Low budget breeding and seed production with special attention to a seed orchard proposal of ash (Fraxinus)
Gerry enquired to the discussion group about an ash (and sycamore) seed orchard, and I felt it would be a shame for the Group to leave Gerry without a reply. Gerry is the enthusiastic founder of this discussion group and a stubborn believer that things can benefit from discussion in this form, so he deserves an answer if anyone does. Gerry's question is at the bottom.
As a background some links connected to Fraxinus (ash, mostly Fraxinus exelcior),
among other bad habits the discussion group facility breaks links so long links
have to be glued!
There is an EU cooperation which has resulted in a book and a web with
another EU-cooperation has resulted in provenance trials including Ireland.
And an Irish pamphlet
From a more general botanic point of view
Euforgen on fraxinus
has made an own webside focusing on low budget breeding and ash, but mainly in Swedish
There is nowadays a disease (probably Chalara fraxinea, fungi spread by spores) which spread fast from the east and is a severe threat to ash trees in Sweden (identified in Sweden 2003, first occurrence perhaps 2000) and elsewhere, so there may be considerable hesitation to invest in seed production units of Ash in northern Europe now. It has occurred in Poland and Lithuania since a decade. In Lithuania it seems to have attacked around 60% of the ash forest and in Poland 80%. It has spread extremely fast. In Sweden it was first observed in the east but now covers the whole distribution area. The near future prognosis is bad, many trees are likely to die, sometimes whole stands seem dying. Swedish scientists advice against Ash planting at the moment. The disease exists 2008 in Denmark, Germany, Austria, Slovenia and Norway.
According to Swedish investigation in Snogeholm, there is a difference among the clones, but no resistant ones are found. A genetic cure against the decease seems unlikely so far, thus selection of unharmed genotypes will probably only have marginal effect, but may still be worth it when more has been learned about the disease. In Danish seed orchards it is said that inventories has been done and seed collection is only made from genotypes which appear less harmed.
A Swedish link to the disease:
Forest history of Ireland
Around 7000 years ago 75% of Ireland was forest
Year 1900 around 1% of Ireland was forest
By 1990 around 7% of Ireland was forest, lowest in main Europe
By 2007 around 12 % is forested and the forest share increases
Ireland is to get a compliment for its efficient and successful forest reforestation since 1990! I am sure David Thompson and Gerry Douglas have had an important role in that!
Ash is a native species and has 3% of the current forest, but the bottle-neck in forestation perhaps means that very little is true "natural" and perhaps there is now special natural conservation reason to use ash. The establishment of Ash is supported by considerable subsidies and it is a question if those will survive the establishment time for seed orchards.
There is an EU-funded provenance trial which now can give hints of sources.
Ash stands are genetically diverse but rather similar and
with a lot of gene flow among populations according to the EU project, thus
where seems little reason to try to conserve a mosaic of assumed land races of
Ireland. The pollination seem generally dominated by within stand, thus a mature
seed orchard is expected to produce sufficient amounts of pollen for
pollination. Perhaps the surrounding pollen is enough for seed production in
Ireland, and as the origin probably does not matter much, contamination does not
seem a big problem for first generation orchards but may rather help early seed
Early flushing is to be avoided on Ireland but ash is a late flusher so that may not be a problem.
There are some ash seed orchards on Ireland, Coillte established a seed orchard with grafts of phenotypic selections 2002. It covers 5 ha and comprises 100 clones. It does not produce seeds yet, For 27 of the clones seed production has been observed.
Ash is used for some particular purposes as to produce a hockey type of stick used in an Irish game called "hurling". The rest of the tree goes often for firewood. Because players go through several sticks per year there has always been a demand for the right kind of butt log (with buttress roots) to produce good sticks. Unfortunately this demand has resulted in claims of big money paid for perfect logs which only happens occasionally. Several people have planted ash plantations with the idea of making big money, but usually the stands do not work out and the crop is sold for firewood.
A few seed production
figures by enquiries of Gerry Douglas
Ash SO in Germany 25-45 yr old produced an average of 47 Kg of seeds/ha/year over 4 yrs. Results from Denmark from 60 yr old ash SO produced over 200 Kg/ha/yr.
