POST-PENETRATION RESPONSE OF MELOIDOGYNE INCOGNITA ON CUCURBITA FOETIDISSIMA (BUFFALO GOURD)

Abstract

Buffalo gourd, Cucurbita foetidissima, is a perennial cucurbit that is commonly found in the semi-arid region of the southwestern United States and Mexico. Few studies have investigated the post-penetration response of Meloidogyne incognitaon Cucurbita, and there is no information on any perennial species of Cucurbita such as buffalo gourd. The objectives of this study were to determine the susceptibility of buffalo gourd to M. incognita and evaluate the post-penetration response of M. incognitaon buffalo gourd. Fewer second-stage
juveniles (J2) penetrated the root system of buffalo gourd and horned cucumber (Cucumis metuliferus), which served as a resistant control, from 7 to 21 days after inoculation (DAI) compared to cucumber (Cucumis sativus), the susceptible control. Nematode development was delayed at 14 and 21 DAI in buffalo gourd compared to cucumber, but not as delayed as that observed on horned cucumber. Of the J2 that penetrated the root systems, fewer emerged from buffalo gourd and cucumber at 3 and 4 DAI than horned cucumber. Fecundity of the M. incognitafemales was lower on buffalo gourd and horned cucumber than cucumber. Buffalo gourd would be considered to be susceptible to M. incognitabecause of a lower percentage of J2 emigration from the root system than the resistant control and because the individuals that remained in the root developed into egg-laying females. However, although both buffalo gourd and cucumber were susceptible to M. incognita, buffalo gourd was a much
less suitable host than cucumber.