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Low leaf hydraulic conductance associated with drought tolerance in soybean
Author(s) -
Sinclair Thomas R.,
Zwieniecki Maciej A.,
Holbrook Noel Michele
Publication year - 2008
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.1399-3054.2007.01028.x
Subject(s) - vapour pressure deficit , transpiration , xylem , water use efficiency , agronomy , petiole (insect anatomy) , environmental science , stomatal conductance , hydraulic conductivity , chemistry , horticulture , biology , botany , photosynthesis , irrigation , soil water , soil science , hymenoptera
Lack of water is the most serious environmental constraint on agricultural production. More efficient use of water resources is a key solution for increased plant productivity in water‐deficit environments. We examined the hydraulic characteristics of a ‘slow wilting’ phenotype in soybean ( Glycine max Merr.), PI 416937, which has been shown to have relatively constant transpiration rates above a threshold atmospheric vapor pressure deficit (VPD). The VPD response of PI 416937 was confirmed. Three experiments are reported to examine the hypothesis that the VPD response was a result of low hydraulic conductance in leaves as compared to two other soybean genotypes. Results are reported from experiments to measure transpiration response to VPD when xylem water potential was maintained at zero, leaf rehydration response and leaf carbon assimilation response to petiole cutting. Major interspecific differences in leaf hydraulic properties were observed. The observed low leaf hydraulic conductance in PI 416937 is consistent with an increased water use efficiency, and an increased water conservation by limiting transpiration rates under high evaporative conditions but allowing normal gas exchange rates under more moderate evaporative conditions.