梁子湖苦草繁殖体的分布及其萌发初步研究  

PRELIMINARY STUDY ON PROPAGULUM DISTRIBUTION CHARACTERISTIC AND GERMINATION OF VALLISNERIA SPIRALIS L. IN LIANGZI LAKE

作　　者：杨永清[1] 于丹[1] 耿显华[1] 李永科[1] 

机构地区：[1]武汉大学生命科学学院梁子湖野外生态站,武汉430072

出　　处：《水生生物学报》2004年第4期396-401,共6页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金面上项目 ( 3 0 0 0 0 0 2 2 )资助

摘　　要：苦草鳞茎 (冬芽 )在梁子湖的垂直分布深度与其重量呈显著正相关 ,而重量也与鳞茎芽数显著相关 (P <0 0 5 )。埋藏深度、水分状况和鳞茎本身的大小都显著影响鳞茎的出土能力。去除第一位芽和切碎鳞茎后促进了其余芽的萌发 ;上年产生的未萌发的鳞茎在条件适宜的时候也可以很好的萌发 ,这些可能成为苦草在鳞茎被牧食后 ,维持种群数量的有效对策。沙质底比泥质底更有利于苦草种子的萌发 ,但在没有扰动的情况下 ,幼苗的定植能力在两种基质中没有显著差异。Vallisneria spiralis L. is a common species of submersed macrophytes in Changjiang River Basin. Its stands offer habitats and substrates for fish and many invertebrates at lake and river underlayers. The vegetative propagulum of V. spiralis,which is turion, contain large amount of starch. Its leaves are also palatable to waterfowl and other herbivores. Thus, its population is always undergoing relative high pressure of grazing. Recent studies have shown that herbivory can greatly reduce production of aquatic plant systems and potential reproduction output of each plant species. This means, eventually, their seed bank dynamics and successive vegetation patterns can be considerably changed. However, studies also shown that plants can avoid herbivory in a certain degree by some escaping strategies. As plant-herbivory interactions are essential in aquatic systems, how V. spiralis maintain its dominated role in Liangzi Lake is an interesting question. Our study focused on the primary distribution aspects of propagulum of V. spiralis, involving in turion and seed; in Liangzi Lake, and potential differences in germination performance of the diversely distributed propagulum. We aimed at simulating influences of waterfowl herbivory on the propagulum distribution and the germination of V .spiralis, and exploring the domination mechanism of V.spiralis in Liangzi Lake.\;Firstly,we investigated the vertical distribution pattern of V.spiralis turions in silt of Liangzi Lake in December,2002.An approximate method was used for alternative measurements of turion burial depth.The stolon length was thought to be an appropriate index of the burial depth,since most of the stolons between turions and stalks extended straight downwards in the soft clay.46 random sampling was carried out. After the burial depth was recorded,turion fresh weight were measured immediately.A relationship was analyzed between the turion size and the burial depth.In germination experiment,we collected the V.spiralis turions and classified them according to th

关 键 词：苦草 繁殖体 繁殖策略 鳞茎 萌发 

分 类 号：Q948.8[生物学—植物学]