Main conclusion

The anatomical structures of Carex moorcroftii roots showing stronger plasticity during drought had a lower coefficient of variation in cell size in the same habitats, while those showing weaker plasticity had a higher coefficient of variation. The complementary relationship between these factors comprises the adaptation mechanism of the C. moorcroftii root to drought.

Abstract

To explore the effects of habitat drought on root anatomy of hygrophytic plants, this study focused on roots of C. moorcroftii. Five sample plots were set up along a soil moisture gradient in the Western Sichuan Plateau to collect experimental materials. Paraffin sectioning was used to obtain root anatomy, and one-way ANOVA, correlation analysis, linear regression analysis, and RDA ranking were applied to analyze the relationship between root anatomy and soil water content. The results showed that the root transverse section area, thickness of epidermal cells, exodermis and Casparian strips, and area of aerenchyma were significantly and positively correlated with soil moisture content (P < 0.01). The diameter of the vascular cylinder and the number and total area of vessels were significantly and negatively correlated with the soil moisture content (P < 0.01). The plasticity of the anatomical structures was strong for the diameter and area of the vascular cylinder and thickness of the Casparian strip and epidermis, while it was weak for vessel diameter and area. In addition, there was an asymmetrical relationship between the functional adaptation of root anatomical structure in different soil moisture and the variation degree of root anatomical structure in the same soil moisture. Therefore, the roots of C. moorcroftii can shorten the water transport distance from the epidermis to the vascular cylinder, increase the area of the vascular cylinder and the number of vessels, and establish a complementary relationship between the functional adaptation of root anatomical structure in different habitats and the variation degree of root anatomical structure in the same habitat to adapt to habitat drought. This study provides a scientific basis for understanding the response of plateau wetland plants to habitat changes and their ecological adaptation strategies. More scientific experimental methods should be adopted to further study the mutual coordination mechanisms of different anatomical structures during root adaptation to habitat drought for hygrophytic plants.

中文翻译：

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川西高原苔草根系解剖结构对生境干旱的响应

主要结论

干旱时可塑性较强的苔草根系解剖结构在相同生境下细胞大小变异系数较低，而可塑性较弱的苔草根系细胞大小变异系数较高。这些因素之间的互补关系构成了C. moorcroftii根对干旱的适应机制。

抽象的

为了探讨生境干旱对湿生植物根部解剖结构的影响，本研究重点关注C. moorcroftii的根部。在川西高原沿土壤湿度梯度设置5个样地，采集实验材料。采用石蜡切片获得根系解剖结构，并应用单因素方差分析、相关分析、线性回归分析和RDA排序分析根系解剖结构与土壤含水量之间的关系。结果表明，根系横切面积、表皮细胞、外皮层和凯氏带厚度以及通气组织面积与土壤含水量呈显着正相关（P  < 0.01）。维管柱直径、维管数量和总面积与土壤含水量呈显着负相关（P  < 0.01）。血管柱的直径和面积以及凯氏带和表皮的厚度的解剖结构可塑性较强，而血管的直径和面积的可塑性较弱。此外，根系解剖结构在不同土壤湿度下的功能适应与根系解剖结构在相同土壤湿度下的变异程度之间存在非对称关系。因此， C. moorcroftii的根部可以缩短表皮到维管柱的水分输送距离，增加维管柱的面积和血管数量，并在不同的根部解剖结构的功能适应之间建立互补关系。生境及同一生境下根系解剖结构的变异程度以适应生境干旱。该研究为了解高原湿地植物对生境变化的响应及其生态适应策略提供了科学依据。应采用更科学的实验方法，进一步研究湿生植物根系适应生境干旱过程中不同解剖结构的相互协调机制。