Sci. Agri. 3 (2), 2014: 105-110 © PSCI Publications Scientia Agriculturae www.pscipub.com/SA E-ISSN: 2310-953X / P-ISSN: 2311-0228 DOI: 10.15192/PSCP.SA.2014.3.2.105110 Assessment of variations in growth and ionic concentration of salt tolerant and sensitive cotton genotypes. Fareeha Habib, Zeeshan Akram , Javed Akhtar, Sajid Hussain, Mudassir Mansoor Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan Corresponding Author email: uafshani430@gmail.com Paper Information A B S T R A C T Received: 20 August, 2014 Accepted: 11 May, 2014 Published: 22 July, 2014 This study was conducted for the comparative performance of ten cotton genotypes against salinity sown in solution culture using Hoagland’s nutrient solution. There were three treatments viz., control and saline (100 and 200 mol m -3 NaCl) with three replications in a two factors factorial statistical arrangement. Salinity level of 100 and 200 mol m -3 NaCl had significantly decreased the shoot and root length; shoot fresh and dry weight; root fresh and dry weight; chlorophyll contents; water potential; leaf area and Na + and K + in leaf sap. On the basis of physical and chemical parameters it was concluded that BH-172 was salt tolerant and VH-277 as sensitive one. © 2014 PSCI Publisher All rights reserved. Key words: cotton genotypes, salinity, hydroponic (solution culture). Introduction Salinity is a major problem which decreases crop production worldwide. Salinity threatens agricultural productivity on 77 million hectares of agriculture land, out of which 45 million hectares (20% of irrigated area) is irrigated and 32 million hectares (2.1% of dry land) is unirrigated. (Ansari et al; .2006) The excessive accumulation of salts in soils of semi arid and arid regions is a potential factor for limiting productivity of irrigated agriculture. Low precipitation accompanied by high evapotranspiration results in salt accumulation in the root zone, which hinders the plant growth. A total loss of 20 billion rupees has been estimated from the salt-affected irrigated areas of Indus Basin on account of decreased crop yield (Anonymous. 2007-2008). Salt affected soils can be managed by reclamation, but due to less availability of good quality water, low soil permeability and high cost of amendments, this approach is not feasible on large scale (Qureshi et al. 1990). Biosaline approaches are more effective both for soil and environment. Different plant species differ in their salinity tolerance. Some plant species are tolerant e.g. barley, cotton and sugar beet; some are moderately tolerant e.g. rya, sunflower, sorghum and soyabean while some are salt sensitive e.g. carrot, okra, onion and peas (Manjunatha et al. 2003). Cotton (Gossypium hirsutum L.) is one of the main cash crops of Pakistan. It has played a significant role in industrial development and employment generation. It is known as backbone of Pakistan’s economy. Pakistan is one of the ancient homes of cultivated cotton, 4th largest producer and the 3rd largest exporter of yarn in the world. Pakistan is by and large mono crop economy as cotton accounts for 7.5 percent of the value added in agriculture and about 1.6 percent to GDP. Three Asian countries (China, India and Pakistan) are expected to produce more than half (59%) of the global cotton production in 2008-09 (Anonymous. 2007-2008). Cotton can grow on moderately saline soils where its yield and quality is much lower as compared to normal soils. Although cotton is considered as being fairly tolerant to salinity, yet its yield is drastically reduced due to poor germination and subsequent abnormal plant development under saline conditions (Khan, 1998). In saline soils, Na + and Cl - are the dominant ions affecting plant growth (Manjunatha et al. 2003). Under saline conditions, the activities of some essential nutrients may also be reduced (Gratten and Grieve, 1992) and plant may experience nutritional disorder. It is now evident that some plant species can tolerate high salinity (Rehman et al., 1998). Limited sodium uptake is a trait related to salinity tolerance in several crop plants (Fortmeier and Schubert, 1995; Gregorio and Senadhira,; 1993). Significant differences have also been reported among varieties of different species including wheat (Saqib et al., 1999) and cotton (Ashraf and Ahmad, 2000). Improving plant resistance to salt may provide yield stability in subsistence agriculture and limit salinization due to irrigation by reducing inputs (Flowers and Yeo, 1995). In cotton (Gossypium hirsutum L.), early work of Lauchli and Stelter (1982) found that salt tolerance appeared to be related to accumulation of Na+ and Cl- in the shoot. This study is planned, 1. To screen a different set of cotton genotypes for their tolerance to salinity stress. 2. To identify plant characteristics(s) responsible for tolerance of cotton genotypes to salinity stress