Theses and Dissertations Collection

Wheat is the second largest cereal crop in the United States. Unseasonal activation of α-amylase genes in developing kernels may lead to low falling numbers in wheat, which can compromise the end-use quality and causes substantial profit losses to wheat growers. In wheat, there are four subfamilies of α-amylases; each subfamily has multiple α-amylase genes. The Amy3.1 and Amy3.2 of α-amylase III (Amy3) are mainly expressed in developing kernels.

The goal of the present study was to test whether these two genes affect wheat falling numbers by creating mutants in each of these two groups of genes. First, the Clustered Regularly-Interspaced Short Palindromic Repeats (CRISPR) system was used to edit these two groups of genes in tetraploid wheat ‘Kronos’ and hexaploid wheat ‘CB037’. The preliminary sequencing results showed a gene editing efficiency of 33.3%. In the preliminary tests, fourteen plants with edited versions of Amy3.1 and/or Amy3.2 genes were obtained. Second, using the Targeting Induced Local Lesions IN Genomes (TILLING), 21 mutants of Amy3.1 and Amy3.2 were identified in the tetraploid wheat ‘Kronos’. The identified CRISPR and TILLING mutants of Amy3 will be used to understand the gene’s role in regulating falling numbers and other essential traits in wheat.