Canadian Forest Service Publications
Efficient method for rapid multiplication of clean and healthy willow clones via in vitro propagation with broad genotype applicability. 2015. Palomo-Ríos, E.; Macalpine, W.; Shield, I.; Amey, C.; Karaoglu, C.; West, J.; Hanley, S.; Krygier, R.; Karp, A.; Jones, H.D. Canadian Journal of Forest Research 45(11):1662-1667.
Issued by: Northern Forestry Centre
Catalog ID: 36389
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Willow is a versatile crop with considerable potential as a source of renewable biomass for bioenergy. Although breeding new varieties takes less time compared with some other tree species, producing new willow varieties is still a slow, labour-intensive process, partly because clonally propagating the results of each cross is a bottleneck early in the breeding scheme. In this paper, we describe a facile, rapid method for the in vitro culture of a wide range of willow genotypes. We have developed a combination of media and methods for efficient tissue-culture propagation to rapidly multiply individual plants and simultaneously produce clean, stock germplasm applicable to a wide range of willow genotypes that can be phytosanitary tested to demonstrate their disease-free status. The micropropagation method described could generate in the order of 5000 viable, transplantable clones from a single plant in just 24 weeks and was used to produce phytosanitary tested breeding material for export to overcome restriction on the international transport of woody cuttings. This method could represent a valuable biotechnology adjunct to willow breeding programmes and could accommodate early selection via molecular or biochemical markers.
Plain Language Summary
Willow is a versatile crop with considerable potential as biomass, a renewable energy source. Although new willow varieties can be bred more quickly than some other tree species, producing new varieties is still slow and labour intensive, partly because the need to propagate the results of each cross using stem cuttings creates a bottleneck early in the breeding scheme. Here we describe a straightforward and rapid way to grow a wide range of willow varieties in sterile growing media (in vitro). The plants grown in vitro were clean and healthy and our propagation method could generate roughly 5000–6000 viable, transplantable clones from a single plant in just 24 weeks. We used this method to produce breeding material certified disease free for export. We also demonstrated that plants produced in this way could be shipped and then grown in Canadian fields. When combined with early selection via molecular or biochemical markers, our method could be very useful in willow breeding programs. No willow breeding programs for biomass are currently active in Canada, and disease concerns have restricted imports from Europe in the past. This technology provides a novel means of importing genetically superior willow material for biomass production in Canada.