Rhizobial consortium improves germination attributes and salinity tolerance in maize (Zea mays L.)

Abstract

Salinity is one of the major factors which affect the overall growth of plants in the whole world. Germination of seed under saline conditions is of great importance for the survival and continued growth of many plant species. Most sustainable and environment friendly management of saline soil is to inoculate seed with a salt tolerant microbe like rhizobia. Although potential of rhizobia has been explored in legume for salinity tolerance but still knowledge about their role in non-legumes is missing.  Therefore, in the present experiment, the potential of rhizobial strains alone and in consortia has been evaluated at three salinity levels (control, 4 and 8 dS m^-1) for inducing salt tolerance in maize, especially at germination and early growth. Results revealed that all rhizobial strains (four strains) significantly (p<0.05) improved all the attributes regarding germination and seedling growth under both salinity levels and control, however, best results were recorded with rhizobial consortia comprising of all four strains. Moreover, better improvement following rhizobial consortium in the germination % (37%), germination speed (13%), germination rate (39%), mean germination time (18%) and mean daily germination (20%), vigor index (2.76 times), coleoptile length (15%), plumule length (26%), radical length (76%) length of seedlings (26%) and salt tolerance index (117%) was observed at 8 dS m^-1 in comparison to respective un-inoculated control.