Effects of Transgenic Rootstocks on Growth of Scion Cultivars in Apple

Although cultivation of GM crops has been steadily increasing, the commercial cultivation of GM fruit tree is still very limited and reports of field trials on GM fruit trees are rare. So far, the only GM tree species that are commercially cultivated are GM poplar with insect resistance grown in China and GM papaya with virus resistance grown in USA and China.

Researchers from the Swedish University of Agricultural Sciences are investigating the effects of transgenic apple rootstocks on growth, flowering and fruit quality of non-transgenic scion cultivars grafted onto these rootstocks. The rootstocks express the rolB gene, a well documented rooting related gene and has been proved to stimulate rooting in different plant species when over expressed. In apple production, dwarfing rootstocks are commonly used for achieving high production efficiency.

The researchers, reporting in the journal Transgenic Research, found that all rolB transgenic rootstocks significantly reduced vegetative growth including tree height regardless of scion cultivar, compared with the non-transgenic rootstocks. Flowering and fruiting were also decreased for cultivars grown on the transgenic rootstocks in most cases, but the fruit quality was not clearly affected by the transgenic rootstocks. The use of GM rootstocks in combination with non-transgenic scion cultivars may circumvent the food safety issue if the transgenes or their products are not present in scion fruits. 　

The original paper is available at http://dx.doi,.org/10.1007/s11248-010-9370-0