干旱胁迫对麻栎无性系蒸腾作用的影响

Effect on transpiration among Quercus acutissima clones under drought stress

以13个3年生麻栎无性系为研究对象,采用盆栽试验方法,研究了在持续干旱胁迫条件下的麻栎无性系土壤水势、叶片水势光合速率和蒸腾速率变化规律及其关系。结果表明,随着干旱胁迫的加剧,13个麻栎无性系土壤水势呈现出不断下降的变化趋势,叶片水势的变化无一致规律,光合速率则先下降而后上升,蒸腾速率的变化规律不尽相同。在13个麻栎无性系中,2、4、5、7、9和16号无性系的蒸腾速率、叶片水势和光合速率具有相同规律,随着干旱胁迫的加剧先下降而后上升,具有较强的适应干旱逆境的能力。对不同干旱条件下无性系的蒸腾速率、土壤水势、叶片水势和光合速率的相关性分析发现,干旱胁迫7天时,蒸腾速率和光合速率达极显著正相关;干旱胁迫12天时,蒸腾速率和土壤水势间呈极显著负相关,光合速率与土壤水势呈显著负相关;干旱胁迫17天时,蒸腾速率与光合速率呈显著正相关。

The paper was to study the variation of soil water potential, leaf water potential, photosynthetic rate, transpiration rate, and their relations among thirteen clones of Quercus acutissima under drought stress by pot experiment. The results showed that the soil water potential continuously declined, the variation of leaf water potential was different, the variation of transpiration rate was not same, and photosynthetic rate first decreased then increased with the increase of drought stress. The variation of transpiration rate, leaf water potential and photosynthetic fate of clone No. 2,4,5,7,9 and 16 had the same properties, first decreased then increased with the increase of drought stress, and adaptability of these clones to drought stress were stronger than others. The correlation of transpiration rate, soil water potential, leaf water potential and photosyn- thetic rate was analyzed under different drought condition and found that the positive correlation between transpiration rate and photosynthetic rate was significant at 0.01 levels under 7days drought stress; the negative correlation between transpira- tion rate and soil water potential was significant at 0.01 levels, between photosynthetic rate and soil water potential was sig- nificant at 0.05 levels under 12 days drought stress; the positive correlation between transpiration rate and photosynthetic rate was significant at 0. 05 levels under 17 days drought stress.