Variation in vernalization and photoperiod response in tetraploid wheat (Triticum turgidum dicoccoides) ecotypes.
Five lines of tetraploid wheat from 2 contrasting wild habitats in Israel, and 2 hexaploid wheat (T. aestivum vulgare) cv., 1 of spring habit and the other of winter habit, were compared for responses to vernalization and photoperiod. The responses of the dicoccoides lines were within the ranges observed for the hexaploid cv. However, there were differences in the responses of the dicoccoides lines from the 2 habitats, those from the habitat with the shorter-growing season (Bet Shean Valley) having generally lower levels of vernalization and photoperiod response than those from the habitat with the longer-growing season (Mt Hermon slopes). These differences indicate genetic differentation amongst 'wild' populations of this sp. for developmental responses. It appears that the spring habit of T. turgidum dicoccoides arose from winter habit forms. Within-population differences were also observed for these characters, indicating that the 'wild' populations of dicoccoides are most likely to be genetically polymorphic for developmental responses.