Evaluating Potential Genetic Gains in Wheat Associated with Stress‐Adaptive Trait Expression in Elite Genetic Resources under Drought and Heat Stress
- 1 December 2007
- journal article
- conference paper
- Published by Wiley in Crop Science
- Vol. 47 (S3) , S-172-S-189
- https://doi.org/10.2135/cropsci2007.10.0022ipbs
Abstract
While genetic resources provide an invaluable gene pool for crop breeding, the majority of accessions in germplasm collections remain uncharacterized and their potential to improve stress adaptation is not quantified. A selection of 25 elite genetic resources for wheat (Triticum aestivum L.) were characterized for agronomic and physiological trait expression in drought‐ and heat‐stressed environments. Under drought, the physiological traits best associated with yield were canopy temperature, associated with water uptake, and carbon isotope discrimination, associated with transpiration efficiency. Under heat stress stomatal conductance, leaf chlorophyll content, and canopy temperature (associated with radiation use efficiency in this environment) were well correlated with yield. Theoretical yield gains based on extrapolating the best trait expression to the highest yielding backgrounds were also estimated. Under drought, the best expression of canopy temperature and carbon isotope discrimination suggested potential yield gains of approximately 10 and 9% above the best yielding cultivars, respectively; under heat stress, canopy temperature and remobilization of stem carbohydrates suggested potential yield gains of approximately 7 and 9%, respectively. Other physiological trait expression was associated with potential yield gains to varying degrees. When considering agronomic traits, the best expression of harvest index suggested yield gains of approximately 14 and 24% in drought and hot environments, respectively, while the combined best expression of both harvest index and final aboveground biomass suggested yield gains of 30 and 34%, respectively. Principal component analysis indicated that many of the physiological traits that were associated with yield and biomass were not strongly associated with each other, suggesting potential cumulative gene action for yield if traits were combined. When comparing trait expression across drought and hot environments, several physiological traits (e.g., canopy temperature) showed closer association with each other than did performance traits, supporting the idea that such stress‐adaptive traits have generic value across stresses.Keywords
Funding Information
- Australian Grains Research and Development Corporation
This publication has 54 references indexed in Scilit:
- Wheat breeding assisted by markers: CIMMYT’s experienceEuphytica, 2007
- Spectral Reflectance Indices as a Potential Indirect Selection Criteria for Wheat Yield under IrrigationCrop Science, 2006
- Prospects for utilising plant-adaptive mechanisms to improve wheat and other crops in drought- and salinity-prone environmentsAnnals of Applied Biology, 2005
- Gene-to-phenotype models and complex trait geneticsAustralian Journal of Agricultural Research, 2005
- Genic microsatellite markers in plants: features and applicationsTrends in Biotechnology, 2005
- Association between canopy reflectance indices and yield and physiological traits in bread wheat under drought and well-irrigated conditionsAustralian Journal of Agricultural Research, 2004
- Loss of chlorophyll with limited reduction of photosynthesis as an adaptive response of Syrian barley landraces to high-light and heat stressFunctional Plant Biology, 1999
- 'Haying-off', the negative grain yield response of dryland wheat to nitrogen fertiliser III. The influence of water deficit and heat shockAustralian Journal of Agricultural Research, 1998
- Refixation of respiratory CO2in the ears of C3cerealsJournal of Experimental Botany, 1996
- Canopy Temperature Depression Association with Yield of Irrigated Spring Wheat Cultivars in a Hot ClimateJournal of Agronomy and Crop Science, 1996