IMPROVING GRAIN YIELD ON ACID SOILS BY THE IDENTIFICATION OF GENETIC FACTORS UNDERLYING DROUGHT AND ALUMINUM TOLERANCE IN MAIZE AND SORGHUM
Plant, Soil and Nutrition Research
2012 Annual Report
1a.Objectives (from AD-416):
Develop a whole genome association platform for sorghum and identify SNP markers associated with aluminum tolerance.
Identify polymorphisms associated with Al tolerance in maize.
Develop innovative methods for analysis of root architecture and the role it plays in acid soil tolerance.
Determine the genetic architecture of high Al tolerance in maize based on previously identified Al tolerance QTL and orthology to sorghum AltSB.
Improve Al tolerance in maize by introgressing AltSB homologs co-localized with Al tolerance QTLs as well as other Al tolerance QTLs into maize tropical breeding lines.
Assess the yield advantage of Al tolerant maize in Kenyan environments and begin to investigate the contribution of Al tolerance to drought tolerance.
1b.Approach (from AD-416):
We will use a combination of association and QTL mapping to identify and verify novel sorghum and maize Al tolerance genes, and use marker assisted breeding to introgress the best alleles of these genes into maize and sorghum for generating cereal crops better suited for cultivation on acidic, Al toxic soils.
In 2012, progress on this project involved field phenotyping of sorghum and maize drought tolerance that was conducted by our collaborators at Embrapa Maize and Sorghum in Sete Lagoas, Brazil. This involved growing a large number of lines from our maize and sorghum diversity panels in the field under well watered and drought conditions, and measuring a number of shoot yield parameters including grain yield, shoot biomass, tiller number, etc. Subsequently, we will conduct genetic analysis to corrolate with this data to identify regions of the sorghum and maize genomes that associate with drought tolerance with the long term goal of identifying certain genes that confer the ability of sorghum and maize to have improved yields under drought. These findings may lead to the identification of genetic markers and gene sequences that can be used to improve sorghum and maize drought tolerance through molecular breeding.