| 摘要: |
| 棉花 LER 对水分胁迫极其敏感。ψw下降时 LER 比 Pa受抑制时间早且更严重。ψw为-0.8MPa 时,生长停止,而 Pn 仍维持较高水平。ψw大于-1.6MPa,Pn 随ψw下降而变化不大;ψw小于-1.6MPa,Pn 显著降低;ψw 达-2.5MPa时,Pn 为零。Pn 和 DR 之间为显著负相关。ψw为-1.6MPa 以上,DR 变化不大;ψw低于-1.8MPa 时,Pn 随 DR 增加而显著降低,ψw为-2.5MPa 时,因气孔关闭,Pn 为零。经受水分胁迫棉株以渗透调节方式适应胁迫条件。P-V 曲线表明,在任何 RWC 下,干旱处理ψw 比灌水处理的更负;干旱处理叶片膨压消失点ψw为-1.90MPa,灌水处理为-1.54MPa。 |
| 关键词: 水分胁迫,水势,叶片延伸生长速率,渗透调节,净光合速率,棉花 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目的一部分 |
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| EFFECTS OF WATER STRESS ON GROWTH AND PHOTOSYNTHESIS OF COTTON LEAVES |
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Jing Jiahai Ma Shushang
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| Abstract: |
| Results obtained from the experiment showed that leaf elongation rate (LER) was extremely sensistive to water stress.As ψw decreased,LER was inhibited earlier and more severely than Pn.When ψw dropped to above-0.8MPa,leaf groeth stopped while Pn still remained the maximal level.As stress was imposed,Pn was observed to be at first relatively a little change with ψw (ψw>-1.6MPa),but then (ψw<-1.6MPa) to decrease markedly,reaching zero at greater stress levels (ψw=-2.5MPa).Under water stress,there was the strong negative correlation between pn and DR to water vapor loss.DRwas little changed under above -1.6MPa which decreased Pn.When ψw was below -1.8MPa,Pn decreased markedly.When ψw got to -2.5MPA,Pn stopped for stomatal closure. Cotton plants subjected to water stress exhibited stress adaptation in the form of osmoregulation.There was more negative ψw.The results obtained from P-V curves showed that ψw of drying plants was more negative than that of control irrgated plants.ψw in the point of lossing turgor was -1.90MPa and -1.54MPa for drying and control irrigated plantsr,espectively. |
| Key words: water stress,water potential,leaf elongation rate,osmoregulation,net photosynthesis rate:cotton |
