Studies On Propagation Technology And Chemical Regulation On Bulblet Of Lvcoris Spp

Species of Lycoris are perennial bulb flowers distributed in East Asia. It is a genus of beautiful flowers with remarkable ornamental and application value, can be used in flower beds, flower border, and forest edge, also can be used in combination of potted plants and cut flower production, has a great promotion potential. And now they have been widely applied in Zhejiang, Jiangsu, Shanghai and other areas. However, bulbs of Lycoris had low natural proliferation, development slow, and need four to five years before first blossom. These factors greatly restrict propagation and application of Lycoris species. Therefore, how to effectively increase reproductive rate, accelerate bulb development, establishing genetic transformation system, create excellent new germplasm resources of Lycoris, have great significance in resource conservation, propagation and application.We studied sexual and vegetative propagation technologies of Lycoris species, including seed propagation and tissue culture. We also carried out interspecific cross breeding work to create new germplasm of Lycoris. In order to provide some reference for practice of chemical reagent treatment Lycoris plants, we discussed biochemical and physiological response of bulblets of L. sprengeri and L. aurea to exogenously applied CPPU. The main research conclusions are as follows:1. Seed vigor of L. chinensis was higher than L. radiata and L. sprengeri;4℃wet sand storage was the effective storage condition for L. sprengeri seeds. Appropriate concentration of GA3solution had acceleration on germination rate and germination time for L. chinensis and L. radiate seeds germination. Asepsis sowing significantly increased seed propagation coefficient, one seed of L. sprengeri got seven bulblets for the most.2. Pollen vitality from high to low in turn is:L. sprengeri, L. radiate, L. aurea and L. chinensis. Best storage condition for pollen of L. aurea was-70℃, but for pollen of L. radiate and L. chinensis was-20℃. After20days Storage, pollen vitality of L. sprengeri declined most, pollen vitality of L. aurea almost did not decline. Eight hybrid combinations got hybrid seeds, and highest hybrid seed setting rate was80%.3. All the floral organs which were five kinds of L. aurea and L. sprengeri respectively were able to generate callus. Among these, the ovary of L. aurea gave the highest calluses induction rate which was88.2%. While after cultured on MS medium supplemented with lmg/L BA and lmg/L2,4-D, all the floral organs of L. sprengeri could generate calluses and the highest calluses induction rate could reach64.7%. The induced callus can be divided into three types according to color and texture of callus. After analyzed submicrostructure of the above three type calluses, we found that light yellow granular callus was embryonic callus.4. Appropriate concentration of CPPU treatment promoted enlargement of L. sprengeri bulblets. The optimal CPPU concentration was7.5mg/L. Bulblet growth showed a significantly positive correlation with content of starch and activities of SSS and GBSS. Bulblet growth had significant positive correlation with the endogenous GA/ABA ratio. GA/ABA ratio showed a significantly positive correlation with activities of (α+β)-amylase and GBSS. Exogenous application of CPPU promoted activities of enzymes related to starch metabolism thus accelerated starch synthesis and accumulation in the bulblets of L. sprengeri. An increase in endogenous GA/ABA ratio had a synergistic effect.5. Results showed that spring treat with an appropriate concentration of CPPU was beneficial for the enlargement of L. aurea bulblet. The optimum concentration was1.0mg L1. Bulblet growth had a significant positive correlation with starch content.The concentration of zeatin riboside (ZR) showed significant positive correlation with soluble starch synthase (SSS) and granule-bound starch synthase (GBSS) activities. Our study indicated that an appropriate concentration of CPPU promoted the activity of starch synthase and accelerated the accumulation of starch in bulblets, and that the observed increase in endogenous ZR may have an important role.