Variations in phosphorus uptake and its utilization in pigeonpea genotypes grown under phosphorus deficiency

Phosphorus (P) is one of the most important nutrients for plant growth and development and its fixation is a major constraint for crop production in low input agriculture. Crop species vary in their ability to acquire P under limited supply of the nutrient. Variation within the species among genotypes is also reported. An investigation was carried out to examine the extent of variability in the uptake and utilization of P and its association with root associated traits among 76 medium duration pigeonpea genotypes. Significant variation was found among genotypes for root associated traits and P content in root and leaf. Genotypes like ‘GS-1’ and ‘BSMR-736’ recorded high root volume, dry weight and P content in the leaf. There was good correlation between shoot P content and total dry matter. Based on the root dry weight and leaf P content, genotypes were classified as high, medium and low root types with high and low P uptake capacity. High P uptake genotypes showed high total dry matter compared to low P uptake types. Such genotypes will be utilized in breeding for development of appropriate genetic stocks.