202
cuttings, taken from branches of 52 trees, were planted in rows in a field clone bank
at Paraná Delta Experimental Station of INTA (34° 10′ 28″ S; 58° 51′ 45″ W; 0 m
asl), with ten plants per genotype. After the first year, 89% of the genotypes had
survived, with significant differences in survival rate between them (from 0% to
100% surviving plants/genotype). The average total height of the dominant stem in
the first year was 2.90 m, with a mean of five stems per plant. A low incidence of the
main leaf diseases (rusts caused by Melampsora spp. and anthracnose by Marssonina
spp.) was registered using a scale of six grades (no differences in susceptibility were
observed between genotypes) (Cerrillo et al. 2018). Recently (2019), a field test was
established in Paraná Delta Experimental Station with a selection of the most promising 16 genotypes of that collection (Teresa Cerrillo, pers. comm.).
In addition, some variation studies were performed with Patagonian populations.
Variation of frost susceptibility among provenances was studied in a clonal bank
installed in Bariloche Experimental Station of INTA (41° 7′23″S; 71°14′ 56″ W;
790 m asl) with 39 genotypes of the Negro River provenance and 33 genotypes of
the Chubut River provenance (Leonardo Gallo, data not published). Phenological
differences were preliminary observed between those two provenances. Chubut
River flows from the Andes Range to the Atlantic Ocean at about 43° S. Its mean
annual temperature is lower than that of Negro River, which flows in the same direction but about 4 latitudinal degrees northwards. At the clonal bank, spring sprouts
developed 3 weeks later in Chubut River clones than in Negro River clones, whereas
autumn leaf drop took place up to 1 month earlier in the Chubut River clones. This
means that Chubut River clones had an almost 2-month shorter growing season. The
genetic signal from the home environment is maintained in Bariloche, that is, at an
intermediate latitude between the two provenances. This has consequences in frost
resistance. The trial included 5 ramets per clone (N = 360). Frost damage was
described with six categories considering the necrosis in the main shoot. Category
1, no damage at all; 2, up to 10% of the main shoot necrotic; 3, 10 to 30%; 4, 30 to
60%; 5, more than 60% necrotic but plant still alive; and 6, plant dead. The average
value of all Negro River clones was 2.33, whereas that of Chubut River clones was
1.30. The clones of the two provenances were compared statistically with a T test
for paired comparisons. Significant differences were found between the two provenances in the average early frost damage (Fig. 7.12).
A study of the architecture of the species was initiated also with the Patagonian
provenances (Salgado et al. 2018, 2019). In the clonal bank of Bariloche, the length,
diameter and number of nodes of annual shoots of 15 clones of Negro and Chubut
provenances were recorded every 10 days in the 2017/2018 season. Maximum and
average growth during the growing season were also calculated. The moment at
which the maximum growth rate occurred was more variable in clones of Chubut
than in those of Negro, being the date for this trait in both provenances between
December 17 and January 7. No differences between provenances were found for
the number of nodes and the maximum and average growth rates. However, shoots
of Negro provenance were longer and thicker, which could be associated with the
longer duration of their growth period.
P. Marchelli et al.
cuttings, taken from branches of 52 trees, were planted in rows in a field clone bank
at Paraná Delta Experimental Station of INTA (34° 10′ 28″ S; 58° 51′ 45″ W; 0 m
asl), with ten plants per genotype. After the first year, 89% of the genotypes had
survived, with significant differences in survival rate between them (from 0% to
100% surviving plants/genotype). The average total height of the dominant stem in
the first year was 2.90 m, with a mean of five stems per plant. A low incidence of the
main leaf diseases (rusts caused by Melampsora spp. and anthracnose by Marssonina
spp.) was registered using a scale of six grades (no differences in susceptibility were
observed between genotypes) (Cerrillo et al. 2018). Recently (2019), a field test was
established in Paraná Delta Experimental Station with a selection of the most promising 16 genotypes of that collection (Teresa Cerrillo, pers. comm.).
In addition, some variation studies were performed with Patagonian populations.
Variation of frost susceptibility among provenances was studied in a clonal bank
installed in Bariloche Experimental Station of INTA (41° 7′23″S; 71°14′ 56″ W;
790 m asl) with 39 genotypes of the Negro River provenance and 33 genotypes of
the Chubut River provenance (Leonardo Gallo, data not published). Phenological
differences were preliminary observed between those two provenances. Chubut
River flows from the Andes Range to the Atlantic Ocean at about 43° S. Its mean
annual temperature is lower than that of Negro River, which flows in the same direction but about 4 latitudinal degrees northwards. At the clonal bank, spring sprouts
developed 3 weeks later in Chubut River clones than in Negro River clones, whereas
autumn leaf drop took place up to 1 month earlier in the Chubut River clones. This
means that Chubut River clones had an almost 2-month shorter growing season. The
genetic signal from the home environment is maintained in Bariloche, that is, at an
intermediate latitude between the two provenances. This has consequences in frost
resistance. The trial included 5 ramets per clone (N = 360). Frost damage was
described with six categories considering the necrosis in the main shoot. Category
1, no damage at all; 2, up to 10% of the main shoot necrotic; 3, 10 to 30%; 4, 30 to
60%; 5, more than 60% necrotic but plant still alive; and 6, plant dead. The average
value of all Negro River clones was 2.33, whereas that of Chubut River clones was
1.30. The clones of the two provenances were compared statistically with a T test
for paired comparisons. Significant differences were found between the two provenances in the average early frost damage (Fig. 7.12).
A study of the architecture of the species was initiated also with the Patagonian
provenances (Salgado et al. 2018, 2019). In the clonal bank of Bariloche, the length,
diameter and number of nodes of annual shoots of 15 clones of Negro and Chubut
provenances were recorded every 10 days in the 2017/2018 season. Maximum and
average growth during the growing season were also calculated. The moment at
which the maximum growth rate occurred was more variable in clones of Chubut
than in those of Negro, being the date for this trait in both provenances between
December 17 and January 7. No differences between provenances were found for
the number of nodes and the maximum and average growth rates. However, shoots
of Negro provenance were longer and thicker, which could be associated with the
longer duration of their growth period.
P. Marchelli et al.