Premium
Aggressiveness and diversity of P hytophthora capsici on vegetable crops in G eorgia
Author(s) -
Yin J.,
Jackson K.L.,
Candole B. L.,
Csinos A.S.,
Langston D.B.,
Ji P.
Publication year - 2012
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.2012.00532.x
Subject(s) - biology , rapd , pepper , phytophthora capsici , mating type , genetic diversity , cultivar , host (biology) , microbiology and biotechnology , blight , genotype , genetic variability , colletotrichum capsici , veterinary medicine , horticulture , agronomy , botany , genetics , population , gene , fungicide , medicine , demography , sociology
Phytophthora blight induced by P hytophthora capsici causes significant yield loss in a number of vegetable crops. It is imperative to understand the diversity and aggressiveness of the pathogen to design more efficient disease management programs. A collection of P . capsici strains isolated from different vegetable crops in G eorgia, USA , were characterised in this study. Of the 49 isolates tested, 24 were A 1 and 25 were A 2 mating type, respectively, with both mating types found in the same fields. Variability of the isolates was assessed in terms of their aggressiveness on six pepper genotypes. The isolates differed in their aggressiveness on different pepper cultivars with 10 pathotypes identified. No correlation between aggressiveness of the isolates and their host origin or geographical location of isolation was observed. Randomly amplified polymorphic DNA ( RAPD ) analysis was used to evaluate genetic variability among P . capsici populations. RAPD analysis using 15 random primers resulted in 133 reproducible bands and cluster analysis separated the isolates into 5 groups. Analysis of molecular variance showed that there was moderate genetic differentiation associated with host origin and geographical location of the isolates. No correlation was found between RAPD groups and pathotypes or mating types. These results indicate that P . capsici populations infecting vegetable crops in G eorgia were genetically diverse, which should be taken into account in developing resistant cultivars or other disease management programmes.