Liu Guolan, Fu Peili, Mao Qinggong, Xia Jiangbao, Zhao Wanli
Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Shandong University of Aeronautics, Binzhou, Shandong, China.
CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Jinghong, Yunnan, China.
AoB Plants. 2024 Feb 20;16(2):plae007. doi: 10.1093/aobpla/plae007. eCollection 2024 Feb.
Life cycle (annual vs perennial) and leaf venation pattern (parallel and reticular) are known to be related to water use strategies in herb species and critical adaptation to certain climatic conditions. However, the effect of these two traits and how they influence the coordination between vein density (vein length per area, VLA) and stomatal density (SD) remains unclear. In this study, we examined the leaves of 53 herb species from a subtropical botanical garden in Guangdong Province, China, including herbs with different life cycles and leaf venation patterns. We assessed 21 leaf water-related functional traits for all species, including leaf area (LA), major and minor VLA, major and minor vein diameter (VD), SD and stomatal length (SL). The results showed no significant differences in mean SD and SL between either functional group (parallel venation vs reticular venation and annual vs perennial). However, parallel vein herbs and perennial herbs displayed a significantly higher mean LA and minor VD, and lower minor VLA compared to reticular vein herbs and annual herbs, respectively. There was a linear correlation between total VLA and SD in perennial and reticular vein herbs, but this kind of correlation was not found in annual and parallel vein herbs. The major VLA and minor VD were significantly affected by the interaction between life cycle and leaf venation pattern. Our findings suggested that VLA, rather than SD, may serve as a more adaptable structure regulated by herbaceous plants to support the coordination between leaf water supply and demand in the context of different life cycles and leaf venation patterns. The results of the present study provide mechanistic understandings of functional advantages of different leaf types, which may involve in species fitness in community assembly and divergent responses to climate changes.
生命周期（一年生与多年生）和叶脉模式（平行脉和网状脉）与草本植物的水分利用策略以及对特定气候条件的关键适应性有关。然而，这两个性状的影响以及它们如何影响叶脉密度（单位面积叶脉长度，VLA）和气孔密度（SD）之间的协调尚不清楚。在本研究中，我们检查了来自中国广东省一个亚热带植物园的53种草本植物的叶子，包括具有不同生命周期和叶脉模式的草本植物。我们评估了所有物种的21个与叶水相关的功能性状，包括叶面积（LA）、主叶脉和小叶脉的VLA、主叶脉和小叶脉直径（VD）、SD和气孔长度（SL）。结果表明，各功能组（平行脉与网状脉、一年生与多年生）之间的平均SD和SL没有显著差异。然而，与网状脉草本植物和一年生草本植物相比，平行脉草本植物和多年生草本植物的平均LA和小叶脉直径显著更高，而小叶脉VLA则更低。多年生和网状脉草本植物的总VLA与SD之间存在线性相关性，但在一年生和平行脉草本植物中未发现这种相关性。主叶脉VLA和小叶脉直径受生命周期和叶脉模式相互作用的显著影响。我们的研究结果表明，在不同的生命周期和叶脉模式背景下，VLA而非SD可能是草本植物调节的一种更具适应性的结构，以支持叶水供需之间的协调。本研究结果为不同叶型的功能优势提供了机制性理解，这可能涉及群落组装中的物种适应性以及对气候变化的不同响应。
