| 摘要: |
| 构树 Broussonetia papyrifera 具有良好的抗逆性，在受到逆境时自身形态建成发生改变来应对环境。研究通过对一年生构树幼苗进行干旱胁迫和盐胁迫，测定叶型、光合气体参数、黄酮含量并采用计盒法分析构树叶片分形维数，结果表明干旱胁迫和盐胁迫都能显著减弱构树光合作用，相较于对照组，干旱胁迫与盐胁迫的构树叶片胞间 CO2 浓度、气孔导度和净光合速率分别显著下降了 23.41% 与 41.16%、 62.50% 与 69.72%、16.43% 与 17.60%。盐胁迫导致构树深裂叶占比显著增大，较对照组增加了 58.96%。两种胁迫都能增加构树正视图和俯视图的叶片分形维数，尤其是两种胁迫分别使正视图的分形维数显著提高了 7.90%、11.58%。同时，盐胁迫使黄酮在老叶中显著降低了 17.85%。因此，面临渗透胁迫时，构树通过改变叶片形状、增加叶片占据空间的有效性和减少黄酮在老叶中的积累来应对。 |
| 关键词: 干旱胁迫 盐胁迫 叶型 分形维数 构树 |
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| 基金项目:国家自然科学基金青年科学基金项目（32001289） |
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| Effects of Osmotic Stress on Leaf Type and Leaf Distribution Fractal Dimension of Broussonetia papyrifera |
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LONG Shuo1, ZHANG Huanxin1, QIAN Zhiliang1, YAO Jinghong1, WANG Yangwen1, LIU Yuhan1, MENG Sen2, HU Wentao1
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1.College of Forestry and Landscape Architecture,Guangdong Provincial Key Laboratory of Forest Plant Germplasm Innovation and Utilization,South China Agricultural University;2.Key laboratory and Grassland Administration on Tropical Forestry,Chinese Academy of Forestry
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| Abstract: |
| Broussonetia papyrifera has good resistance to adverse stresses and can adapt to the adverse stress by changing its morphogenesis. In this study, the one-year-old B. papyrifera seedlings were subjected to drought and salt stress, and then leaf shape, photosynthetic gas parameters, and ?avonoid content were measured, and leaf distribution fractal dimension was analyzed using the box-counting method. The results showed that both drought and salt stress inhibited the photosynthesis of B. papyrifera significantly. Compared with the control group, intercellular CO2 concentration, stomatal conductance and photosynthetic rate of B. papyrifera leave under drought stress and salt stress decreased by 23.41% and 41.16%, 62.50% and 69.72 %, 16.43% and 17.60%, respectively. Salt stress led to a signi?cant increase in the proportion of deeply lobed leaves, which was 58.96 % higher than that of the control group. Both drought stress and salt stress increased the leaf distribution fractal dimension of B. papyrifera at the front view and vertical view, and the two stresses increased the leaf distribution fractal dimension at the front view by 7.90% and 11.58% signi?cantly and respectively. Meanwhile,salt stress reduced the accumulation of ?avonoids in old leaves by 17.85% signi?cantly. Therefore, our results suggest that B. papyrifera changed the leaf shape, increased the effectiveness of leaf space occupation and reduced the accumulation of total ?avonoids in old leaves to cope with osmotic stress. Our results will contribute to the exploration of the response mechanism in B. papyrifera leaves under osmotic stress. |
| Key words: water stress salt stress leaf type fractal dimension Broussonetia papyrifera |
