Effects Of Ethephon, Glycine Betaine And Epibrassinolide On The Growth Of Maize

Ethephon is used for dwarfing plant and enhancing the lodging resistance in agricultural production. However, it brings a little harm to vegetative and reproductive growth, and finally affects the yield of maize. Using ’NingYu 614’ as material, this thesis compared the effects of ethephon and ethephon plus glycine betaine (GB) on the growth of maize. Then the effect of exogenous epi-Brassinolide (epi-BL), which absorbed by the aerial roots system arising from higher nodes induced by ethelene, on the growth of ear was studied. The main results are as follows:1. Effects of ethephon and glycine betaine on the growth of maize.By spraying 640 mg· L-1 ethephon at 10 leaves unfold stage, an obvious inhibition effect on the growth of plant height, ear height, internodes’ length and the chlorophyll content of three ear leaves was observed. These suppressive effects of ethephon can be rescued by adding 200 mg· L-1 glycine betaine, and the area of three ear leaves and internodes’width were added. In addition, GB induced higher nodes to produce more aerial roots and thereby enhancing the lodging resistance. This indicates that betaine may alleviate the inhibition of ethephon on maize growth and enhance the inductive effect of ethephon on aerial roots development, and finally, enhance the yield of single plant.2. Effects of epi-BL absorbed by aerial-roots system on the growth of ear development in maize.The aerial roots soaked in the concentrations of 1-100μmol·L-11-aminocyclopr-opane-1-carboxylic acid (ACC) can produce more root hairs than the control and with the best effect at the concentration of 10 μmol·L-11 reflected by the highest root activity.10 μmol·L-11 ACC also made the decapitated aerial roots to produce more lateral roots, thereby forming an aerial-roots system with the ability to absorb and transport the mineral nutrition.1～100μg epi-BL absorbed by the aerial-roots system affected the growth and development of the maize ear. The ear weight, ear length, kernel number per row, the length of barren ear tip, kernel number per plant, and kernel weight per plant were all significantly improved by the treatment of 10μg epi-BL, but row number and 1000-kernel weight were similar between the treatment and control.1 μg epi-BL mainly added the kernel number per plant, other characteristics were not affected. However, the treatment of 100μg epi-BL increased ear length, kernel number per plant, kernel weight per plant, and 1000-kernel weight, but it had little effect on ear length, kernel number per row, and kernel number per plant. Theses results indicate that aerial-roots system induced by ethelene has the ability to absorb and transport nutrition and epi-BL absorbed by this system can affect ear development in maize.