464
clonal replicates, in view of the very probable absence of pedigree information. The
presence of clones will allow measurements with less environmental noise, because
a single plant may be subject to microsite effects. In its development, the registration of kinship relations is very important, for greater certainty of the identity by
descent of the alleles of interest. The “application population” could be all trees
available for selection in both natural stands and plantations.
There are still few studies on forest species in which the next generation of a
breeding programme is predicted. Bartholomé et al. (2016) were the first to report
genomic selection in Pinus pinaster with data from generations G0 and G1, to predict in G2 obtaining satisfactory results. In a more recent study, Thistlethwaite et al.
(2019) performed cross-generational GS analysis on coastal Douglas-fir
(Pseudotsuga menziesii) and obtained predictive accuracies almost as high as that of
ABLUP (traditional BLUP based on the pedigree-based A matrix) and concluded
that more markers or improved distribution of markers are required to capture LD in
Douglas-fir (genome size ~16 Gpb). The latter supports the need for the development of mass genotyping methods in natives for better GS performance.
17.4 HTS Technologies Applied to Argentina’s Native
Tree Species
The native forest tree species of economic and ecological importance in Argentina
such as Nothofagus alpina (= N. nervosa), N. obliqua, N. pumilio and Austrocedrus
chilensis of the Andean Patagonian forest; Cedrela balansae, Cordia trichotoma
and Handroanthus impetiginosus from the subtropical rainforests of Argentina; and
Prosopis alba of Chaco, among others, are being affected by global change (e.g.
deforestation, forest exploitation, grazing, drought and thermal stresses (SAyDS
2007). Furthermore, predicted changes in temperature (Barros et al. 2015) may alter
selective pressures on trees and, therefore, have the potential to influence evolutionary processes, which depend fundamentally on the genetic diversity existing in
populations.
In this context, the conservation and management of the remaining forests, as
well as the reforestation of degraded areas, requires knowledge of the genetic bases
underlying adaptive traits. This knowledge is also crucial for breeding programmes.
Therefore, the development of genomic tools, such as collections of genes and
adaptive molecular markers, are required for monitoring the genetic diversity of
natural populations, identifying individuals/populations with greater adaptation
ability in the context of climate change and providing propagation of selected material for restoration and breeding programmes.
The lack of genomic information for native Argentinean forest species has been
a limitation. Previous studies, like the candidate genes characterization of adaptive
genetic variation in native species from Argentina [Austrocedrus chilensis
(Pomponio et al. 2013) and Prosopis alba (Pomponio et al. 2014)], were performed
S. L. Torales et al.
clonal replicates, in view of the very probable absence of pedigree information. The
presence of clones will allow measurements with less environmental noise, because
a single plant may be subject to microsite effects. In its development, the registration of kinship relations is very important, for greater certainty of the identity by
descent of the alleles of interest. The “application population” could be all trees
available for selection in both natural stands and plantations.
There are still few studies on forest species in which the next generation of a
breeding programme is predicted. Bartholomé et al. (2016) were the first to report
genomic selection in Pinus pinaster with data from generations G0 and G1, to predict in G2 obtaining satisfactory results. In a more recent study, Thistlethwaite et al.
(2019) performed cross-generational GS analysis on coastal Douglas-fir
(Pseudotsuga menziesii) and obtained predictive accuracies almost as high as that of
ABLUP (traditional BLUP based on the pedigree-based A matrix) and concluded
that more markers or improved distribution of markers are required to capture LD in
Douglas-fir (genome size ~16 Gpb). The latter supports the need for the development of mass genotyping methods in natives for better GS performance.
17.4 HTS Technologies Applied to Argentina’s Native
Tree Species
The native forest tree species of economic and ecological importance in Argentina
such as Nothofagus alpina (= N. nervosa), N. obliqua, N. pumilio and Austrocedrus
chilensis of the Andean Patagonian forest; Cedrela balansae, Cordia trichotoma
and Handroanthus impetiginosus from the subtropical rainforests of Argentina; and
Prosopis alba of Chaco, among others, are being affected by global change (e.g.
deforestation, forest exploitation, grazing, drought and thermal stresses (SAyDS
2007). Furthermore, predicted changes in temperature (Barros et al. 2015) may alter
selective pressures on trees and, therefore, have the potential to influence evolutionary processes, which depend fundamentally on the genetic diversity existing in
populations.
In this context, the conservation and management of the remaining forests, as
well as the reforestation of degraded areas, requires knowledge of the genetic bases
underlying adaptive traits. This knowledge is also crucial for breeding programmes.
Therefore, the development of genomic tools, such as collections of genes and
adaptive molecular markers, are required for monitoring the genetic diversity of
natural populations, identifying individuals/populations with greater adaptation
ability in the context of climate change and providing propagation of selected material for restoration and breeding programmes.
The lack of genomic information for native Argentinean forest species has been
a limitation. Previous studies, like the candidate genes characterization of adaptive
genetic variation in native species from Argentina [Austrocedrus chilensis
(Pomponio et al. 2013) and Prosopis alba (Pomponio et al. 2014)], were performed
S. L. Torales et al.