If a stacked variety of a transgenic plant is obtained by crossing the two transgenic plants, transgenic for different traits, does the stacked variety contains new events apart from those present in the parental plants?
If you are working with T-DNA insertions, they are generally stable and shouldn't produce new events after crossing.
Thank you Hugo Alnso-Cantabrana Sir, but I'm working with the plant resulting from the crossing of two varieties which were transformed by microparticle bombardment method using plasmids, so what could be the status in this stacked variety?
Well, T-DNA is also delivered in a plasmid via agrobacterium infection or otherwise... I don't think the transformation method makes a difference, but if you were using viral vectors then they may not be that stable.
Madhu, I don't understand how can a new trait appear from something that doesn't contain it. But here is some thoughts about your question:
If the plants were transformed and you checked that their traits are there, then when you cross these transgenic plants, each with different traits, you are going to have these traits in your progeny. The probability of this event to happen will depend if the parents, each of which with a different transgene, have it in homozygosity or hemizygosity. So, in the end you will have 100% of your progeny stacked if both parents are homozygous for the traits.
It all depends on what you are doing and how do you design your gene-of-interest cassette. It could have new events.
For example,
Transgenic plant A with: Cre enzyme gene
Transgenic plant B with cassette: 35S-lox-(stop)-lox-GUS
When you cross these two plants, and the progeny have both transgenic cassettes, then the Cre gene can delete the 'stop' fragment in-between the 2 lox sites. This leads to the fusion of 35S promoter and GUS gene. The progeny can turn blue when assay in GUS solution, while both parents will not turn blue.
Kian Eghrari Moraes Sir, that is not what I mean,of course, no new genes will be produced but when two plants transgenic for different transgenes are crossed, there is a chance of rearrangement of positions of these genes, mostly during meiosis ( during gamate formation), so they may create new events ( and not new genes).