河北木蓝叶表型对干旱胁迫的响应

干旱胁迫下植物叶表型可塑性研究可揭示植物在不同自然环境中的生态意义并了解其适应性进化机制。木蓝属是豆科第三大属,其生境多样,形态复杂,因此其分类和进化研究还存在很多问题。该研究以木蓝属中生态幅最宽、形态变异最大的河北木蓝为研究对象,选取四川省石棉县,云南省蒙自市、砚山县3个种源地的河北木蓝一年生幼苗进行盆栽控水试验,设置4个干旱胁迫梯度,从植物叶片的宏观形态及表皮毛两个方面探究河北木蓝对干旱胁迫的响应。结果表明:河北木蓝叶片随干旱程度的增加和干旱时间的延长,3个种源地的植株均呈现出叶变短,叶片变小,叶柄缩短的趋势;同时,叶下表皮毛密度显著增加,长度显著减小;砚山和石棉种源的上表皮毛长度减小,但石棉种源的上表皮毛密度无显著变化,蒙自种源的上表皮毛长度及密度均无显著变化。该研究结果为河北木蓝的分类及其适应性进化研究奠定了基础。

Leaf Morphological Responses of Indigofera bungeana to Drought Stress

The phenotypic plasticity of plant leaves under drought stress can reveal the ecological significance of plants in different natural environments and understand their adaptive evolution mechanism. Indigofera is the third genus of Leguminosae, and its habitat is diverse and complex, so there are many problems in its classification and evolution. In this study, we chose I. bungeana, which has the widest ecological amplitude and the largest morphological variation in Indigofera. One year old seedlings of I. bungeana from Shimian of Sichuan Province, Mengzi, Yanshan of Yunnan Province were treated with the gradient drought stress. The results were as follows: as the stress of drought was intensified and last, the leaf length and area kept on decreasing, the petiole length appeared much smaller for all three populations of I. bungeana. The density of trichomes on abaxially increased significantly, the length of trichomes on abaxially decreased significantly, the length of trichomes on adaxially change significantly in the populations from Yanshan and Shimian. There was no significant difference on the density of trichomes on adaxially in the populations from Shimian and Mengzi, while the length of trichomes on adaxially did not change in the population from Mengzi. The results of this study can not only provide the evidence for the classification of I. bungeana, but also lay a foundation for the studies on its adaptation and evolution.