Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2009
Publication Date: 5/8/2009
Citation: Clement, S.L., Sharma, H.C., Muehlbauer, F.J., Elberson, L.R., Mattinson, D.S., Fellman, J.K. 2009. Resistance to Beet Armyworm in a Chickpea Recombinant Inbred Line Population. Journal of Applied Entomology. Online, doi:10.1111/j.1439-0418.2009.01411.x. Interpretive Summary: Chickpea is an important grain legume crop in the world with major U.S. production in the Palouse region of eastern Washington and northern Idaho. Although insects impact chickpea yields in the Palouse region, they are more damaging to chickpea crops on the Indian subcontinent and Australia. A large publicly available chickpea seed collection is stored at the USDA-ARS Western Regional Plant Introduction Station in Pullman, Washington, and is an important source of seeds for developing new or improved cultivars by a global cadre of chickpea breeders. This research paper by a team of scientists from the USDA-ARS, Washington State University, and the International Crops Research Institute for the Semi-Arid Tropics in India, shows the Pullman chickpea collection is an excellent source of material for breeding cultivars to resist attack by important insect pests. Additionally, the research in this paper is noteworthy because it identifies highly insect-resistant breeding material for use in global chickpea breeding programs. Finally, this paper shows that collaborative research between American and foreign scientists is required to address important insect pest problems that plague farmers in the U.S., India and other countries.
Technical Abstract: Cicer reticulatum Ladzinsky, a good source of insect resistance, was used to develop a chickpea (Cicer arietinum L.) recombinant inbred line population (CRIL-7) using FLIP 84-92C (kabuli chickpea) and PI 599072, a resistant C. reticulatum accession, as parents. CRIL-7 lines, parents, and checks were screened for resistance to beet armyworm (Spodoptera exigua (Hübner), a pest of chickpea in Mexico and the Indian sub-continent. Resistance and susceptibility of entries (CRIL-7 lines, parents, resistant and susceptible checks) was based on the fate and average weight gain of early-stage larvae on pre-flowering plants. Forty-two CRIL-7 entries segregated for resistance (9 lines with larvae weighing 0.42–0.59 mg after the assay), susceptibility (8 lines, larval weights 0.61–0.99 mg), and for intermediate levels of resistance and susceptibility (25 lines, larval weights 1.01–2.17 mg). In a second trial, early-instar larval weight gain differed significantly (P < 0.0001) among entries (12 CRIL-7 lines, parents, checks), with mean weights from 4.03 mg (susceptible kabuli cultivar) to 0.80 mg (resistant CRIL-7 line). There was no significant effect (P > 0.05) of entry on larval mortality, although mortality rates were 28.2% to 61.9%. Flavonoid and isoflavonoid extractions and analyses did not clarify the role played by these phytochemicals in chickpea resistance to lepidopterous pests. The highly resistant CRIL-7 entries identified in this study might be promising breeding material for global chickpea breeding programs, compared to previously identified chickpea germplasm that exhibit low to moderate levels of resistance to pod borers (Helicopera armigera (Hübner)).