Introgression of Helicoverpa armigera Resistance from Cajanus acutifolius-a Wild Relative from Secondary Gene Pool of Pigeon Pea (Cajanus cajan)

The aim of the study was to introgress Helicoverpa armigera resistance from wild relative Cajanus acutifolius into pigeonpea, (Cajanus cajan L.), an important grain legume in South Asia, East Africa and the West Indies. Pigeonpea grain yields on farmer’s fields are quite low, largely because of damage by insect pests, of which legume pod borer Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is the important pest worldwide. Pod borer has developed high levels of resistance to chemical insecticides. Currently, there are no cultivars of pigeonpea with high levels of resistance to H. armigera. Therefore, there is a need to identify and introgress resistance genes from the wild relatives of this crop. Wild relative of pigeonpea, Cajanus acutifolius (ICPW 15613) and the interspecific derivatives C. acutifolius x C. cajan have shown resistance to H. armigera. The results showed that all the test lines and C. acutifolius had high levels of flavonoids such as chlorogenic acid, quercetin and rutin in the flowers and buds, which may have resulted in less damage due to H. armigera larvae. Most of the test lines had more than 15.00 g of seed weight (100 seed weight) and beige seed color. These lines can be used for pigeonpea improvement for resistance to H. armigera.