贫、富营养湖泊中苦草的形态解剖结构比较

A comparison on morphology and anatomy of Vallisneria natans from oligotrophic and eutrophic lakes

比较了生长于贫营养的大溪水库(江苏)和富营养的太湖梅梁湾苦草的根系形态性状特征和叶片与匍匐茎的解剖结构差异,结果表明:生长于贫营养状态的大溪水库中的苦草根系形态性状的总根长、表面积、截面积、体积、平均直径和总分叉数等特征参数都显著高于生长于富营养状态的太湖梅梁湾的苦草.大溪水库的苦草叶片表面光洁,受附着生物影响明显较来源于梅梁湾的苦草小.大溪水库的苦草叶片和匍匐茎解剖结构发育完整,叶片中叶脉明显,细胞圆润,匍匐茎解剖结构由外向内分为表皮层、薄壁组织、大量气室和数个维管束,并且细胞中有大量淀粉体存在.梅梁湾苦草的解剖结果显示其生长受到明显抑制.表明随着湖泊富营养化程度加深,苦草的形态结构发生改变,进而可能对其生存造成影响.

Vallisneria natans from oligotrophic water body（Daxi Reservoir,Jiangsu） and eutrophic bay of Lake Taihu（Meiliang Bay） was studied to observe morphological characteristics of roots and anatomical structures of leaves and stolons.The results showed that root morphological characteristics,including total root length,root surface area,projected root area,total root volume,average root diameter,and total forks of V.natans from oligotrophic Daxi Reservoir,were significantly higher than that of V.natans from eutrophic Meiliang Bay.Leaf surface was glabrous of this species from Daxi Reservoir,which implied less influence by epiphytes than leaf of V.natans from Meiliang Bay.The leaf and stolon anatomical structures of V.natans from Daxi Reservoir developed well.Leaf had obvious veins and rounded cells and stolon was composed by epidermis,parenchymatous cell,number air chambers and several vascular bundles from external to internal,and there were great numbers of starches in cells.Anatomical structures of V.natans implied growth was inhibited in Meiliang Bay.That morphological and anatomical structure changed along with the lake eutrophication,which would be a great threat to its existence.