| Autor: |
El-Ganainy SM; Department of Arid Land Agriculture, College of Agriculture and Food Sciences, King Faisal University, P.O. Box 420, Al-Ahsa 31982, Saudi Arabia.; Vegetable Diseases Research Department, Plant Pathology Research Institute, ARC, Giza 12619, Egypt., Iqbal Z; Central Laboratories, King Faisal University, P.O. Box 420, Al-Ahsa 31982, Saudi Arabia., Awad HM; Agriculture Botany Department, Menofia University, Shibin El-Kom 32415, Egypt., Sattar MN; Central Laboratories, King Faisal University, P.O. Box 420, Al-Ahsa 31982, Saudi Arabia., Tohamy AM; Vegetable Diseases Research Department, Plant Pathology Research Institute, ARC, Giza 12619, Egypt., Abbas AO; Department of Animal and Fish Production, College of Agricultural and Food Sciences, King Faisal University, P.O. Box 420, Al-Ahsa 31982, Saudi Arabia., Squires J; The James Hutton Institute, Dundee DD2 5DA, UK., Cooke DEL; The James Hutton Institute, Dundee DD2 5DA, UK. |
| Abstrakt: |
Late blight disease of potato and tomato, caused by Phytophthora infestans , results in serious losses to Egyptian and global potato and tomato production. To understand the structure and dynamics of the Egyptian population of P. infestans , 205 isolates were collected from potato and tomato plants during three growing seasons in 2010-2012. The characterization was achieved by mating-type assay, metalaxyl sensitivity assay, and virulence pattern. Additionally, genotyping of 85 Egyptian isolates and 15 reference UK isolates was performed using 12 highly informative microsatellite (SSR) markers David E. L. Cooke and five effector (RxLR) genes. Mating-type testing showed that 58% (118 of 205) of the isolates belonged to mating type A1, 35% (71 isolates) to mating type A2, and the rest 8% (16 isolates) were self-fertile. The phenotype of metalaxyl response was represented as 45% resistant, 43% sensitive, and 12% as intermediate. Structure analysis grouped the 85 identified genotypes into two main clonal lineages. The first clonal lineage comprised 21 isolates belonging to A2 mating type and 8 self-fertile isolates. This clonal lineage was identified as Blue_13 or EU_13_A2. The second main clonal lineage comprised 55 isolates and was identified as EU_23_A1. A single isolate with a novel SSR genotype that formed a distinct genetic grouping was also identified. The effector sequencing showed good correspondence with the virulence data and highlighted differences in the presence and absence of loci as well as nucleotide polymorphism that affect gene function. This study indicated a changing population of P. infestans in Egypt and discusses the findings in the context of late blight management. |
