Flowering traits and their genetic basis in the ancestral tetraploid wheat varieties 'Emmer' and 'Pyramidale'

Abstract

The flowering traits of 'Emmer' and 'Pyramidale', two ancestral wheat varieties that are now used to make two types of beer brewed in partnership with Kyoto University scientists, were investigated in detail. These varieties are classified as T. turgidum L. ssp. dicoccon and ssp. turanicum, respectively, and little information is available about their agronomic characteristics. Through evaluation of the internal factors determining their flowering time (photoperiodic response, vernalization requirement and narrow-sense earliness), we revealed that the two varieties are spring-habit and photoperiod-sensitive. While the narrow-sense earliness of 'Emmer' is less intense than that of 'Pyramidale', the photoperiodic response of 'Emmer' is more intense than that of 'Pyramidale'. Based on a genetic analysis using the F₂ population of the two varieties, we concluded that 'Pyramidale' harbors a photoperiod-insensitive allele in the Ppd-A1 locus, the same allele reported by Wilhelm et al. (2009). This photoperiod-insensitive allele is expected to be a useful genetic resource in the breeding of tetraploid and hexaploid wheat.