Phenomics allows identification of genomic regions affecting maize stomatal conductance with allelic effects dependent on water deficit and evaporative demand.

SANTIAGO ALVAREZ PRADO; AUDE COUPEL-LEDRU; FRANÇOIS TARDIEU; ANTONIN GRAU; CLAUDE WELCKER; LLORENÇ CABRERA-BOSQUET; EMILIE J. MILLET

PLANT, CELL AND ENVIRONMENT (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 41 p. 314 - 326

0140-7791

Stomatal conductance is central for thetrades-off between hydraulics and photosynthesis. We aimed at deciphering its genetic control andthat of its responses to evaporative demand and water deficit, a nearlyimpossible task with gas exchanges measurements. Whole-plantstomatal conductance was estimated via inversion of the Penman Monteithequation from data of transpiration and plant architecture collected in aphenotyping platform. We have analyzed jointly four experiments with contrastingenvironmental conditions imposed to a panel of 254 maize hybrids. Estimated whole-plantstomatal conductance closely correlated with gas-exchange measurements andbiomass accumulation rate. Sixteen robust quantitative trait loci (QTLs) wereidentified by genome wide association studies (GWAS), and co-located with QTLsof transpiration and biomass. Light, vapour pressure deficit or soil waterpotential largely accounted for the differences in allelic effects betweenexperiments, therebyproviding strong hypotheses for mechanisms of stomatal control and a way toselect relevant candidate genes among the 1-19 genes harboured by QTLs. The combination ofallelic effects as affected by environmental conditions accounted for thevariability of stomatal conductance across a range of hybrids and environmentalconditions. This approach may therefore contribute to genetic analysis andprediction of stomatal control in diverse environments.