不同生境天女木兰叶片解剖结构比较

Comparative Study on Anatomical Structure of Leaf of Magnolia sieboldii under Different Ecological Habitats

应用石蜡切片技术,对不同生境下天女木兰叶片解剖结构的演化进行了研究。结果揭示:天女木兰叶片的原始特征表明其在系统演化上处于原始地位。较干旱生境中的天女木兰与较湿润生境中相比,其叶片单位长度下表皮气孔数减少而栅海比和单位叶宽叶肉组织中油细胞数目增加。在其他环境因子相同的情况下,光照强度增大可使天女木兰叶片栅栏组织厚度、栅海比、主脉维管束枚数和单位叶宽叶肉组织中油细胞的数目增加;土壤含水量较低、树龄较大的天女木兰与土壤含水量较高、树龄较小的天女木兰相比,其叶片厚、栅栏组织厚、海绵组织厚、栅海比以及单位叶宽叶肉组织中油细胞的数目值均较大。

Anatomical structural development of leaf of Magnolia sieboldii K. Koch under different ecological habitats was studied using manual slicing techniques. The results were as follows： Compared with that of M. sieboldii under moister ecological habitat, the number of stomata per 1 mm leaf width on the lower epidermis of M. sieboldii under adder ecological habitat decreased, but the ratio of thickness of palisade tissue to that of spongy tissue and number of oil cell per 1 mm leaf width in mesophyll tissue increased. Under the ecological habitat with the same other environmental factors, the increase of light intensity made the thickness of palisade tissue, the ratio of thickness of palisade tissue to that of spongy tissue, the number of vascular bundles in main vein and number of oil cell per 1 mm leaf width in mesophyll tissue increase. Under the ecological habitat with the same other environmental factors, the thickness of leaf, palisade tissue and spongy tissue, the ratio of thickness of palisade tissue to that of spongy tissue and number of oil cell per 1 mm leaf width in mesophyll tissue of older plants with lower soil moisture content increased, compared with that of younger plants with higher soil moisture content.