An example of an ash seed orchard in Sweden
Sweden has one clonal ash seed orchard. To assure Swedish seed sources (much material used originated in Poland and Germany) and adaptations one seed orchard with 5 hectares was established 91/92 with 100 clones selected from 25 stands in southern. Sweden, average lat 56°11.and alt 113. The clones are represented by 20-60 grafts (ramets). The spacing at establishment was 3.5*3.5 m. The intention was to thin this down. It was not known when establishing the seed orchard if the clones were male or female (the selections where in rather dense forests and the reproductive function was difficult to evaluate at selection, in ash males seem more often preferred to females by selectors, and therefore probably overrepresented), but it is registered now and it seems to be more males (Lars-Göran Stener can give exact figures). The establishment was not quite successful so a fraction of the trees has not developed well, but a fraction of the trees develop well. Now the seed orchard is attacked by the disease and an number of trees are dead or dying. Some seeds have been collected (probably by Claes Ohlsson) and plants produced and marketed by Ramlösa plantskola (contact Max Jensen), who probably can give an opinion about the seed quality and if the pollination seem satisfactory, but the guess is that it did. Seed production has developed and some trees now produce considerable amounts of seeds. To get seeds at accessible heights and stimulate a high seed production which is easy to collect it is recommended to prune the orchard, but it is unlikely anyone will invest in management of the orchard. If survival had been good and up to expectations at establishment, thinning would have been desirable, but now it is probably not needed from a seed production point of view. Name: Snogeholm situated at lat 55°32' alt 50 Registration number in the national list :FP-870. The background for the establishment is in a Swedish report. The plant demand on ash is low (say 50000 plants annually) and it is predicted to decrease or vanish completely because of the spread of the disease described on this web. One reason it is difficult to comment on the production of the seed orchard, is that the plant demand is low, so there is no reason to harvest all seeds the seed orchard may actually produce, and because of disease, Swedish ash planting is predicted to decrease from low to lower. The clonal variation of the disease has been registered.
I would like to focus attention on low budget breeding (as opposite to high budget breeding which we can work with for e.g. Norway spruce and Scots pine in Sweden). The borderline to low budget can be discussed and depend on many factors, but I suggested some years ago to exploit the idea for Swedish ash. Four million plants of ash in Ireland annually justifies more than low-budget options, but the prognosis may look uncertain because of the disease and because it is dependent on political decisions (degree and form of subsidies)
Dag L has made an own website focusing on low budget breeding and ash, but mainly in Swedish
Grafted seed orchards are not easy to deal with, and fail sometimes, in particular if the owner is not well motivated to invest rather much and rather sustainable during decades and have not easy access to appropriate competence. There are economical advantages if wood production, testing, gene conservation and seed production can be combined using the same plantations. I developed my low-budget ideas at some occasions, latest at the low input breeding conference in Turkey 2006, see a slideshow
and the proceedings paper
Low-budget maybe focus more interest in countries like India, where I discussed the concept:
Difficulties with the grafts in a
low budget situation:
* Grafts are more sensitive and exposed to injuries than seedlings;
* Grafts are more expensive and more technically complicated to make than seedlings;
* Grafts are more difficult to manage and requires more supervision than seedlings;
* Grafts do not produce valuable timber, just seeds, and in the long run probably not more seeds than seedlings;
* For the high-input species the likelihood of a failure with a whole seed orchard may be 30% and for an individual graft 50%;
* For marginal species with little experience; high chance of future neglect; and risk for unforeseen injuries and events higher, the chance of failure is comparatively high;
* For some cases doubtful fit in landscape scenarios and may be experienced as alien elements in agricultural landscapes;
* Driving forces for grafts may be that advisers get most of their experience from high-input situations; large area of abandoned agriculture land is available; costs are not severely limiting because of special support programs from marginal species; with grafts often the initial gain is higher and the seeds come faster, but the relative advantages of these benefits may get too high weight.
Seed collection areas which looks
more as stands and may offer advantages:
Low investment (most of it will be made anyway)
If the seeds sales does not become important wood sales can still motivate land use.
Wood production need to be sacrified for seed production (e.g. by topping trees or intensive thinning) first when seeds are needed, thus seed production needs little long term investment.
Phenotypic thinning and selection of mothers in a seed stand may offer gains comparable to genetic thinning in a seed orchard
Low cost of seeds as far as investment costs are concerned
Perhaps it is an alternative to establishing a clonal seed orchard to establish a plantation/seedling seed orchard with open-pollinated offspring from the selected plus trees. That could not just serve the function a seed orchard serves but also long-term breeding, gene-conservation, information on genetic variation, wood production. In the short time perspective the out-put of gain and seeds may be lower than a grafted seed orchards, but that may be affordable for minor species, and compensated by other advantages. There may also be long term problems as if the seeds really are considered needed after a decade, much of the value of the stand may be lost on intensive thinnings, top pruning or early fellings to get seeds down. In a situation where the disease make the amount of future planting uncertain, but a situation where selection for disease resistance may be urgent, it may seem a good idea. But why not make both things at the same time and side by side?
