低磷胁迫对不同基因型水稻阶段生物学特征的影响

采用盆栽试验研究了低磷胁迫下不同基因型水稻在分蘖期、孕穗期和成熟期的生物学特征。结果表明，不同基因型水稻在不同的生长发育阶段对低磷胁迫的反应存在明显差异。分蘖期，耐低磷基因型水稻的耐低磷特性主要表现在相对分蘖数、相对绿叶数和相对地上部干重三个性状上，其中以相对分蘖数的差异较大，但这个时期水稻的任一性状不足以反映其耐低磷特性；孕穗期，耐低磷基因型水稻的相对分蘖数、相对绿叶数和相对地上部干重虽仍表现出明显的优势，但与分蘖期不同的是相对分蘖数受低磷胁迫的影响程度趋于稳定，相对绿叶数的差异明显下降，相对干重的高低逐步成为区别耐低磷基因型的主要依据；成熟期，耐低磷基因型的相对地上部干重优势进一步加强，远远超过其它生物学性状。耐低磷基因型的相对经济产量显著高于低磷敏感基因型。在水稻生长的各个时期中，耐低磷基因型水稻的相对株高、相对叶宽和相对叶长与低磷敏感基因型水稻对应的指标相比均未表现出明显差异。

Influence of low-P stress on the biological characteristics of different rice genotypes at different stages

Phosphorus deficiency is one of the limited factors on the growth of rice. Evaluating traits of P-tolerant genotypes offered the materials and basis for identifying genes involved in phosphorus efficiency and genetic mechanism. The biological characteristics of P stress tolerant rice genotypes were studied at tillering, booting and maturity stages with pot culture, setting different levels of phosphorus deficiencies. The responses of various rice genotypes to low-P stress were different at different stages. At tillering stage, P-tolerant genotypes had different relative numbers of tillers, green leaves and shoot dry weight than P-sensitive genotypes. However, no characteristics were good indicators of P-tolerance at this stage. As for booting stage, the relative values of tiller, green leaves and shoot dry weights of P-tolerant genotypes were still higher than P-sensitive genotypes. Compared with tillering stage, however, relative shoot dry weight became the primary indicator of P stress tolerance. At maturity stage, relative shoot dry weight of P-tolerant genotypes was a much better indicator than other biological characteristics. The relative grain yield of P-tolerant genotypes was higher than that of P-sensitive genotypes. There wasn’t obvious difference between P-tolerant and P-sensitive genotypes in relative plant height, leaf width and leaf length at any stage.