Factors influencing the development of bread wheat plant types to be grown in the ‘transitional zone’ in northern Syria

This study sought to identify factors that influence wheat development in the transitional wheat growing zone of northern Syria. Three development factors were studied, intrinsic earliness, and responses to vernalization and to photoperiod. Two sets of wheat were studied, each composed of lines with differing combinations of development factors. Set 1 comprised 20 parental and breeding lines utilized by the CIMMYT/ICARDA facultative and winter wheat breeding program based at Tel Hadya. Set 2 comprised 19 parental and breeding lines utilized by an Australian winter wheat breeding program based at Temora. Field development was recorded in greatest detail at one site. Tel Hadya, using the state of differentiation of the apex of the main tiller of sampled plants. To extend findings, development was also recorded as the time from sowing to ear emergence for later sowings of wheat at Tel Hadya, and in sowings at four other regional sites.