Effects of phosphorus fertilizer on root morphology, physiological characteristics and yield in peanut (Arachis hypogaea)

Abstract

Aim Phosphorus(P) is one of the most important nutritional elements required by plants.The objective of our study was to evaluate the effects of P fertilizer on root morphology,physiological characteristics and yield of peanut(Arachis hypogaea).Methods Pool experiments were conducted to elucidate the influence of phosphorus application on peanut.The root system under different phosphorus levels(P-level) was analyzed using a WinRHIZO system to quantify root volume and morphology.The following parameters were determined for all treatments:root activity,catalase(CAT) activity,concentration of soluble protein and malondialdehyde(MDA).Yield was recorded during the harvest period and analyzed using SPSS 13.0.Important findings During the pod-filling stage,the length,volume,surface area and tip numbers of root increased with increasing P-level.When P 2 O 5 was applied at 30-90 kg.hm-2,the above parameters increased by 3.5%-20.7%,9.3%-21.9%,9.7%-20.3% and 12.6%-21.4%,respectively,compared to the control(no P treatment) group.P-levels could affect enzyme activities.In P treatment group,the activity of superoxide dismutase(SOD),peroxidase(POD) and CAT was increased by 12.7%-20.6%,14.8%-36.8% and 17.0%-41.8%,respectively.Some other parameters could be influenced by P availability,including increased root activity,soluble protein content nodule number and fresh nodule weight.In contrast,MDA content was decreased by 8.4%-19.5% after the P treatment.In the harvesting stage,all parameters decreased with increasing P-level,except the MDA content.But for most parameters,there were no statistically significant differences among treatments.The number of pods per plant,shelling percentage,economic coefficient and biological yield were enhanced with increasing P-level.