Development of Heterodera glycines in resistant and susceptible soybean cultivars

Abstract

The objective of this study was to evaluate the development of race 3 of H. glycines in susceptible and resistant soybean cultivars. A completely randomized block design with four replications was used for the assessments, which involved Liderança, Centennial and Doko cultivars. Soybean plants with the first pair of leaves developed were inoculated with 4,000 eggs and evaluated 3, 6 and 10 days after the inoculation (DAI). The multiplication of the nematode was assessed by counting the numbers of nematodes per root system using a stereoscopic magnifying glass. The nematode was detected in all treatments but only second phase juveniles (J2) were found in the resistant cultivars Liderança and Centennial, in all evaluation phases. In the susceptible cultivar Doko, however, J2 juveniles in all evaluations and J3 and J4 10 DAI were observed. The results indicate that the nematode does not complete its cycle, which was interrupted around the 10th day after inoculation, in the resistant Liderança and Centennial cultivars.