Transcript Cynthiana Propagation

Propagating
Cynthiana/Norton
Grapes
Basic Overview and MTSU Research Update
Tony V. Johnston, PhD, CFS, MS, MPH
Professor
School of Agribusiness and Agriscience
Middle Tennessee State University
Overview
• Propagation Basics
• Dormant (Hardwood)
Propagation
• Softwood Tip
Propagation
• Bench Grafting
• Tissue Culture
• From the Greenhouse
to the Vineyard
• Hardwood
Propagation Issues
• Propagate or Not?
• MTSU Research
Updates
• Endophytes and their
Impacts
• Current and Future
MTSU Research
Goals
• Research Credits
• Questions
Propagation Basics
• Always use clean, sharp knife and sterile
rooting medium (no fertilizer)
• Never use pruning shears or knife used to
cut other plants without prior sterilization
– Can transfer infectious viruses, mold, etc.
• High humidity environment is essential (no
roots!)
• 75oF minimum temp at all times
• Good light– use a grow light if necessary
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Dormant (Hardwood)
Propagation
Traditional method
Pencil diameter, 1-1.5 ft long
Must be viable wood (green pith)
Collect after vines are completely dormant
Remove all shoots and leaves
Set in sand, vermiculite/soil, or potting soil
– Largest diameter end down; dip in rooting
hormone (e.g. Roottone® or Hormonex®)
• Constant temperature above 60oF
Softwood Tip Propagation
– Collect cuttings anytime during growing
season
– Cut 3-4 inches from growing tip end
– Strip all but 3-4 leaves on growing end of
shoot
– Dip end in rooting hormone (e.g. Roottone®
or Hormonex®)
– Place in sterile sand, vermiculite or peat moss
– Keep moist but not soaking
– Minimum temp 72oF; warmer better
Bench Grafting (pt. 1)
• Dormant propagation technique
• Not widely employed at home
• Essential for protection of non-phylloxera
resistant varieties of grapes
• Must have rootstock and scion
• Both rootstock and scion must be very
similar in diameter
Bench Grafting (pt. 2)
• Both rootstock and scion are cut in
identical ways (slant or z)
• With machine, omega cut can be made
• Join at cut, aligning carefully
• Wrap union with grafting tape and allow to
heal
• Transfer to ground after viability is
established
• Do not remove grafting tape!
Tissue Culture (pt 1)
• Definitely not a home-based technique
• Sterile environment and technique
essential
• Plant cells are extracted from carefully
washed and sterilized plant parts (leaf,
stem or root)
• Place cells on specialized growth medium
• Cells grow into undifferentiated (nonspecialized) “callus”
Tissue Culture (pt. 2)
– Callus is then transferred to different
medium and conditions adjusted to
stimulate the development of roots and
stems
– Hormone and medium composition is
different for almost all plants
– End result is a true clone– an exact
replica of the source cells
Greenhouse/Lab to Vineyard
• Propagated vines should be planted
outdoors ASAP
• Vines don’t do well in a greenhouse
environment
• Best to plant in spring after last frost
• Two to three years to first harvest
Cynthiana/Norton Hardwood
Propagation Issue
• 20 – 40% success rates typical
– Success = viable plant
• Common result: leaf production without
root development
• Must compensate by trying to root
hundreds to get tens of successes
– Time and resource intensive with low return
on investment
Propagate or Not?
• Commercial plants are available to
purchase
• Best to purchase from nurseries “close” to
Tennessee
• If you have a “facility” in which to grow out
your cuttings, home propagation is
inexpensive, albeit time consuming and
inefficient
– Can be significantly more cost effective than
purchasing vines from a nursery
MTSU Research Update
• Focused on finding ways to better
propagate Cynthiana/Norton grapes
• Both hardwood and tissue culture
techniques being studied
• A follow-on to research conducted in
Honduras
– Enormous difficulty in rooting dormant vines
– Complete failure of tissue culture efforts due
to mold growth on plates
MTSU Hardwood Propagation
Research
• Evaluating:
– Timing of hardwood collection (12 month
project)
– Efficacy of rooting hormone use
– Timing of planting of hardwood propagated
plants in the vineyard
• Is dogma correct?
MTSU Tissue Culture Research
• Initial attempts to culture Cynthiana/Norton
grapes totally unsuccessful
• 100% failure to stimulate mold-free callus
formation
• While using different antifungal
compounds and trying different presampling techniques discovered an
endophyte in the vines
What is an Endophyte?
• Organisms, often fungi and bacteria, that
live between living plant cells
• Relationship with the plant varies from
symbiotic to bordering on pathogenic
• Extremely unusual and valuable organic
substances are produced that may assist
in helping solve not only human health, but
plant and animal health problems
– From
http://plantsciences.montana.edu/facultyorstaff/faculty/strobel/endophytes.html
Endophyte Impact
• Being a mold and living between the cells,
it always contaminates tissue culture
medium
• Must eliminate endophyte to allow for
tissue culture
• Role of endophyte in Cynthiana/Norton
grapes unclear
• May play a role in the difficulty to
propagate via hardwood culturing
Current MTSU Research
Outcomes and Focus
• MTSU research has resulted in technique
to eliminate endophyte without killing plant
tissue
• Now researching techniques to take
endophyte free tissue to plantlet
development
• Looking to create line of endophyte free
plants
Future MTSU Research
• Focus on
– Exploration of role of endophyte in
Cynthiana/Norton grapevines
– Determine whether endophyte-free
Cynthiana/Norton are viable and can remain
endophyte-free once planted
– Determine productivity of potentially
endophyte-free Cynthiana/Norton
– Determine quality of fruit produced by
potentially endophyte-free Cynthiana/Norton
– Identify Cynthiana/Norton endophyte
Research Credits
• Dr. John DuBois, MTSU Biology Professor
• Mr. Shannon Smith, MTSU Biology
Graduate Student
• Ms. Amanda Leachman, MTSU Biology
Undergraduate Student
• Ms. Aimee Wilson, MTSU Biology
Undergraduate Student
Questions?