Endophytic Azospirillum for enhancement of growth and yield of wheat

Abstract

The present study was aimed at the isolation of nitrogen fxing bacteria belonging to genus Azospirillum from wild wheat and their growth promoting efect on the bread wheat, under pot culture and fled conditions in semi-arid environment. Two bacterial strains were obtained on the NFb (N-free malate medium) medium with ability to produce phytohormone (indoleacetic acid; IAA) and fx atmospheric nitrogen. Based on 16S rRNA sequence analysis, one isolate (Sp1) showed 99% homology with Azospirillum brasilense and the second isolate (Sp2) showed 99% homology with Azospirillum zeae. Efect of these two isolated strains on bread wheat was examined under pot experiment. Both bacterial strains were found to be efective in enhancing wheat growth. However, best results were obtained with isolate Sp2. Therefore, only this strain was introduced as inoculum in feld experiment, to investigate its efect on wheat yield under semi arid conditions during winter growing season 2016–2017. Based on the obtained feld results, wheat inoculated with isolate Sp2 displayed an increased total grain yield by up to 18% as compared to un-inoculated plants. These results show the potential of these bacteria to be used as biofertilizer.