IntroductionChickpea (Cicer arietinum L.) is a plant from the legume family, which is usually cultivated under rainfed conditions. This crop is mostly cultivated in late winter or early spring. In these conditions, there is a high probability of heavy rains (short or long term) and there is a possibility of waterlogging in early spring and during the early growing stages of chickpea. In waterlogged conditions, due to the lack or absence of oxygen in the plant roots occur anaerobic conditions and greatly reduced the amount of energy production in the roots. In this case, the root does not have the necessary energy to transport materials from the cell membrane, and plants face ionic stress, reduced hydraulic conductivity, and reduced water absorption. Reduced and disrupted root growth leads to diminished shoot growth, impaired water and nutrient absorption, and ultimately lower grain yield. In general, the extent of damage caused by oxygen deficiency depends on the plant species, variety, growth stage, soil type, and environmental conditions. Therefore, the purpose of this experiment was to investigate the effects of waterlogging on chickpea cultivars (Desi and Kabuli), physiological characteristics, root growth and yield. Materials and MethodsThis experiment was carried out as factorial based on completely randomized design (CRD) in three replications in the research farm via pot of the Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran in 2013-2014. Factors included chickpea cultivars ILC482 and Azad (from Kabuli type) and Kaka and Pirooz (from Desi type) and duration of waterlogging including no waterlogging (control), 4, 8 and 12 days at 30 days after planting (vegetative stage). Physiological traits (relative water content, membrane stability and pigments) as well as total root length, root dry weight, number of nodes, main root length and root volume in a destructive way in the pod setting stage, as well as in the ripening stage, root traits, remobilization, relative water content, membrane stability, pigments, seed protein, biological yield, seed yield, 100-seed weight and plant height were investigated. Planting was done in the first year on March 11, 2013 and in the second year on March 15, 2014. The size of plastic pots was 30 x 30 cm. 30 days after planting were applied treatments. Compound analysis of data was done with SAS software and means comparisons were performed using the least significant difference (LSD) at the 5% level. Results and DiscussionThe results of compound analysis showed that there were significant differences between the two years in seed yield and the number of seeds per plant. In the second year, the seed yield and the number of seeds per plant compared to the first year increased by 16.9% and 12.1%, respectively. In the second year, the ambient temperature was lower. At a lower temperature, the waterlogging damage is more severe to plants. The total dry matter yield of chickpea cultivars in waterlogged conditions was significantly different and Kaka, Pirooz, ILC482 and Azad cultivars were 4.42, 3.19, 2.99 and 2.54 g.plant-1, respectively. The highest damage to seed yield in waterlogging in 12 days was related to Azad variety (71% compared to the control). In waterlogged conditions, the seed yield was in Kaka (1.51 g.plant-1), Pirooz (1.16 g.plant-1), ILC482 (0.95 g.plant-1) and Azad (0.97 g.plant-1). There was a significant difference between Kabuli type and Desi type, however, grain yield in Desi type was 28.3% higher than Kabuli type. In the pod setting stage, the Pirooz cultivar in the control treatment had the highest total root length with 7741 cm (in the first year) and 7432 cm (in the second year), but the lowest was in the second year at the Kaka cultivar and 12 days with 440 cm. In general, with the increase of the duration of flooding in chickpea cultivars, the total root length decreased significantly and between 4 days, 48.4 to 60.4 percent, 8 days to 8.8 to 70.8 percent, and 1.12 days from 81 to 89.4 percent. In all treatments, the control treatment (without waterlogging) had the highest chlorophyll a, and the amount of chlorophyll a decreased in other treatments. However, no reduction was observed in Pirooz in 4, 8 and 12-day treatment. Chlorophyll b had a different response to waterlogging levels and cultivar. Chlorophyll b was the highest in ILC482 in control treatment, while in Azad, Kaka and Pirooz treatments, chlorophyll b increased with increasing duration of waterlogging. Pigment carotenoids in ILC482 and Azad significantly decreased with increasing duration of waterlogging, but it was not significant in Kaka and Pirooz cultivars. Overall, carotenoids were less fluctuating in the desi type. ConclusionsWaterlogging in the vegetative stage even for 4 days with a decreasing effect on total root length, number of nitrogen fixing nodes, plant height, total dry matter, chlorophyll and carotenoids content, membrane stability index, relative leaf water content, biological yield, seed protein, the number of seeds per plant and the weight of 100 seeds and finally caused a decrease in seed yield. Among the components of seed yield, the amount of damage was higher on the number of seeds per plant. In general, the seed yield of ILC482 and Azad (Kabuli type) was lower than that of Kaka and Pirooz (Desi type). In the second year, due to the lower air temperature compared to the first year, the damage to the total root length and total dry matter decreased. This experiment provides valuable results on the response mechanisms of chickpea to waterlogging stress and can help develop strategies to improve its performance in waterlogged environments, which are expected to waterlogging increase due to climate change. However, more research is needed to investigate the response of different chickpea species to short-term and long-term waterlogging conditions.