386
14.4 First Steps Toward the Breeding of the Genus
in Argentina
The first progeny trial of the genus in Argentina corresponds to C. balansae and was
installed in April 2001 in Valle Morado (23° 28′ 11.8″ S, 64° 25′ 52″ W, 385 m asl)
by Fundación Proyungas (Balducci et al. 2009). It includes 42 open-pollinated families obtained from mass selected trees in the natural forest according to forestry
shape and sanitary criteria. Seeds were collected from five provenances: Ingenio
Ledesma, Yuto, Campo Chico, Los Naranjos, and Orán. The trial has an area of 2 ha
and an experimental design of incomplete blocks, with 20 repetitions of single-tree
plots (40 treatments per block; N = 800). It was installed without any coverage.
First evaluations were made at 4 years of age (Horlent and Monteverde 2006).
Significant differences were demonstrated for survival: families without mortality
were observed throughout the trial, as well as families with up to 47% mortality. No
significant differences were found between families in terms of shoot borer resistance. The percentage of plants attacked per family varied between 35% and 79%.
Accordingly, differences could not be shown for the stem shape either, a variable
closely related to the H. grandella attack. Similarly, families did not show significant differences for the “burning of the bark.” This damage is caused by direct
insolation in the north face of the stem. It begins as spots in the bark and progresses
to wounds that reach the cambium, which can reduce the value of the wood and
allow the entry of pathogens.
At the age of 5 years, height and diameter increments were evaluated (Balducci
et al. 2009), and differences between families were demonstrated. The best ten families had a mean DBH of 14.4 cm and a mean height of 7.1 m. Maximum mean
annual increment was 3.89 cm for DBH and 1.67 m for height. In addition to the
information that it provides, this trial is important as a source of genetically proven
material for further advances in the improvement of the species.
In 2006, INTA formally began a breeding program for this genus. The planned
strategy was to create clonal seed orchards from mass selected trees from the natural
forest, while different genetic trials were carried out. In December 2008, a small
network of three trials was established, in order to test species, provenances, and
progenies. They were composed by 110 open-pollinated families coming from
seeds collected from trees selected in the natural forest according to growth, health,
and shape criteria (Grignola 2014). All Argentinian species of the genus were
assayed: five provenances of C. balansae, two of C. fissilis, two of C. saltensis,
three of the hybrid (C. saltensis × C. balansae), and a pool of several provenances
for C. angustifolia as in the previous trial. Seed pools from C. odorata and Toona
ciliata (a Meliaceae from Australia) were used as controls. The test sites were La
Moraleja (24° 17′ 59″ S, 64° 1′ 19″ W, 375 m asl), La Fronterita (26° 58′ 18″ S, 65°
30′ 7″ W, 655 m asl), and El Siambón (26° 42′ 49″ S, 65° 26′ 35″ W, 1170 m asl),
with strong altitudinal and rainfall contrasts (mean annual rainfall: 850 mm,
1400 mm and 1200 mm, respectively). The experimental design was in randomized
complete blocks, with 16 repetitions of single-tree plots in the first two sites and
J. Grignola et al.
14.4 First Steps Toward the Breeding of the Genus
in Argentina
The first progeny trial of the genus in Argentina corresponds to C. balansae and was
installed in April 2001 in Valle Morado (23° 28′ 11.8″ S, 64° 25′ 52″ W, 385 m asl)
by Fundación Proyungas (Balducci et al. 2009). It includes 42 open-pollinated families obtained from mass selected trees in the natural forest according to forestry
shape and sanitary criteria. Seeds were collected from five provenances: Ingenio
Ledesma, Yuto, Campo Chico, Los Naranjos, and Orán. The trial has an area of 2 ha
and an experimental design of incomplete blocks, with 20 repetitions of single-tree
plots (40 treatments per block; N = 800). It was installed without any coverage.
First evaluations were made at 4 years of age (Horlent and Monteverde 2006).
Significant differences were demonstrated for survival: families without mortality
were observed throughout the trial, as well as families with up to 47% mortality. No
significant differences were found between families in terms of shoot borer resistance. The percentage of plants attacked per family varied between 35% and 79%.
Accordingly, differences could not be shown for the stem shape either, a variable
closely related to the H. grandella attack. Similarly, families did not show significant differences for the “burning of the bark.” This damage is caused by direct
insolation in the north face of the stem. It begins as spots in the bark and progresses
to wounds that reach the cambium, which can reduce the value of the wood and
allow the entry of pathogens.
At the age of 5 years, height and diameter increments were evaluated (Balducci
et al. 2009), and differences between families were demonstrated. The best ten families had a mean DBH of 14.4 cm and a mean height of 7.1 m. Maximum mean
annual increment was 3.89 cm for DBH and 1.67 m for height. In addition to the
information that it provides, this trial is important as a source of genetically proven
material for further advances in the improvement of the species.
In 2006, INTA formally began a breeding program for this genus. The planned
strategy was to create clonal seed orchards from mass selected trees from the natural
forest, while different genetic trials were carried out. In December 2008, a small
network of three trials was established, in order to test species, provenances, and
progenies. They were composed by 110 open-pollinated families coming from
seeds collected from trees selected in the natural forest according to growth, health,
and shape criteria (Grignola 2014). All Argentinian species of the genus were
assayed: five provenances of C. balansae, two of C. fissilis, two of C. saltensis,
three of the hybrid (C. saltensis × C. balansae), and a pool of several provenances
for C. angustifolia as in the previous trial. Seed pools from C. odorata and Toona
ciliata (a Meliaceae from Australia) were used as controls. The test sites were La
Moraleja (24° 17′ 59″ S, 64° 1′ 19″ W, 375 m asl), La Fronterita (26° 58′ 18″ S, 65°
30′ 7″ W, 655 m asl), and El Siambón (26° 42′ 49″ S, 65° 26′ 35″ W, 1170 m asl),
with strong altitudinal and rainfall contrasts (mean annual rainfall: 850 mm,
1400 mm and 1200 mm, respectively). The experimental design was in randomized
complete blocks, with 16 repetitions of single-tree plots in the first two sites and
J. Grignola et al.