Field Trials with Genetically Modified Plants- In case of plants conventional breeding cell and tissue culture and genetic engineering share some major similarities in the method of generation the magnitude and type and the methods of detection of the genetic changes but they do differ in some important features.

Usually products of both tissue culture and genetic engineering are subjected to few to many back crosses and selection and before that they both are subjected to tissue cukture.

Transgeneic varieties of crops expressing cry genes for insect resistance are in commercial cultivation. Cry proteins are rapidly degraded by the stomach juices of vertebrates, but they could have harmful effects on nontarget insect species, e.g., honeybees.

Oilseed rape (B. napus) expressing C_pTI (Cowpea trypsin inhibitor), chitinase and β-1, 3- glucanase has been used for assaying the impack of these genes on honey bees. Chitinase did not affect learning performance, while C_pTI and β-1, 3-glucanase had detrimental effects.