Population Structure ofMycosphaerella graminicola: From Lesions to Continents

• DOI: 10.1094/phyto.2002.92.9.946
• Publication Date: 2007-05-11T11:13:41Z
• Authors: C. C. Linde; J. Zhan; B. A. McDonald
• Keywords: Graminicola; Isolation by distance

ABSTRACT The genetic structure of field populations Mycosphaerella graminicola was determined across a hierarchy spatial scales using restriction fragment length polymorphism markers. hierarchical gene diversity analysis included 1,098 isolates from seven populations. Spatial ranged millimeters to thousands kilometers, including comparisons within and among lesions, fields, regions continents. At the smallest scale, microtransect sampling used determine distribution 15 genotypes found 158 sampled five individual lesions. Each lesion had two six different both mating types in four but most cases composed one or that occupied majority lesion, with other rare interspersed common genotypes. (77%) distributed plots ranging approximately 1 9 m(2) size. Genotype (G / N) fields for Swiss, Texas, Israeli high, 79 100% maximum possible values. Low population differentiation indicated by low G(ST) values populations, suggesting corresponding high degree flow these largest Switzerland, Israel, Oregon, Texas were compared. Population (G(ST) = 0.05), identity between high. A significant correlation geographic distance (r -0.47, P 0.012), probably have not reached an equilibrium drift. Gene on regional level can be reduced implementing strategies, such as improved stubble management minimize production ascospores. possibility levels indicates potential risk spread mutant alleles enable fungicide resistance breakdown genes.