Study On Regulating Yield And Quality Of Rice With Exogenous ABA (Abscisic Acid)

As one of several endogenesis plant hormones, ABA has abundant physiological fuctions, it participates in many vital processes in plant growth and department. There were few relative studies on ABA in rice. Through the experimentation method of controlling in laboratory and field, this article studied the regulation effects of exogenous ABA on seed germination, seedling growth, tiller, yield traits and quality traits of rice and the physiological mechanism in order to provide scientific bases for ABA appliance in rice production. The results were showed below.1. Soaking treatment with ABA solutionAfter soaking treatment with ABA solution, the activity of a -starch enzyme in endosperm reduced, ABA had restraining effect on a -starch enzyme. The germination rate of rice seed reduced, but the effect of ABA on the germination rate of rice seed was not significant.Soaking rice seed with ABA solution was benefit for seedling' s growth, the height of seedling increased, the leaf age increased little, the number of lower tiller increased little, the neat weight of seedling increased. The content of dissociative amino acid reduced with the increasing of concentration of ABA solution, the content of soluble sugar increased with the increasing of concentration of ABA solution, the content of chlorophyll increased with the increasing of concentration of ABA solution, ABA advanced the synthesize and :rsansform of substance in seedling.Soaking rice seed with ABA solution affected the process of tiller occurring, the final tiller number increased, some treatments (especially 3. 125X104 mol/L) preceded the CK in all periods.Soaking rice seed with ABA solution, the panicle length increased under some concentrations. The response of the primary branches to different concentrations varied in d fferent varieties. The secondary branches increased under some concentrations. The spikelets per panicle increased. The shrunken grain rate reduced mostly. The weight of 1000 grains increased. The yield increased. The effects of soaking treatment with ABA on all characters above are not significant.2. Treatment with ABA solution in differentiation period of infant paniclespraying ABA solution to rice leaf in differentiation period of infant panicle , if the treatment was before the differentiation period of the secondary branches and spikelets anlage, the panicle length and the primary branches number and the spikelets per panicle increased, The secondary branches increased under some concentrations, The shrunken grain rate reduced mostly, The weight of 1000 grains increased under some concentrations. If the treatment was behind the differentiation period of the secondary branches anlage andspikelets anlage, the panicle length and the primary branches reduced, the secondary branches reduced universially, The spikelets per panicle and the weight of 1000 grains reduced. The shrunken grain rate was not well-regulated. There were not significant difference in every character between different concentrations. There were not significant difference in all characters except the secondary branches and the panicle length between different treatment time, the treament before the differentiation period of the secondary branches anlage and spikelets anlage exceled the other treatment.3. Treatment with ABA solution in full heading stageSpraying ABA solution to rice leaf in full heading stage, The shrunken grain rate increased, the weight of 1000 grains increased, ABA had significant effect on the two characters. The yield increased under some concentrations, ABA had not significant effect on the yield. ABA had not significant effect on The spikelets per panicle.Spraying ABA solution to rice leaf in full heading stage, the milling quality of paddy-rice got improved. The milled rice rate increased universially, the head rice rate increased. ABA had significant effect on the milled rice rate at 0.05 level, ABA had significant effect on the head rice rate at 0.01 level. There were not significant effect of ABA on the brown...