Abstract
1) The effect of the low temperature treatment (seed treatment: 3°C : 40 days) on the structure of the vegetative shoot apex and leaf in the wheat plant (variety : Satuki) was investigated histologically. 2) The distinct establishment of fundamental zonal structure (or Stratification) in the apex was accelerated by the treatment, and the volume of the apex in the treated plant became larger than that in control plants, owing to promoted cell division in every structural zone of the apex. 3) The leaf blades in the treated plant were larger both in length and width than that in control plants (except the Ist leaf length) and, according to the observation on the epidermal cells the increase of leaf area seemed to come chiefly from increase of the number of cells. 4) In the treated plant, the differentiation of stomatal rows, stomata and vascular bundles was accelerated and the remarkable development of mechanical tissues was observed. 5) From the facts above mentioned, it was concluded that the vegetative shoot apex and leaf in the wheat plant turned to more meristematic and differential condition by the low temperature treatment.
