摘要

Stem rust, caused by Puccinia graminis, is a potential threat to wheat production in Central Asia. To investigate if sexual reproduction is important for the epidemiology of the disease, the population biology of the fungus was studied. Samples of P. graminis were collected from six wheat fields and from wild oats within two of the wheat fields during the growing season of 2010. The population structure of P. graminis was investigated by evaluating a total of 121 single uredinia collected from wheat and wild oats, using nine polymorphic simple sequence repeat (SSR) markers. The results presented in this study indicate that there is a selection process by the grass host, in particular wheat, that favours certain clones, which in turn affects the population structure of P. graminis in Tajikistan. The genotypic variation was large, both within and between the wheat fields and three populations were in linkage equilibrium, indicating that sexual reproduction within the P. graminis population takes place. This leads to the conclusion that the presence of Berberis spp. in Tajikistan has an important role in the population dynamics of P. graminis within the country, even if the fungus must reproduce primarily in a clonal manner during most of the year. Results also confirm that the two formae speciales, P. graminis f. sp. tritici and P. graminis f. sp. avenae, are genetically different even if they were collected in the same field.

  • 出版日期2015-1