四种菊科植物开花期构件生物量及表型可塑性比较

Comparative study of biomass of modules and morphological plasticity of four Asteraceae species at the flowering stage

本文对粤东地区菊科2种入侵植物三叶鬼针草(Bidens pilosa)、加拿大蓬(Conyza canadensis)以及2种本土植物宽叶鼠曲草(Gnaphalium adnatum)、夜香牛(Vernonia cinerea)3种生境下的构件生物量、生物量分配及变异趋势进行了研究,对株高与各构件之间的关系建立了定量化描述模型,以揭示4种菊科植物在不同小生境中各构件的变异大小及生殖分配策略;对4种植物繁殖与营养构件之间的关系进行相关性、回归分析和生长趋势分析,以确定入侵种是否存在较高的表型可塑性。结果表明:三叶鬼针草在贫瘠、干燥的生境中,茎生物量分配显著增大,叶和花序生物量分配有减小的趋势;加拿大蓬在肥沃、潮湿的生境中其茎、叶、花序及总生物量显著大于其他2个生境(P<0.01);宽叶鼠曲草和夜香牛在肥力较差、干燥的环境中,根生物量分配增大,茎和花序生物量分配有减小的趋势;三叶鬼针草、加拿大蓬和夜香牛各构件生物量的变异系数>宽叶鼠曲草;相关性检验和生长趋势分析显示,三叶鬼针草、加拿大蓬和夜香牛繁殖与营养构件之间为异速生长。因此,三叶鬼针草、加拿大蓬和夜香牛具有较高的表型可塑性,以增强对多样环境的耐受性和适应性。

The biomass and allocation of modules, as well as their variation of four Asteraceae species including two invasive alien species Bidens pilosa and Conyza canadensis, and two native species Gnaphalium adnatum and Vernonia cinerea at the flowering stage were studied, and the correlation models on plant height and each module of four species under three habitats, and on reproductive and nutritional modules were built to reveal the strategy of reproductive allocation of these species in different habitats, and to determine whether the phenotypic plasticity of invasive species is greater than that of non-invasive ones. The result showed that the biomass of stems of B. pilosa in the nutrient-poor and dry habitat exhibited an increasing tendency, and that of leaves and capitulums decreased. The biomass values of stems, leaves, capitulums, and total biomass of C. canadensis in the nutrient-rich and moist habitat were significantly greater than in the other two habitats （P〈O. O1 ）. The biomass of roots of G. adnatum and V. cinerea in the nutrient-poor and dry habitat had an increasing tendency, and that of stems, capitulums decreased. It is indicated that the invasive plants can regulate their growth and biomass allocation to adapt to the heterogeneous environment. In addition, the coefficients of variation of modules of B. pilosa, C. canadensis, V. cinerea were greater than that nutritional modules of those species displayed species may have a high phenotypic plasticity environments. of G. adnatum. The correlation of reproductive and a tendency of allometry, indicating that these three to enhance the tolerance and adaptability to diverse