Physiological phenotyping of plants for crop improvement

• Phenotyping should be focused on specific traits rather than aggregated processes.
• Parental phenotyping is likely to be successful based on multi-tier screening.
• Progeny selection should involve a mix of agronomic evaluation and phenotyping.
• High throughput phenotyping platforms (HTPPs) are only one tier of several required for phenotyping.

Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping.