Greenbug, Schizaphis graminum (Rondani), populations over-summering on noncultivated grass hosts may be implicated in early fall infestations in wheat. The purpose of this study was to examine the relationship between over-summering greenbugs on noncrop hosts and fall infestations on wheat. Since greenbug populations on noncultivated hosts may also act as reservoirs of virulence genes, the biotypes of collected aphids were also determined. The grass species present at three sites (two in Oklahoma and one in Kansas) were identified and a species richness curve was generated. Greenbugs were collected at these sites and their hosts and biotypes determined. At Hays, KS, a persistent over-summering greenbug population lead to an early fall infestation in wheat. At the sites in Oklahoma, where over-summering greenbugs were not detected, the fall infestation occurred 3 months later. Biotypes G, I, K, and a new biotype (i.e., previously undescribed) were found on noncultivated hosts at Hays, but only biotypes I and K were found on the cultivated wheat. Finding a new biotype supports the hypothesis that biotypic diversity (new combinations of virulence genes) is generated and maintained on noncultivated grasses, which may then act as reservoirs of virulence genes found in populations on crops.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.