Agronomy Journal • Volume 106, Issue 1 • 2014 185 Agronomic Application of Genetic Resources Assessing the Salt Tolerance of Sulla carnosa Genotypes by Agronomic Indicators Mhemmed Gandour,* Mohamed Neji, Kamel Hessini, Malek Smida, Chedly Abdelly, and Wael Taamalli Published in Agron. J. 106:185–190 (2014) doi:10.2134/agronj2013.0124 Copyright © 2014 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. ABSTRACT e progressive salinization of arable lands at a rate of 3 ha min –1 worldwide is a major concern for agricultural crop production. e future of crop improvement to resist or tolerate environmental stresses requires selecting halophytes that will produce high yield and profit. A halophyte, Sulla carnosa (Hedysarum carnosum Desf.), collected from southern and central Tunisia is considered a salt-resistance species. A group of five populations represented by 150 genotypes (30 genotypes per population) were tested under greenhouse conditions with salt treatments 0 mM (control) and 300 mM (stressed). Fiſteen agronomic traits related to vegetative and reproductive growth were evaluated for their responses to salinity stress. Analysis of the population effect and genotypes within population’s effect shows that both population and genotype factors have a significant effect for almost all measured traits. e highest diversity in traits was found within progeny originating from Douiret and Kairouan populations (mean and CV across the 15 traits 48.4 and 46.5%, respectively). Level of phenotypic differentiation (Q _ST) varied according to measured traits; it ranged from 0.108 for flowering time to 0.63 for mean crown width with an average of 0.29. Means comparison and principal component analysis showed that six genotypes from different origins were ranked as salt tolerant and three others as salt sensitive. ese findings indicate the potential for selecting plants or traits with improved salt tolerance within that species. e method used allows detection plants or traits with enhanced salinity tolerance aſter 2 mo of growth for the ability to grow at salt concentrations that prevent the growth of other plants. Center of Biotechnology of Borj-Cédria BP 901 hammam-lif Hammam-lif, TN 2050, Hammam-Lif 2050, Tunisia. M. Gandour and M. Neji contributed equally to this article. Received 11 Mar. 2013. *Corresponding author (gandourmed@yahoo.fr). Abbreviations: SRI, salt response index; Vbp, variance between populations; Vwp, variance within population. According to the U.S. Census Bureau and United Nations (U.S. Census Bureau, 2011), the total population of the World is more than 7 billion and growth projections suggest that the world’s population will reach 9 billion before 2050. As a result of this increase, the demand for food and fuel will increase signi fcantly. Paralleled with this popula- tion increase, there is a subsequent increase in abiotic stress limiting plant growth resulting in severe desertifcation over much of the world’s terrestrial ecosystem. Te estimation of potential yield losses due to temperature, salinity, and drought stresses are estimated at 55, 20, and 17%, respectively (Ashraf and Harris, 2005). Tus, the efect of increasing salinity will pose serious implications on plant production in hot and dry environment. Te Food and Agriculture Organization of the United Nations (FAO) estimate that more than 800 million hectares of land throughout the world are salt afected, either by salinity (397 million ha) or by the associated condition of sodicity (434 million ha) (FAO, 2008; Munns and Tester, 2008). Approximately 7% of the total area and about 5% of cul- tivated land in the world are afected by salinity (Flowers and Yeo, 1995). Because of its importance, considerable research has been done to investigate the mechanism of salt tolerance (Sreenivasulu et al., 2000; Kaya et al., 2001a, 2001b, 2002; Jumberi et al., 2002; Baba and Fujiyama, 2003; Lopez Aguilar et al., 2003). Breeding for salinity tolerance has been going on for many years and crops have been developed with increased salt tolerance. One option to reclaim saline sites is by the use of salt-tolerant crops. One such species of interest is Sulla carnosa (Hedysarum carnosum Desf.) which is an important legume grown as animal feed on salt-afected areas (McDonald et al., 1991). It is a diploid (2n = 16), allogamous, seed-propagated species and has a vegetative shoot system characterized by an orthotropic main stem bearing lateral plageotropic shoots. It is a short-lived perennial legume native to North Africa. Mirali et al. (2007) recommended that the genetic diversity within a species should be evaluated and preserved in locations where it is endemic and represents a center of origin or initial distribution. Traits of interest under salt conditions are nutritive quality and yield; however, most of the research has been limited to physiological (gas-exchange parameter, stomatal response), biochemical (plant hormone, polyamine accumulation, starch analysis…), and molecular (expression of stress signaling pathway genes) descriptions of stress tolerance. Published November 22, 2013