Leaf-level water use efficiency determined by carbon isotope discrimination in rice seedlings: genetic variation associated with population structure and QTL mapping.

Increasing the water use efficiency (WUE) of our major crop species is an important target of agricultural research. Rice is a major water consumer in agriculture and it is also an attractive genetic model. We evaluated leaf-level WUE in young rice seedlings using carbon isotope discrimination (Delta(13)C) as an indicator of the trait.

Fine mapping a QTL for carbon isotope composition in tomato.

Carbon isotope composition (delta(13)C) and leaf water-use efficiency vary in concert in C3 plants, making delta(13)C useful as a proxy for plant water-use efficiency. A QTL for delta(13)C was detected in the Solanum pennellii chromosome fragment of IL5-4, an introgression line with S. lycopersicum cv.

The effects of resource availability and environmental conditions on genetic rankings for carbon isotope discrimination during growth in tomato and rice.

Carbon isotope discrimination (Δ) is frequently used as an index of leaf intercellular CO concentration (c) and variation in photosynthetic water use efficiency. In this study, the stability of Δ was evaluated in greenhouse-grown tomato and rice with respect to variable growth conditions including temperature, nutrient availability, soil flooding (in rice), irradiance, and root constriction in small soil volumes. Δ exhibited several characteristics indicative of contrasting set-point behaviour among genotypes of both crops.

Estimating water use by sugar maple trees: considerations when using heat-pulse methods in trees with deep functional sapwood.

Accurate estimates of sapwood properties (including radial depth of functional xylem and wood water content) are critical when using the heat pulse velocity (HPV) technique to estimate tree water use. Errors in estimating the volumetric water content (V(h)) of the sapwood, especially in tree species with a large proportion of sapwood, can cause significant errors in the calculations ofsap velocity and sap flow through tree boles. Scaling to the whole-stand level greatly inflates these errors.