Pathogenic variation of Olpidium viciae isolates on faba bean varieties and other legumes.

Faba bean is an important cool-season food legume currently constrained by an emerging gall disease (Olpidium viciae) in Ethiopia's highlands. Variability tests of O. viciae isolates were conducted to determine its pathogenic variation on six faba bean varieties in the growth chamber and eight other legumes in the screen house. Each faba bean variety and legume was inoculated with zoospores suspension (106 spores mL−1) of each isolate. The variability tests were conducted twice on six faba bean varieties to identify the pathogenic level of 30 O. viciae isolates and the experiments were factorially arranged in a completely randomized design with three replications. There was significant variation (P < 0.01) among faba bean varieties, other legumes, and isolates in the components of disease development in both experiments. Isolates ST8 and SL4 caused the highest disease severity (34.23%) and area under the disease progress curve (AUDPC) (180.56%-days) on faba bean variety Bulga 70. Seven pathogenic isolates were identified as causing more disease on faba bean varieties than the remaining 23 isolates and then inoculated on other legumes. Isolate SEL caused the highest disease severity on grass pea (Lathyrus sativus) (20.99%). Next to faba bean, higher AUDPC (156.64%-days) was calculated from inoculated grass pea with WQZ isolate. Thus, the isolates varied in their infection ability in the tested legumes and faba bean varieties, and the pathogen had a wide range of hosts. [ABSTRACT FROM AUTHOR]