Canadian Forest Service Publications
International effort to induce somatic embryogenesis in adult pine trees. 2016. Trontin, J.-F.; Aronen, T.; Hargreaves, C.; Montalbán, I.A.; Moncaleán, P.; Reeves, C.; Quoniou, S.; Lelu-Walter, M.-A.; Klimaszewska, K. Pages 211-260 in Park, Y.-S.; Bonga, J.M.; Moon, H.-K., eds. Vegetative Propagation of Forest Trees, National Institute of Forest Science, Seoul, Korea.
Issued by: Laurentian Forestry Centre
Catalog ID: 36687
Availability: PDF (request by e-mail)
The genus Pinus includes several species that are economically important and planted outside their natural ranges as plantation species. Somatic embryogenesis (SE), a biotechnological tool for mass propagation of pines, has been reported for many species but only from seed embryos. Cloning the individual adult trees, through SE from vegetative explants, could potentially benefit the forest industry in that only trees with elite characteristics would be planted commercially. The attributes of conifer trees may only be evaluated after many years of growth and often not until the reproductive growth phase. This chapter describes a concerted effort by several research teams in five countries to initiate SE in primordial shoot explants of six pine species, each commercially important in its respective country. In spite of the multi-year experiments, SE was induced in only one species (Pinus sylvestris), but embryogenic lines showed some instability at microsatellite loci and the somatic embryos did not germinate. Some cell lines initiated in different species showed embryogenic-like characteristics at the microscopic level. Expression of embryogenesis specific genes (LEC1/CHAP3A, WOX2, VP1) was detected in such calli/cell aggregates of all three tested pine species (including those with embryogenic-like characteristics) even when the presence of early somatic embryos could not be confirmed. Overall, the results presented in this chapter are indicative of the existing challenges in propagation of adult pines as in other conifers.
Plain Language Summary
This chapter describes the results obtained through an international collaborative attempt to induce somatic embryogenesis in adult pine species from vegetative tissues (shoot buds). If adult/mature trees with desired characteristics could be multiplied and planted, it would accelerate the breeding cycle, which would greatly benefit the forest industry.
Somatic embryogenesis is a biotechnology that makes possible the multiplication (cloning) of a single seed embryo into a huge number of somatic embryos that grow into plants. Conifer seeds have been cloned, but somatic embryogenesis has yet to be induced in mature trees.