| Zingiberaceae plants are widely distribute around torrid zone and subtropical zone.There are nearly 50 genus,1300 species Zingiberaceae around the world,and about 20 genus 216 species in C hina,and Guangdong,Guangxi,and Yunnan are the three richest province in it.Most of the Zingiberaceae plants have high ornamental value,especially Z.zerumbet(L.)Smith,which had been sale as high end cut-flower in the market.Other species in Zingiber adans,because of the low seed setting rate,their flowers were sale in the market basically through using technique of introduction and cultivation,which is asexual propagation and have disadvantage inevolution and diversification.Z.nudicarpum and Z.zerumbet(L.)Smith can be complementary.Therefore,it is pos sible to culture new species which gather their advantage through the way of crossing,which will have great significance to species varieties of cut-flowers and huge market prospect.However,research data on the reproductive biology of Zingiber is lack a t present,and the reasons and the period of sterile of Zingiber are still not clear.Thus,more detailed basic cell research is necessary to solve this issue.Our studies indicate the process of microsporogenesis and macrosporogenesis of these two species are uniformity through slide,paraffin section,and semi-thin section and by observation in the fluorescent microscopy and the light microscopy.Their anthers are both contain two microsporangia.After twice meiotic division,microspore mother cell split into tetrad,then separated and released as pollens.With the formation of irregular and discontinuous primexine wall,mature pollen grains were defined as 2-cell type.It is an inferior ovary which is axospermous and contain 3 rooms in Zingibereceae.O vule is axile anatropous and have thick nucellus and 2 layers of integument.The embryo sac of Zingibereceae is Polygonum type.After twice meiotic,megaspore mother cells split into tetrads,but only one functional megaspore can be cellularization,and develop to a 7-cell embryo sac.We detect the pollen activityof Z.zerumbet(L.)Smith and Z.nudicarpum D.Fang by MTT,and find them both have high activity and can germinate on stigma.The pollen tube of Z.zerumbet(L.)Smith andZ.nudicarpum D.Fang reach o vary in 8h and 10 h after fertilization respectively,and enter ovule in 18 h through micropyle.We observed embryological characteristics of these two species of Zingiber through paraffin sectioning.The result show that Endosperm type of Z.zerumbet(L.)S mith is helobial type A.All ovules are deformed irregularly,whose integuments are sunken and most of the embryo sac are empty in 7D after pollination.On the contract,the endosperm type of Z.nudicarpum D.Fang is helobial basic type,that ovules begin to split in 7d after pollination,and form multinucleated embryos in 15 d after pollination.Our study found that the developmental process of microsporogenesis and macrosporogenesis of Z.zerumbet(L.)Smith and Z.nudicarpum D.Fanga are similar,and can develop normally.Their pollen tubes can grow in style and enter embryo sac,then form endosperm,which mean the pollen tubes can release the sperm cells normally.However,Z.zerumbet(L.)Smith egg cell will degrades earlier compare with Z.nudicarpum D.Fang.As result,we can draw an inference that the another sperm cell may not successful fuse with egg cell which cause the abortion in Z.zerumbet(L.)Smith. |
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