磷素处理对不同磷效率基因型大豆根系性状的影响

Effect of Phosphorus on Root Traits of Soybean Cultivars with Different Phosphorus Efficiencies

大豆的耐低磷能力与根系性状密切相关。以磷高效基因型大豆锦豆33和磷低效基因型大豆铁丰3号为试材,采用沙培的方法,设5个磷浓度,研究了不同生育时期磷效率基因型大豆的主根长、根冠比、根体积、根系活性和根系比表面积对磷素处理的反应。结果表明:不同生育时期磷效率基因型大豆根系性状对磷浓度的反应比较复杂。幼苗期,不同磷浓度处理下主根长度和根冠比磷高效基因型品种均显著高于磷低效基因型品种;在有些磷浓度处理下根体积、根系活力和根系比表面积等指标基因型间差异达到显著水平,指标值的大小随磷浓度的变化没有一致的规律性。分枝期,不同磷效率基因型品种间和不同磷浓度处理间主根长度都没有显著差异。开花期,不同磷浓度处理下主根长度和根冠比存在显著的基因型间差异,表现为磷高效品种显著大于磷低效品种。结荚期,根系活力和根体积在不同磷浓度处理下均表现出显著的基因型间差异。在各磷浓度下,磷高效品种的根系活力都显著大于磷低效品种的。在0.5、1.0、1.5和2 mmol.L-1的磷浓度下,磷高效品种的根体积显著大于磷低效品种。

The ability of soybean tolerant to low-phosphorus is closely related to root traits. A sand culture experiment was carried out to study the effect of phosphorus levels on taproot length,root/shoot ratio,root volume,root activity and specific root area at different growth stages of Jindou 33 and Tiefeng 3 with different phosphorus effieiencies. Five concentrations of phosphorus in the experiment was designed. Results showed that the relationship between root traits of soybean eultivars with different phosphorus effieieneies at different growth stages and phosphorus levels was very complicated. At seedling stage, the taproot length and root/shoot ratio of phosphorus efficient genotypc species were significantly higher than that of phosphorus inefficient genotype under different phosphorus levels ;root volume, root activity and specific root area had a significant response to certain phosphorus levels between genotypes, and with the changes of phosphorus levels, these certeria changed non-uniformly. At branching stage,there was no significant response for taproot length in different genotypes with different phosphorus efficiency and under the different phosphorus level treatments. At bloomming stage,the taproot length and root/ shoot ratio of phosphorus efficient genotype species were significantly higher than that of phosphorus inefficient genotype under different phosphorus levels. At podding stage, roots activity and root volume of phosphorus efficient genotype were significandy higher than that of phosphorus inefficient genotype under 0.5,1.0,1.5 and 2.0 mmol·L^-1 phosphorus levels.