Phosphorus assimilation i mycorrhizal moong ( Vigna radiata L.) plants under different phosphorus levels

Abstract

Influence of phosphorus on its assimilation was studied in a pot experiment at two growth stages at different phosphorous (P) levels control (P 0), 10 μg P g −1 soil (P 10) and 20 μg P g −1 soil (P 20) in non-mycorrhizal (NM) and mycorrhizal (M) moong plants. The response of M plants to P application varied both with growth stage and P level. In NM plants, total P, shoot fresh weight (FW) and exopoly-phosphatase (ExoPase) activity in roots was enhanced with both P levels while root peroxidase and acid phosphatase activities (APase) in leaves increased with P 20 level only. Ester P, root FW, inorganic phosphate (P i) and APase activity in roots were not affected at P 10 level. Total P and P i in leaves were enhanced with MP 10 but were unaltered with MP 20 treatment at 38 days after sowing (DAS). ExoPase and peroxidase activities increased but total P in leaves decreased with MP 10 and MP 20 plants at 50 DAS. APase activity and ester P in leaves increased with MP 20 while Chl concentration decreased at 38 as well as 50 DAS. Soil available P increased with both levels in M plants but only with P 20 with NM plants. The comparison of M and NM plants showed that M plants had greater P i at both samplings whereas root total P and Chl only at 50 DAS at each P level. Shoot FW and root ExoPase activity were greater in M plants with P 0 and P 10 levels. NM plants accumulated ester P more in roots while M plants in leaves at 50 DAS.