18
After the first steps in gaining baseline information on the path to domestication,
pilot afforestation trials continue on an “almost-industrial” scale. Indeed, these
assays overlap chronologically with the genetic trials, at least partially. For both, it
will be necessary to adjust previously the technology for the production of seedlings
in the nursery, from the harvesting and stocking of seeds to the development of sowing, irrigation, and fertilization protocols. The development of this technology
requires knowledge of the autoecology of the species, its reproductive system, and
its physiology, especially up to the seedling ontogenetic stage.
1.8 Low-Intensity Breeding of Forest Tree Species
Low-intensity (or low input) breeding is characterized by being cheap, simple,
robust, locally projected, undemanding in record keeping and central control, capable of being continued after periods of neglect, and not dependent on high technology or highly complex specializations, in short, possible to be sustained on a small
be at least half siblings. It is commonly of interest to test the difference
between the means of provenances assayed (considering therefore that this
factor is of fixed effects) and if the variability of the open-pollinated families
has a significant influence on the character of interest (and consequently this
factor is considered to have random effects). These considerations define a
mixed linear model, which in the case of having an experimental design in
blocks with single tree plots, its symbolic expression would be the following:
y ijk
i
j
k
ijk
i
= + +
+ +
( )
µ ρ ϕ
β ε
ρ
where y ijk is an observation of the variable of the seedling from the jth family
within the ith population, located in the kth block, μ is the overall mean of the
variable, ρ i is the effect (fixed) of the ith population, φ j (ρ i ) is the effect (random) of the jth family within the ith population, β k is the effect (random) of
the kth block, and ε ijk is the general error ~NID(0, σ
2
).
Knowing the kinship relationships among the individuals of the trial allows
estimating various genetic parameters such as additive genetic variance (V A ),
narrow sense heritability (h
2
), coefficient of additive genetic variance (CV A ),
or quantitative differentiation (Q ST ). With them, it is possible to characterize
the patterns of genetic variation of a species (inter- and intra-population variation) analogously to that achieved with genetic markers, although including
the adaptive portion of the genome. In addition, they allow selecting provenances, families, or individuals in an improvement program, through the estimation of breeding values, the prediction of genetic gains, and finally the
establishment of genetic rankings.
M. J. Pastorino
After the first steps in gaining baseline information on the path to domestication,
pilot afforestation trials continue on an “almost-industrial” scale. Indeed, these
assays overlap chronologically with the genetic trials, at least partially. For both, it
will be necessary to adjust previously the technology for the production of seedlings
in the nursery, from the harvesting and stocking of seeds to the development of sowing, irrigation, and fertilization protocols. The development of this technology
requires knowledge of the autoecology of the species, its reproductive system, and
its physiology, especially up to the seedling ontogenetic stage.
1.8 Low-Intensity Breeding of Forest Tree Species
Low-intensity (or low input) breeding is characterized by being cheap, simple,
robust, locally projected, undemanding in record keeping and central control, capable of being continued after periods of neglect, and not dependent on high technology or highly complex specializations, in short, possible to be sustained on a small
be at least half siblings. It is commonly of interest to test the difference
between the means of provenances assayed (considering therefore that this
factor is of fixed effects) and if the variability of the open-pollinated families
has a significant influence on the character of interest (and consequently this
factor is considered to have random effects). These considerations define a
mixed linear model, which in the case of having an experimental design in
blocks with single tree plots, its symbolic expression would be the following:
y ijk
i
j
k
ijk
i
= + +
+ +
( )
µ ρ ϕ
β ε
ρ
where y ijk is an observation of the variable of the seedling from the jth family
within the ith population, located in the kth block, μ is the overall mean of the
variable, ρ i is the effect (fixed) of the ith population, φ j (ρ i ) is the effect (random) of the jth family within the ith population, β k is the effect (random) of
the kth block, and ε ijk is the general error ~NID(0, σ
2
).
Knowing the kinship relationships among the individuals of the trial allows
estimating various genetic parameters such as additive genetic variance (V A ),
narrow sense heritability (h
2
), coefficient of additive genetic variance (CV A ),
or quantitative differentiation (Q ST ). With them, it is possible to characterize
the patterns of genetic variation of a species (inter- and intra-population variation) analogously to that achieved with genetic markers, although including
the adaptive portion of the genome. In addition, they allow selecting provenances, families, or individuals in an improvement program, through the estimation of breeding values, the prediction of genetic gains, and finally the
establishment of genetic rankings.
M. J. Pastorino