Breeding/Seed & Pod Resistance




					Breeding/Seed & Pod Resistance
					Breeding/Seed & Pod Resistance
				There are several insect species that attack cowpea in the field. These include the legume pod borer, Maruca testulalis, commonly called the cowpea pod borer because its principal host is cowpea. A complex of pod-sucking bugs also damage the crop in the field; they insert their mouthparts into the developing seeds and suck the contents of the seeds. Flower thrips are also a major problem. The cowpea weevil is a perennial pest of the stored grain. Traditional host plant resistance - the development and deployment of cultivars carrying genes that condition resistance to the insect pests - has proven to be of limited value. The traditional breeding/screening approach requires that the genome of the crop plant include genes for resistance to the pests. To find these genes, teams of entomologists and plant breeders screen accessions of the plant until sources of resistance are discovered. The resistance traits are then transferred into desirable cultivars by a process of breeding and selection. Unfortunately, the genome of cowpea seems to be devoid of the necessary resistance genes to major insect pests, blocking the path of this approach. IITA, among other organizations, has carried out extensive screening of cowpea germplasm for resistance to cowpea pod borer, thrips, pod-sucking bugs, and weevil. At best, weak sources of resistance were found, if at all. In the case of cowpea weevil there is a single known source of resistance, but the genes conditioning resistance are only moderately effective. A biotype of cowpea weevil able to overcome this moderate resistance has recently been discovered. • Seed & Pod Resistance • Striga Resistance • Genetic Tranformation • New Cowpea Varieties • Screening Tools for Bruchid-Resistant Germplasm

• Seed & Pod Resistance • Striga Resistance

• Genetic Tranformation • New Cowpea Varieties

• Screening Tools for Bruchid-Resistant Germplasm