Date of Award

Summer 2014

Degree Type


Degree Name

Master of Science (MS)



First Advisor

Gebisa Ejeta

Second Advisor

Sylvie Brouder

Committee Member 1

Michael Mickelbart

Committee Member 2

Clifford Weil

Committee Member 3

Rebecca Doerge


Acid soils are estimated to cover up to 30% of arable soils globally and lead to significant limitations on agricultural productivity, primarily through aluminum toxicity. In sorghum [Sorghum bicolor (L.) Moench], significant genetic variation exists for tolerance to phytotoxic species of aluminum; tolerance is conferred through the exudation of citrate at the root tip, binding aluminum in the soil rhizosphere. A gene in the multidrug and toxic compound extrusion (MATE) family is the primary tolerance locus in sorghum. The purpose of this research was to evaluate a recombinant inbred line (RIL) population of sorghum segregating for SbMATE to establish potential relationships between the SbMATE gene and agronomic performance. The study was conducted in a two-year, two-location replicated field trial during the 2012 and 2013 crop seasons. Lines were subsequently genotyped and screened in the lab for aluminum tolerance. While there was an apparent relationship between some agronomic characters and the allele of the gene, such as for plant height at maturity, it was shown that there was no discernible relationship between yield and the SbMATE locus in a non-stress environment. This suggests that tolerance to aluminum in sorghum is an inducible response such that there is not a metabolic cost for genetics conferring aluminum tolerance when plants are not subjected to the acid soil stress.