Genotypic variability for phosphorous acquisition efficiency of chickpea in P-deficient inceptisol

Impact of soil phosphorous deficiency on nodulation, biomass development in elite breeding and selected minicore lines of chickpea were assessed during 2014-18. Reduction in nodule number and its mass per plant due to P-deficiency ranged from 2 to 70% among tested elite chickpea genotypes. Maximum reduction in nodulation and non-significant reduction in plant weight of IPC 2010-88 under conditions of low and high fertility soil indicated the efficiency of alternate nutrient uptake mechanisms operating under low fertility soils. At late vegetative stage, IPC 2010-167 and IPC 2010-55 showed minimum biomass reduction of 12%, while IPC 2009-197 and IPC 2010-88 showed almost 70% reduction in plant dry weight. Among tested chickpea minicore lines, there were significant variations in reduction in total plant dry weight due to P-deficiency among the accessions evaluated in the field. Highest dry weight was recorded in ICC 13219 (26.1 g/plant) compared to ICC 2507 (7.13g/plant). Poor root hair density of ICC 13219 indicated the presence of alternate mechanisms other than root hair density for high P acquisition efficiency. Nitrogen and phosphorus uptake in seed and total plant at harvest also showed significant variations among the different accessions of chickpea. ICC 6537 and ICC 7272, with no significant difference in total nitrogen and phosphorus uptake in plants grown under low and high phosphorus availability in soil, were selected for further studies. The variation in total phosphorus uptake in different accessions under limited soil-P availability was due to the differences in both Pacquisition efficiency and its utilization for various physiological functions including biological nitrogen fixation.