Genotypic variation in Root Phenes for Efficient Acquisition of Phosphorus in Advanced Breeding Lines of Groundnut

A pot culture experiment with fifteen advanced breeding lines of groundnut along with 5 varieties were sown both in phosphorus (P) sufficient (78.6 kg/ha) and deficient soils (23.5 kg/ha) to screen for P efficiency based on their root morphology. The data revealed that root dry weight showed no significant differences among the treatments (P sufficient and deficient soils). Root length, shoot length and shoot dry weight recorded low for the plants grown in P deficient soils compared to P sufficient soils irrespective of genotypes. The root biomass recorded more in all the genotypes grown in P deficient soils except in TCGS 1511, 1517, 1528, 1603,1609, 1613 and 1616 compared to P sufficient soils whereas, shoot biomass found more in TAG 24, Narayani and Kadiri-6, TCGS 1602, 1609, 1611 and 1622 grown in P deficient soils. In P deficient soils, highest root length recorded in TCGS 1616 followed by TCGS 1623, Greeshma, TCGS 1517 and 1603. Root dry weight recorded highest in 1621 followed by TCGS 1624 whereas shoot biomass recorded highest in TCGS 1624 followed by Greeshma, TCGS 1517 and 1621 grown in P deficient soils. In the P responsive genotypes, enormous amount of root growth occurred to adapt with P stress condition thus providing greater contact area, which is particularly important in the uptake of less mobile ions like P. Therefore, genotypes having greater ability to tolerate P insufficient condition would be able to extract P efficiently from low P soil. Hence from the study, it can be concluded that, TCGS 1624 and 1621 can be identified as P efficient groundnut lines based on their high root biomass and also shoot biomass.