不同生境天女木兰叶片解剖结构比较

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。

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

Anatomical structural development of leaf of Magnolia siebo ldii K. Ko
ch under different ecological habitats was studied using manual slicing techniqu e
s. The results were as follows: Compared with that of M. sieboldii under moi s
ter
ecological habitat, the number of stomata per 1　mm leaf width on the lower epid er
mis of M. sieboldii under arider 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 wi th  the same other environmental factors, the increase of light intensity made the  th ickness 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 ce ll per 1　mm leaf width in mesophyll tissue increase. Under the ecological habit at  with the same other environmental factors, the thickness of leaf, palisade tiss ue and spongy tissue, the ratio of thickness of palisade tissue to that of spong y tissue and number of oil cell per 1　mm leaf width in mesophyll tissue of olde r plants with lower soil moisture content increased, compared with that of younger  plants with higher soil moisture content.