IN VITRO REGENERATION OF ONION (Allium cepa L.) UNDER SALT STRESS CONDITION

Abstract

The present research was carried out in Biotechnology Laboratory of the Department of Biotechnology, Sher-e-Bangla Agricultural University, Sher-eBangla Nagar, Dhaka-1207 from the period of September 2016 to July 2017 for

in

vitro regeneration of onion (Allium cepa L.) under salt stress condition. Three genotypes namely Faridpuri, Taherpuri and Pusa red (Indian) were used as investigated genotypes in this study. Shoot tip segments of these genotypes were cultured in MS (Murashige and skoog, 1962) media having 0.0 (control), 25, 50, 75 and 100 mM NaCl. The shoot tips of experimental onion genotypes were not significantly affected upto 75 mM salinity level in comparison with control treatment. The experiment was conducted at two factorial (variety and Treatment) Completely Randomized Design (CRD) with 3 replications for each treatment. Salinity response on days required for shoot regeneration varied significantly from different salinity condition. The genotype Faridpuri was found maximum tolerant upto 100mM salinity level with 10.60 cm shoot length and 1.43 cm root length having the highest relative shoot and root growth. Besides, Pusa red was found as salinity sensitive genotype showing the lowest 7.03 cm shoot length and 0.60 cm root length at 100 mM NaCl treatment. However, Taherpuri was found tolerant up to 75 mM salinity level with 8.30 cm shoot length and 1.43 cm root length, respectively. The genotypes Faridpuri, Taherpuri and Pusa red (Indian) can be used for further investigation in field condition to evaluate their performance at various salinity levels. Therefore, a convenient in vitro regeneration protocol of onion genotypes under different salinity level has been developed which can be used for screening salinity tolerant variety of onion within a very short period of time.