[Biological characters of rice on P-deficient soils with different pH value]

With pot culture, this paper studied the biological characters of four low-P tolerant rice genotypes 99011, 580, 508 and 99112 and two low-P sensitive rice genotypes 99012 and 99056 on three P-deficient soils with different pH. The results indicated that on test soils, 580, 508 and 99112 had similar low-P tolerant ability. 99011 had poor low-P tolerant ability on alkaline soil, with its relative grain yield being 11.9% and 10.4% less than that on acid and neutral soil, respectively. 99012 showed a relatively stronger low-P tolerant ability on alkaline soil, and its relative grain yield was 19.6% higher than that on acid soil and 22.2% higher than that on neutral soil. 99056 showed a stronger low-P tolerant ability on acid soil, and its relative grain yield was 25.0% and 19.6% higher than that on alkaline and neutral soil, respectively. The effects of soil P level and soil type on rice grain yield mainly manifestied on the number of available spike. The P concentration and its relative value in flag leaves of 99011, 580, 508 and 99112 were significantly higher than those of 99012 and 99056, which might be another factor resulting in the stronger low-P tolerant ability of 99011, 580, 508 and 99112 than 99012 and 99056.