ICRISAT IPM project 02: Exploitation of wild relatives of crops for resistance to insect pests in sorghum, pigeonpea and chickpea

Duration: 3 years (2005 –2007)

Purpose: To identify wild relatives of sorghum, pigeonpea and chickpea as sources of resistance to insect pests to diversify the basis, and increase the levels of resistance to the target insects and develop cultivars with high levels of resistance to the target insect pests.

Background/description: Insect control is currently based on heavy insecticide use. Environmentally safe techniques such as the release of Trichogramma egg parasitoids, the use of Bt sprays, nuclear polyhedrosis virus (HaNPV), and sex pheromones are not yet readily available in rural areas or are too expensive. It has long been recognized that host plant resistance would be the most effective management option, but thus far, adequate levels of resistance have not been found in the primary genepool against some of the important insect pests such as Helicoverpa in chickpea and pigeonpea, and Atherigona in sorghum. Therefore, there is a need to evaluate wild relatives of crops for resistance to the target insects (Helicoverpa in chickpea and pigeonpea; and shoot fly, Atherigona soccata, stem borer, Chilo partellus, and sorghum midge, Stenodiplosis sorghicola in sorghum), to understand the mechanisms and inheritance of resistance, and to transfer the resistance genes into agronomically acceptable cultivars with adaptation to different agro-ecosystems. Wild relatives of sorghum have been screened for resistance to shoot fly, stem borer, and midge, while those of chickpea and pigeonpea have been evaluated for resistance to pod borer, H. armigera. Several accessions with high levels of resistance to the target insect pests have been identified. There is a need to tap the resistance genes via wide hybridisation or cloning for use in crop improvement, and to understand the bases of resistance to insect pests.

Agroecozone(s) and location(s): Semi-arid tropics in Asia and Africa.

Expected outputs: The project will lead to the development of varieties with durable resistance to insect pests, and information on the nature and mechanisms of resistance.

Potential impact and beneficiaries: The outputs from this project will be used by the NARS, NGOs, Networks, and Private sector, and the farmers in Asia and Africa. The outputs of this project will lead to increased production and productivity of crops in the SAT primarily by supporting the development of genotypes that suffer less damage from insect pests than those currently under cultivation. Production of insect-resistant crops will avoid the need to use expensive pesticides for insect control.

Partners: a) ICRISAT, b) NARS in Asia and Africa, c) Private Seed Industry, and d) NGOs.

Development investor(s): AP Netherlands Biotechnology Project, GRDC (Australia), and USAID.

ICRISAT contact person(s)/principal investigator(s): H.C. Sharma (H.Sharma@cgiar.org), N. Mallikarjuna, P.M. Gaur, and H.D. Upadhayaya (ICRISAT). J.T. Ridsdill-Smith (CSIRO, Australia). S.L. Clements (USDA, Pullman).