ДИНАМИКА РОСТА ЗАРОДЫША РАЗНОКАЧЕСТВЕННЫХ СЕМЯН УКРОПА В ЗАВИСИМОСТИ ОТ ТЕМПЕРАТУРЫ

Abstract

Temperature is one of the most important abiotic factor, the critical values of which can have a negative impact at different stages of plant growth and development. The work shows the effect of this factor on corcule growth of different quality dill seeds obtained from different tillering parts. Experimental data indicate that the initial sizes of a corcule of the first tillering part are 34.6% higher than the second. A significant variation in morphometric parameters of dill seeds was noted including those characterizing the correlation of the corcule, endosperm and seed, both within individual parts and the plant as a whole. New data on the influence of high and low temperature factors on corcule growth of dill seeds from different tillering parts were obtained. First and second part corcules showed significant sensitivity to prolonged continuous exposure to increased temperatures during the upswelling period. Second-part seed corcules appeared to be more sensitive to temperature stress and reacted to it more explicitly. The corcule growth and germination of seeds slowed down in case of increase of the upswelling temperature to 30-35 ° C for the first part and 25-30 ° C for the second one. The physiological response to continuous increased temperatures (30-40 ° C) is a progressive inhibition of the corcule growth. The maximum temperature which allows corcule growth differs significantly for different tillering parts. When approaching the critical temperature (40 ° C), the differences are leveled. Significant (p <0.001) differences in dynamics of corcule growth in comparison with the control (20 ° C) were observed only at temperatures below 10 ° C for seeds of the first part and 15 ° C for seeds of the second part.