干热胁迫对罗布麻幼苗生理特性的影响

为研究罗布麻(Apocynum venetum)抗干热胁迫能力,在不同温度(25℃,30℃,35℃)下,用不同水势(0,-0.3,-0.6,-0.9,-1.2,-1.5 MPa)的PEG溶液对罗布麻幼苗进行模拟干热胁迫试验,测定其生理生化指标变化。结果表明,总体上,随干热胁迫程度的增加,植物体内相对电导率逐渐上升,可溶性糖含量先上升后下降,丙二醛含量先下降后上升,而超氧化物歧化酶活性则随水分胁迫逐渐增加,随温度的升高而逐步下降。综合各指标,罗布麻在30℃,-0.9~-1.2 MPa的干热胁迫下表现出极强的抗干热能力。

Physiological Characteristics of Apocynum venetum under the Stress of Drought and Heat

To estimate the drought and heat tolerance of Apocynum venetum, seedlings were irrigated by PEG in different water potentials of 0,-0.3,-0.6,-0.9,-1.2,-1.5 MPa, under the difference temperatures of 25, 30, 35℃,respectively. Different physiological indices including the electronic conductivity(RPP), superoxide dismutase(SOD) activity, soluble sugar(SS) and malondialdehyde(MDA) contents of leaf were measured. The results showed that RPP increased with the increase of drought and heat stress. The contents of SS increased firstly and then decreased with the drought and heat stress increased, and the contents of MDA had an opposite trend to the contents of SS. For the activity of SOD, it increased with the decreasing of water potential, and declined with the increasing of temperature. All of these variation suggested that the seedling of Apocynum venetum had the highest resistance under the stress of-0.9~-1.2 MPa in 30℃.