Penapisan dan Identifikasi Bakteri Rhizosfer Padi Penghasil Asam Indol Asetat pada Kondisi Salin

Abstract

Increased salinity in farmland due to the rising sea level have an impact on ion balance, an increased of ethylene in roots, caused of hypo-osmotic condition in roots, and finally hinder the growth of root. Utilization of indigen rhizobacteria with ability to produce growth phytohormone indole-3-acetic acid (IAA) could become one of solution of this problem. This research aims to screening a number of rhizobacteria which have ability of producig phytohormone IAA and tolerant of salinity stress. A total of 48 rhizobacteria isolates from coastal rice field of Patimban and Eretan, west Java have been analyzed. Isolates Er B1.3 and Er B1.7a have ability to grow on minimal salt medium content with 15 % NaCl. Both isolates are still capable of producing IAA with consecutive concentrations at 11 ppm and 3.1 ppm on minimal medium salt content with 10 % NaCl. IaaM gene identification results prove that isolates Er B1.3 and Er B1.7a producing IAA through the IAM pathway. Based on the result of sequencing 16S Rrna gene known that isolate Er B1.3 and Er B1.7a belong to genus Brevibacterium and Aeromonas, respectively.