Effects of elevated temperature and drought stress on fruit coloration in the jujube variety ‘Lingwuchangzao’ (Ziziphus jujube cv. Lingwuchangzao)

Abstract

Fruit color of jujube is an important horticultural trait contributing to nutritional components, market value and consumer preference. The objective of this investigation was to gain insight into the influences of elevated atmospheric temperature and drought stress on the coloration of jujube fruits. The fruit skin color, as well as the content of anthocyanins, carotenoids and chlorophyll under different atmospheric temperature and drought stress treatments were analyzed for a traditional jujube cultivar ‘Linwuchangzao’. The elevated temperature (1.5–2.5 ℃) significantly increased the fruit redness and the content of anthocyanins and carotenoids by 21.02 %, 13.20 % and 30.90 %, respectively, in three different stages of fruit ripening. The drought stress, with soil moisture at 30 %–50 % of the field capacity, significantly decreased the fruit redness and the content of anthocyanins and carotenoids but increased the content of chlorophyll under the same temperature. Significant temperature x drought interactions were observed for fruit color and pigments, showing that the positive effect from the elevated temperature was reduced as the drought stress intensified. The present results suggest that under the scenario of a 2 ℃ increase in atmospheric temperature, fruit coloration of jujube cultivar ‘Lingwuchangzao’ can be enhanced. However, drought stress negatively affected fruit coloration and reduced the positive effects resulting from the elevated temperature. This study, therefore, provides novel information for understanding environmental effects on fruit quality attributes of jujube. This knowledge will be useful for developing appropriate crop management practices for jujube production in the arid and semiarid regions in northwest China.