摘要
以盆栽2年生的金矮生为试材研究了短期土壤干旱对苹果叶片光合速率日变化的影响以及光合速率日变化与叶片水势日变化的关系.短期土壤干旱明显改变了苹果叶片光合速率的日变化进程.夏、秋季节短期中度土壤干旱导致叶片产生“午休”现象.“午休”发生时先表现为气孔限制,后为非气孔限制.叶片水势与光合速率、气孔导度呈阈值关系,阈值水势为-2.15MPa,叶片水势降至阈值之下,光合速率,气孔导度迅速降低,但叶片水势的日变化与光合速率的日变化没有明显的关系.
2-year old pot-cultured“Gold Spui”trees were used to study the effectof short-term soil drought on diuinal changes of photosynthetic rate(Pn)in apple leaves and the relation between diurnal changes of photosyntheticrate and daily changes of leaf water potential(?).It was found that short-term soil drought obviously changed Pn diurnal courses.Short-term moder-ate soil diought in summer and autumn caused the“midday depression”of pho-tosynthetic rate in apple leaves.When“midday depression”occurred,thephotosynthetic rate was limited firstly by stomata,then by non-stomatalfactors.The threshold value of(?)_1 was-2.15MPa,below which the Pn andGs declined sharply.But no obvions comelation exists between Pu diurnalchanges and daily changes of(?)_1.
出处
《果树科学》
CSCD
北大核心
1990年第4期193-200,共8页
Journal of Fruit Science
关键词
苹果
光合速率
日变化
土壤干旱
Apple
Photosynthetic rate
Diurnal change
Short-term soil drought
Leaf water potential
