Effect of Phosphorus on Root Traits of Soybean Cultivars with Different Phosphorus Efficiencies

The ability of soybean tolerant to low-phosphorus is closely related to root traits.A sand culture experiment was carried out to study the effect of phosphorus levels on taproot length,root/shoot ratio,root volume,root activity and specific root area at different growth stages of Jindou 33 and Tiefeng 3 with different phosphorus efficiencies.Five concentrations of phosphorus in the experiment was designed.Results showed that the relationship between root traits of soybean cultivars with different phosphorus efficiencies at different growth stages and phosphorus levels was very complicated.At seedling stage,the taproot length and root/shoot ratio of phosphorus efficient genotype species were significantly higher than that of phosphorus inefficient genotype under different phosphorus levels;root volume,root activity and specific root area had a significant response to certain phosphorus levels between genotypes,and with the changes of phosphorus levels,these certeria changed non-uniformly.At branching stage,there was no significant response for taproot length in different genotypes with different phosphorus efficiency and under the different phosphorus level treatments.At bloomming stage,the taproot length and root/shoot ratio of phosphorus efficient genotype species were significantly higher than that of phosphorus inefficient genotype under different phosphorus levels.At podding stage,roots activity and root volume of phosphorus efficient genotype were significantly higher than that of phosphorus inefficient genotype under 0.5,1.0,1.5 and 2.0 mmol·L-1phosphorus levels.