Investigation of the effects of high light and starvation stress in Azolla caroliniana

In this study, the effects of high light intensity and starvation stress in Azolla caroliniana were investigated. The plants were grown in nitrogen-free Hoagland medium under greenhouse. Light stress (450 µmolm-2 s-1) was applied to the plants for 7 days. For starvation stress, plant nutrient solutions were diluted gradually and the experiment was terminated after two months. Plant growth, photosynthetic pigment contents, anthocyanin, total phenolic and flavonoid amounts were measured in order to investigate the effects of abiotic stress on plants. Although high light stress increased the relative growth rate, did not differ significantly (P> 0.05). Total chlorophyll and carotenoid content remained at the control level, while chlorophyll a / b ratio increased significantly. According to control in light stress conditions, anthocyanin content increased 8.2 fold, the amount of total phenolic and flavonoid increased 38% and 45%, respectively. Starvation stress increased the amount of total chlorophyll (P <0.01) and carotenoid (P <0.05). Starvation stress conditions induced the production of anthocyanin, total phenolic and flavonoids. As a result, it can be said that the increase in carotenoid, total phenolic and flavonoid amounts, especially the anthocyanin accumulation in A. caroliniana leaves against to abiotic stress conditions, protects the plant from the harmful effects of high light intensity and starvation stress.