Trontin et al. (2016) - Scientific and review paper - Somatic embryogenesis from mature pines
In: PARK Y.-S., BONGA J.M., MOON HK (Eds), Vegetative Propagation of Forest Trees. Korea Forest Research Institute. Seoul, Korea, pp. 211-260. Published online 05/03/2016, http://www.iufro20902.org/.
Trontin JF, Aronen T, Hargreaves C, Montalbán IA, Moncaleán P, Reeves C, Quoniou S, Lelu-Walter MA, Klimaszewska K
A collaboration between FCBA Pierroton, Luke (Finlande), Scion (Nouvelle-Zélande), Neiker/Tecnalia, INRA Orléans,
CFS (Canada, coordination)
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 multiyear experimentations, 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.