Evidence for Different Genes Controlling Insect Resistance in Three Soybean Genotypes¹

Abstract

Soybean [ Glycine max (L.) Merr.] introductions PI 171451 (‘Kosamame’), PI 227687 (‘Miyako White’), and PI 229358 (‘Sodendaizu’) have been reported to be resistant to several insect species. Although these foreign cultivars have been used in breeding programs to develop enhanced germplasm having resistance to foliar feeding insects, it is unknown if resistance is controlled by identical genes. The objective of this study was to determine if the same or different genes control resistance in the three sources. Parents and F 3 lines from crosses among the resistant cultivars were rated visually for leaf feeding damage by velvetbean, caterpillar ( Anticarsia gemmatalis Hübner) in a greenhouse and a field cage. A highly consistent pattern of very susceptible F 3 lines recovered from crosses between resistant parents suggests that each carries at least one gene for resistance that is different from the other sources. This finding suggests a potential for developing gene pools from which selection of higher levels of resistance might be made.