Application of ACC-deaminase containing PGPR improves sunflower yield under natural salinity stress

Salinity increase ethylene level in root rhizosphere. plant growth promoting rhizobacteria having acc deaminase have ability to mitigate the adverse effect of enhanced level of ethylene. two field experiments were carried out at two different sites during 2013. the site1 had ece 9.42 ds m-1 and sar 20.75 (mmolc l-1)1/2,while site2 had ece 7.51 ds m-1 and sar 16.25 (mmolc l-1)1/2. four pgpr strains (ks 44,ks 7,ks 41,ks 42) having acc deaminase activity were selected for this study. randomized completes block design (rcbd) was used and hybrid sunflower seeds (smh-0917) were inoculated with these pgpr strains. the crop was harvested at maturity and data were recorded about plant height,shoot dry weight,head dry weight,number of seed head-1,1000 seed weight,seed weight head-1 and seed yield kg ha-1. the data were statistically analyzed by using soft ware statistic 8.1. the average increase in grain yield (site 1 + site 2) was 110.07,108.89,49.09,65.77 and 69.70% over control due to inoculation with ks 44,ks 7,ks 41,ks 42 and ks mix treatments respectively. on the basis of statistical analysis,the bacterial strains ks 44 and ks 7,were declared as most promising strains on both sites. hence these two strains (ks 44 and ks 7) could be used to mitigate negative impact of salinity stress on sunflower. © 2016,pakistan botanical society. all rights reserved.