Studies On The Mechanism Of Soaked Seeds With S-3307 On High Quality Plant Of Maize

The effects of soaked seeds with different concentrations(0,10,20,40,80mg/kg)on plant of maize c.v. (chuandan13) were stuided. The results were showed as follows:l.The elongation of leaf blades and leaf sheaths of the treated plants was inhibited at 3~7-leaf stage, the inhibiting effect of S-3307 diminished at seventh leaf stage, and the higher of the concentration, the stronger of the effect. At the same time, as compared to the control, the plant in S-3307-treatment showed an appearance of high quality plant with increased specific leaf weight, leaf width and stem thickness as well as root number and root length, the root dry weight.2. S-3307 treatment decreased the levels of endogeneous IAA and GA3 in whole plant, the reduction of GA3 and IAA in leaf sheath were stronger than in leaf blade and shoot, and the reduction of GA3 was more than that of IAA. The reduction of GA3 and IAA was the major reason for the lower plant. The level of endogeneous ZT was increased in top and decreased in root markedly, which was benifit to plant growth. The level of endogeneous ABA had no significant difference in the treated plant, but the content of ABA for 80mg/kg treatment was significantly higher than that of control. While the blances of endogenous hormone was changed.3. S-3307 treatment increased PEP carboxylase activity, enhanced chlorophyll content and chlorophyll a/b ratio, and improved net photosynthetic rate in the leaves at 3~7-leaf stage. Meanwhile the contents of soluble carbohydrate and starch were increased in different organs of maize plant, the increasing in root was more than in shoot. S-3307 increased root activity.4. S-3307 treatments increased root-top ratio and the superoxide dismutase activity, prevented electrolyte leakage and the enhancing of MDA content, reduced the injuries caused by the soil drought in chlorophyll, and inhibited the reducing of photosynthetic rate during water stress.5. S-3307 treatments decreased bald tip length, increased obviously grain number per ear 1000-grain weight. So, S-3307 treatments increased yield significantly. Moreover 40mg/kg treatment was the best, the yield increased by 1301kg per hm2.41Therefore, it was suggested that the action of S-3307 on promoting strong plant was correlated with the changes of endogenous hormone, improvement of photosynthetic capacity, increasing of root activity and superoxide dismutase activity, which is the biological base for increasing grain yield.