Response of Cucumber Cultivars and Other Cucurbitaceous Species to Infection by Hop Stunt Viroid¹

Abstract

Abstract The response of 8 different species within the Cucurbitaceae to hop stunt viroid (HSV) was examined. Some of these plants developed several kinds of systemic symptoms depending upon species, variety or cultivar infected. Among 12 out of 26 cucumber cultivars become infected severely, so visual symptoms are reliable for diagnosis because symptom severity is correlated with viroid content. Other cucurbitaceous species except Citrullus lanatus, Cucurbita maxima and Cucurbita moschata were also susceptible. Among them, Benincasa hispida was found to be a more suitable bioassay plant than Suuyou cucumber which has been hitherto used.