Living Ash Project
Screening and selection of common ash
(Fraxinus excelsior)
for resistance to Chalara fraxinea.
Dr Jo Clark
Earth Trust
[email protected]
Overview
• Who we are
–
–
–
–
Earth Trust
Forest Research
Future Trees Trust
Sylva Foundation
• What we’ve got
– 20 years tree breeding for timber characteristics
– Large collection of ash genotypes
• What we’re doing
Forest Reproductive Material
• Source identified: no selection
• Source selected: plus trees; seed stands
• Qualified: clonal seed orchards
• Tested: for a specified trait
Source Selected FRM
- plus tree
A tree selected from within
stand that shows outstanding
form and vigour, compared to
others in the stand.
Qualified FRM –
clonal seed orchard
3 year old clone. Scion material
is collected from the plus trees,
and grafted on to rootstocks. The
researcher's hand indicates this
years growth.
Tested FRM
The seedling seed orchard is rogued after
many years of assessments for form, vigour,
gender and phenology, leaving the best
trees to produce seed
Living Ash Project
• 6 work programmes to screen the various
categories of FRM
• To find 400 tolerant individuals
• To secure on public forest estate and make
freely available
WP 1 - Citizen Science
• Most ash are source identified – no
improvement
• 126 millions trees in woodlands and
hedgerows
• Public participation ~
www.livingashproject.org.uk
Screening source identified trees
WP 2 – screening orchards and trials
• 26 various trials across the whole UK
• Visually screening all each year
• But no tolerant trees found until Chalara
gets there……
Yellow = provenance trial (source identified)
Blue = clonal seed orchard (qualified)
Green = seedling seed orchard (tested)
WP 3 – screening tested seedlings
WP 4 – screening plus trees
WP 5 - Correlation with senescence
0: Dark green
1: Dark green with
yellowing leaf nerves
2: Green with yellow
spots on leaflets
3: Yellowing leaflets
4: Completely yellow leaf
5: No leaves
Class: 0
1
2
3
4
Courtesy of Lea McKinney
WP 6 - Tissue Culture
a)
c)
b)
Photos courtesy
Trevor Fenning and
Shelagh McCartan,
Forest Research
a) 3 week old excised
embryos on filter paper
b) 1 day old embryos on
agar
c) same embryos two
weeks later
What next
• All WP will feed in tolerant trees (years 1-5)
• Scion material will be collected and grafted (year 4-5)
• Screen tolerant trees for markers for resistance
(years 4-5)
• Bulk up for establishment on public forest estate
(year 5)
• Cryopreservation of tissue cultures (years 4-5)
• Start another breeding programme using tolerant
genotypes (2018 and on)
Thank You …..
Landowners