Role of the rooting system in salt tolerance potential of different guar accessions

To examine the role of the rooting system in salt tolerance of 15 guar (Cyamopsis tetragonoloba L.) accessions collected from arid and semi-arid regions of Pakistan, a pot-culture experiment was conducted under natural conditions in a net house. The experiment comprised three salinity treatments, i.e., 3, 9 and 15 dS m(-1), with three replications. The results showed that whole plant dry weight, root length, root dry weight and number of nodules decreased due to salinity in all the accessions; however, different guar accessions showed variation in root length, dry weight and number of nodules under normal and stressed conditions. The root morphology revealed that accessions with a longer root, greater root dry weight and higher number of nodules had higher seed yield. A positive relationship was found between the rooting system and seed yield under salt stress. It is concluded that accessions with better rooting systems produced higher seed yield and were more salt-tolerant than others.