Diversity of agronomic and morphological traits in a mutant population of bread wheat studied in the Healthgrain program

A mutant population of spring wheat cv. Cadenza was produced at Rothamsted Research in 2004-5, both for TILLING and to generate variation in the contents of phytochemical components studied in the Healthgrain program. The agronomic and morphological properties of this mutant hexaploid wheat population (generations M(3)-M(6)) were studied in a 3-year field experiment. Most of the traits were scored according to UPOV TG/3/11, namely the time of ear emergence, plant height, ear glaucosity, shape, density and length, presence of awns and scurs, seasonal type, and grain colour. Other characters such as visible mutant phenotypes, ear sterility, heterogeneity of head rows, leaf colour and responses to powdery mildew and leaf rust were also studied. Variation in certain breadmaking quality parameters was also studied. The EMS mutant Cadenza lines studied showed wide diversity in terms of morphological and agronomic properties. The variation in agronomic properties was lower in 2007 and 2008 than in 2006, partly because of the SSD (single seed descent) in the M(4) generation and partly because of the loss of late heading genotypes. The diversity was lowest in 2007, probably due to the extremely dry weather.