Contents - Faperta

Deployment of Insect-Resistant Transgenic Crops for Pest Management 323
deregulated for cultivation by farmers. Transgenic Bt rice released in Iran in 2004 was
grown on over 4,000 ha in 2005 ( James, 2007).
Grain Legumes
Groundnut plants with the cry1Ac gene have shown resistance to lesser corn stalk borer,
Elasmopalpus lignosellus (Zeller) (Singsit et al., 1997). Chickpea cultivars transformed with
the cry1Ac gene have been found to inhibit feeding by H. armigera (Kar et al., 1997; Sanyal
et al., 2005). Transgenic pigeonpea plants with cry1Ab (Gopalswamy et al., 2003; Sharma,
Lavanya, and Anjaiah, 2006) and cry1E genes have also been developed (Surekha et al., 2005).
Potato
Transgenic potato plants containing cy1Ab and a truncated gene cry1Ab6 resulted in less
damage by the potato tuber moth, Phthorimaea opercullela (Zeller) (Arpaia et al., 2000).
Picentia and the wild species Solanum integrifolium Poir. have also been transformed with
four mutagenized versions of Bt 43 belonging to cryIII (Innacone, Grieco, and Cellini, 1997).
The cry5-Lemhi Russet and cry5-Atlantic potato lines have shown up to 100% mortality of
fi rst-instar larvae of the potato tuber moth (Mohammed et al., 2000). Transgenic potato
expressing the oryzacystatin (OCI) gene resulted in up to 53% mortality of L. decemlineata
(Lecardonnel et al., 1999). Some of the potato cultivars have been tested on farmers’ fi elds
and released for cultivation.
Vegetables
Tomato plants expressing cry1Ab and cry1Ac genes are effective against the lepidopteran
insects (Fischhoff et al., 1987; Delannay et al., 1989; Van der Salm et al., 1994). Tomato plants
with the cry1Ac gene are highly effective against H. armigera (Mandaokar et al., 2000).
Transformed brinjal plants have also shown signifi cant insecticidal activity against the fruit
borer, Leucinodes orbonalis (Guen.) (Kumar et al., 1998). A synthetic cry1C gene in broccoli
provides protection from cabbage looper, T. ni, cabbage butterfl y, Pieris rapae L., and diamondback
moth, P. xylostella (Cao et al., 1999). Chinese cabbage, Brassica campestris subsp.
parachinensis with cry1Ab or cry1Ac genes is resistant to P. xylostella (Xiang et al., 2000).
Deployment of Transgenic Plants for Pest Management
Transgenic crops will have similar effects on insect damage and population dynamics as
the insect-resistant varieties derived through conventional breeding (Sharma and Ortiz,
2002). The effects of transgenic resistance are expected to be much higher than those of
conventional varieties, and such effects should be cumulative over time. Models predicting
the effect of insect-resistant cultivars on insect abundance have been developed for
several insect pests (Luginbill and Knipling, 1969; Knipling, 1979; Sharma, 1993; Sharma
and Ortiz, 2002). As the insects are continuously exposed to the transgene product in
genetically modifi ed plants, there are distinct possibilities of a different type of effect on
the population dynamics of the target and nontarget pests. There is a need to develop a
better understanding of the fi eld performance of insect-resistant transgenic cultivars