摘要： 在自然光照和人工遮荫的弱光条件下研究了生长调节剂DPC（缩节胺）和营养物质KH₂PO₄单独和混合浸种处理对棉苗下胚轴形态和组织解剖结构的影响，结果表明，在弱光下棉苗的下胚轴生长发育差、结构较差，在两种光照条件下，DPC、KH₂PO₄、DPC+KH₂PO₄对棉苗下胚轴的形态和结构都有不同程度的影响，其中以DPC+KH₂PO₄处理效果优于单独使用，特别是在弱光下此效应更明显。DPC+KH₂PO₄处理使棉苗下胚轴缩短、变粗，其维管组织发育好，维管束中的导管数目增多；木质部、韧皮部面积大且发育好，从而改善下胚轴的结构。为茎的组织结构和生理功能的改善奠定了基础，有利于培育壮苗。

关键词: 生长调节剂, 营养物质, 棉苗下胚轴, 解剖结构

Abstract: The effects of the single and combined application of DPC(N, N-dimethyl perperidinium chloride)and KH₂PO₄ on the morphological characters and anatomical structure of the hypocotyl of cotton seedlings were studied under natural and shaded light condition (30-40% of natural light level).The results were as follows:the hypocotyl of the shaded cotton seedlings developed the poor tissue structure with small vascular bundles and fewer vessels, treatments of soaking cotton seeds with DPC, KH₂PO₄ and DPC+KH₂PO₄ solution respectively influenced the morphological characters and anatomical structures of hypocotyl among with the DPC+KH₂PO₄ treatment had the better effects.The synergism of DPC and KH₂PO₄showed that DPC+KH₂PO₄ treatment made the hypocotyl wider and shorter, and the hypocotyl possessed well developed vascular tissues, such as more vascular bundles and increased vessels and developed phloem and xylem. In the low light level owing to shading the effects were more significant than that in natrual lighting condition.

Key words: Plant growth regulator, Nutrient substance, Hypocotyl of cotton seedling, Anatomical structure