Bacterial Coating on Seeds as a Potential Application of Bio-inoculants

Abstract

Seed inoculation with plant growth promoting bacteria (PGPB) is an ideal tool to supply the soil with a high density of beneficial microorganisms. However, viability of microorganisms is a major problem during seed treatment and storage. In this research, seed inoculated by PGPB was conducted to prove the presence and colonization the bacteria on the seed and their impact to the germination and plant growth of soybean. Soybean seed was coated by 4 endophytic bacteria strains ( Pseudomonas sp. PIR3C, Pantoea sp. KD6.2, Raoultella sp. PCM8, and Pseudomonas sp. KS12). The ability of the endophytic bacteria to colonize soybean seeds was observed by scanning electron microscopy (SEM). Then, we observe the efficacy of endophytic bacteria inoculation on Soybean growth. The result demonstrated that seed inoculation was able to enter and colonize soybean seed. Seed inoculated with Pseudomonas sp. PIR3C and Raoultella sp. PCM8 significantly increased germination, chlorophyll content, shoot length, root length, and shoot diameter. Furthermore, Pseudomonas sp. PIR3C inoculation increased leaf number and dry weight of the soybean seedlings. Therefore, inoculation method by coating seeds with bacteria could be considered as a promising technique to apply inoculants as biofertilizer in improving plant growth and productivity.