Evaluation of PGPR isolated from Sesuvium portulacastrum on crop growth under salinity

Salinity is one of the major factors that adversely affect plant growth causing considerable loss in agricultural production. The halotolerant bacteria associated with halophyte rhizosphere can be used as a cost effective and economical tool for salinity tolerance and growth promotion in plants. The total of 8 independent isolates from the rhizosphere of Sesuvium portulacastrum from coastal soils were isolated for their plant growth promotion potential. All the isolates had at least one plant growth promoting property. In order to ascertain the true salinity tolerance levels of the isolates, a growth curve experiment with 0, 3, 5 and 7% NaCl was carried out. Among all the isolates RB₅ and RB₆ had high tolerance for salinity. The highest ammonia production was in RB₅ at 1.46 mg/Land IAA (Indole Acetic Acid) production was in RB₆ at 21.75 μg/ml. The bioinoculation of Neobacillus niacini increased seed germination (23.2%), shoot length (35.1%), root length (34.2%), and total dry matter (43.5%) even under high salinity (7.78 dS/m). These saline tolerant beneficial bacteria could serve as inoculant for non-host plant cultivation or for phytoremediation of saline soils.