© 2016 Tapaswini Hota et al. This is an open access article distributed under the terms of the Creative Commons Attribution License -NonCommercial-ShareAlike Unported License ( http://creativecommons.org/licenses/by-nc-sa/3.0/ ). Journal of Applied Biology & Biotechnology Vol. 4 (05), pp. 014-025, Sep-Oct, 2016 Available online at http://www.jabonline.in DOI: 10.7324/JABB.2016.40503 Physiological and biochemical characterization of Sesamum germplasms tolerant to NaCl Tapaswini Hota 1 , C. Pradhan 2 , G. R. Rout 1* 1 Department of Agril. Biotechnology, College of Agriculture, OUAT, Bhubaneswar-3, India. 2 Post Graduate Department of Botany, Utkal University, Bhubaneswar-4, India. ARTICLE INFO ABSTRACT Article history: Received on: 30/03/2016 Revised on: 14/05/2016 Accepted on: 28/07/2016 Available online: 23/10/2016 Sesamum indicum L. (family-Pedaliaceae) is an economically important oil seed crop grown in tropical and sub- tropical countries. It is widely used in food, nutraceutical, pharmaceutical industries. Salinity is considered as the most important abiotic stress limiting to crop production. In this context, the present study was to evaluate the Sesamum genotypes for salinity tolerance. Germinated seedlings (15-d-old) were used to screen the germplsm at different concentrations (0, 25mM, 50mM, 75mM, 100mM) of NaCl and observation was taken after 15 th , 30 th and 45 th days of treatment. Ion content (Na + , Cl - , Ca ++ , Mg ++ and K ++ ) were measured after 15 days of treatment. Fresh and dry weight was less in salt sensitive genotypes than tolerant genotypes. During increase of salinity concentration, all the genotypes had a negative impact on roots. The seedlings showed reduced growth and displayed variation in ion uptake thus accumulating Na + and Cl - in the roots. At higher concentration of salt treatment showed the more dry weight and displayed more effective ion regulation by manipulating low Na + /K + and Na + /Ca ++ ratio. The tolerant genotypes exhibited the lowest shoot Na + content under salinity conditions. Higher proline accumulation was observed at 100 mM after 15 days of NaCl treatments in ‘KM-13’ genotype. After 15 days of treatment, the genotype ‘ES 2138-2’ showed maximum proline accumulation. The total carbohydrates contents increased in all the ten genotypes in presence of NaCl. Highest carbohydrate content was found in genotype ‘SI-1926’ grown in 100 mM NaCl. Enzyme activities are variable in different genotypes with different concentration of NaCl. This study will help in Sesamum improvement programme. Key words: Sesamum genotype, Protein, Proline, Salinity stress, Oxidative enzymes. 1. INTRODUCTION Sesame (Sesamum indicum L.) family Pedaliaceae, is one of the oldest high-value, multipurpose oil seed crop grown widely in tropical and subtropical areas [1, 2]. The average yield of sesame on global scale is 5.1 quintals/ha while, current world production is estimated at about 4.04 million tons annually [3]. India placed second in the world after Myanmar with 18.20 lakh ha and 6.10 lakh tons production respectively. The average yield of sesame on global scale is 5.11 q/ha, while in India, it is 3.30 q/ha which is very low [3]. It is widely used against various diseases including cancer, cold, colic etc [4]. Sesame oil contains an unique compound known as lignans. Lignans comprises sesamin, sesamolin, and a small amount of sesamol [5]. Lignans * Corresponding Author Email: grrout @ rediffmail.com are also phytoestorgens and their conversion to enterolactone is very important in preventing hormone-dependent cancers (like breast and prostate) and cardiovascular diseases. Soil salinity is one of the most important problems for irrigated agriculture, which drastically affect crop productivity throughout the world. It is mainly due to low precipitation and high transpiration causing disturbance in salt balance in the soil and also renders ground water brackish and affects plant growth adversely [6,7]. Nearly, 80 million hectares of arable lands of the world are estimated to be affected by salt [8]. Salinity effects are more noticeable in arid and semiarid regions, mainly due to the acceleration of salinity by a deficit of precipitation and high temperature coupled with a high evaporation demand [9]. Salt stress changes the morphological, physiological and biochemical responses of plants [10]. High salinity causes lower water potential and induces both hyper osmotic and ionic stress and results in alteration in plant metabolism including ionic imbalances, water potentials and specific ion toxicity [6].