Resistance of Sarepta mustard to a decrease in ambient temperature during vegetation

Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, 11, Pushkinskaya St., Petrozavodsk, 185910, Russia

^* Correspondence: kaznina@krc.karelia.ru

Abstract

Brassica juncea (L.) Czern. is an important edible oilseed crop. This species is currently well studied from the point of view of its use in the phytoremediation of contaminated soils. There is practically no information about the resistance of Sarepta mustard to low temperatures. However, they are important for identifying the possibility of growing this species in northern conditions. In this regard, the effect of low temperature (4° C) on the B. juncea var. Nika growth, photosynthesis and water exchange was studied. An exposure to 4 °C inhibit the plants’ growth, but the photosynthesis rate does not exchange. At the same time, under the hypothermia, the chlorophyll a content and the chlorophylls a/b ratio increase. The carotenoids content and the size of stomatal aperture remained at the optimal temperature conditions level, and the Fv/Fm increased, indicating the efficient operation of photosystem II. Being exposed to low temperatures, the transpiration rate slowed down, which ensured the maintenance of the necessary tissue hydration and increased the ability to efficiently utilize water in the photosynthesis (WUE). A conclusion was made about the resistance of B. juncea var. Nika to low temperature (4° C) and about the possibility of growing this species in northern regions, including the phytoremediation of polluted areas.