Effect of Supplied P Levels on Rice Growth and Uptake of P and Zn in Different P-Efficiency Genotypes

摘要

A soil pot culture experiment with four supplied P levels (i.e. P30, P50, P100, P200, representing supplemental P 30, 50, 100, 200 mg/kg, respectively) was conducted to investigate uptake and use ability to P and Zn in the rice genotypes with different P-efficiency, of which rice genotypes 508, 99011, 580, 99112 were low-P tolerant and 99056, 99012 were low-P sensitive. Low-P tolerant rice 580 and 99011 absorbed more P than the others, and rice genotype 580 had stronger uptake ability especially at low-P level such as P50 and P30. 508 could absorb considerable P, and had the lowest P percentage of shoot, indicating it had good performance in P-use efficiency. These three rice genotypes had larger biomass and less response to changed P level than rice genotype 99112, 99056 and 99012. Rice genotype 99112 showed Low-P tolerance mainly by sacrificing biomass to maintain high relative grain yield. The least amount of P absorbed by 99056 showed it had the lowest P uptake efficiency, and the highest P percentage in shoot of 99012 meant it had the lowest P use efficiency. So they two showed low-P sensitivity. Zn contents in shoot under P200, P100 and P50 were similar, but P30 increased Zn content in shoot significantly. The Zn contents in shoot of 99112, 99056 and 99012 were higher than those of 508, 99011 and 580, especially at tillering stage and booting stage. As for total Zn content in shoot, Low-P tolerant rice genotype 580 had the largest amount and followed by 99011 and 508, low-P tolerant rice genotype 99012 had the smallest amount at the three sampling stage and followed by 99056. Furthermore, P/Zn in shoot of 99012 was the highest, and that of 99056 was the smallest at the same P level.