干旱胁迫对牛樟幼苗生理生化及光合特性影响的研究

发布时间：2019-03-28 09:07

【摘要】：为探讨干旱胁迫对牛樟(Cinnamomum kaneirae)光合和生理特性的影响,本研究以一年生牛樟扦插苗为材料,模拟干旱胁迫。分别于处理0天、5天、10天、15天及15天后复水5天共5个阶段取样,分析主要生理指标的变化,研究其抗旱特性,结果如下。(1)绝对含水率随着胁迫天数的增加而降低,第15天绝对含水率降为最低,显著低于处理第0天,但复水5天后接近干旱前的水平。相对膜透性呈"单峰型"变化趋势,其峰值出现在第10天,复水后相对膜透性恢复到接近处理前的水平。(2)受胁迫后各阶段的叶绿素含量均低于第0天的叶绿素含量,但叶绿素含量在干旱处理过程中差异不显著。(3)干旱胁迫及复水对F0值无显著影响。胁迫及复水期间Fm表现为先下降后上升,但复水后Fm值仍远低于受胁迫前的水平。Fv/m呈现上下波动。(4)在胁迫第10天SOD、POD、CAT的活性达最大值,后持续下降,复水能使其接近处理前的水平,胁迫在复水后可能解除。综上所述,各生理指标的测定和分析表明一年生牛樟幼苗对干旱胁迫反应较为敏感,其抗旱性较弱,可以适应短期程度较弱的干旱胁迫,但复水有助于其恢复生长。在牛樟幼苗培育期间应及时灌溉,做好防旱抗旱措施。
[Abstract]:In order to study the effects of drought stress on photosynthetic and physiological characteristics of Cinnamomum camphora (Cinnamomum kaneirae), a year-old camphor cutting seedling was used to simulate drought stress. After 0 days, 5 days, 10 days, 15 days and 15 days of rehydration, the main physiological indexes were analyzed and their drought resistance characteristics were studied. The results were as follows: (1) the absolute water content decreased with the increase of stress days, and the absolute water content decreased to the lowest on the 15th day, which was significantly lower than the 0 day after treatment, but approached the pre-drought level after 5 days of rewatering. The relative membrane permeability showed a trend of "single peak", and its peak appeared on the 10th day. After rehydration, the relative membrane permeability returned to the level close to that before treatment. (2) the chlorophyll content in all stages after stress was lower than that on day 0. However, there was no significant difference in chlorophyll content during drought treatment. (3) drought stress and rehydration had no significant effect on F _ 0 value. During stress and rehydration, Fm decreased first and then increased, but Fm value after rehydration was still much lower than that before stress. FV / m fluctuated up and down. (4) the activity of SOD,POD,CAT reached the maximum value on the 10th day of stress, and then decreased continuously. Rehydration can make it close to the level before treatment, and the stress may be relieved after rehydration. In conclusion, the determination and analysis of each physiological index showed that one-year-old Cinnamomum camphora seedlings were more sensitive to drought stress, their drought resistance was weak, and they could adapt to short-term drought stress, but rehydration was helpful to restore their growth. In the seedling cultivation period of Cinnamomum camphora should be irrigated in time to do a good job drought prevention and drought relief measures.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S792.23

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