BREEDING PIERCES DISEASE RESISTANT WINEGRAPES

• Author(s): Tenscher, Alan; Walker, Andrew;
• Abstract: Strong and continued progress is being made in breeding Pierces disease (PD) resistant grapes. Fruit quality has markedly improved while maintaining high levels of PD resistance. We continue to make many crosses, produce thousands of seeds, and plant about two thousand plants in the field each year. We have been increasing the number of seedlings and high fruit quality selections we test under our greenhouse screen. This screening is very severe, but material that passes the screen is reliably resistant and dramatically restricts Xylella fastidiosa (Xf) movement. We are also co-screening for powdery mildew resistance. The heritability of Xf resistance from a range of resistant southeast US (SEUS) cultivar and species parents is not consistent some parents produce few resistant offspring, while others produce a large percentage making careful parental screening very important. We have been able to expand our Xf screening the past few years and have tested hundreds of potential parents before we need to make breeding decisions the following year.
• Publication Date: Dec 2004
• Journal: 2004 Pierce's Disease Research Symposium