四种含笑叶解剖性状与抗旱性的研究

Studies on Leaf Anatomic Indexes and Their Relations to Drought Resistance of the Four Species of Michelia

对2年生乐昌含笑、金叶含笑、阔瓣含笑和深山含笑等4种含笑叶片组织解剖性状的测定与盆栽抗旱性观测表明:供试树种间叶解剖性状在叶片厚度、角质层厚度、栅栏组织厚度、海绵组织的厚度、栅栏组织与海绵组织的厚度比、叶片结构紧密度、叶片结构疏松度和气孔密度等指标有显著差异;上表皮和下表皮厚度结构指标差异不显著。叶片厚度、角质层厚度、栅栏组织厚度、栅栏组织与海绵组织厚度的比值、叶片结构紧密度和气孔密度等值越大的含笑,受旱危害愈轻,其抗旱性就越强。叶片厚度、尤其是角质层的厚度和海绵组织厚度是评价供试含笑抗旱性的重要解剖指标。依据叶解剖性状结构指标,并结合盆栽试验旱害观测,供试树种的抗旱性大小为:阔瓣含笑>深山含笑>金叶含笑>乐昌含笑。研究结果与大田容器苗受持续秋旱产生的旱害观测结果吻合,为苏南地区北移引种提供了科学依据。

Anatomic indexes in leaves of 4 species of Michelia including Michelia platyetala, Michelia tsoi,Michelia foveolata and Michelia maudiae （two-year-old seedling ）and the performances in farm were observed and measured. The results showed that the differences of leaf thickness, cutin layer thickness, stockade tissue thickness, sponge tissue thickness, ratio of stockade tissue thickness to sponge tissue thickness, tightness of leaf tissue structure, sedimentation of leaf tissue structure and stoma density were significant, while the differences of the sizes of upper epidermis and lower epidermis were not. The trees with thick cutin layer, high stoma density, thick stockade tissue, high ratio of stockade tissue thickness to sponge tissue thickness, and high sedimentation of leaf tissue structure are of greater drought resistance. Leaf thickness, especially cutin layer thickness and sponge tissue thickness, are three important anatomic indexes of drought resistance. The order of their drought resistance are Michelia platyetala 〉 Michchelia maudiae 〉 Michelia foveolata 〉 Michelia tsoi.