National Center of Excellence in Molecular Biology (CEMB)
Abstract
Background: Onion (Allium cepa) is a vital vegetable as well as medicinal crop grown all over the world. A considerable area in Pakistan is under salinity stress which markedly reduce the average yield of many crops. Salicylic acid is an important growth regulator and has mitigating effects against saline adversities.Methods: A study was conducted in complete randomized design (CRD) using two onion varieties, Phulkaara and Desi Red, under Faisalabad, Punjab conditions. The level of salinity was kept 50 mM NaCl and 100 mM NaCl while 400 ppm of salicylic acid was applied weekly. The data was analyzed through Statix 8.1 to compute analysis of variance (ANOVA).Results: All the growth and physiological parameter of onion seedlings were decreased significantly with the increasing level of salinity while increased with the application of salicylic acid except total soluble protein. Salicylic acid (@400ppm) mitigated the adverse effects of salinity by enhancing photosynthetic activities. The total soluble protein was increased in leaves with increasing salinity stress whereas the application of SA has non-significant effects. The performance of both varieties remained significantly same for the parameters dry shoot weight, plant height, chlorophyll a, b and total chlorophyll contents. The variety Desi Red performed better for shoot length while Phulkaara was better in fresh shoot/root weight, length of root, dry root weight and total soluble protein.Conclusion: The application of foliar spray of salicylic acid is potential growth regulator to increase the growth parameters of onion under saline stress conditions.Keywords: Onion; Salinity; Salicylic Acid; Mitigating Effects; Growth Parameters
