Effects of rhizobia and plant growth promoting bacteria inoculation on germination and seedling vigor of lowland rice

Abstract

Plant growth promoting rhizobacteria (PGPR) stimulate plant growth by producing phytohormone which enhances the growth and physiological activities of the host plant. Recently, legume bacteria (Rhizobium spp.) have been considered as a PGPR for legume as well as non-legumes and have the potential for growth stimulation. A laboratory experiment was conducted to observe the effect of PGPR and Rhizobial inoculation on seed germination, seedling emergence, growth and development of lowland rice variety MR219. The experiment was conducted under laboratory condition using filter paper in Petri dish. The design of the experiment was completely randomized (CRD) with six replicates. The PGPR strains UPMB10 (Bacillus sphaericus), Rhizobium strains SB16, UPMR1006 and UPMR1102 were used in the experiment. Seeds inoculated with those PGPR and Rhizobium strains and the Petri dish were kept in an incubator at 30 ± 2°C for 120 h. The seeds germination and other related attributes were measured. The results suggested that inoculation significantly increased the seedling emergence, seedling vigor, root growth namely root length, root surface area and volume. Among the strains, UPMB10 performed better in seedling growth and strain UPMR1006 produced profuse hair in the radical. The results concluded that PGPR and Rhizobia strain can promote seed emergence and seedling attributes which benefits the early seedling establishment and consequently the crop growth and development.

Endophytic bacteria associated with tissue culture and leaves of Plinia peruviana

“…The treatment with isolate M4 also sped up germination, when compared with the negative control (Table 2), but it did not alter the germination rate. Likewise, Mia et al (2012) found a higher growth of rice (Oryza sativa L.) in the presence of Bacillus sphaericus; however, as in the present study, the germination rate did not vary.…”

Isolation and Characterization of Rhizobia and Plant Growth-Promoting Rhizobacteria and Their Effects on Growth of Rice Seedlings

“…In their case, inoculation with bacterial isolates which produced IAA caused longer primary roots of canola and more numerous adventitious roots in mung bean cuttings. PGPR and rhizobia have been suggested to stimulate growth of rice seedlings by producing phytohormones, particularly IAA, which promote seed emergence and other seedling attributes (Mia et al, 2012;Keyeo et al, 2011). Battacharjee et al (2012) also found that rhizobial strain namely Rhizobium leguminosarum could secrete phytohormones such as IAA and increase the biomass, root branching and N content of rice plants.…”

“…Research on Plant Growth-Promoting Rhizobacteria (PGPR) with non-legumes such as rice have shown beneficial effects through biological N 2 fixation (Malik et al, 1997), increased root growth (Mia et al, 2012) with enhanced nutrient uptake (Yanni et al, 1997), phytohormone production (Chabot et al, 1996), plant growth enhancement stimulation by other beneficial bacteria and fungi (Saharan and Nehra, 2011) and disease control (Ramamoorthy et al, 2001). Peng et al (2002), however, reported that rhizobial inoculation known for their symbiotic relationship with legumes, could also increaserice grain yield, but little is known about the mechanism(s) involved.…”

Quality of Immature and Mature Pepper (Capsicum annuum L.) Seeds in Relation to Bio-Priming with Endophytic Pseudomonas and Bacillus spp.

“…Endophytic bacteria are microorganisms living inside plants without creating noxious efficacy [9]. Many endophytic bacteria that are in strong contact with seeds may have adapted to link with embryos or seedlings to regulate seedling growth [10][11][12][13][14] and improve plant growth through enhanced nutrient uptake, nitrogen fixation, synthesis of enzymes, siderophores production and growth phytohormones [15][16][17][18][19]. Bio-priming organisms with PGPB comprise species of the genera Pseudomonas and Bacillus [20,21] along with Burkholderia, Stenotrophomonas, Micrococcus, Rhizobium, and Pantoea, Microbacterium [22][23][24][25][26][27].…”