Vernalization in wheat II. Genetic variability for the interchangeability of plant age and vernalization duration uri icon

abstract

  • Differences in response to vemalization in wheat (Triticum aestivum L.) were quantified through controlled environment experiments with 26 lines with diverse geographical origins. Vernalization treatments of 0 to 56 d were applied to plants at their first leaf stage, All plants headed irrespective of duration of vernalization treatment. Vemalization response was assessed through the change of final leaf number (FLN) on the main stem at heading. Five lines did not respond to vernalization. FLN for vernalization-sensitive lines generally decreased to a minimum as days of vemalization treatment increased. Plants at and after the stage where additional vernalization did not reduce FLN were vemalization insensitive. The quantitative features of this vernalization response, up to the point of insensitivity, were characterized with a linear regression: (F-i-6) = alpha-beta T-v, where F-i is FLN observed for a particular vernalization treatment, T-v is the time in days of that vernalization treatment, and alpha and beta are the Y-intercept and the slope of the regression, respectively. This model fitted the experimental results well, The parameters alpha and beta varied among lines, and are useful for quantifying vernalization response in wheat. The implication of each parameter can be interpreted biologically: alpha is the ''changeable number of leaves'', i.e., how many leaves can be potentially decreased by vemalization treatment, and beta represents the ''exchange rate'' between leaf numbers and vemalization days, i,e., how many leaves can be reduced by one day of vemalization treatment.

publication date

  • 1995
  • 1995