A genome-wide approach combining field and platform phenotyping to investigate plant responses to drought and high temperatures
Résumé
Natural genetic resources need to be fully explored for designing
novel genotypes able to cope with climate change, with special
emphasis on identification of traits and allelic sources of adaptation
to drought and high temperature. We base our approach
on a combination of methods involving genetic analyses in phenotyping
platforms and in the field. The rationale is that a given
trait or allele confers advantages for yield in specific scenarios
of water deficit or high temperature, but most often not in all of
these scenarios. We have explored, in a network of field experiments,
a series of environmental scenarios for identifying the
scenarios where a given allele has positive, negative or no effect
on yield. We have then dissected these effects into responses
to specific environmental conditions and their genetic variability.
The latter step involves phenotyping in an automated phenotyping
platform, allowing one to infer traits that are impossible to
measure in the field, such as radiation use efficiency, sensitivity
of growth to water deficit or stomatal control. We have applied
this strategy to a panel of 250 maize hybrids allowing a multi-
scale multi environment whole-genome association study.
Resulting pattern of QTL effects expressed as function of environmental
variables and traits can be used for assessing the performance
of genotypes and the contribution of genomic regions
under current and future stress situations, and for accelerating
the breeding for drought-prone environments.
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