Analysis of the Abnormal Segregation of Pathogenicity in Magnaporthe grisea by Using a Genetic Cross of Oryza and Eleusine Isolates  

作　　者：YIN Liang-fen LUO Chao-xi Kusaba Motoaki Yaegashi Hiroshi 

机构地区：[1]Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R.China [2]Key Lab of Crop Disease Monitoring ＆ Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, P.R.China [3]Faculty of Agriculture, Saga University, Saga 840-8502, Japan

出　　处：《Agricultural Sciences in China》2010年第3期383-391,共9页中国农业科学（英文版）

基　　金：supported by a project (11660050) from the Ministry of Education, Culture, Sports, Science;Technology of Japan and the project of the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Huazhong Agricultural University, China(4002-30541)

摘　　要：A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showed that the segregation of pathogenicity in this genetic cross was abnormal, i.e., most of the progeny isolates were nonpathogenic on both host plants. However, no abnormal segregation was observed when middle repetitive sequence MGR586 and 31 single-copy RFLP markers from all of the chromosomes were genetically analyzed. At the same time, comparison of the chromosomal organization among two pairs of parental isolates did not find any genomic abnormity. These results suggested that the ＂abnormal＂ inheritance of pathogenicity in this cross was most likely due to the reassortment of numerous host species specificity genes but not the biased segregation of the host species specificity genes. The host species specificities in M. grisea were likely to be multigenically controlled, at least in the genetic cross involving rice pathogen and the grasses pathogen other than rice.A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showed that the segregation of pathogenicity in this genetic cross was abnormal, i.e., most of the progeny isolates were nonpathogenic on both host plants. However, no abnormal segregation was observed when middle repetitive sequence MGR586 and 31 single-copy RFLP markers from all of the chromosomes were genetically analyzed. At the same time, comparison of the chromosomal organization among two pairs of parental isolates did not find any genomic abnormity. These results suggested that the ＂abnormal＂ inheritance of pathogenicity in this cross was most likely due to the reassortment of numerous host species specificity genes but not the biased segregation of the host species specificity genes. The host species specificities in M. grisea were likely to be multigenically controlled, at least in the genetic cross involving rice pathogen and the grasses pathogen other than rice.

关 键 词：Magnaporthe grisea rice blast fungus host species specificity PATHOGENICITY contour-clamped homogeneous electric field （CHEF） electrophoresis Southern hybridization 

分 类 号：S511.035.1[农业科学—作物学] TV6[水利工程—水利水电工程]