Effect of mucilage on salinity tolerance of Lallemantia ibrica at seed germination stage

Seed germination is the most sensitive growth stages of the plant to salinity stress. Seeds of many species produce a jelly-like layer called mucilage upon exposure to water. The purpose of this study was to determine the role of mucilage in increasing salinity tolerance of Lallemantia ibrica. Seeds of this plantcontain mucilage that can be used to treat some diseases such as neurological, liver and kidney disorders. Thus, a factorial experiment was conducted arranged in completely randomized design with four replications at Botany Laboratory of Yazd University in 2013. Salinity stresses (0, 5, 10, 15 and 20 dS m-1) and seed type (with and without mucilage) were considered as first and second factors, respectively. Results showed that all traits were significantly affected by salinity stress. Germination and early growth of both seeds type decreased with increasing salinity stress. The highest and lowest seed germination rates were obtained in control and salinity level of 20 dS/m, respectively. Seeds with mucilage had higher seed germination and shoot length compared to seeds without mucilage. Overall, results indicated the positive role of mucilage in improving germination of L. ibrica seeds under salinity stress. However, the ability of mucilage in improving seed germination depends on plant species and amount of seeds mucilage.