1 Consideration of Combined Stress 13
tools for association mapping (e.g., GWAPP for Arabidopsis; TASSEL) and suc-
cessful association of candidate genes have begun to realize the power of candidate-
gene association mapping.
1.9 Conclusions/Perspectives
Studies of stress combinations that naturally occur under field conditions must be
a priority for researchers working on abiotic and biotic stresses. Studies of such
combined stresses should exploit the naturally occurring variation in the germplasm
of crop plants to identify novel sources of resistance or tolerance. While impos-
ing stress combinations, it is important to consider the plant developmental stages
that can have the most detrimental agronomic consequences and conduct surveys
of germplasm during these critical stages. Phenomic screening using noninvasive
high-throughput phenotyping platforms will provide a wide spectrum of observa-
tions that span metabolic, physiological, and biochemical parameters. Though the
initial costs are high for these setups, the long-term benefits are beyond compari-
son. Finally, integrating data from multiple omics platforms in conjunction with the
phenotyping data will provide a cogent view of the responses to combined stresses
in different genotypes. This is crucial for identifying the elite germplasm that can
tolerate multiple stresses and provide maximum yields.
Acknowledgments This work was partially supported by the Oklahoma Agricultural Experiment
Station. My sincere thanks to Dr. Yixing Wang for conducting the combined stress experiments in
soybeans reported in this chapter.
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