Temperature Sensitivity of Chromosomes in Diploid and Polyploid Species of Wheat

Abstract

THE two genera, Triticum and Gossypium, provide classical examples of evolution of agronomically superior plants through allopolyploidy. While the role of genome addition in this respect has been generally recognized, not much attention has been paid to the interaction between polyploidy and such components of the natural environment as temperature, which determines the adaptability of the newly arising species. The work on thermal sensitivity of chromosomes and of the meiotic cell division in Triticum monococcum, T. durum, T. dicoccum and T. aestivum recorded here was undertaken to obtain a measure of the adaptability of A, AB and ABD genome and genome combinations in a temperature-conditioned environment. Stability of the nuclear material constitutes a primary requirement of adaptation and it is known that plants of the temperate region often show a breakdown of their chromosomal mechanisms under conditions of high temperature¹.