低磷胁迫对水稻地上部氮、钾吸收和积累的影响

Effects of low phosphorus stress on nitrogen and potassium absorbed and accumulated in rice shoot

在盆栽土培条件下,采用耐低磷水稻基因型508T、580T、99011T和99112T及低磷敏感基因型99012S和99056S为材料,研究了不同生育时期,低磷胁迫对水稻氮、钾吸收和积累的影响。结果表明,在分蘖期,低磷处理对水稻体内氮、钾含量的影响较小,但低磷敏感基因型水稻受影响较大;孕穗期,除508T的氮含量变化不明显外,其它基因型体内氮、钾含量均显著增加。在这两个时期,低磷敏感基因型99012S氮、钾含量的变化幅度在所有基因型中最高,而另一个低磷敏感基因型99056S则相反。至成熟期,由于受吸收效率和转运效率的共同影响,不同基因型水稻体内氮、钾含量的变化趋势明显比生育前期复杂,耐低磷基因型水稻茎叶的氮、钾含量与低磷敏感基因型没有明显的差异。在生育前期,耐低磷基因的氮、钾积累量显著高于低磷敏感基因型;生育后期,耐低磷基因型的绝对积累量优势消失,但相对积累量优势增大。

Pot experiments were conducted to investigate effects of low-P stress on nitrogen and potassium uptake and accumulation in P-tolerance rice genotypes 508, 580, 99011, 99112, and P-sensitive rice genotypes 99012 and 99056. The result showed that low phosphorus stress had larger influence on nitrogen and potassium content of rice at tillering in low-P sensitive rice genotypes than in low-P tolerance rice genotypes. At booting stage, the potassium content of all supplied rice genotypes increased markedly under low phosphorus stress, and nitrogen content also increased markedly except 508. At both stages, the largest variation on nitrogen and potassium content was found in low-P sensitive rice genotype 99012, while the lowest was found in low-P sensitive rice genotype 99056. At maturity stage, low P stress had slight effects on nitrogen and potassium content for all rice genotypes due to the co-influence with absorbability and transportabili- ty. The accumulation of nitrogen and potassium was significantly higher in P-tolerance rice genotypes than in P-sensitive rice genotypes in the early growth stages. The difference of accumulation of nitrogen and potassium between two rice geno- types was declined, but the relative accumulation of nitrogen and potassium in P-tolerance rice genotypes increased in the latter growth stage.