Host and yield responses of soybean genotypes resistant or susceptible to Meloidogyne incognita in vivo

Abstract

Host and yield responses of soybean genotypes resistant to Meloidogyne incognita were verified in semi-field and field trials at four different localities in South Africa. The resistant cultivar LS5995 and susceptible cultivars Prima and Prima2000 were used and each trial consisted of two treatments: fumigated (control) and nematode-infected plots. The number of rootknot nematode eggs and J2 in roots of nematode-infected plants was significantly higher in Prima and Prima2000 compared with those of the resistant genotypes in all trials. Low root and soil nematode population densities were consistently recorded for LS5995 in all trials. Yield of the resistant genotypes did not differ significantly between the fumigated and the nematode-infected plants for all trials, while yields of the susceptible Prima and Prima2000 grown in fumigated plots were significantly higher than those in nematode-infected plots for one microplot as well as one field trial. LS5995 is no longer commercially available in South Africa but is used as a superior source of M. incognita-resistance in breeding programmes for introgression of resistance into high-yielding, locally adapted soybean cultivars.