淹水时水翁幼苗光合特性与不定根的关系(简报)

THE RELATIONSHIP BETWEEN PHOTOSYNTHETIC CHARACTER AND ADVENTITIOUS ROOTS IN FLOODED CLEISTOCALYX OPERCULATUS SEEDLINGS

摘要:

淹水引起水翁幼苗净光合速率、气孔导度和蒸腾速率发生变化。淹水5 d后,水翁幼苗净光合速率、气孔导度和蒸腾速率慢慢下降。但从淹水第35天开始,部分水翁幼苗在淹水的茎部产生不定根,有不定根的水翁幼苗的净光合速率、气孔导度和蒸腾速率逐渐提高,到第80天后维持在较高水平。有不定根的水翁幼苗的净光合速率、气孔导度和蒸腾速率的日进程呈双峰型,回归分析表明,净光合速率与气孔导度呈正相关(r=0.69,p<0.05)。

关键词:水翁; 淹水;净光合速率; 气孔导度; 蒸腾速率

Abstract:

Flooding induced the changes in net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of 17-month-old seedlings of Cleistocalyx operculatus. Pn, Gs and Tr began to decline progressively after 5 days of flooding. However, a few seedlings which developed adventitious roots (AR) on submerged portion of the stem starting on the 35th day of flooding showed a gradual increase in Pn, Gs and Tr, and maintained a higher level of Pn, Gs and Tr by the 80th day of flooding. The daily courses of Pn，Gs and Tr of seedlings with AR showed a pattern of two peaks，and the regression analysis indicated that Pn was positively correlated with Gs (r=0.69,p<0.05)．

Key words:Cleistocalyx operculatus; Flooding; Net photosynthetic rate; Stomatal conductance; Transpiration rate