水淹对消落带水生苔藓植物优势种生理生态特征的影响及耐水淹评价

Effects of Waterlogging on Eco-physiological Characteristics of Aquatic Bryophytes and Their Comprehensive Evaluation of Water Tolerance in Hydro-fluctuation Belt

摘要:

为了解冷水河消落带水生苔藓植物的种类及其对水淹的耐受机制，对5种水生苔藓植物优势种在水淹时的叶绿素、可溶性糖、丙二醛（MDA）含量和过氧化物酶（POD）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性进行了测定，并对其耐水淹性进行了综合评价。结果表明，冷水河消落带有水生苔藓植物优势种11种，以水生长喙藓（Rhynchostegium riparioides）、深绿褶叶藓（Palamocladium euchloron）、卷叶湿地藓（Hyophila involuta）、仰叶藓（Reimersia inconspicua）和大叶凤尾藓（Fissidens grandifrons）为优势种，平均优势度≥0.02。随水淹时间延长，5种水生苔藓植物的叶绿素含量显著下降（P<0.05），可溶性糖和MDA含量、POD、SOD和CAT活性先增加后下降，但都高于对照，表明5种苔藓植物优势种经过长期水淹后，表现出较强的生理适应性，主成分分析和隶属函数表明，水生长喙藓的耐水淹性最强（D=0.953）。这说明水生长喙藓对水淹的适应能力较强，可作为冷水河消落带植被恢复与重建的先锋物种。

Abstract:

In order to understand the dominant species and water tolerance of aquatic bryophytes in hydro- fluctuation belt of Lengshui River Nature Reserve, Guihzou, China, the contents of Chl a+b, methane dicarboxylic aldehyde (MDA) and soluble sugar, and activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) of five dominant bryophytes were determined, and their water tolerances were evaluated. The results showed that there were 11 dominant bryophytes in Lengshui River Nature Reserve, in which Rhynchostegium riparioides, Palamocladium euchloron, Hyophila involute, Reimersia inconspicua and Fissidens grandifrons were the most dominant species with average dominance≥0.02. With the extension of waterlogging time, the content of Chl a+b in five mosses decreased significantly (P<0.05), and the contents of soluble sugar and MDA, activities of POD, SOD and CAT increased at first then decreased, showing strong water tolerance in five mosses for long term. The comprehensive evaluation value D of Rhynchostegium riparioides was the highest (0.953) by PCA and subordination function method. Therefore, it was suggested that Rhynchostegium riparioides had strong adaption to waterlogging, could be used as pioneer species in vegetation recover and restoration in hydro-fluctuation belt of Lengshui River.