Pleiotropic effects of the ea7 photoperiod response gene on the morphology and agronomic traits in barley

The photoperiod-insensitive barley mutant 'Atsel', carrying the recessive gene ea(7) was studied together with the donor variety 'Atlas' (wildtype, Ea(7)) under different daylengths with the aim of analysing pleiotropic effects. Grown under long and short photoperiods 'Atsel, flowered about 10 days and 34 days, respectively. earlier than 'Atlas'. The significantly shorter life-cycle of the photoperiod-insensitive mutant resulted in several changes of plant morphology. Tillering, plant height. number of leaves and number of internodes were reduced " A lower number of florets per main spike was observed for 'Atsel', but only in the long photoperiod experiment. Finally, photoperiod insensitivity combined with a lower grain yield per plant was most pronounced under long-day treatment. The data are comparable with results obtained from single chromosome recombinant lines of wheat that have differences in their photoperiod response caused by the genes Ppd1 or Ppd2.