(Keshavarzi et al. 2005; Shojaaddini et al. 2010; Marzban 2012a; Sarrafzadeh 2012;
Salehi Jouzani et al. 2015b; Marzban et al. 2014, 2016; Maghsoudi and Jalali 2017),
and utilization of Bt in IPM programs (Moazami 1997, 2004, 2005; Marzban et al.
2009; Magholli et al. 2013; Kalantari et al. 2014; Abedi et al. 2014; Nazarpour et al.
2014). These studies led to the development and application of Bt-based products in
Iran. Based on the national Plant Protection Organization (PPO) report, the annual
use of Bt-based bio-insecticides in Iran was about 200,000 ha (Personal communication). In the following sections, the significant research studies on Bt in biological
control in Iran are listed and discussed.
10.7 Isolation, Natural Occurrence, and Geographical
Diversity
Regarding the importance of Bt in biological control, several studies have focused
on the isolation of Bt from diverse sources in different geographical regions worldwide (Bravo et al. 1998; Bel et al. 1997; Uribe et al. 2003; Djenane et al. 2017;
Boonmee et al. 2019). In Iran also, researchers have attempted to collect native Bt
strains from different habitats (Keshavarzi 2008; Salehi Jouzani et al. 2008b, c;
Seifinejad et al. 2008; Nazarian et al. 2009; Aramideh et al. 2010; Senfi et al. 2012;
Shojaaddini et al. 2012; Khojand et al. 2013; Moazamian et al. 2016; Khorramnejad
et al. 2018). It has been clearly demonstrated that Bt is a ubiquitous bacterium. In this
context, several Iranian authors attempted to correlate the natural occurrence of
Iranian Bt strains isolated from diverse environments with ecological distribution.
The extensive screening program performed in different parts of Iran led to the
establishment of many Bt collections at universities or research institutes. In 2008,
Keshavarzi isolated 127 Bt strains from 514 samples collected from soil and dead
larvae in diverse environments including high altitude mountains, non-cultivated
lands, beaches, agricultural lands, urban locations, and forests, in Khorassan,
Lorestan, Tehran, Ghazvin, East Azarbaijan, West Azarbaijan, Mazandaran and
Hamedan Provinces. The relationship of Bt occurrence with vegetation was
addressed. It was found that a high level of vegetation is not a requisite for high
Bt occurrence. B. thuringiensis subsp. kurstaki was reported as the most frequent Bt
strain in the studied Bt collection (Keshavarzi 2008). In the same year, a massive
screening program funded by the Iranian Agricultural Research and Education
Organization (AREO) was carried out as a collaboration between different Iranian
institutes (Agricultural Biotechnology Research Institute of Iran (ABRII) and Plant
Protection Institute of Iran) and universities (Zanjan University and University of
Tehran). In this screening, 2292 soil samples from agricultural fields in 28 provinces
located in the different geographic and climatic regions were collected (Salehi
Jouzani et al. 2008b). This is one of the most important countrywide screenings
carried out in Iran in terms of the number of provinces, samples and more importantly, the identification of different cry genes. Based on the isolation results, 128 Bt
408
A. Khorramnejad et al.
Salehi Jouzani et al. 2015b; Marzban et al. 2014, 2016; Maghsoudi and Jalali 2017),
and utilization of Bt in IPM programs (Moazami 1997, 2004, 2005; Marzban et al.
2009; Magholli et al. 2013; Kalantari et al. 2014; Abedi et al. 2014; Nazarpour et al.
2014). These studies led to the development and application of Bt-based products in
Iran. Based on the national Plant Protection Organization (PPO) report, the annual
use of Bt-based bio-insecticides in Iran was about 200,000 ha (Personal communication). In the following sections, the significant research studies on Bt in biological
control in Iran are listed and discussed.
10.7 Isolation, Natural Occurrence, and Geographical
Diversity
Regarding the importance of Bt in biological control, several studies have focused
on the isolation of Bt from diverse sources in different geographical regions worldwide (Bravo et al. 1998; Bel et al. 1997; Uribe et al. 2003; Djenane et al. 2017;
Boonmee et al. 2019). In Iran also, researchers have attempted to collect native Bt
strains from different habitats (Keshavarzi 2008; Salehi Jouzani et al. 2008b, c;
Seifinejad et al. 2008; Nazarian et al. 2009; Aramideh et al. 2010; Senfi et al. 2012;
Shojaaddini et al. 2012; Khojand et al. 2013; Moazamian et al. 2016; Khorramnejad
et al. 2018). It has been clearly demonstrated that Bt is a ubiquitous bacterium. In this
context, several Iranian authors attempted to correlate the natural occurrence of
Iranian Bt strains isolated from diverse environments with ecological distribution.
The extensive screening program performed in different parts of Iran led to the
establishment of many Bt collections at universities or research institutes. In 2008,
Keshavarzi isolated 127 Bt strains from 514 samples collected from soil and dead
larvae in diverse environments including high altitude mountains, non-cultivated
lands, beaches, agricultural lands, urban locations, and forests, in Khorassan,
Lorestan, Tehran, Ghazvin, East Azarbaijan, West Azarbaijan, Mazandaran and
Hamedan Provinces. The relationship of Bt occurrence with vegetation was
addressed. It was found that a high level of vegetation is not a requisite for high
Bt occurrence. B. thuringiensis subsp. kurstaki was reported as the most frequent Bt
strain in the studied Bt collection (Keshavarzi 2008). In the same year, a massive
screening program funded by the Iranian Agricultural Research and Education
Organization (AREO) was carried out as a collaboration between different Iranian
institutes (Agricultural Biotechnology Research Institute of Iran (ABRII) and Plant
Protection Institute of Iran) and universities (Zanjan University and University of
Tehran). In this screening, 2292 soil samples from agricultural fields in 28 provinces
located in the different geographic and climatic regions were collected (Salehi
Jouzani et al. 2008b). This is one of the most important countrywide screenings
carried out in Iran in terms of the number of provinces, samples and more importantly, the identification of different cry genes. Based on the isolation results, 128 Bt
408
A. Khorramnejad et al.