Liang Zhengchuan, Liu Tingting, Chen Xiaoyan, Xu Wenjuan, Dong Tingfa, Liu Qinsong, Xu Xiao
College of Life Science, China West Normal University, Nanchong, Sichuan, China.
Scientific Research and Testing Unit, Sichuan Mabian Dafengding National Nature Reserve Protection Center, Leshan, Sichuan, China.
Front Plant Sci. 2023 Jan 13;13:1088955. doi: 10.3389/fpls.2022.1088955. eCollection 2022.
Adaptive traits are an important dimension for studying the interactions between rare plants and environment. Although the endangered mechanism of rare plants has been reported in many studies, how their twigs adapt to heterogeneous environments associated with latitude is still poorly known. Dove tree ( Baill.), a monotypic rare species in China, was employed as a model species in our study, and the differences in functional traits, growth relationships and resource allocation among components of annual twig were investigated in three latitudinal regions (32°19' N, 30°08' and 27°55') in the Sichuan, Southwest China. Compared with low- and middle-latitude regions, the twig diameter in high-latitude region decreased by 36% and 26%, and dry mass decreased by 32% and 35%, respectively. Moreover, there existed an allometric growth between flower mass and stem mass or leaf mass in high-latitude region but an isometric growth in low- and middle-latitude regions. At the flower level, an isometric growth between bract area and flower stalk mass was detected among in three latitudinal regions, and the flower stalk mass in the low-latitude region was higher than in the middle- and high-latitude regions for a given bract area and flower mass. At the leaf level, the growth rate of petiole mass was significantly higher than those of leaf area, lamina mass and leaf mass among three latitudinal regions, and the petiole mass in the low-latitude region was higher than in the other two regions for a given leaf mass. Our research demonstrated that the twigs of dove tree in high-latitude region tend to become smaller, and resource input increase in stems and leaves but decrease in flowers, which reflects that dove tree can adapt to the environmental changes across different latitudes by adjusting phenotypic traits growth and biomass allocation of twigs.
适应性性状是研究珍稀植物与环境相互作用的一个重要维度。尽管许多研究报道了珍稀植物的濒危机制，但它们的小枝如何适应与纬度相关的异质环境仍鲜为人知。珙桐（Davidia involucrata Baill.）是中国的单型珍稀物种，在我们的研究中被用作模式物种，我们在中国西南部四川省的三个纬度区域（北纬32°19′、30°08′和27°55′）调查了一年生小枝各组成部分的功能性状、生长关系和资源分配差异。与低纬度和中纬度地区相比，高纬度地区的小枝直径分别下降了36%和26%，干质量分别下降了32%和35%。此外，高纬度地区花质量与茎质量或叶质量之间存在异速生长，而低纬度和中纬度地区则为等速生长。在花的水平上，三个纬度区域苞片面积与花柄质量之间均为等速生长，对于给定的苞片面积和花质量，低纬度地区的花柄质量高于中纬度和高纬度地区。在叶的水平上，三个纬度区域叶柄质量的生长速率显著高于叶面积、叶片质量和叶质量，对于给定的叶质量，低纬度地区的叶柄质量高于其他两个地区。我们的研究表明，高纬度地区珙桐的小枝趋于变小，茎和叶的资源投入增加而花的资源投入减少，这反映出珙桐可以通过调整小枝的表型性状生长和生物量分配来适应不同纬度的环境变化。
