Biotech Updates

First Report of Stacked Traits in Biotech Tomato in Thailand

May 2, 2013

Virus diseases are one of the important limiting factors in tomato production in Thailand. Genetically modified (GM) tomatoes can be used to effectively control viral infections. However, resistance in transgenic tomato is shown to be virus specific. Gene stacking is an alternative approach to develop tomato lines with multiple viral resistances. 

Thai scientists from Kasetsart University stacked two genes, the CMV replicase and CaCV nucleocapsid protein conferring resistance to CMV and CaCV, respectively, into cultivated tomato. These two genes were previously transformed to Seedathip 3 and Seedathip 4 varieties, respectively, by Agrobacterium. Reciprocal crossing between transgenic Seedathip 3 and Seedathip 4 tomatoes resulted in transgenic segregation in progeny seedlings as detected by polymerase chain reaction (PCR) using specific primers for both genes. Out of 685 tomato lines (F1) derived from crossing, 247 lines (36.06%) contained both transgenes, 172 lines (25.11%) contained single transgene and 266 lines (38.83%) were without transgene.

This study which was conducted under greenhouse condition showed that stacking of transgenes in tomatoes can be successfully accomplished by reciprocal crossing. Tomato lines with stacking genes showed no significance difference on horticultural characters as compared with singly transformed lines and original parental lines.

Source: Paniti, 2012 Gene Stacking in Transgenic Tomato Resistance to Viral Diseases. Agricultural Sci.J. 43 (2-3):311-324.