ARS | Publication request: Nitrogen fixation potential in global chickpea mini-core collection

Submitted to: Biology and Fertility of Soils
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 13, 2011
Publication Date: May 7, 2011
Repository URL: http://hdl.handle.net/10113/49738
Citation: Biabani, A., Carpenter-Boggs, L., Coyne, C.J., Taylor, L.D., Smith, J.L., Higgins, S. 2011. Nitrogen fixation potential in global chickpea mini-core collection. Biology and Fertility of Soils. 47:679-685.

Interpretive Summary: The challenge of feeding 9 billion people by the year 2050 is intimidating. Multiple strategies are needed to meet this challenge. Strategies include reducing human population growth, decreasing protein consumption, increasing crop and animal production and increasing the agricultural land base for production. While some food staples (crops and livestock) are increasing others are static or decreasing. Currently food production for 6 billion people occurs on 13% of the global land surface. The strategy of increasing crop and animal production is challenging but manageable. One avenue to achieve this goal is to increase biological nitrogen fixation (BNF) of plants. Increasing BNF decreases the reliance on nitrogen fertilizer and will increase crop production. We investigated BNF of chickpeas from the USDA global chickpea collection. In 39 cultivars the BNF ranged from 47 to 78% of the total plant nitrogen which correlated with shoot weight and total plant weight. The variation among N fixation capacities of the cultivars suggests that N fixation in commercial chickpea varieties may be improved by introgressing positive alleles from the global chickpea germplasm collections. This study suggests to plant breeders and BNF scientists that breeding should take into consideration BNF and not just yield production.

Technical Abstract: Biological nitrogen fixation (BNF) is a sustainable alternative for nitrogen supply to agriculture worldwide. One approach to increasing BNF in agriculture is to breed and use legumes with greater BNF capacity. To assess the capacity for BNF in chickpea (Cicer arietinum) global germplasm, a genetically diverse subset from the USDA global chickpea core collection was assayed for BNF potential.The greenhouse experiment assayed 39 global accessions and commercial cultivar UC-5, inoculated with Mesorhizobium ciceri. Plant height, branch number, nodule number, shoot weight, root weight, nodule weight, proportion of nitrogen fixed and total nitrogen fixation were determined. All characteristics varied significantly among the accessions. Proportion of plant nitrogen fixed ranged from 47-78%, and was correlated with shoot weight (r = 0.21, P<0.01) and total plant weight (r = 0.20, P<0.01), but not with nodule number or weight. Accession 254549 from Iraq produced the greatest total fixed nitrogen, more than any other accession and 121 % more than that fixed by UC-5. The variation among N fixation capacities of the accessions supports the preservation and use of global germplasm resources, and suggests that N fixation in commercial chickpea varieties may be improved by introgressing positive alleles from the global chickpea germplasm collections.