Water drives most of the processes involved in plant growth and significant relationships exist between crop performance and many water-relations related traits such as leaf water potential, water uptake by roots, stomatal conductance, transpiration efficiency, osmotic adjustment, etc. Understanding of these relationships has permitted the identification of efficient tools that are used in plant selection for adaptation to water limited environments; including canopy temperature (CT) which is related to root depth and hydration status, and carbon isotope discrimination which ?when measured on non-water stressed tissue is related to intrinsic transpiration efficiency. These tools have also been applied in identifying QTLs for drought adaptation. Knowledge of water relations traits has also been used to identify complementary parents in breeding for improved adaptation of wheat to water limited environments. Both CT and leaf conductance can be used as surrogates for measuring photosynthetic rate, and have application in breeding for irrigated environments, especially where yield is source limited, by heat stress for example. Water relations traits such as leaf water potential, relative leaf water content, root characteristics, and osmotic adjustment are generally too time consuming to be applied in routine breeding but are useful experimentally as accurate indicators of stress levels in field trials.

Global Wheat Program

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CPIJ01|INT1511|INT3189

CIMMYT Staff Publications Collection