Clone-testing can be an efficient tool even in low-budget breeding for species there vegetative propagation is very simple. Probability of large "c-effects" is a possible contra-indication. Probably vegetativ propagation is not the simple with Ash, but this can at least be given a thought.
I comment directly on the first
of Gerry's questions, not to remove the incitement for others to comment on the
1. The clone numbers to use, ramet numbers / clone,
The reason to have a low clone number is that a higher selection intensity can be obtained, but selecting trees from forests, the selection intensity is so high so it matters rather little for the gain if it is made higher by using few clones. One reason with high clone numbers is to avoid selfing, in ash most seeds come from trees which does not pollen, so selfing is not a problem or argument for many clones. Neither much selfing has been found in hermaphrodites. If tested clones are used the benefit in terms of a higher selection intensity becomes important, for Swedish conifers 20 clones may be good or rather 25 if deployed linearly, but in other situation lower numbers may be more optimal (Prescher
A reason to choose a high number is that the seed orchard may serve as an initiation to a breeding program and from that point of view 100 clones (as in Snogeholm) is preferable to a lower number. Then the ramet number per clone could be adjusted to that. The seed orchard itself may serve as a clonal test and with 100 it is room for sufficient ramets to get reliable clone averages, and the results can be used for genetic thinning of the seed orchard. The evaluation has to be done before pruning of the grafts start. A high number of clones also assures a mix of males and females which can be adjusted at thinning when some information about the pollen production and its influence of good seeds in the orchard is available. A higher number of clones assures that the crop will not be heavily depending on the characteristics of a single or very few clones, and thus will be more predictable and reproducible. Thus, as long as we talk about phenotypic selections in stands I suggest not use less than about 100 clones and 150 as collected by Gerry is good if successful and give some room for failures in propagation.
According to the Nordic (Norse) mythology, Ask (Ash) was the first Man
and the World tree, Yggdrasil, is an ash
What to use this knowledge for? Well baptising things like clones and orchards and trade names of cultivars may be one thing. Or - if searching arguments for planting ash - why not the mythological?
Note that many of my links are from Wikipedia where much knowledge is accumulating and searched for. But nothing about ash breeding or seed production or seed orchards.
The only thing where is on Wikipedia is a seed orchard page, could someone not write an "ash seed production page" linking to and from relevant pages? When no-one needs to ask again!
Contact on Swedish Ash genetics and seed production: Lars-Göran Sterner, email@example.com
Email from Gerry to the discussion group at 080814
Dear Colleague I am taking up the opportunity of the TREEBREEDEX discussion group to ask the experts some questions.
In Ireland we need seed orchards for ash and sycamore because we ... and we do not collect from seed stands. Our nurseries produce approximately 4 million ash plants (Fraxinus excelsior) and 0.5 million sycamore ( Acer pseudoplatanus ) per year.
I have read the Proceedings of the Seed Orchard Conference athttp://mediasfrance.org/treebreedexData/events/Seed-Orchard-Summary-080812.doc
and the Summary of the papers and posters at:http://daglindgren.upsc.se/Umea07/ZProcFinalFeb08.pdf
The Conference papers concentrated on important conifer species and I could see that the genetic gains from first generation seed orchards are in the order of 10- to-20 % for wood volume with higher gains of 20-25 % expected from further generations of Seed Orchards.
The conference had some information on the broadleaves of birch and cherry. The genetic gain in wood volume with birch was reported as 25% and with quality improvements on branch thickness and stem taper of 10-13 %. Accessibility of improved seeds in SO is also important for us.
Any other information to support the argument for Seed Orchards for ash and sycamore would be welcome ?.
For ash and sycamore the stem Quality aspect of straightness and apical dominance (as well as volume) had a high priority in selection of mother trees which we have made over the past few years. It would be interesting to know if these characters have high heritability values ?
For ash and sycamore we have selected and grafted shoots already from approximately 150 selected trees to make clonal Seed Orchards. For planning of the seed orchards I greatly would appreciate any general or specific comments on the following points:
1. The clone numbers to use, ramet numbers / clone,
2. field design, spacing ?,
3. time to first seeds ?, and expected seed yield per annum at full production ?,
4. when we know and ash tree is predominantly male-should we plant more ramets of the male clones ?
The views of TREEBREEDEX and other ' experts' would be welcome on the above points.
Thank you for your interest
Last edit 080930