Amplified fragment length polymorphism amongRhynchosporium secalisisolates collected from a single barley field in Syria.

AFLP markers were used to measure the amount and distribution of genetic variation amongRhynchosporium secalisisolates on a microgeographical scale in Syria. Forty isolates hierarchically sampled from a single barley field were assayed for AFLP variation using primer combinations not previously tested in populations of the pathogen from Syria. In contrast to a previous study, which showed high clonality within field populations ofR. secalisin Syria, the present study revealed a much higher level of genetic diversity, stressing the important roles that sampling strategies and the choice of primers/primer combinations play in the evaluation of genetic variation inR. secalispopulations at a microgeographical scale. A high level of genetic variation was found to occur on a fine scale throughout the pathogen population examined, with 40 different haplotypes being identified among the 40 isolates sampled. Data were consistent with the hypothesis that the primary inoculum originated from a genetically diverse founding population, which may have consisted of ascospores of an as yet undescribed teleomorph and/or asexual spores of a highly mutable local population. [ABSTRACT FROM AUTHOR]