Reproduction potential of soybean cyst nematode, Heterodera glycines, and synergetic interaction with Fusarium virguliforme on dry bean cultivars
Mamadou L. Fall: Agriculture and AgriFood Canada
<div>Dry bean has been known as a host of soybean cyst nematode (SCN), by <em>Heterodera glycines</em>, since it was first reported in Japan in the 1930s. However, there are few studies on SCN reproduction potential on dry bean and its interaction with <em>Fusarium virguliforme</em>, the causal agent of sudden death syndrome (SDS). Three growth chamber studies and two years of field experiments were conducted to determine the reproduction potential of <em>H. glycines </em>and its interaction with<em> F. virguliforme </em>on 10 dry bean classes grown in the Midwestern United States in comparison with 3 soybean varieties. Soybean cyst nematode reproduced on all 10 dry bean classes, on the susceptible soybean variety (Archer) and on the resistant soybean variety (PI 88788). Based on the female indices (FIs), only Peking (soybean) was consistently classified as resistant (FI < 10) across all the experiments. According to the least-squares means analysis, only the Zorro, Matterhorn and Merlot dry bean classes were less susceptible to SCN than the susceptible soybean variety. Foliar SDS like symptoms were observed on the soybean check and on most of the dry bean classes. Among all soybean varieties and dry bean classes, only Vista did not express foliar symptoms despite the presence of <em>F. virguliforme</em> in the roots. A polynomial model described a synergetic relationship between the number of cysts, the female index and the relative DNA concentration of <em>F. virguliforme</em>. The results suggested that SCN and SDS represent a serious threat not only to soybeans, but also to dry beans.</div>
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