在极度弱光和两种底质条件下苦草的生长和生理响应  

GROWTH AND PHYSIOLOGICAL RESPONSE OF VALLISNERIA NATANS UNDER EXTREME LOW LIGHT AND TWO SUBSTRATE CONDITIONS

作　　者：张忠海 杨桐 文紫豪 张霄林[1] 曹特[1] 倪乐意[1] 袁昌波 ZHANG Zhong-Hai;YANG Tong;WEN Zi-Hao;ZHANG Xiao-Lin;CAO Te;NI Le-Yi;YUAN Chang-Bo(Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;Dali Erhai Lake Administration,Dali 671000,China)

机构地区：[1]中国科学院水生生物研究所,武汉430072 [2]大理市洱海管理局,大理671000

出　　处：《水生生物学报》2021年第3期652-662,共11页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31870446);淡水生态与生物技术国家重点实验室项目(2019FBZ01);中国科学院科技服务网络计划重点项目(KFJ-STS-QYZD-156)资助。

摘　　要：实验以云南大理州洱海水生植被重度退化区(湖心平台)作为实验地点,探究极度弱光和两种底质(黏土、淤泥)环境下苦草(Vallisneria natans)在恢复过程中的形态及生理响应,并依此探讨底质改善对苦草种群恢复的作用。结果表明:(1)在极度弱光环境下,苦草部分死亡,存活数量下降,并在形态特征和生理特征上均表现出胁迫响应,其形态特征值下降,氮(N)含量和游离氨基酸含量上升,碳(C)含量和淀粉含量下降;(2)苦草不同器官对弱光环境的响应有所差异,叶片(地上部分)受到的胁迫影响大于根茎(地下部分);(3)苦草对弱光环境的响应在不同底质条件下有显著性差异,苦草在黏土底质上表现出更小的胁迫反应和更高的存活数量,两种底质相比较,黏土更适合作为苦草恢复的底质条件。研究表明在洱海当前的水质环境下有希望结合局部的底质改善来实现在南部湖心平台的沉水植物恢复。In restoration of aquatic vegetation in the degraded area of shallow lakes,it is necessary to study the effects of low light stress and sediment types on aquatic plants.Vallisneria natans has strong tolerance to low light and sediment,and can be selected as a restoration species.The central part of the southern Erhai Lake(a mesotrophic lake in Yunnan Province,China)is flat,with an average annual water depth of about 6.3 m,which was called the“lake center platform”(LCP).Large areas of aquatic vegetation,including V.natans,was used to exist in LCP,it played important roles in the lake ecological function,but has completely disappeared since 2003.So,we chose V.natans as experimental material,and set two kinds of sediment conditions to study the morphological and physiological responses of V.natans under weak light of LCP and two kinds of sediment(clay and silt)environment,in order to explore the effect of substrate improvement on the restoration of V.natans.The results showed that:(1)Under the extremely low light environment,the survival number of V.natans decreased,and it also showed morphological and physiological responses to stress.The biomass and length of leaf and rhizome decreased in both sediments,and the contents of carbon(C),soluble carbohydrate and starch decreased,but the contents of free amino acid(FAA)and nitrogen(N)increased.The low light intensity inhibited the growth of V.natans and caused some plant deaths.(2)The effect of weak light stress on leaves in both sediments was greater than that on rhizome,which was shown in the increasing biomass ratio of rhizome and leaf.The physiological stress response of leaves was relatively greater than that of rhizomes,which was reflected in the decrease in the ratio of N and FAA contents,and the increase in the ratio of soluble carbohydrate and starch contents.(3)There were significant differences in the responses of V.natans to weak light environment under different sediment conditions,which was shown below:the survival number,starch content and biomass of

关 键 词：弱光胁迫 底质 水生植被恢复 苦草 

分 类 号：Q142[生物学—生态学]