434
13.6 cm and a mean total height of 9.5 m. The species showed a very good behavior
in full sun conditions at 6 years of age, being the straightness of the stem and good
response to pruning the main characteristics that deserve to be highlighted for its
use in forestry.
16.2.3 An Incipient Breeding Program
Given its promising characteristics, the Instituto Nacional de Tecnología
Agropecuaria of Argentina (INTA) has recently begun a low-intensity breeding program for Cordia trichotoma. Planned strategy included the identification of the most
representative populations, their phenotypic and molecular characterization, selection of plus trees, their vegetative propagation for the installation of seed orchards,
and their open pollinated sexual propagation for testing the genetic merit of the
mothers. Given its disjunct distribution, the strategy decided was to advance separately in each subtropical rainforest until having the molecular information to make
further decisions related to the conformation of unique base populations and clonal
gardens. The progeny tests are planned to be conducted in a network of trials including material from both rainforests, which will thus be tested together.
Since the natural range of the species is only coarsely known, a modeled niche
distribution was performed by means of Maxent software (Ledesma 2014) to define
the sites to search for plus trees (Fig. 16.3a). The predictive bioclimatic variables
with the highest weight were the average temperature of the coldest quarter and
temperature seasonality. This procedure allowed identifying numerous populations
that were still unknown. The initial theoretical range was successively adjusted, first
Fig. 16.3 (a) Potential distribution of Cordia trichotoma obtained by Maxent modeling (Ledesma
2014). The most probable areas are indicated with dark red. (b) Potential distribution in the Yungas
adjusted with a cutoff threshold of 0.596. (c) The same potential distribution of B, but indicating
the loss due to the change in land use
L. F. Fornes et al.
13.6 cm and a mean total height of 9.5 m. The species showed a very good behavior
in full sun conditions at 6 years of age, being the straightness of the stem and good
response to pruning the main characteristics that deserve to be highlighted for its
use in forestry.
16.2.3 An Incipient Breeding Program
Given its promising characteristics, the Instituto Nacional de Tecnología
Agropecuaria of Argentina (INTA) has recently begun a low-intensity breeding program for Cordia trichotoma. Planned strategy included the identification of the most
representative populations, their phenotypic and molecular characterization, selection of plus trees, their vegetative propagation for the installation of seed orchards,
and their open pollinated sexual propagation for testing the genetic merit of the
mothers. Given its disjunct distribution, the strategy decided was to advance separately in each subtropical rainforest until having the molecular information to make
further decisions related to the conformation of unique base populations and clonal
gardens. The progeny tests are planned to be conducted in a network of trials including material from both rainforests, which will thus be tested together.
Since the natural range of the species is only coarsely known, a modeled niche
distribution was performed by means of Maxent software (Ledesma 2014) to define
the sites to search for plus trees (Fig. 16.3a). The predictive bioclimatic variables
with the highest weight were the average temperature of the coldest quarter and
temperature seasonality. This procedure allowed identifying numerous populations
that were still unknown. The initial theoretical range was successively adjusted, first
Fig. 16.3 (a) Potential distribution of Cordia trichotoma obtained by Maxent modeling (Ledesma
2014). The most probable areas are indicated with dark red. (b) Potential distribution in the Yungas
adjusted with a cutoff threshold of 0.596. (c) The same potential distribution of B, but indicating
the loss due to the change in land use
L. F. Fornes et al.