Canadian Forest Service Publications
Adventitious rooting of conifers: influence of biological factors. 2016. Zavattieri, M.A.; Ragonezi, C.; Klimaszewska, K. Trees 30: 1021-1032.
Issued by: Laurentian Forestry Centre
Catalog ID: 37123
Availability: PDF (request by e-mail)
Available from the Journal's Web site. †
† This site may require a fee
Vegetative propagation of superior conifer trees can be achieved, e.g., through rooted cuttings or rooted microshoots, the latter predominantly through in vitro tissue culture. Both techniques are used to achieve rapid multiplication of trees with favorable genetic combinations and to capture a large proportion of the genetic diversity in a single generation cycle. However, adventitious rooting of shoots (cuttings) is often not efficient due to various problems, such as scarcity of roots and cessation of their growth, both of which limit the application of vegetative propagation in some conifer species. Many factors are involved in the adventitious rooting of shoots, including physical and chemical ones, such as plant growth regulators, carbohydrates, light quality, temperature and rooting substrates, or media [reviewed by Ragonezi et al. (Trees 24(6):975–992, 2010)]. The focus of this review is on biological factors, such as inoculations with Agrobacterium rhizogenes, plant-growth promoting rhizobacteria and other endophytes, and mycorrhizal fungi, which were found to stimulate adventitious rooting. These microorganisms could contribute not only to adventitious root development but also to help in protecting conifer plants against pathogenic microorganisms, facilitate acclimation and transplanting, and contribute to more sustainable, chemical-free forests.
Plain Language Summary
When planning plantations, tree breeders select trees that are among the best families to produce seedlings. These trees are then propagated, namely by cuttings. However, in conifers, it is difficult for cuttings to develop roots.
This study provides a snapshot of the factors that influence root development in cuttings of conifer seedlings, including light quality, temperature, soil, the influence of mycorrhizae (fungi that associate with plant roots to form a complex structure). It thereby increases our knowledge of the factors that improve rooting success in cuttings of conifer seedlings.