ABSCISIC ACID INDUCED CHANGES IN SEED GERMINATION, SEEDLING GROWTH AND WATER RELATION BEHAVIOR OF WHEAT UNDER SALT STRESS CONDITION

Abstract

Pre-sowing seed treated with Abscisic acid (ABA) assumed to be a potential priming agent to increase the germination, seedling growth and water relation behavior of grain under salt stress condition. With this view, a lab experiment was carried out to find out the effect of various ABA concentration on the germination, seedling growth and water relation behavior of wheat under salt stress condition at central laboratory of Sher-e-Bangla Agricultural University (SAU), Sher-e-Bangla Nagar, Dhaka-1207 during the period from 21 September, 2016 to 19 November, 2016. This study was conducted with two different experiments. The experiment was laid out in a Completely Randomized Design (CRD) with five replications. In this experiment three wheat genotypes (ESWYT-5, ESWYT-6, and BARI Gom 28) were used as test crop; ABA and water were utilized as priming agent for hormonal and hydro priming and salt stress was induced by sodium chloride (NaCl) solution. Germination parameters of wheat like germination percentage, germination coefficient; growth parameters like shoot length, root length, fresh weight, vigour index, water relation parameters like water retention capacity, relative water content etc. were collected form this experiment. Data were analyzed by MSTAT-C software. The significance of difference among the treatment means was estimated by the Least Significant Difference (LSD) test at 1% level of probability. In the first experiment, the best treatment was carried out among different ABA concentrations on germination, seedling growth and water relation behavior of three wheat genotypes without any stress condition. It was found that ESWYT-5 (V 1 ) showed the highest germination rate (91.71%), shoot length (160.6 mm), root length (112.4 mm), shoot dry weight (54.58 mg), root dry weight (47.64 mg), relative water content (93.8%), water retention capacity (18.7) and vigour index (196.5) with 40 ppm ABA primed seeds for 9 hours. In the second experiment, seeds primed with 40 ppm ABA for 9 hours placed under salt stress condition and found that ESWYT-5 (V 1 ) showed the highest germination rate (93.2%), shoot length (160.6 mm), root length (110.0 mm), shoot dry weight (54.58 mg), root dry weight (47.64 mg), relative water content (90.39%), water retention capacity (12.6.) and vigour index (220.6) under control treatment. With other salt treatments all growth parameters of V 1 (ESWYT-5) reduced slowly but in other cultivars all parameters reduced drastically with increasing salt stress. From the result of the study, it was revealed that seeds primed with 40 ppm ABA for 9 hours showed the best result under salt stress condition.