RESEARCH, ACQUISITION, MANAGEMENT, AND DOCUMENTATION OF PLANT GENETIC RESOURCES
Location: Plant Germplasm Introduction and Testing
Title: 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
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: Loss of biodiversity and the over-supply of reactive nitrogen have been cited as the
most out-of-balance factors in the global environment. Agriculture accounts for most of the additional reactive nitrogen in soil and water. Biological nitrogen fixation can produce plant-available nitrogen while releasing less reactive N to the environment. Legume biological nitrogen fixation in agricultural systems also provide an array of ecological services including increased biodiversity, increased soil organic matter, and reduced erosivity. The grain legumes or pulses are targets for increased biological nitrogen fixation because of their high food value and suitability in crop rotations worldwide. Chickpea (Cicer arietinum) is one of the most important pulse crops, providing high quality protein for human nutrition. The U.S. National Plant Germplasm System maintains and evaluates highly diverse germplasm collections in order to preserve plant biodiversity and supply genetic resources for crop improvement. Germplasm collections must be genotyped and phenotyped for characteristics of interest to provide usable information to plant breeders. This study addresses the potential to use global germplasm in crop breeding to increase biological nitrogen fixation. The objective of this study was to determine the biological nitrogen fixation potential in a diverse subset of global chickpea germplasm, and we identified chickpea germplasm with higher nitrogen fixation potential.
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.