植物的性别

引言人们在观察植物世界的时候,往往只注意叶色的鲜艳和花朵的华丽,而不知道它们也有性别之分。众所周知,花是植物的性器官,它是植物生长发育到一定阶段上才产生的生殖器官。植物花器官性别的分化不但可以作为植物分类的依据之一,而且是植物生理学和遗传学值得研究的问题之一。例如许多雌雄异株植物在经济上的价值明显不同,以收获果实种子为目的那些植物如银杏、菠菜。

Effects of Hormone Factors on the in vitro Culture Flowering Induction of Dendrobium officinate Kimura et Migo

[Objective]The aim was to select the suitable hormone factors for flowering induction in vitro culture of Dendrobium officinate Kimura et Migo.[Method]The test-tube plantlets from the stems of Dendrobium officinate Kimura et Migo were used as the experimental materials and MS medium as the basic medium.Comparative tests have been done between single-factor hormone treatments（different concentrations of PP333 or TDZ） and multi-factor hormone treatments（different combinations of PP333,TDZ,6-BA and NAA） to research the effects of hormone factors on the flowering induction of the plantlets.[Result]Among the single-factor hormone treatments,the suitable concentration and the rate of flower buds formation of PP333 treatment were 0.2 mg/L and 8.5%,the that of TDZ treatment were 0.06 mg/L and 15.5%;the effects of multi-factor hormone treatments on the flowering induction were ordered as follow：（PP333 ＋ 6-BA ＋ NAA ＋ TDZ）〉 （PP333 ＋ 6-BA ＋ NAA）〉 （PP333 ＋ 6-BA） and（PP333 ＋ NAA） ;the most suitable treatment was PP333 0.3 mg/L ＋ 6-BA 0.5 mg/L ＋ NAA 0.5 mg/L ＋ TDZ 0.06 mg/L,the rate of flower bud formation and the rate of the blossomed flower were respectly reached to 80.4% and 90.3%.[Conclusion]PP333 and TDZ showed the important effect on the flowering induction in vitro culture of Dendrobium officinate Kimura et Migo.The effect of TDZ was better than that of PP333.It is much more conducive to the flower bud formation,when using appropriate concentration of TDZ combined with other hormones properly.

知风知雨风雨花

在形形色色的自然界有这么一类四季常绿的花草,在夏秋季节茂盛地生长,从外表似乎看不出它与平时有什么异样,其实球形的鳞茎内,有一种对空气、水分、气压变化特别敏感的开花激素已在悄悄地孕育幼花。当气温升高,植株蒸腾量增大时,风雨花体内开花激素倍增,刺激花芽迅速形成。

植物可以预测天气吗

植物可以预测天气吗?答案是肯定的。比如中国西双版纳生长着一种奇妙的花,当暴风雨将要来临时,它便会开出许多花朵。根据它的这一特性,人们可以预先知道天气的变化,因此大家叫它“风雨花”。在风雨花贮藏养料的鳞茎中,有一种控制开花的激素。当暴风雨快来时,由于气温高、气压低,这种刺激使开花激素猛增,促使它绽放出许多花朵。

Assumption of Phyto-Hormone Regulation and Gene Activation of Phyllostachys praecox Flowering

By determination of the change of endogenous hormone Zr,iPA,GA3,IAA and ABA during different flower bud differentiation stages of Phyllostachys praecox,which is identified through both field observation and lab analysis,and with the reference to the previous research achievements on bamboo flowering,the flowering mechanism assumption of Phyto-Hormone Regulation and Gene Activation of Ph.praecox is induced in this article:Bamboo flower bud differentiation can be divided into 3 stages,i.e.flower bud induction,flower bud initiation and flower bud development;Bamboo leaves sense and receive flowering signals from environments to change its hormone level,esp.ratios of iPA/ABA and iPA/GA3;Flowering gene is activated once the ratios of iPA/ABA and iPA/GA3 reach a proper threshold,and it produces DNA and RNA carrying flowering code and transports them to top or side buds nearby,and then protein necessary for flower bud differentiation comes out,as a result of which the flower bud induction is trigged and started,followed by flower bud initiation and development.In the induction stage,ratio of C/N is nearly constant,but increases in the initiation stage.Therefore it clarifies that the rising of C/N ratio does not bring about bamboo flowering initially,and it is a follow-up reactions of process initiation of bamboo flowering.It proves that bamboo rhizome is directly involved in the flower bud differentiation.This assumption can well explain mysterious phenomena of bamboo flowering,and by integrating the current several assumptions,answer the difficult and perplexing questions regarding bamboo flowering which have not been answered by the present assumptions.