Host specificity of Colletotrichum truncatum from lentil

Abstract

Isolates of Colletotrichum truncatum from lentil (Lens culinaris) and soybean (Glycine max) were shown to have different host ranges and patterns of latent infection. A smaller number of studies on an isolate from scentless chamomile (Matricaria perforata) indicated that this isolate likely differs from either lentil or soybean isolates. In growth-cabinet trials, lentil isolates were pathogenic on lentil, faba bean (Vicia faba), field pea (Pisum sativum), narrow-leaf vetch (Vicia americana), and chickpea (Cicer arietinum). Latent infection by lentil isolates was observed only in scentless chamomile, and no symptoms were observed on alfalfa (Medicago sativa), dry bean (Phaseolus vulgaris), or lupin (Lupinus albus). Isolates from scentless chamomile had a short latent period and produced abundant disease on scentless chamomile and limited symptoms on lentil, faba bean, field pea, and chickpea. In contrast, soybean isolates had an extended latent period and produced visible lesions on soybean, chickpea, lupin, and dry bean, but not on faba bean, field pea, or narrow-leaf vetch. Latent infection by soybean isolates was identified in inoculated plants of all the plants species in the trial. Field trials confirmed that C. truncatum from lentil causes disease symptoms on faba bean and field pea (but not chickpea) under field conditions. There were no substantive differences in the pattern of pathogenicity or disease severity between the races of C. truncatum from lentil (Ct0 and Ct1) on the plant species in the study. Narrow-leaf vetch was generally susceptible to C. truncatum from lentil