LOW CONCENTRATION OF ETHEPHON PROMOTING DIFFERENTIATION OF VASCULAR BUNDLES IN LEAVES OF SUGARCANE (SACCHARUM OFFICINARUM L.)

摘要

Two sugarcane vaieties, belonging to early and mid-late maturing group, were subjected to foliar spray of ethephon @ 100 mg.L~(-1) and 400 mg.L~(-1) at tillering stage. Investigation on the new leaves within 2 to 10 weeks after treatment showed that growth of newly born leaves was retarded in both length and width. The treatment with 100 mg.L~(-1) ethephon resulted in less retardation than that with 400 mg.L~(-1) ethephon did. The treatment with 100 mg. L~(-1) ethephon promoted the differentiation of vascular bundles in the leaves, increased the relative number of vascular bundles and ratio of total width of vascular bundles and total width of vascular bundle phloem in leaves while retarding the growth of the vascular bundles in some extension. Spray with 400 mg.L~(-1) ethephon retarded both growth and morphological differentiation of the vascular bundles in the leaves.