| Phosphorus is one of the essential nutrients for the growth and development of rice,and plays an important role in the growth and development of rice.The total phosphorus content in the soil is high,but the solubility of phosphorus in the soil is low,the mobility is poor,and it is easily fixed by iron and aluminum oxides,resulting in low available phosphorus and limiting the growth of rice.It is an effective way to improve the efficiency of soil phosphorus utilization by excavating the genetic potential of crops and using the difference of phosphorus absorption and utilization by crops themselves to breed crops with high phosphorus utilization efficiency.Therefore,in this study,40 rice materials with obvious differences in phosphorus absorption and utilization obtained by the preliminary screening of the research group were used as the objects to carry out field experiments to re-screen rice materials with high phosphorus utilization efficiency,and to explore the phosphorus accumulation and distribution of various organs at different growth stages and the characteristics of phosphorus utilization at filling stage through soil culture experiments,in order to provide a theoretical basis for the breeding of rice with high phosphorus utilization efficiency.The main findings are as follows:（1）Under low phosphorus conditions,the above-ground biomass and phosphorus accumulation of 40 rice materials at heading stage ranged from 18.00 to 88.04 g（CV=31.85%）and 47.39 to 237.60 mg plant-1（CV=31.98%）,respectively,and the maximum values were 4.89and 5.10 times of the minimum values,respectively.At maturity stage,the variation ranges of phosphorus grain production efficiency and grain yield of 40 rice materials were 13.31～25.31 g DW g-1 P（CV=16.87%）and 24.51～50.02 g（CV=16.28%）,respectively.The maximum values were 1.90 and 2.04 times of the minimum values,respectively.There were significant differences in phosphorus absorption and utilization among the materials.Finally,the rice material 527 R with high phosphorus utilization efficiency and the rice material IR58025 with low phosphorus utilization efficiency were screened.In the field validation experiment,the P grain production efficiency and yield of 527R were 19.89 g DW g-1 P and 51.21 g,respectively,which were 1.20and 1.86 times that of IR58025.527R takes into account the characteristics of high phosphorus use efficiency and high yield,and provides an ideal material for studying the characteristics of high phosphorus use efficiency in rice.（2）Under low phosphorus conditions,the aboveground biomass and phosphorus accumulation of P-efficient rice material 527R were significantly higher than those of P-inefficient rice material IR58025 at different growth stages,which were 1.15-1.69 times and 1.31-1.98 times of IR58025,respectively.The root-stem transfer coefficient of 527R at tillering stage and booting stage and the flag leaf-panicle/grain transfer coefficient at filling stage and mature stage were significantly higher than that of IR58025.The P grain production efficiency and yield per plant of527R were 32.41 g DW g-1 P and 45.98 g,which were 1.40 and 1.74 times of IR58025,respectively.Under normal phosphorus conditions,the differences in aboveground biomass and phosphorus accumulation between the two types of rice were small.Compared with normal phosphorus,low phosphorus has a stronger inhibitory effect on phosphorus inefficient utilization material IR58025,and phosphorus efficient utilization material 527R has stronger phosphorus utilization efficiency and yield formation ability.（3）Under the condition of low phosphorus,the phosphorus content of the two rice leaves showed a trend of flag leaf>second and third leaf>lower leaf,and the proportion of phosphorus components in flag leaf was inorganic phosphorus>nucleic acid phosphorus>lipid phosphorus>metabolic phosphorus>residual phosphorus.The content of inorganic phosphorus in leaves of 527R,the content of nucleic acid phosphorus in the second and third leaves,and the content of lipid phosphorus in flag leaves and lower leaves were significantly lower than that of IR58025.The acid phosphatase activity of leaves in different parts of 527R was significantly higher than that of IR58025,which was 1.07-1.19 times that of IR58025.Under normal phosphorus conditions,there was no difference in the distribution of phosphorus components in the flag leaves of the two rice materials.The acid phosphatase activity of flag leaf and lower leaf of 527R was stronger than that of IR58025.Compared with normal phosphorus,the contents of inorganic phosphorus and lipid phosphorus in flag leaves of the two rice materials increased under low phosphorus conditions,the content of nucleic acid phosphorus decreased,and the activity of acid phosphatase increased.The acid phosphatase activity of 527R leaves increased under low phosphorus conditions,which could efficiently utilize soluble phosphorus components and enhance the ability of plants to reuse phosphorus in leaves.In summary,the high-efficiency utilization of phosphorus rice material 527R takes into account the characteristics of high-efficiency utilization of phosphorus and high yield,and has stronger phosphorus absorption,transport and utilization ability,which provides an ideal material for studying the characteristics of high-efficiency utilization of phosphorus in rice. |
