干旱胁迫对三种藓类植物生理特性的影响

Effect of Drought Stress on Physiological Characteristics of Three Moss Species

以东亚砂藓、毛尖紫萼藓和山墙藓3种藓类植物为试材,选取不同的时间梯度,对其进行3个月的硅胶干燥处理,研究了干旱胁迫对3种藓类植物相对水分含量(RWC)、丙二醛(MDA)含量、过氧化物酶(POD)活性、游离脯氨酸(Pro)含量、可溶性蛋白质(SP)含量、可溶性糖(SS)含量等6项生理指标的影响。结果表明:经硅胶干旱胁迫处理的3种藓类,随着相对水分含量的逐渐降低,3种藓类植物体内的丙二醛含量均呈现先降低后升高再下降再升高的趋势;山墙藓POD活性较另外2种藓类低,且变化不明显,而东亚砂藓和毛尖紫萼藓在不同时期POD活性有较大变化;3种藓类的渗透调节物中,游离脯氨酸含量变化与可溶性糖含量变化呈反相关,可溶性蛋白质含量变化与POD活性呈正相关;6种生理指标的变化从一定程度上反映出3种藓类具有不同于其它植物的特殊抗旱生理机制。

Taking three kinds of mosses including Racomitrium japonicum Dozy ＆ Molk,Grimrnia pilifera P. Beauv. and Tortula ruralis Gaertn as materials, three kinds of mosses were subjected to drought treatment by silica gel for three months of different time gradients ,and the effect of drought stress on six physiological indexes of them including relative water content （RWC）, malondialdehyde （MDA） content, POD activity, free proline （Pro） content, soluble protein （SP） content and soluble sugar （SS） content were studied. The results showed that the malondialdehyde content in the three mosses treated with silica drought stress was gradually decreased and then increased and reveals the same trend once again along with the relative water content reduced. POD activity of Tortula ruralis was lower than those of the other two mosses,and changes inconspicuously, while the POD activity of Racomitriurn japonicum and Grimmia pilifera in different periods showed great changes. Among osmoregulation substances of the three moss species, the change of free proline content and soluble sugar （SS） content were inversely related,however, change of soluble protein （SP） content and POD activity was positively related. To some extent, the six physiological indexes indicated that the three mosses may have some special physiological mechanisms those were different from other plants.