Download Marker-assisted selection of a new mapping population

VitisGen Breeding Team
The VitisGen Breeding Team is responsible for maintaining the
mapping populations selected to use in the VitisGen project and to
supply the genotyping and phenotyping centers plant material. Data
generated from the genotyping and the phenotyping centers will be
integrated with feedback from trait economics and consumer surveys.
Breeders will use these integrated analyses to select individuals
segregating desirable traits from each population. These selections will
be planted in vineyards and used in future crosses. Breeders will
benefit from these analyses because they can discard plants with
undesirable traits before transferring them to the vineyard. This will
preserve valued space in their vineyards and reduce production costs.
Marker-assisted selection of a new mapping population
Postharvest, seeds from one
of the selected VitisGen mapping
populations were removed from
the flesh of the grape and cleaned.
Prior to planting, the grape seeds
were stratified by being placed on a
damp paper towel in a plastic bag
and incubated at 32°F for three
months. Stratification is a process
that simulates the natural winter
conditions required for
germination.
Fifty seeds were
planted in each flat and
the temperature of the
greenhouse was set
high (~82°F) to induce
germination
Two weeks after planting,
the cotyledons of
germinated seedlings
have fully expanded.
One month after planting,
seedlings have initiated
several leaves.
Approximately two months after seeds were first planted,
leaves were harvested from seedlings for genotyping-bysequencing (GBS) or SSR marker analysis.
The Genotyping Team sent
pre-labeled 96-well plates to each
breeder to collect leaf samples for
genotyping-by-sequencing (GBS)
and SSR marker analysis.
Steve Luce (Research Support Specialist) harvests
dime-sized leaves from each seedling and puts each
sample into a specific position in a 96-well plate. To
track each sample, Bruce Reisch (Project Director and
Breeding Team leader) records the plant identification
number, the 96-well plate identification number, the
location of the seedling in the flat , and the leaf
position in the 96-well plate. The plates containing the
leaf samples are shipped back to the Genotyping Team
for DNA extraction and subsequent GBS or SSR marker
analysis (see Genotyping Workflow).
The plants are
transferred to a nursery
for the summer. SSR
marker analysis and
natural disease infection
of plants in the nursery
will be used to select
disease resistant plants.
Selected plants will be
planted in the vineyard
next year for further
analyses.