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Flooding, gas exchange and hydraulic root conductivity of highbush blueberry
Author(s) -
Davies Frederick S.,
Flore James A.
Publication year - 1986
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1986.tb05053.x
Subject(s) - stomatal conductance , carboxylation , photosynthesis , chemistry , carbon assimilation , horticulture , carbon dioxide , vaccinium , botany , hydraulic conductivity , zoology , environmental science , biology , soil science , soil water , biochemistry , organic chemistry , catalysis
Highbush blueberry plants ( Vaccinium corymbosum L. cv. Bluecrop) growing in containers were flooded in the laboratory for various durations to determine the effect of flooding on carbon assimilation, photosynthetic response to varying CO 2 and O 2 concentrations and apparent quantum yield as measured in an open flow gas analysis system. Hydraulic conductivity of the root was also measured using a pressure chamber. Root conductivity was lower and the effect of increasing CO 2 levels on carbon assimilation less for flooded than unflooded plants after short‐(i‐2 days), intermediate‐(10–14 days) and long‐term (35–40 days) flooding. A reduction in O 2 levels surrounding the leaves from 21 to 2% for unflooded plants increased carbon assimilation by 33% and carboxylation efficiency from 0.012 to 0.021 mol CO 2 fixed (mol CO 2 ) −1 . Carboxylation efficiency of flooded plants, however, was unaffected by a decrease in percentage O 2 , averaging 0.005 mol CO 2 fixed (mol CO 2 ) −1 . Apparent quantum yield decreased from 2.2 × 10 −1 mol of CO 2 fixed (mol light) −1 for unflooded plants to 2.0 × 10 −3 and 9.0 × 10 −4 for intermediate‐ and long‐term flooding durations, respectively. Shortterm flooding reduced carbon assimilation via a decrease in stomatal conductance, while longer flooding durations also decreased the carboxylation efficiency of the leaf.