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Distribution of mating‐type alleles and genetic variability in field populations of Leptosphaeria maculans in western Canada
Author(s) -
Zou Zhongwei,
Zhang Xuehua,
Fernando Wannakuwattewaduge Gerard Dilantha
Publication year - 2018
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/jph.12706
Subject(s) - leptosphaeria maculans , biology , canola , genetic diversity , allele , population , genetic variation , analysis of molecular variance , canker , gene flow , genetics , botany , gene , demography , sociology
Leptosphaeria maculans is the most important fungal pathogen of canola ( Brassica napus , oilseed rape) that causes the devastating stem canker in canola fields of western Canada. The population genetic structure of L. maculans , represented by nine subpopulations from a 6‐year period and three different provinces in western Canada, was determined using ten minisatellite markers. Isolates collected at different locations in six consecutive years had an even distribution of MAT 1‐1 and MAT 1‐2 across the nine subpopulations. All subpopulations of L. maculans exhibited a moderate gene diversity ( H = 0.356–0.585). The majority of the genetic variation occurred within subpopulations. Approximately 8% and 4% of the variations were distributed between sampling year and location, respectively. Genetic distance ( F ST ) results, using analysis of molecular variation ( AMOVA ), indicated that subpopulation pairing within isolates by year ranged from F ST = 0.010 to 0.109, and the location subpopulation ranged from F ST = 0.038 to 0.085. Bayesian clustering analyses of multiloci inferred two distinct clusters in all the subpopulations examined. This study indicates a relatively high degree of gene exchange between the different L. maculans isolates. Our results suggest that this can occur in the wide growing areas of canola fields in western Canada. This gene exchange produced different gene allele frequencies and divergence between populations.