林芝入侵植物印加孔雀草花期种群构件生物量研究

Biomass Study on the Modules of Invasive Plant Tagetes minuta Populations at Flowering Stage in Nyingchi Area

本研究旨在了解印加孔雀草花期种群构件生物量分配特征,揭示其表型可塑性,为阐明印加孔雀草的入侵机理和入侵性提供理论依据。通过样方调查,研究了印加孔雀草花期植株根、茎、叶和花生物量及其分配特征。结果表明,(1)印加孔雀草花期各构件生物量及其分配比大小关系为:茎>叶>根>花,生物量变异系数CV为105.49%~149.08%,分配比CV为11.77%~38.30%。(2)株高与各构件生物量存在显著正相关关系(P <0.01),相关系数r在0.3850~0.5703间,幂函数模型为表示其间关系的最佳模型。(3)各构件生物量间显著正相关(P<0.01),r均大于0.8130,可用线性函和幂函数模型较好的表达。研究表明:印加孔雀草各构件具有紧密和相互协调的分配策略,较强的表型可塑性增强了对环境的适应能力,这可能是其成功入侵的原因之一。

The aim of this study was to understand the biomass allocation characteristics on the modules of invasive plant Tagetes minuta, reveal its phenotypic plasticity and provide theoretical basis for elucidating the invasion mechanism and invasiveness of T. minuta. The biomass and its distribution characteristics of root, stem, leaf and flower in flowering stage of T. minuta were studied by quadrat investigation. The results showed that the relationship between the biomass and the ratio of each modules of T. minuta populations was decreased in the sequence of stem, leaf, root and flower, and the variation coefficient of biomass was 105.49%-149.08%;the variation coefficient of ratios were 11.77%-38.30%. Plant height had significant positive correlation within each module biomass(P < 0.01), and correlation coefficient(r) was 0.3850-0.5703. The biomass of each component was significant positive correlation(P < 0.01) between each other, and r was greater than 0.8130, which was better expressed by the power function model. The results also showed that the tight and coordinated allocation strategy among the components of the T. minuta and the strong phenotypic plasticity enhanced the adaptability to the environment, which might be one of the reasons for the invasion.