鸢尾属植物部分种幼苗发育形态学的比较

通过对鸢尾属植物从种子到种苗发育过程的观察,确定了区分种的稳定性状,发现胚芽鞘膨大的形态与子叶联结的位置存在相关性,并得出所研究的鸢尾属植物系统演化关系。鸢尾属植物种子胚的苗端发育较好,根端发育较弱,突出表现为：子叶节以上长于子叶节以下,根端短而钝,结构上分化不明显。种子萌发时,部分个体早期初生根紧邻根尖分生区之上产生环状膨大生毛区。这些个体性状与单子叶沼生目和双子叶睡莲目多数水生植物相似,从一定程度上可以反映鸢尾属植物从水生到旱生的系统发生上的关系。

Comparison of Seedling Developmental Morphology of Some Iris Species

The stable properties that can be used for species identification were obtained through the observations on the develop- ment process of some Iris species from seeds to seedlings.The phylogenetic relationships of Iris are confirmed based on the fact that the morphology of swelling process in coleoptile is related to the position of cotyledon coupling.The development of the part of embryo is better than that of the part of root judging from the prominent performance that the length above the cotyledon nodes is longer than that below the cotyledon nodes and the part of root is short and obtuse,but there is no obvi- ous structural differentiation.When the seeds sprout,some individuals produce annularly inflated hair zones above early initial roots near root tip meristematic zones.These individual characters are similar to those of most aquatic plants in mon- ocotyledonous Helodiales and dicotyledonous Nymphaeales,which reflects the phylogenetic relationships of Iris from aquat- ic plants to xerophil.