The exogenous hormonal control of the development of regenerated flower buds in Hyacinthus orientalis

外源激素在诱导再生花芽花器官发生和控制它们的数目中的关键作用被进一步证实。首先通过 2mg/L6_BA和 0 .1mg/L 2 ,4_D的激素组合诱导风信子 (HyacinthusorientalisL .cv .Whitepearl)花芽从花被外植体发生 ,然后保持这种激素浓度 ,成功地控制了 10 0多片花被片的连续发生 (自然情况下一个风信子花芽仅有 6片花被片 )。改变激素浓度 ( 2mg/L 6_BA和 0～ 0 .0 0 0 1mg/L 2 ,4_D)终止了花被片的连续发生和诱导了雄蕊的发生。保持被改变的激素浓度成功地控制了 2 0多枚雄蕊的连续发生 (自然情况下一个风信子花芽仅有...The critical role of exogenous hormone on inducing the initiation of different floral organs in the regenerated flower bud and controlling their numbers was further evidenced, The initiation of the flower buds was first induced from the perianth explants of Hyacinthus orientalis L, cv, White pearl by a combination of 2 mg/L 6-BA and 0.1 mg/L 2,4-D, and then a continuous initiation of over 100 tepals (a flower bud of H. orientalis in situ has only 6 tepals) was successfully controlled by maintenance of such a hormone concentration. However, a change of hormonal concentration (2 mg/L 6-BA and 0-0.0001 mg/L 2,4-D) caused cessation of continuous initiation of the tepals hut gave rise to induction of stamen initiation. Keeping the changed hormone concentrations could successfully control the continuous initiation of over 20 stamens (a flower bud of H, orientalis in situ has only 6 stamens), The experiment showed that the number of identical floral organs in the regenerated newer buds can be controlled by certain defined concentrations of the exogenous hormones, and the amount of the induced identical floral organs has no effect on the differentiation sequence of the different floral organs in the regenerated flower bud, Based on a systematic research on controlling the differentiation of the floral organs from both the perianth explants and the regenerated flower buds by the exogenous hormones in H. orientalis over the past decade, the authors put forward here a new idea on the role of phytohormone in controlling the automatic and sequential differentiation of the different floral organs in newer development. The main points are as follows: 1. the development of flower bud in plant is a process in which all of the floral organs are automatically and sequentially differentiated from the newer meristem. 2. Experiments in vitro showed that the effect of exogenous hormones in controlling the initiation of different floral organs is strictly concentration dependent, i.e., one kind of the floral organ can continuously and repeatedly initiate from the flower meristem as long as it is maintained in that specific concentration of the exogenous hormone which is suitable for the initiation of that particular kind of floral organ. 3. It shows that the newer buds in situ must be automatically able to adjust the endogenous hormonal concentrations just after the completion of the differentiation of one whorl of floral organ to suit the differentiation of the next whorl. Thus, the phytohormone in different concentrations takes after many change-over switches of the organ differentiation and plays a connective and regulatory role between the differentiation of every two whorls of the floral organ. In other words, these changeover switches play the roles of inhibiting the expression of the genes which control the initiation of the floral organs in the first whorl, meanwhile, activating the expression of the genes which control the initiation of the floral organs in the second whorl during the successive initiation of the different floral organs from the newer bud. It results in the automatic and sequential initiation of the various floral organs from the floral meristem.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000165203400002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701SCI(E)中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)1110996-10024