不同生境自交植物黄花大苞姜生殖分配的研究

Research on Reproductive Allocation of Selfing Plant Caulokaempferia coenobialis in Different Habitats

摘要:

为了探讨自交植物黄花大苞姜(Caulokaempferia coenobialis)对石壁附生这一特殊生境的生态适应，对其不同物候期和不同生境的生殖分配进行了对比研究。结果表明，在生殖生长过程中，黄花大苞姜种群用于营养生长的生物量分配占有绝对优势，而用于生殖的生物量分配比例较小(<13%)。在黄花大苞姜各构件的生物量分配中，根茎和叶的比重较大(24.22%~43.25%)。在光线较弱生境中的种群，为了提高资源获取能力，黄花大苞姜分配到叶的比重明显高于光线较强的种群，而分配给根茎的比例却明显低于光线较强的种群。随着物候期的推移，黄花大苞姜生殖分配的比例不断增加，到果期达到最大值。不同种群间和年度间黄花大苞姜分配给生殖构件的比例没有显著差异，推测其生殖分配可能受遗传因素控制。个体大小与根茎生物量呈极显著线性函数同速生长，而与生殖分配在云天海种群没有表现出相关性，在上坪和天堂顶种群表现为同速生长关系，但决定系数小于40%。因此，黄花大苞姜能有效调节其在不同生境的生物量分配以适应石壁附生的特殊生境，在光线较弱的种群提高叶的生物量分配并降低根茎的生物量分配以提高资源的获取能力。整体上投资到营养构件的生物量占比高达87%以上，生殖构件在居群间和年度间均保持稳定。这种繁殖策略，一方面较高的营养构件投资可以获得更多的资源,另一方面稳定的生殖投资可以保证种群的延续，各构件相互协调以更好适应石壁这一资源匮乏的生境。

关键词:黄花大苞姜;异速生长;繁育;生活史;光照;生殖分配

Abstract:

To explore the ecological adaptation of selfing plant Caulokaempferia coenobialis to the special habitat, hanging on rock walls, the reproductive allocation in different phenological stages and different habitats was studied. The results showed that in the process of reproductive growth, the biomass allocation for vegetative growth of C. coenobialis was overwhelmingly high, while the biomass allocation for reproduction was relatively small (less than 13%). Of all the modules, the biomass allocation of rhizomes and leaves accounted for the larger proportion (24.22%-43.25%). In population with weak light, the biomass allocation to leaves was significantly higher than that of population with strong light to obtain more resources, while the biomass allocation to rhizomes was significantly lower than that of population with strong light. With the phenological phase, the reproductive allocation of C. coenobialis increased and reached the maximum at the fruiting stage. There was no significant difference in biomass allocation to reproductive components among different populations and different years, suggesting that the reproduction allocation of C. coenobialis might be controlled by heredity factors. Individual size and rhizomes biomass significantly increased with linear function of isogony growth, while there was no significant correlation between plant size and reproductive allocation in YTH population, and they followed the low of isogony growth in SP and TTD populations, but the coefficient of determination was less than 40%. Therefore, Caulokaempferia coenobialis could effectively adjust its biomass allocation in different habitats to adapt to the special habitat of rock wall epiphytes, and increase the biomass allocation of leaves and reduce the biomass allocation of rhizomes to improve resource acquisition ability in populations with weak light. As a whole, the biomass invested in vegetative components accounted for more than 87%, and that in reproductive components remained stable between populations and years. In this reproductive strategy, on the one hand, higher investment in vegetative components can obtain more resources; on the other hand, stable investment in reproductive component can benefit generation of the population. The coordination between each module can better adapt to the resource-poor habitat of rock walls.

Key words:Caulokaempferia coenobialis;Allometry; Breeding;Life history;Light;Reproductive allocation