SCAR Conversion of Two RAPD Markers Linked to An Avirulence Gene Cluster in Magnaporthe grisea
LIN Yan;WANG Bao-hua;YANG Jie;LEI Cai-ling;LU Guo-dong;WANG Zong-hua
Key Laboratory of Bio-pesticide and Chemistry Biology, Ministry of Education, Functional Genomics Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China； 2. National Key Engineering Center, Chinese Academy of Agricultural Sciences, Beijing 100080, China
Abstract：To clone and characterize the avirulence gene cluster of Avr-Pi1, Avr-Pi2 and Avr-Pi4a, genomic DNAs of Magnaporthe grisea strains FJ81278ZB15, GUY11 and their F1 progenies were isolated and used as templates to screen for tightly linked random amplified polymorphic DNA(RAPD) markers . Two RAPD markers, P1414700 and P1389420 were identified using bulk segregant analysis, then cloned and sequenced. To overcome difficulty in reproducibility of RAPD markers, conversion of sequence characterised amplified region(SCAR) was further conducted. Two pairs of primers were designed based on sequences of P1414700 and P1389420 and their amplification polymorphism was validated with templates from FJ81278ZB15, GUY11 and their F1 progenies. The PCR results indicated that P1414700 was converted into a SCAR marker SC1414 successfully, but not for P1389420 . The genetic distances of molecular markers, including SC1414, P1389420, RPF1.2 and the avirulence gene cluster of Avr-Pi1,Avr-Pi2 and Avr-Pi4a, were then calculated by using program Mapmaker. The genetic distances were 5.8, 2.2 and 4.4 cM respectively from SC1414, RPF1.2 and P1389420 to Avr-Pi2; 15.9,7.9 and 5.7 cM to Avr-Pi1; 20.7, 12.7 and 10.5 cM to Avr-Pi4a. These markers will facilitate the map-based cloning of the avirulence gene cluster.
