Studies On Root Morphology Of Oat Different P-efficiency Cultivars Under Phosphorus Stress And Phosphorus Uptake

Phosphorus is one of the three essential nutrients for crop growth.It is an important material guarantee for agricultural production as well as a major limiting nutrient element.The massive application of chemical fertilizers in modern agriculture has significantly enhanced the phosphorus content in the farmland soil.However,phosphorus has poor mobility in soil and is easy to be immobilized.Most of them are difficult to be absorbed and utilized by crops.And 60%-80%of soil total phosphorus is inorganic phosphorus,and organic phosphorus has a large variation.Thus study on the physiological response of oat to low phosphorus stress and the difference in the utilization of inorganic phosphorus and organophosphorus,that is of great theoretical and practical significance to the rational fertilization and genetic improvement of phosphorus nutrition in oat.In this study,oat P-efficient cultivar 56 and P-inefficient cultivar 60 were selected as test materials.By pot experiments of hydroponics and soil culture,the morphological adaptation of different phosphorus efficiency oat cultivars at the seedling stage was studied under low phosphorus stress,and the differences in the absorption and utilization of inorganic phosphorus and organophosphorus were made.The main results are as follows:?1?Under low phosphorus stress,the dry matter growth of oat P-efficiency cultivar56 was higher than that of P-inefficiency 60,and the maximum root length,adventitious root number,root surface area and root volume of 56 root were significantly higher than P-inefficiency cultivar 60,indicating that the low phosphorus coercive ability of P-efficiency cultivar 56 was greater than P-inefficiency cultivar 60.?2?Low phosphorus stress can increase the phosphorus uptake rate of two cultivars,and the I_maxax of P-efficiency cultivar 56 is higher than P-inefficiency cultivar 60.The C_minin of P-efficiency cultivar 56 was smaller than P-inefficiency cultivar 60,indicating that P-efficiency cultivar 56 could absorb lower concentrations of P and be more tolerant to low phosphorus environment.?3?Inorganic phosphate can significantly improve the dry matter quality of two oat cultivars.The dry matter quality of oat plants under the treatment with K-P was the largest,followed by Al-P and Fe-P,and CK was the smallest.Under the treatment of Al-P and Fe-P,the total Pi content of oat P-efficiency cultivar 56 was significantly reduced,while the total Pi in P-inefficient cultivar 60 increased.Under Al-P,the root-to-crown ratio of P-efficient cultivar 56 was significantly lower than that of P-inefficiency cultivar60.It shows that the P-efficiency cultivar 56 has a strong ability to activate and absorb inorganic phosphorus in soil.The difference of two phosphorus efficiency cultivars is mainly in the use of insoluble inorganic phosphorus,especially Al-P.?4?Organic phosphate can significantly increase the dry matter quality of two phosphorus efficiency cultivars,and the dry matter quality of shoots,underground and whole plants of P-efficient cultivar 56 is significantly greater than that of P-inefficient cultivars 60,indicating that the absorption and utilization efficiency of the P-efficient cultivar 56 for organic phosphates is greater than P-inefficient cultivars 60.