10.16 Future Research Direction
Biological control by means of Bt has proven to be an effective and valuable strategy
for insect control and also for diminishing the application of chemical insecticides.
Moreover, due to the multifunctional role of Bt, as it has been comprehensively
discussed in Salehi Jozanai et al. (2017) review, this bacterium has a great potential
to be applied in different areas. Therefore, the search for discovering novel Bt strains
and toxins with improved efficiency, wider insecticidal toxicity, antagonistic activity
against plant pathogens and plant growth-promoting function, has to be continued.
After discovering novel Bt toxins, in the next step, the appropriate formulation of
bacterial products that enhance both survival and efficiency of the organisms is
needed. Bt products are not cost-effective, though the effectiveness of Bt based
insecticides has to be improved and the cost of production has to be lowered.
Evidently, optimization of the growth conditions leads to the highest yields, while
utilization of locally available materials, low-cost materials, agricultural and industrial by-products, improves the local cost-effective production. Undoubtedly, this
issue needs more sufficient techniques in the fermentation, quality control, formulation and delivery system of Bt. Finally, the current registration protocols of the
Plant Protection Organization (PPO) needs to be revised to facilitate the procedures.
Decreasing the costs related to the Bt-based mass-production and supporting native
Bt products could be helpful in the development of local production and the
application of these products in the country.
Understanding the mechanism of action of Bt toxins would definitely lead to the
development of high potent and more efficient Bt-based products and Bt crops. On
the other hand, pyramiding two or more Bt toxins with different modes of action has
been considered as an effective strategy for delaying resistance (Ferré et al. 2008).
Therefore, future studies can be focused on the mode of action and binding behavior
of Bt toxins in the midgut of susceptible larvae. Genetic manipulation of the Bt
toxins with enhanced and broadened insecticidal activity must be taken into
consideration.
10.17 Conclusion
B. thuringiensis as one the most successful microbial control agents for controlling
agricultural, forestry, medical and veterinary pests, is being used as part of integrated
pest management strategies. Commercial Bt products are used worldwide, as well as
in Iran. Based on the several extensive Bt screening projects carried out in Iran, the
high rate of Bt recovery from different ecosystems, depending on the geographical
region, demonstrates the richness and variability of biological control agent
resources. In these screenings, Iranian Bt isolates were found to be highly toxic to
different species within Lepidoptera, Coleoptera, and Diptera, pointing to the fact
that the Iranian Bt strains have a huge potential to control different agricultural pests.
430
A. Khorramnejad et al.
Biological control by means of Bt has proven to be an effective and valuable strategy
for insect control and also for diminishing the application of chemical insecticides.
Moreover, due to the multifunctional role of Bt, as it has been comprehensively
discussed in Salehi Jozanai et al. (2017) review, this bacterium has a great potential
to be applied in different areas. Therefore, the search for discovering novel Bt strains
and toxins with improved efficiency, wider insecticidal toxicity, antagonistic activity
against plant pathogens and plant growth-promoting function, has to be continued.
After discovering novel Bt toxins, in the next step, the appropriate formulation of
bacterial products that enhance both survival and efficiency of the organisms is
needed. Bt products are not cost-effective, though the effectiveness of Bt based
insecticides has to be improved and the cost of production has to be lowered.
Evidently, optimization of the growth conditions leads to the highest yields, while
utilization of locally available materials, low-cost materials, agricultural and industrial by-products, improves the local cost-effective production. Undoubtedly, this
issue needs more sufficient techniques in the fermentation, quality control, formulation and delivery system of Bt. Finally, the current registration protocols of the
Plant Protection Organization (PPO) needs to be revised to facilitate the procedures.
Decreasing the costs related to the Bt-based mass-production and supporting native
Bt products could be helpful in the development of local production and the
application of these products in the country.
Understanding the mechanism of action of Bt toxins would definitely lead to the
development of high potent and more efficient Bt-based products and Bt crops. On
the other hand, pyramiding two or more Bt toxins with different modes of action has
been considered as an effective strategy for delaying resistance (Ferré et al. 2008).
Therefore, future studies can be focused on the mode of action and binding behavior
of Bt toxins in the midgut of susceptible larvae. Genetic manipulation of the Bt
toxins with enhanced and broadened insecticidal activity must be taken into
consideration.
10.17 Conclusion
B. thuringiensis as one the most successful microbial control agents for controlling
agricultural, forestry, medical and veterinary pests, is being used as part of integrated
pest management strategies. Commercial Bt products are used worldwide, as well as
in Iran. Based on the several extensive Bt screening projects carried out in Iran, the
high rate of Bt recovery from different ecosystems, depending on the geographical
region, demonstrates the richness and variability of biological control agent
resources. In these screenings, Iranian Bt isolates were found to be highly toxic to
different species within Lepidoptera, Coleoptera, and Diptera, pointing to the fact
that the Iranian Bt strains have a huge potential to control different agricultural pests.
430
A. Khorramnejad et al.