The primary challenge for Florida grape production continues to be Pierce’s disease (PD) and various fungal diseases. The main strategy to combat these diseases is interspecies gene transfer.
The bacterium responsible for PD, Xylella fastidiosa, thrives in hot, humid climates and has proven resistant to all control strategies except genetic improvement. With interspecies gene transfer, researchers insert genes from one grape variety into another to boost desirable traits, resulting in a modified plant that contains only grape genes. Such plants are more acceptable to consumers than plants produced via cross-species gene transfers, and may be more amenable for federal agency approval.
One recent study showed that it was possible to significantly enhance the fungal disease resistance of ‘Thompson Seedless’ grapes by inserting a gene from the ‘Chardonnay’ grape. Other studies have aimed to enhance the resistance to PD in V. vinifera grapes and their hybrids. Another project focuses on development of seedless, muscadine cultivars resistant to fruit rot.