Isolation and molecular identification of Zhihengliuella alba from rhizosphere of Bassia sp.

BACKGROUND AND OBJECTIVESThe rhizosphere microbiome of halophyte plants harbors various groups of halotolerant plant growth-promoting rhizobacteria (HT-PGPR) that can increase plant growth and yield under salinity stress conditions. Bassia plants can be found in semideserts or dry steps, and, as halophytes, can exist in habitats characterized by high salinity. This study focused on the rhizosphere bacteria of Bassia sp., a halophytic plant collected from pistachio orchards.MATERIALS AND METHODSThe Bassia plants in pistachio orchards were uprooted, and samples of soil adhering to the roots were collected into sterile bags for transport to the lab. To identify halotolerant PGPRs, the bacterial isolates were screened for halotolerance on NA supplemented with ۰%, ۵%, ۱۰% and ۱۵% NaCl at ۲۸ °C. The halotolerant bacterial isolates were screened for IAA production. Molecular identification of the HT-PGPRs was performed by sequencing of V۳-V۴ region of the ۱۶S rRNA gene.RESULTS AND DISCUSSIONThe pure culture of ۱۴ rhizosphere bacterial isolates was prepared and subjected to biochemical tests. Most of them were able to grow at ۱۵% salt concentration. Screening for IAA production by salkowsky's method showed positive results for only one strain. Based on the sequencing results of the V۳-V۴ region of the ۱۶S rRNA gene, this isolate shared ۹۹.۵۰% similarity with Zhihengliuella alba strains deposited in Genbank.CONCLUSIONThe identification of HT-PGPRs from the rhizosphere of halophyte species in saline soils provides evidence that these halophiles can be used as inocula to promote the growth of salt-sensitive crops.

کلیدواژه ها:

PGPR ، Soil salinity ، Halophyte