Winter is not a quiet time for the grape breeding and enology project. Although we shrink to skeleton staff for a few months at the Horticultural Research Center, there is still a buzz of activity in the winery, laboratory, greenhouse and vineyards.
Grape seeds were extracted at harvest from the crosses we made in June. Nearly 11,000 seeds were produced which needed to be removed from the berries, washed, and stored. For an even germination, the seeds need stratification, basically a cold damp treatment that mimics winter conditions under the snow.
Monitoring winter damage in the vineyard is important for understanding which potential new varieties are capable of surviving the winter, but for also helping commercial growers make pruning decisions. Jenny and John Thull spend many hours examining the dormant buds under microscopes to determine which buds are alive and will leaf out in the spring. Additionally, vine cuttings are collected for propagation. Grapes do not grow true from seed, which is a benefit for the breeding program, but a hindrance for propagation. However, grapes grow very easily from cuttings which can be coaxed to grow roots in a warm environment or can be grafted on to an established rootstock. The project replicates vines by cuttings to send to nurseries and universities for testing purposes, and to expand advanced material from one vine to many for robust evaluation.
The winery is also a busy during winter. Over 75 research wines were produced in 2016. These will need to be stabilized, bottled, and then evaluated by the sensory panel. Drew Horton, who leads the winemaking project, will also be conducting analyses of the wines and stored juice samples to examine the acid content, sugar content, percent alcohol and other traits of commonly planted varieties and advanced plant breeding lines.
Greenhouse and laboratory experiments are ongoing during the winter months. PhD candidate Soon Li Teh is researching genetic resistance to powdery mildew and is conducting growth chamber experiments in St. Paul. Laise Moriera, a technician on the project, has been implementing protocols for embryo rescue, a specialized technique used in breeding seedless table grapes. Also, greenhouse experiments have been conducted in conjunction with collaborators in the Entomology Department to study the genetic resistance to phylloxera in a hybrid grape population. Integral to that project are Bill Hutchison, Eric Burkness, Grace Watson, Lu Yin, and everyone previously listed.
Having a team of hard-working and ambitious people who love grapes and wine propels the research at the University of Minnesota. One advantage of winter research is that that the daily maintenance of vines subsides and allows other projects to come to the forefront. The wines are done fermenting, and soon the team will get rewarded by analyzing the efforts from the previous year.