Oryza sativa L.). Sci. Agric. Sin., 42 (5): 1601-1615.
Yang Z Y, Lu Y X, Chao Y S. 2007. Research on ecological patterns of resources of indigenous rice (Oryza sativa L.) in Yunnan. Kunming: Press of Science and Technology in Yunnan. (in Chinese)
Zhu Y Y, Chen H R, Fan J H, et al. 2000. Genetic diversity and disease control in rice. Nature, 406: 718-722.
