In the present study, the tested chickpea cultivars showed different tolerance levels in response to NaCl stress levels. The inhibitory effects of salinity on morphological traits were observed on the plants at the beginning of the third week after NaCl application. However, the early negative effect of NaCl was observed during seed germination, where NaCl reduced FGP and GI.
Final germination percentage (FGP)
The final germination percentage (FGP) showed significant differences between varieties and NaCl treatments with a significant interaction between the two factors (Table 1). In comparison, all tested varieties completed the FGP in the control treatment (100% of the seeds germinated). The same germination reduction pattern was reported by
Farooq et al., (2017) and
Dadaþoðlu et al., (2020) on other chickpeas varieties and the 100 mM NaCl concentration found to be the critical threshold for germination in chickpea (
Dadaþoðlu et al., 2020).
Similar results were also reported in rice (
Islam and Karim, 2010) and chickpea (
Özaktan et al., 2018;
Ceritoðlu et al., 2020). Although 50 and 100 mM NaCl did not significantly affect the final germination percentage and germination index of Arij (Small seed variety) (93.33 and 83.33% respectively). Einalbeda was the most affected variety where FGP was significantly reduced at 50 and 100 mM NaCl (80 and 73.33% respectively). Hadas (big seed variety) germination was not affected under 50 mM NaCl (86.67%) while FGP was significantly reduced under 100 mM NaCl (76.67%).
Al-Mutawa (2003) reported that the rate and percentage of seed germination of chickpea were significantly reduced by increasing salinity levels and the magnitude of the reduction varied among genotypes
Kaya et al., (2008) reported that small seed chickpea varieties can germinate in a shorter time than large seed varieties under saline conditions. The results showed that increasing NaCl concentration caused crucial impacts not only on germination rate but also on the agronomic traits; these findings agree with the results reported by
Ceritoðlu et al., (2020).
Flowers et al., (2010) stated that chickpea is a plant affected by salinity, where the most tolerant genotypes can’t survive for a long time at 100 mM NaCl solution while the susceptible genotypes will die in just 25 mM NaCl solution.
Plant height
After 70 days of growth under different NaCl concentrations (50, 75 and 100 mM), the tested chickpeas varieties showed some differences in terms of growth parameters. The plant height showed significant differences between varieties and NaCl treatments with a significant interaction (Table 2). These findings agreed with the results reported by Ceritoðlu
et_al(2020) and
Yousef et al., (2020). The highest plant height was obtained by Einalbeda (38.63 cm) in the control group, while the lowest one was found in Arij (28.25 cm) under 100 mM NaCl. The mean plant height of cultivars ranged between 31.67 and 34.42 cm. The reduction rates in plant height depending on NaCl treatments are given in Fig 1. Plant height reduction was relatively higher under 100 mM than the lower NaCl concentrations.
Welfare et al., (2002) reported that high salinity has negative effects on plant height. Arij showed a higher tolerance rate regarding plant height under 50 mM and 75 mM, respectively, while it was the most sensitive under 100 mM NaCl. It was reported that the growth rate was higher in tolerant chickpea genotypes compared with susceptible ones under salinity stress
(Kafi et al., 2011).
Root/shoot ratio
To test the effect of different NaCl levels on plant growth, the shoot/root ratio was calculated (Table 2). Obtained results show that NaCl did not affect root/shoot ratio in all genotypes, indicating that roots and shoots are in the same range of sensitivity to NaCl stress. A higher root shoot length ratio indicated that the selection of stress tolerance might help improve grain yield
(Mazhar et al., 2020; Masood et al., 2020).
Plant fresh and dry weight
There were significant differences in plant fresh and dry weight between varieties and NaCl treatments. Significant interaction also affected the fresh and dry weights of the plants (Table 3). These findings are consistent with those stated by
Ceritoðlu et al., (2020). According to
Welfare et al., (2002), Sohrabi et al., (2008) and
Hossain et al., (2015), high salinity has a negative impact on shoot weight. Fig 2 showed the reduction percentage in plant fresh weight. The reduction was varied among the three varieties, Hadas was the most influential one. Reduction in fresh weight ranged between 25.6% and 74.2% under 50 and 100 mM NaCl, respectively (the average reduction was 54.3%). The least affected variety was Arij; the reduction in fresh weight ranged between 4.9% and 27.2% under 50 and 100 mM NaCl, respectively affected by NaCl. Similar results were reported in chickpea and pea
(Yousef et al., 2020; (the average reduction was 12.9%). Einalbeda showed the lowest reduction in plant fresh weight under 100 mM (0.1% reduction) (Fig 2). Plant dry weight was significantly
Dadaþoðlu et al., (2020) Einalbeda showed the highest dry weight over NaCl treatments without significant difference from the control (Table 3).
Root fresh and dry weight
The root fresh weight showed significant differences between varieties and NaCl treatments, whereas no significant difference was observed in root dry weight between the tested varieties (Table 4). This is in agreement with the results reported in chickpea
(Abdiev et al., 2019) and forage pea
(Acikbas et al., 2021). Despite the salinity, Hadas showed the highest root fresh and dry weights (14.77 and 0.96 g, respectively) compared to Einalbeda and Arij.
