低磷胁迫对熊猫豆生殖生长及某些生理特性的影响

在水培条件下研究了低磷胁迫对熊猫豆形态学及一些生理特性的影响.结果表明:低磷胁迫下,熊猫豆根、茎、叶及全株磷含量减小,开花期和成熟期延迟；叶面积减小,正常供磷条件下第一、第二和第三片三出复叶分别比低磷组高出21.38％、19.24％和26.76％；低磷条件下植株生物量减小,但根冠比显著增加至对照组1.5倍；根系活力和硝酸还原酶活性减小；但是低磷环境下其根系和叶片酸性磷酸酶(APase)活性显著增加,根系APase活性增加至220％；但根、叶的膜透性几乎没有变化.因此熊猫豆适应贫瘠可能主要是通过较大根系的构建,具有比较高的膜稳定性及提高酸性磷酸酶的活性而实现的.

Effects of P deficiency on reproductive growth and some physiological characteristics of Phaseolus coccineus L. seedlings

Under hydroponic condition, the effects of P deficiency stress on reproductive growth and some physiological characteristics of Phaseolus coccineus L. seedlings were investigated. The results indicated that under P deficiency, the P contents in roots, stems leaves and whole plants were decreased, and the flowering stage and maturity stage were delayed, as compared to those under adequate P; the area of the 1st, 2nd and 3rd leaf of the seedlings under P deficiency was reduced by 21.38%, 19.24% and 26.76% respectively; the biomass of plants was reduced, but the root/shoot ratio was significantly increased by 50%; the root vigor and the activity of nitrate reductase were reduced, the activity of APase in roots and leaves was increased significantly, but the membrane permeability was not affected by P deficiency. It was concluded that the physiological mechanism of tolerance to poor soil fertility of Phaseolus coccineus L. was mostly due to the improvement of roots so as to maintain the membrane permeability and to rai se the activity of APase.