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The relationship between stomatal conductance, transpiration rate and tracheid structure in Pinus radiata clones grown at different water vapour saturation deficits
Author(s) -
WHITEHEAD D.,
SHERIFF D. W.,
GREER D. H.
Publication year - 1983
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/1365-3040.ep11589331
Subject(s) - transpiration , tracheid , pinus radiata , stomatal conductance , radiata , conductance , horticulture , botany , shoot , saturation (graph theory) , chemistry , biology , vigna , xylem , mathematics , photosynthesis , combinatorics
. Stomatal conductance and needle water potential of P. radiata clones were measured after 2, 5 and 8 months on plants grown in controlled environment rooms with markedly different water vapour saturation deficits (D). Conductance was significantly lower at high D, but water potential differences between treatments were not significant. When trees were moved between treatments most of the changes in conductances occurred within 2 h, with residual changes after 24 h. Water potentials were not different 24 h after the trees were moved. The effects were completely reversible. Transpiration rates of individual trees were highest in the high D treatment and lowest in the low D treatment. They were not linearly related to D because of decreasing conductance with increasing D. Height growth, diameter growth and foliage areas were not significantly different between treatments. Tracheid lumen diameters tended to be larger in trees grown at higher D although treatment differences were not significant. There were significant clonal differences in shoot conductance and tracheid dimensions.