EFFECT OF EXOGENOUS AUXIN ON DYNAMICS OF COLD RESISTANCE IN VEGETATING PLANTS DURING THE INITIAL PERIOD OF COLD ADAPTATION

The effect of heteroauxin introduced through the roots or directly int o leaves on cold resistance and processes of cold adaptation has been investigated in seedlings of the Mironovskaya 808 cultivar of winter w heat under controlled environmental conditions. Regardless of the mann er of pretreatment, exogenous auxin stimulated and accelerated the pro cess of cold adaptation iu a wide range of concentrations (10(-7)-10(- 5) M). The hormone introduced directly into leaves shortened the lag p eriod of cold adaptation characteristic of wheat plants under normal c onditions and induced significant increase in the level of cold resist ance at low hardening temperatures. The obtained data enable us to hyp othesize that auxins are involved in trigger mechanisms of the adaptat ion of vegetating plants to low temperatures.