簇枝补血草花部综合特征及繁育系统的初步研究

Primary Study on Floral Syndrome and Breeding System of Limonium chrysocomum

以野外居群中的簇枝补血草为试材,采用花粉/胚珠比、杂交指数、套袋和萌发试验等方法,初步研究特定地理条件对簇枝补血草开花动态、繁育系统和种子特性的影响。结果表明:簇枝补血草开花期5—6月,单花持续期约3d,单株花持续期约30d,种群花持续期约40d;将单花发育过程分为4个阶段,在第2阶段雌雄蕊同时成熟,并存在空间异位现象;一天中花粉活力和柱头可授性在15:00—17:00,二者出现重叠的高峰期;P/O值、OCI值以及授粉试验表明,簇枝补血草的繁育系统为兼性异交,自交亲和,有时需要传粉者;自然状态下,种子附属物对其萌发有抑制作用,其中花萼对其影响最大,且种子经过储存后萌发率更高;簇枝补血草为适应干旱多变的荒漠环境,采用这种特殊方式来保证有一定数量的后代而不致于导致该种群个体数量的衰退。

Taking wild Limonium chrysocomum as materials, Pollen/Ovule ratio （P/O）, Outcrossing Index （OCI）, emasculation and germination experiment were observed to address its flowering phenologies, breeding system and seed feature primarily. The results showed that the flower of this plant blooms from May to June and could last different time at different levels; the development of single flower could be divided into 4 stages and both of the pistil and stamen became mature at the second stage, existing the phenomenon of herkogamy; the overlap peak period of pollen viability and stigma receptivity was occurred at 15.00-17.00;the value of P/O, OCI and pollination experiments display that the breeding system of L. chrysocomum was facultative xenogamy, and self-compatible, however sometimes need pollinators; seed appendages inhibit the process of germinating, especially corolla, and it had a higher germinating rate after being storaged. L. chrysocomurn was born in barren land, which was drought and changeable. It had evolved a special mode to product a certain number offsprings to avoid the declining of individuals in populations.