Studies On Florescence Biological Characteristics And Flower Developmental Anatomy Of Phyllostachys Praecox

Phyllostachys praecox which has the characteristics of sprouting earlier, high yield, and remarkable economical benefit is one of popular bamboo species for shoot production in China. It has been widely extended to Zhejiang and other southern provinces and produced good economic, social and ecological benefit. However, in the process of highly intensive management, Phyllostachys praecox often bloomed fragmentarily. The flowering bamboo forest might decay to death and its shoot yield decreased obviously, which partly impacted on the bamboo management.The bamboo flowering can cause the forest's degeneration or even death, which badly threatens bamboo management and wild animals' survival. Up to now, no systematical theory on bamboo flowering mechanism has been achieved and the researches mostly rest on discussing the behaviors and causes of flowering. Hence, there are important theoretical and practical significances on carrying out the systematical researches on blooming biology's feature and flower development anatomy and discussing the bamboo flowering mechanism.In this paper, the biological characteristics of florescence, spikelet and inflorescence's structure, morphogenesis formation of inflorescence, megasporogenesis and the development of female gametophytes were studied systematically by using anatomy structure, scanning electron microscopic and paraffin section methods. The results were as followed:(1) Phyllostachys praecox was the bamboo flowering fragmentarily; the cultivation changed the characteristic of flowering; the plantlets of flowering were complex and splitted into three kinds: the plantlet flowering before continued flowering; the plantlet flowering before stopped flowering and the plantlet changed into flowering. The inflorescence of Ph. praecox was indefinite inflorescence or called false inflorescence, and actually it was flower stress structure. Its basal unit was pseudospikelet with two kinds: apical spikelet and lateral spikelet. The floret had one lemma, one pelea, three stamens, one pistil and three lodicules.(2) The morphogenesis formation of inflorescence of Phyllostachys praecox could be splitted into six periods: inflorescence rachis's differentiation period, the first lateral spikelet and apical spikelet' differentiation period, glumous flower primordium induction period(flower's differentiation), stamen and pistil formation eriod(flower organ's induction), generative cell induction period(flower organ's maturation) and false spikelet's formation period. The nearby periods had no obvious gap.(3) The ovary of Phyllostachys praecox had one anatropous ovule. The crassinucellate ovule had diploid integuments. The monosporic embryo sac had one tetrad which turned on line and many antipodal cells. The synergid had the obvious filiform appratus.