Somaclonal Variation in a Population of Winter Wheat

Agronomic characteristics were studied in an R 2 plant population, derived by self-pollination from seventy regenerant plants (R 1), derived from immature embryo culture of Norstar, an important Canadian winter wheat cultivar. A total of 1,800 R 2 space planted progeny, representing all 70 regenerant families, were analyzed in field trials during 1985. Significant variation compared to Norstar was observed, among families, for heading date, plant height, hundred kernel weight, tiller number, seed yield and fertility. Variation was also significant within families for all dependent variables except plant height and hundred kernel weight. While much of the variation observed was of negative value compared with the Norstar control, some lines exceeded the control for most of the variables examined. Mitotic and meiotic analyses revealed that at least 65% of the total population appeared cytologically normal. Some, but not most variants were associated with cytogenetic abnormalities.