EVALUATION OF SEED GERMINATION AND SEEDLING GROWTH OF THREE WHEAT CULTIVARS IN RESPONSE TO NaCl SALINITY

Abstract

With the consequence of climate change, salinity gradually extends towards inland water and soil. Salinity affects production in crops by interfering with nitrogen uptake, reducing growth, and stopping plant reproduction. Two experiments were conducted to assess the germination and growth of wheat under saline condition at the Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur from November to December 2023. The experiment was laid out in Completely Randomized Design (CRD) with three replications having two factors. Factor A: Three varieties of wheat viz. V1 - BARI Gom 33, V2 - BWMRI Gom 1, V3 - BWMRI Gom 2; Factor-B: Four levels of salinity (NaCl): S1 - Control (No salt added), S2 - 3.5 dSm-1, S3 -7.0 dSm-1, S4 -10.5 dSm-1. The different amounts of sodium chloride were added to 1 liter of deionized water. In addition, the conversion factor from dSm-1 to g/L is 1 dSm-1 = 0.7 g of sodium chloride per one liter of water was used. The experimental results showed that V3 (BWMRI Gom 2) showed the highest germination percentage (95.95%), vigour index (1600.3), and coleoptile length (2.07 cm), shoot length (16.64 cm), shoot fresh and dry weight (0.110 and 0.020 g, respectively), when V1 (BARI Gom 33) had the maximum root shoot ratio (1.15). Conversely, V2 (BWMRI Gom 1) showed lower values, indicating sensitivity to salt stress. Salt stress negatively affected all parameters, with the decrease being more pronounced in plants growing under S4 levels. Under heavy NaCl stress (S4), germination percentage and index decreased, while S1 treatment recorded the highest values. Considering growth, V1 and V3 showed the highest growth, while V2 was the inferior variety under saline conditions. However, growth characters were negatively affected by increased salinity levels. Shoot and root length (29.76 and 13.80 cm, respectively), shoot fresh and dry weight (0.919 and 0.027 g, respectively), and leaf area index (1153.4) reduced more under S4 treatment compared to other salinity levels. Nonetheless, all growth parameters increased with decreased salt levels from S3 to S1. The study found that under salt stress conditions, V3 (BWMRI Gom 2) outperformed other varieties in growth parameters, particularly under S4 (10.5 dSm-1) and S1 (Control) conditions.