Knowledge about the genetic control of root development and architecture is lagging behind others plant traits and functions. This is negatively impacting modern plant breeding addressing drought tolerance and nutrient use efficiency. In this study, we investigated the genetic control of barley root architecture by exploring both induced and native genetic variation. We screened the barley TILLMore mutagenized population to identify root architecture mutants at seedling stages (2 weeks) using a semi-hydroponic system. We identified approx. 40 mutant lines, which grouped in three categories: root growth rate/length (short and long, 77%), root morphology (coiling or geotropic, 15%) and root hairs (hairless or shorthairs, 8%). Several mutants were tested for Mendelian inheritance and confirmed. SNP-based bulk-segregant analysis combined with exome and/or whole-genome shotgun sequencing enabled us to identify root candidate genes. Using the same root phenotyping protocol, a collection of >400 barley landraces and cultivars was phenotyped and GWA was carried out taking advantage of exome-seq based SNP analysis. Interestingly, the mutant loci and GWA-based QTL showed little if any overlaps, suggesting the presence of a largely undiscovered genetic system controlling root architecture in barley.
Combining Mutant Analysis and Genome Wide Association for Root Genetics Dissection in Barley
Salvi S
2020
Abstract
Knowledge about the genetic control of root development and architecture is lagging behind others plant traits and functions. This is negatively impacting modern plant breeding addressing drought tolerance and nutrient use efficiency. In this study, we investigated the genetic control of barley root architecture by exploring both induced and native genetic variation. We screened the barley TILLMore mutagenized population to identify root architecture mutants at seedling stages (2 weeks) using a semi-hydroponic system. We identified approx. 40 mutant lines, which grouped in three categories: root growth rate/length (short and long, 77%), root morphology (coiling or geotropic, 15%) and root hairs (hairless or shorthairs, 8%). Several mutants were tested for Mendelian inheritance and confirmed. SNP-based bulk-segregant analysis combined with exome and/or whole-genome shotgun sequencing enabled us to identify root candidate genes. Using the same root phenotyping protocol, a collection of >400 barley landraces and cultivars was phenotyped and GWA was carried out taking advantage of exome-seq based SNP analysis. Interestingly, the mutant loci and GWA-based QTL showed little if any overlaps, suggesting the presence of a largely undiscovered genetic system controlling root architecture in barley.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
