Effect of different species of Pseudomonas and Trichoderma on several morpho-physiological traits of roselle (Hibiscus sabdariffa L.)

Abstract

Roselle (Hibiscus sabdariffa L.) is one of the important medicinal herbs with diverse therapeutic properties. A number of bacteria and fungi can stimulate plant as growth‐promoting microorganisms. To assay the nutritional influence of three Pseudomonas bacteria (P. fluorescens, P. putida, P. aeruginosa) and two Trichoderma rifaii (wild type and mutant) strains on the morpho-physiological properties of roselle, a factorial experiment was performed in a completely randomized block design with four replications at two locations. The results showed that the plant height (up to 1.2-fold), fresh/dry weight of aerial parts (up to 1.6-fold), number, and fresh/dry weight of bolls (up to 1.3-fold) were significantly increased by the Pseudomonas spp. and T. rifaii treatments when compared to the control. The chlorophyll content (up to 2.2-fold) and anthocyanin content (up to 3.3-fold) along with catalase activity (up to 3.1-fold) and guaiacol peroxidase activity (up to 2.2-fold) were enhanced by the bacteria and fungi when compared to the control. P. fluorescens, P. putida, P. aeruginosa had the highest effect on the roselle, respectively. The combinatorial use of Pseudomonas spp. and T. rifaii had a greater influence on the improvement of the roselle properties studied than their use alone. Accordingly, the bio-fertilizer management using plant growth-promoting P. putida/P. aeruginosa bacteria and T. rifaii fungus can be an appropriate strategy to increase the yield of roselle. Further, the current study gives a novel insight into the synergistic effect of bacteria and fungi on the plant performance.