不同磷营养胁迫下水稻苗期性状基因型差异的研究

采用水培方法，研究不同磷水平下（常磷、低磷、缺磷）水稻基因型间苗期性状差异性，结果表明：基因型间、处理间苗期性状均存在极显著差异，磷胁迫下的相对总根长、相对根数、相对平均根长、相对根冠比、相对叶片数达到极显著差异，相对苗高、相对地上部干物重、相对地下部干物重存在显著差异。与常磷处理相比，磷胁迫明显抑制分蘖发生，苗高、叶片数、地上部干物重和发根数下降，下降程度随磷胁迫程度增加而增加；而磷胁迫明显促进单根生长，根冠比增加，且随磷胁迫程度增加而增加；不同磷水平下苗期各性状间的相关性表现也不相同。研究表明，水稻分子育种亲本材料耐低磷胁迫存在着广泛的遗传变异。

Studies on Genotypes Differences of the Rice Seedling Characters Under Different Phosphorus Levels

Trait differences at the seedling stage were investigated under different phosphorus deficiencies in the present study. It indicated that significant differences existed among genotypes and treatments. Highly signifi-cant differences were found in relative values of the treatments to the control for total root length (TRL), root number (RN), average root length (ARL), ratio of root to shoot (RRS), leaf number (LN) under phosphorus stress while significant differences in relative values of seedling height (SH), dry weight of biomass above ground (DW-BA) and dry weight of biomass below ground (DWBB). As compared with the control, phosphorus deficiency in-hibits tilling formation, resulting in decreases of SH, LN, DWBA and RN and they decreased with the degree of phosphorus deficiency. However, phosphorus deficiency accelerated the growth of main root and increased the ratio of root to shoot and they increased according to the degree of phosphorus deficiency. Correlations among different traits were different among different levels of phosphorus stress. There are wide genetic variations in tol-erance to phosphorus deficiency among rice molecular breeding materials.