变温处理对西红花花芽分化及其生理生化的影响

Effects of Variable Temperature Treatments on Flower Bud Differentiation of Crocus sativus L.

以西红花球茎为材料,设置20℃-25℃-20℃(T1)、20℃-30℃-25℃(T2)、25℃-35℃-25℃(T3)及25℃-30℃-25℃(经验变温对照,CK1)和25℃-25℃-25℃(恒温对照,CK2)共5组三阶段(Ⅰ-Ⅱ-Ⅲ)变温处理,在各阶段采集球茎样品,用石蜡制片方法观察西红花花芽的分化情况,并测定各处理组球茎的淀粉、可溶性糖、可溶性蛋白、内源生长素(IAA)、赤霉素(GA)的含量及过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)的活性,探索变温处理对西红花花芽分化的影响,为调控其花芽分化提供理论依据。结果表明:(1)T1处理组的西红花球茎先于其他各组开始花芽分化,其花芽长度与生长状况优于其他各处理组,且首花时间较对照组提前1周以上。(2)变温处理期间,T1处理可促进可溶性糖和可溶性蛋白等营养物质的积累,同时有利于SOD、POD以及CAT等抗氧化酶活力的提高,且T1处理可有效调节内源IAA和GA的含量。研究发现,外界环境温度的改变也可间接调节西红花球茎内部营养物质、抗氧化酶及植物激素的合成与运输,从而影响植物的休眠和花芽分化,最终调控花芽分化和开花,适宜的三阶段变温处理(20℃-25℃-20℃)能有效地调控西红花花芽分化的起始与时间长短。

We studied the effect of variable temperature treatment on flower bud differentiation of Crocus sativus in order to provide theoretical basis for early flower bud differentiation.The bulb of C.sativus was treated by three-stage variable temperature treatment[20℃-25℃-20℃(T1),20℃-30℃-25℃(T2),25℃-35℃-25℃(T3),25℃-30℃-25℃(CK1)and 25℃-25℃-25℃(CK2)].The differentiation of flower bud was observed by paraffin section technique.The contents of starch,soluble sugar,soluble protein,endogenous auxin IAA,gibberellic acid(GA)and activities of catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD)were measured.The results show that:(1)the corm of C.sativus treated with T1 started flower bud differentiation earlier than other groups,the length and growth of flower bud of C.sativus treated with T1 were better than other groups,and the first flowering time of C.sativus treated with T1 was more than one week earlier than that of control group.(2)T1 treatment could promote the accumulation of soluble sugar,soluble protein and other nutrients,and increase the activities of SOD,POD and CAT.In addition,T1 treatment could effectively regulate the contents of endogenous IAA and GA.The results showed that the change of external temperature could also indirectly regulate the synthesis and transportation of nutrients,antioxidant enzymes and plant hormones in Crocus sativus bulbs,thus affecting the dormancy and flower bud differentiation of plants,and ultimately regulating the flower bud differentiation and flowering.The appropriate three-stage variable temperature treatment(20℃-25℃-20℃)could effectively regulate the initiation and duration of flower bud differentiation of Crocus sativus.