7 Tropical Endophytic Bacillus Species …
173
control (de Sousa et al. 2020). After testing for different mechanisms of PGP in vitro,
the strains were co-inoculated in maize seeds, tested in controlled conditions and in
the field. The selection of the adjuvant and method required for inoculation is based
on the microorganism’s viability, crops, and application method. Positive results in
the field attract the attention of inoculant-producing industries, an important step for
the formulation, large-scale production, product marketing, and training to farmers.
7.6 Conclusion and Future Prospects
Tropical endophyte Bacillus is well known for their capacity to confer plant growth
promotion and to increase resistance toward various diseases as well as abiotic
stresses. However, some strains fail to confer these beneficial effects when applied in
the field. The lack of various characteristics, which are important for efficient colonization of the plant environment and the limited supply of the appropriate formulation, could explain poor plant host colonization. Further analysis of sequenced
genomes, the characterization of unknown genes and the identification of genes
expressed during colonization may lead to a better understanding on how beneficial
bacteria colonize different plant niches, thus result not only in scientific knowledge on
plant microbe interactions, but also in a more successful and reliable use of bacterial
inoculants.
The use of PGPB for mineral solubilization and N fixation has progressed well, but
yet to be done more for zinc and potassium solubilization and sulphur oxidation. The
exploration of the more efficient use of these nutrients has the potential to increase
the field of the inoculants and create confidence among the farmers for their use.
In order to accomplish this, there is a need to invest more in research regarding
plant–microorganism–soil interaction, growth condition optimization, tolerance to
adverse environmental condition, and provide higher yield and longer shelf life with
cost-effective for farmers for long-term applications.
References
de Abreu CS, Figueiredo JEF, Oliveira CA et al (2017) Maize endophytic bacteria as mineral
phosphate solubilizers. Genet Mol Res 16:1–13. https://doi.org/10.4238/gmr16019294
Agarwhal S, Shende ST (1987) Tetrazolium reducing microorganisms inside the root of Brassica
species. Curr Sci 56:187–188
Ahmad F, Ahmad I, Khan MS (2008) Screening of free-living rhizospheric bacteria for their multiple
plant growth promoting activities. Microbiol Res 163:173–181. https://doi.org/10.1016/j.micres.
2006.04.001
Alori ET, Babalola OO (2018) Microbial inoculants for improve crop quality and human health.
Front Microbiol 9:2213. https://doi.org/10.3389/fmicb.2018.02213
Alori ET, Dare MO, Babalola OO (2017) Microbial inoculants for soil quality and plant health. In:
Lichtfouse E (eds) Sustainable agriculture reviews, vol 22, Springer, Cham, pp 281–307. https://
doi.org/10.1007/978-3-319-48006-0_9
173
control (de Sousa et al. 2020). After testing for different mechanisms of PGP in vitro,
the strains were co-inoculated in maize seeds, tested in controlled conditions and in
the field. The selection of the adjuvant and method required for inoculation is based
on the microorganism’s viability, crops, and application method. Positive results in
the field attract the attention of inoculant-producing industries, an important step for
the formulation, large-scale production, product marketing, and training to farmers.
7.6 Conclusion and Future Prospects
Tropical endophyte Bacillus is well known for their capacity to confer plant growth
promotion and to increase resistance toward various diseases as well as abiotic
stresses. However, some strains fail to confer these beneficial effects when applied in
the field. The lack of various characteristics, which are important for efficient colonization of the plant environment and the limited supply of the appropriate formulation, could explain poor plant host colonization. Further analysis of sequenced
genomes, the characterization of unknown genes and the identification of genes
expressed during colonization may lead to a better understanding on how beneficial
bacteria colonize different plant niches, thus result not only in scientific knowledge on
plant microbe interactions, but also in a more successful and reliable use of bacterial
inoculants.
The use of PGPB for mineral solubilization and N fixation has progressed well, but
yet to be done more for zinc and potassium solubilization and sulphur oxidation. The
exploration of the more efficient use of these nutrients has the potential to increase
the field of the inoculants and create confidence among the farmers for their use.
In order to accomplish this, there is a need to invest more in research regarding
plant–microorganism–soil interaction, growth condition optimization, tolerance to
adverse environmental condition, and provide higher yield and longer shelf life with
cost-effective for farmers for long-term applications.
References
de Abreu CS, Figueiredo JEF, Oliveira CA et al (2017) Maize endophytic bacteria as mineral
phosphate solubilizers. Genet Mol Res 16:1–13. https://doi.org/10.4238/gmr16019294
Agarwhal S, Shende ST (1987) Tetrazolium reducing microorganisms inside the root of Brassica
species. Curr Sci 56:187–188
Ahmad F, Ahmad I, Khan MS (2008) Screening of free-living rhizospheric bacteria for their multiple
plant growth promoting activities. Microbiol Res 163:173–181. https://doi.org/10.1016/j.micres.
2006.04.001
Alori ET, Babalola OO (2018) Microbial inoculants for improve crop quality and human health.
Front Microbiol 9:2213. https://doi.org/10.3389/fmicb.2018.02213
Alori ET, Dare MO, Babalola OO (2017) Microbial inoculants for soil quality and plant health. In:
Lichtfouse E (eds) Sustainable agriculture reviews, vol 22, Springer, Cham, pp 281–307. https://
doi.org/10.1007/978-3-319-48006-0_9