Study On Phosphorus Efficiency And Its Related Traits In Different Peanut Cultivars

Phosphorus(P)deficiency in soil has become an significant obstacle to peanut production.The selection and breeding of peanut cultivars with high P efficiency is a great significance for exploring peanut's ability to utilize P,improving its P uptake efficiency and utilization efficiency and making full use of P resources in soil.In this study,using fifteen peanut(Arachis hypogaea L.)cultivars which belongs to five botanical types to study the differences of P uptake efficiency,P utilization efficiency,agronomic traits,yield production and quality of peanut among different cultivars under different P levels.On this basis,using hydroponic to study the differences about the response of root traits to P stress among different peanut cultivars in P efficiency,which provide theoretical basis for improving P efficiency.The main results are as follows: 1.Screening of peanut cultivars with different P efficiencyUsing low P tolerance coefficient(the relative value of yield under no P supply and P supply),fifteen peanut cultivars were classified into three groups,which including 4 of P efficiency cultivars(PI468250,Shanhua17,PI259747,05H511),6 of P intermediate cultivars(Nongda818,Hua17,Jihongtianyidianbai,Shanhua9,Lipudahuasheng,Linhua1),and 5 of P inefficiency cultivars(Pronto,ICGV86699,Krapt.st.16,Rugaoxiyangsheng,ICG6848).In addition,similar results were obtained at seedling stage by using low P tolerance coefficient(the relative value of dry weight per plant under no P supply and P supply)analysis.Therefore,preliminary assessment of P efficiency at seedling stage is feasible.2.High efficiency mechanism of P efficiency cultivarsP efficiency cultivars can be roughly divided into two categories: one is that the P accumulation per plant under low P level is higher than that under high P level while its utilization efficiency is unchanged or slightly reduced,which indicating that this kind of cultivar's absorption ability is stronger,the other is that the P utilization efficiency per plant under low P level is higher than that under high P level while its accumulation is unchanged or slightly reduced,the conversion and reuse ability of this kind cultivar is stronger.Under low P stress,the ratio of root to shoot increased significantly,the length of main root,total root length,root volume and root surface area increased and the average root diameter decreased.3.Relative value correlation analysis of P efficiency and related traits.Relative main root length,relative total root length,relative root surface area,relative root tip number,relative dry weight,relative root-shoot ratio and relative mean root diameter were significantly or extremely significantly correlated with the low phosphorus tolerance coefficient of dry weight.Relative pod numbers per kg,relative Percentage of mature pods,relative Percentage of kernel,relative main stem height,relative side-branch length are significantly or extremely significantly correlated with the low phosphorus tolerance coefficient of yield.It can be used as an indicator for screening phosphorus efficient peanut varieties.