Study On The Flower Bud Differentiation And Its Physiological Mechanism In Panax Ginseng C.A.Mey

It was studied on the morphological progress of flower bud differentiation of overwintering buds through the method of paraffin section when two- year-old and four-year-old panax ginseng were used as experiment materials in this trial. Furthermore we used four-year-old panax ginseng as experiment materials to carry out these works as followed: observed the formation and development of ovule; detected the dynamic variation of content on reducing sugar, total sugar, starch and soluble protein in root, leaves and fruit by UV spectrophotometry; detected the dynamic variation of hormone of GA3,IAA,ZT,ABA in overwintering buds by HPLC. With those researches above-mentioned we determined the morphological progress of flower bud differentiation and the relations between nutrition, hormone and flower bud differentiation during the flower bud differentiation progress.The results showed that:1.The morphological progress of flower bud differentiations were divided into these stages: no differentiation phase, inflorescence primordium differentiation phase, bract primordium differentiation phase,sepal primordium differentiation phase, petal primordium differentiation phase, stamen primordium differentiation phase and pistil primordium differentiation phase.2.In middle July the overwintering bud was in the changing phase from vegetative growth to reproductive growth——inflorescence primordium differentiation phase when above ground parts of ginseng was at the red ripe stage.3.It was a long course of flower bud differentiation in ginseng which lasted about 30 days for a single flower from the initiation of bract primodium to morphological accomplishment. And it lasted about 100 days for the whole overwinterint bud from inflorescence primordium differentiation to accomplishment of all small inflorescence primordium differentiation from the mid July till dormancy stage, the flower bud differentiation would last for two years if the time was counted from the initiation of spore primordium to the end of the morphogenesis. And all types of phases of flower bud differentiation existed and overlapped at the same time in one inflorescence.4.The characteristics of phases of flower bud differentiation were same basically either two-year-old or four-year-old ginseng, while the differences were only bigger bud size and more quantity in four-year-old ginseng and the hysteresis of differentiation phase in two-year-old ginseng.5.During the process of flower bud differentiation in ginseng it had promotion with high capacity of nutrition supplying from leaves. Root of ginseng was not only a sink of nutrition accumulation but also a source for nutrition supplying and the higher content of nutrition in roots had promotion to flower bud differentiation.6.During the phase of flower bud differentiation the higher content of ZT and ABA profit the flower bud differentiation, while IAA and GA3 might had inhibition effects.At the same time, the high ratios of ZT/IAA,ZT/GA3,ABA/IAA and ABA/GA3 profited the flower bud differentiation.