不同淹水梯度对紫穗槐的营养生长和生理响应

Effect of different waterlogging stress conditions on growth and some physiological characteristics of Amorpha fruticosa

通过对紫穗槐幼苗不同梯度淹水处理的研究,发现紫穗槐在短期内能通过不同的不定根生长方式和特化通气组织来适应不同淹水环境,各处理营养生长无明显差异,半淹不定根分枝发达,近全淹不定根数目最多;淹水能降低叶绿素含量和光合速率,并与正常间有显著差异(P<0.05),影响表面和半淹光合数率降低的主要因素是气孔导度降低,影响近全淹是胞间CO2浓度升高;表面淹对根活性影响不显著,虽半淹、近全淹与正常相比根活性分别下降了58%和51%,紫穗槐能通过增加不定根来补充根活性的不足;并且淹水胁迫下紫穗槐能积累可溶性糖和脯氨酸来适应环境,并以此来保护脂膜,这也可能是丙二醛含量无明显差异的原因,其中半淹可溶性糖和脯氨酸含量最高,平均分别为22.43mmol/L和570μg/g,与正常间有显著差异(P<0.05)。因此紫穗槐具有强的抗涝能力,能适应不同淹水程度。

The changes of growth and physiological characteristics of Amorpha fruticosa seedlings under different waterlogging stress conditions were studied by carrying out a water soaking treatment. The nutritive growth had no obvious change although a mass of aquatic adventitious roots and specialized lenticels grew in a short time to adapt to the different waterlogging stresses. Chlorophyll contents in leaves and photosynthetic rate decreased differently in different flooding treatments： the main factor in surface submergence and semisubmergence waterlogging was the reduction of stomal condunctance, while the main factor in the nearly submerged waterlogging was the increase of intercellular COz concentration. Root activity of the surface submerge waterlogging treatments decreased insignificantly, while it fell by 58% between in the semi-submerge waterlogging treatments and the control group, and 51% between the nearly submerge waterlogging treatments and the control. Soluble sugar and proline contents in waterlogging treatments were all more than that in the control while the semi-submerge waterlogging treatments had the highest contents of them with the quantity 22.43mmol/L and 570 μg/g respectively, and had obvious change with the control group （P〈0.05）, while MDA content showed no change. A. fruticosa could adapt to waterlogging stress by the growth of many aquatic adventitious roots and specialized lenticels and by accumulating osmotic adjustment substances. A. fruticosa had strong waterlogging tolerance ability and could be planted in wet land.