Conventional versus genomic selection for white spruce improvement: a comparison of costs and benefits of plantations on Quebec public lands

Abstract

Intensive plantation forestry is a potent strategy for forest managers to increase wood production on a smaller forest land acreage, especially with the use of genetically improved reforestation stock. The main drawback with conventional conifer improvement is the several decades it takes before stock deployment, which is particularly acute in the context of climate change and evolving wood markets. Use of genomic selection allows to drastically shorten breeding cycles, resulting in more flexibility and potentially increasing benefits. This study compares the financial performance of five white spruce (Picea glauca) breeding and deployment scenarios, from conventional breeding to genomic selection in conjunction with top-grafting or the use of somatic embryogenesis, in the context of plantations established by the Quebec government on public lands with banned herbicide use. We estimated the land expectation value (LEV) for the five scenarios applied to eight site productivity indices, and considered costs and revenues from breeding, plantation establishment, silviculture, and harvest. LEVs at 4% discount rate were positive for all scenarios on all site indices, and varied from $197 to $2015 ha −1 assuming mechanical brushing of the plantations. The scenarios integrating genomic selection resulted in the highest LEVs, which increased with site index. We also conducted sensitivity analyses with 3% and 5% discount rates, with a range of costs and benefits, and with herbicide control of competing vegetation. These results should help orientate public investment decisions regarding the integration of genomic selection at the operational level in tree breeding and reforestation programs on public lands.

Favorable Conditions for Genomic Evaluation to Outperform Classical Pedigree Evaluation Highlighted by a Proof-of-Concept Study in Poplar

“…GS has been made possible thanks to easy access to cheap genotyping data, and to recent developments in evaluation methodology (de los Campos et al, 2009). Recent studies of GS in forest trees were conducted on several species: eucalypts (Resende et al, 2012b;Müller et al, 2017;Tan et al, 2017Tan et al, , 2018Cappa et al, 2019;Ballesta et al, 2020), spruce (Gamal El-Dien et al, 2015Ratcliffe et al, 2015;Lenz et al, 2017Lenz et al, , 2020Chen et al, 2018;Chamberland et al, 2020), pines (Resende et al, 2012a;de Almeida Filho et al, 2016;Ratcliffe et al, 2017;Gianola and Fernando, 2020;Ukrainetz and Mansfield, 2020), and rubber trees (Cros et al, 2019;Souza et al, 2019). Given the differences among forest species in general, and between their breeding programs in particular, assessments of GS feasibility at a case-bycase basis are often desirable.…”

Hybrid Pine (Pinus attenuata × Pinus radiata) Somatic Embryogenesis: What Do You Prefer, Mother or Nurse?

“…This storage time, although insufficient for carrying out ex vitro testing of clones, enables a preliminary assessment of the in vitro performance of different ECLs. Results are encouraging as with this storage period and with the development of genomic techniques even an early selection could be performed [38]. Although there are several studies were conifer ECLs has been cryopreserved in liquid nitrogen [39], this is the first report where regeneration of embryogenic tissues has been reported after a long storage period at −80 • C (five years).…”

Genomic Selection for Forest Tree Improvement: Methods, Achievements and Perspectives

“…Another study compared the financial performance of various breeding and deployment scenarios, with or without GS, in the context of intensively managed plantations of white spruce in Quebec (Canada) [149]. The duration of a classical breeding cycle, 34 years, was similar to the previous study, but the rotation period lasted for up to 60 years, and weeds were controlled with herbicides.…”

“…On the other hand, combining GS with top-grafting resulted in a significant increase in additional genetic gain per year in conifers due to the reduced age of coning from 5 to 3 years [35]. Thus, top-grafting could be an interesting alternative to increase genetic gain and shorten breeding cycles for tree breeding programs where SE at an operational scale is yet not available [149]. Finally, the continuing reduction in genotyping costs is making GS increasingly financially attractive for use on forest trees.…”