Genomewide analysis of biomass responses to water withholding in young plants of maize inbred lines with expired plant variety protection certificate

Abstract

Patterns of seasonal variations in rainfall are changing which affects rain-fed agricultural areas. Water deficit during the early vegetative growth poses threat as it causes variability in plant development, makes plant susceptible to other stresses and deteriorates the stands. Plants responses to water deficit are reflected in biomass traits which represent the morpho-physiological adjustments of plant to new conditions. The aims of this study were to assess the biomass responses of maize inbred lines with expired plant variety protection certificate that are freely distributed worldwide using genomewide analysis approach. The collection of 109 maize inbred lines, genotyped using genotyping-by-sequencing, was planted in controlled conditions (16/8 day/night, 25{degrees}C, 50% RH, 200 Mol/m2/s) in trays filled with soil in three replicates. Plants in control (C) were watered every two days with 8 mlH2O, while watering was stopped for 10 days in water withholding (WW) treatment. Fourteen days old plants were harvested and fresh weight (FW), dry weight (DW) and dry matter content (DMC, % of FW) were measured. Different responses to WW were detected in two genetic subgroups: Stiff Stalk and Non-Stiff Stalk. Totally 29 QTLs were detected, and it was shown that genetic regulation of DMC is different than regulation of FW and DW. This was further supported with correlations of rrBLUP marker effects among the traits. It was concluded that measurements of biomass traits in this manner are fast and reliable indicator of plants response to water deficit and can be used for effective screening of breeding progenies.