Identification Of The Physiological Race And Diversity Of Phytophthora Infestans In Gansu Province Using EST-SSR Markers

Late blight, caused by Phytophthora infestans Montagne de Bary, is the most devastating disease of potato worldwide. Gansu is one of the provinces in China well known for potato production, along with the potato transport becoming more frequently and the potato production's fast development, the structure of Phytophthora infestans population is changed, but the change of the structure Phytophthora infestans population have lead to many diffcult in the prevention of this disease. In this research, the diversity among 63 isolates of P.infestans was collected.The aims of the research were to monitor the change in the P.infestans population by EST-SSR primer, to detect the diversity in P.infestans population. These may lay a sound basis for employing the effective control methods and supporting the late blight resistant breeding program, the experimental results are as follow.1. with international diffentiation hosts 63 isolates were identified from Gansu area, they can divide into 16 physiologic races, the type of physiological race were 1.3. 4.5.6.7.8.10.11;1.4.5.6.7.8.10.11;1.4.6.7.10.11;1.3.4.5.6.7.11;1.4.6.7.11;1.4.6.7.10;1.3.4.6.7;1.3.4.11;1.4.6.7;1.4.7.11;4.6.7.11;3.4.6.7;4.7.11;1.3.4;1.4;4.2. A total of 12581 ESTs (Expressed of Sequence Tags) of P.infestans covering 8178kb were screened by SSRIT (SSR Identification Tool), and a total of 389 SSR loci for 389 P.infestans ESTs.Selecting appropriate EST sequence of containing-SSR, the 9 pairs of primers were amplified SSR fragments, and 2 pairs of primers failed to effectively amplified product.3. 1 EST-SSR primer pairs which can better amplified was selected to amplify the total all of 63 P.infestans isolates.The result showed that the genetic diversity of P.infestans population was rich.