Effects Of Low Temperature Storage On Flower Bud Differentiation Of Lily

Lily has many varieties,which are demanded by the flower market largely.The treatment of lily bulbs meets the demand of market to supplying lily for year-round.A large number of studies have shown that low temperature treatment can promote flower bud differentiation and improve the ornamental quality of flowers.Therefore,we study the changes of lily flower bud differentiation process and endogenous substances in low temperature treatment,selecting the optimum storage conditions to provide theoretical and practical basis for florescence regulation of lily.This study carry on by using the cultivar of lily 'Concador'?Lilium OT?Oriental X Trumpet?hybrids Concad'or?as experimental materials and using 4 ?,8 ?,12? as treatment.We observe the proceeding of flower bud differentiation by paraffin section and evaluate the starch,soluble sugar,soluble protein,the activity of peroxidase and endogenous phytohormone changes during flower bud differentiation.The effects of different low temperature on the quality of lily after storage and planting were observed.Research indicates that:1)The results of paraffin sections showed that there are six phases during the flower bud differentiation of lily.the undifferentiation phase,initial differentiation phase,floret primordium differentiation phase,perianth primordium differentiation phase,differentiation phase of stamens primordium and pistil primordium,the whole inflorescence formation phase were included.The lower the temperature,the earlier the flower bud differentiation starts,but the slower the process.After treating 56d,the lily in 4? treatment were at the perianth primordium differentiation phase.The lily in 8? treatmentwere at Differentiation phase of stamens primordium and pistil primordium.The lily in 12 ? treatment were at The whole inflorescence formation phase.2)In the low temperature environment,starch and soluble sugar are directly involved in the flower bud differentiation process.The lily started the differentiation stages of bud development when the soluble sugar content was declining.Accumulating at the initiation stage,soluble protein content had declined after maximizing at perianth primordium differentiation phase and increased at Differentiation phase of stamens primordium and pistil primordium.The peroxidase was activating at the differentiation stages.3)High levels of ABA benefit lily to turn to the reproductive growth and benefit the differentiation phase of stamens primordium and pistil primordium.Lower levels of ABA are beneficial to lily going on the differentiation stages.The initiation stage didn't repuire for excessive GA₃,however in differentiation stages large quantities of GA₃ were needed.High level of ZT was beneficial to differentiation stages,low level of ZT is beneficial to differentiation phase of stamens primordium and pistil primordium.Low level of IAA was needed in initiation stage and the perianth primordium differentiation phase,but high level of IAA was needed in initial differentiation phase and the differentiation phase of stamens primordium and pistil primordium.High ratio of ZT/GA₃,ABA/GA₃ favored flower primordium differentiation and inflorescence differentiation.In the same time,the lower ratio of ZT/GA₃,ABA/GA₃ favors the differentiation of stamen and pistil.The low ratio of IAA/GA₃ is beneficial to lily flower bud differentiation during the whole flower bud differentiation process.4)The high rate of IAA/ZT accelerated the initiate of flower bud differentiation.The high rate of IAA/GA₃ and ZT/GA₃ controled it transforming from initiate stage to inflorescence stage.IAA/GA₃?ZT/GA₃?ZT/ABA?IAA/ABA?GA₃/ABA promoted the differentiation from inflorescence to tepal,when they were in a steady low level.The high rate of IAA/ZTGA₃/ABA promoted the differentiation of stamen and pistil.5)During the low temperature storage,the growth of lily bulbs slowed down as the temperature decreased.The time from the end of low temperature treatment to flowering extended with the temperature reduction and the treatment time extension.There would have flower abortion or no flowers if treatment more than 42d in 4? or more than 49d in 8? and 12?.