大豆苗期磷效率与其构成因素的分析

探讨大豆苗期磷效率特性，研究大豆磷效率与其构成因素的关系。本试验选用4个“磷低效”大豆基因型D03、D05、D17和D18及“磷高效”大豆基因型D31、D34、D37和D38，采用土培试验，设高、低磷两个处理，对大豆基因型磷效率与其构成因素的关系进行了研究。结果表明，低磷处理下，4个磷高效基因型苗期的植株吸磷量的优势均较明显，D34表现出较强的磷吸收能力，但是有3个磷高效基因型，磷利用效率的适应性并未表现出优势，只有D37表现出较强的磷利用能力。相关和通径分析表明，大豆磷效率的高低主要是由吸磷能力的强弱来决定的，（-P）处理明显大于（+P）处理。吸磷量和磷的利用效率对磷效率直接影响均较大，但吸磷量贡献更大，而间接影响均较小。低磷胁迫下，磷高效基因型的适应低机理是不同的，磷吸收效率即吸磷量是不同大豆基因型苗期磷效率的主要变异来源。

Analysis of Soybean Seedling Phosphorus Efficiency and its Component Factor

This paper discussed the characteristics researched the relationship phosphorus efficiency of of phosphorus efficiency of soybean seedlings, and soybean and its components. The author selected four ＂P-inefficient＂ soybean genotypes including D3, D35, D17,D18 and the ＂phosphorus efficiency＂ soybean genotypes including D31, D34, D37 and D38, designed high and low phosphorus treatment in the soil culture experiment, and identified the phosphorus efficiency of soybean genotypes in the seedling stage. The results showed that in the low-phosphorus treatment, the four seedling genotypeswith P efficient had significant advantage in P uptake, in which D34 showed strong ability of phosphorus absorption, but three phosphorus efficient genotypes had no well adaptability in utilization efficiency of phosphorus, only the D37 showed strong ability to make use of phosphorus. The correlation and path analysis showed that the phosphorus efficiency of soybean was mainly determined by the abililty of P uptake, and the （-P） treatment was significantly higher than the （＋P） treatment. P uptake and P utilization efficiency had direct impact on the efficiency of phosphorus, but the P uptake had greater contributions, while the indirect effect was relatively small. In the low-phosphorus stress, the adaptability of phosphorus efficient genotypes had different mechanisms; the phosphorus absorption efficiency （i.e. P uptake） was major source of the variation among soybean genotypes with different phosphorus efficiency in the seedling stage.