Particular aspects provide novel mutant plants and plant parts thereof, derived via mutagenesis, having disease resistance and other useful traits. Particular embodiments provide a wheat genotype `RRR Scarlet` (`Scarlet-Rz1`), plants and seeds thereof, methods for producing a plant comprising crossing `Scarlet-Rz1` plants with another wheat plant, hybrid wheat seeds and plants produced by crossing `Scarlet-Rz1` plants with another line or plant, and creation of variants by mutagenesis or transformation of `Scarlet-Rz1`. Additional aspects provide methods for producing other varieties or breeding lines derived from `Scarlet-Rz1` and to varieties or breeding lines produced thereby. Further aspects provide for mutant plants and plant parts thereof that are resistant and/or tolerant to plant root fungal pathogens such as Rhizoctonia and Pythium. Additional embodiments provide mutant plants and plant parts thereof that exhibit stress tolerance and/or resistance. Yet further aspects provide mutant plants and plant parts thereof that are drought resistant or tolerant.