Assessment on Phosphorus Efficiency Characteristics of Soybean Genotypes in Phosphorus-Deficient Soils

摘要

A glasshouse study compared the growth and phosphorus(P)efficiency of 96 genotypes of soybean[Glycine max(L.) Merrill]in a P-deficient soil.The soybean genotypes differed greatly in growth,nodulation and P uptake after growing in the soil for 45 days,with shoot biomass ranging from 0.91 to 1.75 g per plant.The application of P improved biomass production,nodulation and P uptake and decreased root to shoot ratio,root length and surface area and P utilization efficiency.The 96 soybean genotypes were divided into 3 categories in P efficiency using the principal component analysis and cluster analysis,and 4 categories according to F values in combination with growth potentials.The Pefficient genotypes were associated with high biomass production,root to shoot ratio,root length and surface area and P uptake but low shoot to root P concentration ratio under P deficiency.The results indicate that there is a substantial genotypic variation in P efficiency in existing germplasm,and that P efficiency was correlated positively with dry weights of shoots and roots,ratio of root to shoot dry weight,root length and surface area,root P content and total P uptake.The shoot dry weight under P deficiency and relative shoot dry weight(deficient P/adequate P supply)are effective and simple indicators for screening P-efficient genotypes at the seedling stage.