Morphology, Dispersal And Germination Characteristics Of Synaptospermy Of Tribulus Terrester And Marrubium Vulgare

Synaptospermy was defined as two or more seeds (or single seed fruit) gathered together formed aunite synspermy, it is a mature seeds in order to adapt the environment to evolved a survival strategy.Tribulus terrestris and Marrubium vulgare belong to annual and perennation plants, which dispersal unitshave the common characteristic of synaptospermy, and Marrubium vulgare has another dispersal unit isseed, in this paper we conduct a preliminary comparison and observation on morphology, vigor, waterabsorption and germination characteristics in each dispersal unit. The main experiment results as follows:(1) There was very significantly differences in mass, length, width, the percentage of mass ofappendage and the number of seed; the dispersal distance of Tribulus terrester were significantly negativecorrelation to seed mass, and long thorn has no effect on horizontal dispersal distance; also there was verysignificantly differences between different mature time and vigor, water absorption, germination andgermination rate of synaptospermy, the position of synaptospermy germination was different, the seedgerminated only on the position of the long thorns of Tribulus terrestris synaptospermy, which belongs tonon-random germination, however, the time of synaptospermy germination was interrelated, on the biggestgermination conditions, only part of the seeds germinated in one season of synaptospermy, which accordwith the intermittent germination characteristic.(2) On the other hand, the mass, length, width and water absorption was significantly difference ofMarrubium vulgare dispersal units, but there was no significant difference of vigor; the synaptospermy hasweaker diffusivity than seeds, especially under low wind speed and high wind speed, but under mediumwind speed, the synaptospermy can spread longer than seed; there was no regularity of synaptospermygermination, which belongs to random germination, and also the germination of dispersal units accord withthe intermittent germination characteristic.(3) For different plant life forms, there are common functions in protection, retaining water, dispersaland germination behavior of appendages of synaptospermy. The germination behavior of annual herb wasfocused on population reproduction, therefore the germination and germination rate are higher in oneseason of Tribulus terrestris; And the germination behavior of perennial herb was focused on thepopulation dispersal, so the dispersal units are diverse of Marrubium vulgare, and the germination andgermination rate are lower in one season.In conclusion, the existence of dispersal units of both Tribulus terrester and confers differences inmorphology, dispersal and germination characteristics in responses to environmental variation, which havecommon characteristics of intermittent germination. Lack of seed dispersal and higher germination ofsynaptospermies of Tribulus terrester give the species a better chance of retaining the mother site.Therefore, lower siliques present a phenotypy of “low-risk” strategy. Furthermore, high dispersal abilityand dormancy of seeds of Marrubium vulgare can give the chance of rapidly colonizing new sites andenlarging its population. Thus, the dispersal units present a phenotypy of “high-risk” strategy.