Alterations in Photochemical and Physiological Activities of Chickpea (Cicer arietinum L.) Cultivars under Drought Stress

In this study, some morphological, physiological and biochemical parameters of two chickpea cultivars, cv. Gokce and Canitez, were analysed to understand their tolerance to drought stress. Twenty-day-old plants were subjected to three different regimes of drought stress by withholding water for 3, 5 or 7 days, and then rewatering for 2 days after the initial 7 days of drought stress. Drought treatments only reduced shoot elongation in the Canitez cultivar. Leaf production and fresh biomass decreased in both cultivars under all drought treatments, however to a greater extent in Canitez. In both cultivars, malondialdehyde, proline and anthocyanin accumulation increased significantly, whereas relative water content declined under drought stress. The total chlorophyll and carotenoid contents of Gokce were not affected by drought stress, whereas the chlorophyll content of Canitez increased greatly at the end of the treatments. Using chlorophyll a fluorescence measurements, we found that extended drought treatment caused photoinhibition of PSII activity in both cultivars. However, this was greater in Canitez, especially under severe drought stress. Although Canitez recovered quickly from drought stress and exhibited a good ability to overcome drought stress, via activation of many protection mechanisms such as increasing antioxidant enzymes and proline and anthocyanin accumulation during vegetative stage, our results show that Canitez is less drought tolerant than Gokce.