In order to identify cell-wall related genes with a potential impact on agronomic traits and post-harvest processing, we have screened the maize UniformMu population using near infrared reflectance (NIR) spectroscopy as part of an NSF-funded Plant Genome project that is nearing completion. (http://cellwall.genomics.purdue.edu). The UniformMu population consists of families in a common genetic background (inbred line W22) with a high forward mutation rate as a result of active Mutator transposons. We developed a screening protocol and evaluated 1,500 F2 families (30,000 plants). This resulted in 40 novel mutants with altered NIR spectra but no apparent visual phenotypes. In addition, we identified 29 mutants with distinct visual phenotypes.
These mutants are now being characterized in more detail using pyrolysis-molecular beam mass spectrometry, wet chemical analyses, and lab-scale enzymatic saccharification assays to determine the yield of fermentable sugars from the stover. In addition, the genes underlying the mutations are being cloned using a PCR-based method. An overview of the project and several specific examples will be presented. These combined efforts will allow the development of new lines for specific agro-industrial applications. The mutants will be available to the scientific community.