PGP Characterization of Rhizobacteria Associated with Apple Gourd (Praecitrullus fistulosus L.)
Taqi Raza1*, Sergio de Los Santos Villalobos2, Muhammad Shehzad3, Shakeel Imran4 and Derly José Henriques da Silva5
Plant growth-promoting rhizobacteria (PGPR) are beneficial group of microorganisms which improve plant and soil health by enhancing nutrient availability and protecting plant against stresses. The current study was carried out to characterization of rhizobacteria associated with Apple Guard (Praecitrullus fistulous L.). Morphological, qualitative and quantitative tests were performed to characterize the PGPR abilities of isolated rhizobacteria. Lab study indicated that isolated bacterial strains have morphologically different colonies, shapes, and colors. The isolated strain mostly belonging to Coccus, Bacillus, and Spirillum. Nearly, 63% belonging to Coccus, 23% to Bacillus, and 14% to Spirillum. Only 18% of strains gave the gram positive staining results and 14% strains showed the hydrogen cyanide (HCN) production abilities by slightly changing the color on media. While, in the case of enzyme production test, almost 90%, of isolated strains confirmed the amylase and pectinase production activities and 36% confirms the protease activities. Similarly, 82% and 45% of isolates confirmed the solubilization of zinc (Zn) and phosphorus (P) respectively. Almost, the entire isolated strains were given positive results for ammonia (NH4), nitrogen fixation, and indole acetic acid (IAA). Furthermore, for exopolysaccharide (EPS) test, 73% of isolated strains confirmed the EPS production. The conclusion revealed that almost all isolated bacterial strains exposed the growth-promoting abilities and may be used as bio-fertilizer to enhance crop production.