Issue link: http://winesandvines.uberflip.com/i/528936
July 2015 P R A C T I C A L W I N E R Y & V I N E YA R D 67 W I N E G R O W I N G clonal selections had early or late bud break. The study was complicated by the movement of Grapevine Red Blotch Associated Virus (GRBaV) into one block, which resulted in removal of that data from the analysis. Disease symptoms were generally not found in the other four blocks, and if they were, care was taken not to use the vine as a data vine. The fruit data taken from infected vines were con- sistent with other studies that found GRBaV reduces sugar accumulation. Genetic variation Grapevines are typically propagated vegetatively from cuttings, leading to identical copies of the grapevine vari- ety through each successive generation. The DNA in cells of grape- vine buds, and those of all liv- ing organisms, are constantly mutating at a very slow rate. Most of these mutations are repaired, others damage the buds, and occasionally these mutations result in a notice- able and beneficial change such as a shoot with looser a " ab " ab " c " ab " bc " abc " a 600 500 400 300 200 100 0 10 30 31 40 55 79 80 89 Heritage Zinfandel Selec on ID Cluster Weight (2013) 10 30 31 40 55 79 80 89 Heritage Zinfandel Selec on ID Soluble Solids (2013) Cluster weight (g) °Brix 27 26 25 24 23 22 21 20 ab abc bc bc bc bc c a Figure 1. Average cluster weights of eight Zinfandel selections were evaluated at harvest in 2013 at the Oakville Research Station. Means with the same letter were not different. a " ab " ab " c " ab " bc " abc " a 600 500 400 300 200 100 0 10 30 31 40 55 79 80 89 Heritage Zinfandel Selec on ID Cluster Weight (2013) 10 30 31 40 55 79 80 89 Heritage Zinfandel Selec on ID Soluble Solids (2013) Cluster weight (g) °Brix 27 26 25 24 23 22 21 20 ab abc bc bc bc bc c a Figure 2. Average soluble solids of eight Zinfandel selections in 2013. Means followed by the same letter are not different. Selec on ID Origin Virus Therapy Heritage 10/FPS 10 Sonoma None Heritage 30/FPS 2 FPS Zinfandel 2 None Heritage 31/FPS 24 Sonoma None Heritage 40/FPS 3 FPS Primi vo 3 Heat 59 days Heritage 55/FPS 14 Napa None Heritage 79 Santa Clara None Heritage 80 San Joaquin None Heritage 89 El Dorado None