Poster Session: Mycology

118-P

The population dynamics of Phytophthora infestans in Egypt.
S. M. El-Ganainy (1), A. M. M. TOHAMY (1), M. A. Awad (2), J. N. Squires (3), D. E. Cooke (3)
(1) Plant Pathology Research Institute, Giza, Egypt; (2) Agriculture Botany Department, Minufiya University, Shibin El-Kom, Egypt; (3) The James Hutton Institute, Dundee, Scotland, United Kingdom

For understanding the structure and dynamics of the Egyptian Phytophthora infestans population, 205 P. infestans isolates were collected from commercial potato fields in Egypt during the 3-year period 2010-12. Mating type for each isolate was determined. The test showed that 57% of the isolates were belonged to mating type A1, 35% were belonged to mating type A2 and the rest 8% were self-fertile. Genotyping of 85 Egyptian isolates as well as 15 references isolates represented the United Kingdom population was performed using 12 highly informative microsatellite (SSR) markers. Structure analysis grouped the 84 identified genotypes into two main clonal lineages. The first clonal linage was comprised 21 isolates belonged to A2 mating type and 8 self-fertile isolates. This clone was identified as Blue_13 or 13_A2. Within the 13_A2 clone, 3 distinct sub-clonal lineages were also identified i.e. 13_A2_5, 13_A2_43 and 13_A2_84. The second main clonal lineage was comprised 55 isolates. This clone was identified as 23_A1. Worldwide, 19 sub-clonal lineages were identified within 23_A1. Ten out of 19 were found in the Egyptian population. They are known as: 23_A1_4, 23_A1_10, 23_A_12, 23_A1_13, 23_A1_14, 23_A1_15, 23_A1_16, 23_A1_17, 23_A1_18 and 23_A1_19. In addition, 18 Egyptian isolates were screened for the presence or absence of 5 effector genes which trigger the host susceptibility or immunity. The present gene was sequenced to determine of its function.