漓江流域常见植物叶片非结构性碳水化合物动态及其生态适应性

Dynamics and Ecological Adaptability of Non-structural Carbohydrate in Common Plant Leaves of the Lijiang River Basin

关键词:  非结构性碳水化合物  淀粉  可溶性糖  不同降水季节  生态适应性

Key words:  Non-Structural Carbohydrates (NSCs)  starch  soluble sugars  different precipitation seasons  ecological adaptability

摘要:

非结构性碳水化合物（Non-Structural Carbohydrates, NSCs）能够有效揭示植物对外界环境的适应性机制。为探究漓江流域植物在喀斯特与非喀斯特生境中不同降水季节的适应性变化，通过分析叶片中NSC及其组分（可溶性糖和淀粉）含量的动态变化与差异，旨在为不同生境下的适生植物筛选提供科学依据。在旱季与雨季分别采集12种代表性植物的叶片，测定其叶片NSC、可溶性糖、淀粉的含量。建立贝叶斯多元回归模型，定量分析不同降水季节、生境条件、植物生活型及生长型等因素对植物叶片NSC及其组分含量的影响。结果表明：（1）在12种植物中，叶片NSC的组成以可溶性糖为主，其总体含量为84.23±57.04 mg/g，显著高于淀粉含量30.60±23.06 mg/g，而NSC的总体含量为114.80±62.84 mg/g。（2）在不同降水季节之间，12种植物叶片中的可溶性糖与淀粉含量存在显著的动态转换关系，雨季淀粉含量显著高于旱季，可溶性糖含量显著低于旱季。（3）喀斯特山坡与非喀斯特山坡生境间植物的淀粉、可溶性糖含量有显著性差异，而喀斯特生境洼地、垭口生长的植物与非喀斯特生境的植物叶片NSC及其组分含量无显著差异。（4）不同生活型的植物叶片NSC差异显著，其中落叶植物NSC及其组分含量均显著高于常绿植物；同时，不同生长型间，乔木植物叶片淀粉含量显著高于灌木，而可溶性糖含量显著低于灌木。漓江流域常见植物叶片中NSC、可溶性糖和淀粉含量与自身生物学特性、生境条件密切相关，还受到不同降水季节变化影响，叶片NSC含量的季节变化是一个较为复杂的动态过程。

Abstract:

Non-structural carbohydrates (NSCs) can effectively reveal the adaptive mechanisms of plants to external environments. To explore the adaptive changes of plants in the Lijiang River Basin across karst and non-karst habitats during different precipitation seasons, we analyzed the dynamic changes and differences in the content of NSCs and their components (soluble sugars and starch) in leaves, aiming to provide a scientific basis for the selection of suitable plants in different habitats. Leaves of 12 representative plant species were collected during both the dry and rainy seasons to measure the content of NSCs, soluble sugars, and starch. A Bayesian multivariate regression model was established to quantitatively analyze the effects of different precipitation seasons, habitat conditions, plant life forms, growth forms, and other factors on the content of NSCs and their components in plant leaves. The results showed that: (1) Among the 12 plant species, soluble sugars were the main component of leaf NSCs, with a total content of 84.23 ± 57.04 mg/g, significantly higher than the starch content of 30.60 ± 23.06 mg/g, while the total NSC content was 114.80 ± 62.84 mg/g. (2) Significant dynamic shifts were observed in the content of soluble sugars and starch in the leaves of the 12 plant species between different precipitation seasons, with starch content being significantly higher and soluble sugar content significantly lower during the rainy season compared to the dry season. (3) There were significant differences in the content of starch and soluble sugars in plants between karst hillside and non-karst hillside habitats, while no significant differences were found in the content of NSCs and their components in the leaves of plants growing in karst depressions, passes, and non-karst habitats. (4) Significant differences in leaf NSC content were observed among plant life forms, with deciduous plants showing significantly higher NSC and component contents than evergreen plants; additionally, among different growth forms, tree species had significantly higher leaf starch content but significantly lower soluble sugar content compared to shrubs. The content of NSCs, soluble sugars, and starch in the leaves of common plant species in the Lijiang River Basin is closely related to their biological characteristics and habitat conditions, and is also influenced by changes in different precipitation seasons. The seasonal variation in leaf NSC content is a relatively complex dynamic process.