发菜形态特征及其与环境因子的关系

通过野外调查和室内观察分析 ,天然发菜原植体的形态主要有柱状和带状两种 ;群体形态有单丝体、团块状、辫状、束状和网状。原植体的形态特征受环境湿度的影响较大 ,在降水量较大的地区 ,发菜原植体增粗 ,直径在 0 .0 5～ 0 .2 5 mm之间 ,带状发菜的比例较大 ,占 30～ 60 % ,吸水后藻体的颜色一般呈棕褐色 ;在降水量较小或极端干旱地区 ,发菜以细丝状为主 ,直径在 0 .0 2～ 0 .2 2 mm之间 ,带状发菜的比例不足 2 5 % ,吸水后藻体的颜色呈绿色或浅棕褐色。发菜群体形态的形成和发育与自身的生长特性有关外 ,主要与环境因子特别是降雨量、地形及自然外力 (地面径流和空气流动 )有关。

The Morphological Characterisitics of Nostoc Flagelliforme And The Relationship Betwenen Its Form And Environment

The main morpha of natural frond of Nostoc flagelliforme is column and ribbon-like ;the community morpha is mono-line,lump,braid,bunch and net-like.The morphological characteristic of natural frond is heavily influenced by environmental humid.The fronds of Nostoc flagelliforme increase their thickness in the drought areas of relative bigger precipitation, its diameter is 0.05-0.25mm,the ratio of ribbon frond is higher to 30-60%,frond color usually changes into brown after water absorbed.In the hush drought areas of little precipitation,the frond is thiner,the diameter is 0.02-0.22mm,the ratio of ribbon fronds is less than 25%,and the frond color changes into green or light brown after water absorbed. Except that the formation and growth of community morpha of Nostoc flagelliforme is concerned with self-growing they also concerned with the environmental factors-precipitation,topography and natural force(surface runoff,air current,etc.