68
seedlings transplanted to the nursery soil had lower colonization rates than those
that remained growing in the greenhouse, which was probably related to transplant
stress and changes in the environmental conditions. However, these seedlings had
higher EcM richness (six species) with respect to those that were in the greenhouse
(two species), indicating that after being exposed to a natural soil inoculum they
were colonized by other fungi. These results indicated that mycorrhization of
N. alpina occurs spontaneously under the standard protocols generally used in local
nurseries, and that the abundance and diversity of EcM in domesticated raulí seedlings depends on the cultivation technique (Fernández et al. 2013).
In order to obtain information regarding the colonization dynamics of EcM in
N. alpina outside the greenhouse, the abundance and diversity of EcM in plants of
different age (seedlings, young plants and adults) naturally established in the native
forest, and in young specimens cultivated in the nursery and then implanted in the
same forest (10-year-old provenance trial), were analysed (Fernández et al. 2015).
This study was conducted in a forest located in the Lake Lácar basin (Lanín National
Park). All the specimens were highly colonized by EcM (>90%). The highest colonization values corresponded to the adults and the lowest to the seedlings. A total of
25 fungal species were identified (Fig. 3.5a), being most of them Basidiomycetes
(88%). Richness and diversity of EcM were higher in adults and young specimens
than in seedlings and were also higher in cultivated specimens growing in the native
forest for 10 years than in naturally established plants. This indicates that the passage of the plants through the nursery in addition to the management practices associated with the establishment of the provenance trial (i.e. fences against livestock,
understory removed before plantation, removal of fallen branches and trees) might
influence EcM fungal communities in N. alpina roots. Additionally, the associated
changes are still evident even several years after the trial establishment. It was also
observed that the number of fungal species forming EcM in specimens located in
the forest was significantly higher than in nursery seedlings. Besides, the composition of EcM fungal communities was completely different, and no common fungal
species was found between the native forest (Fernández et al. 2015) and the nursery
(Fernández et al. 2013). According to these findings, plant age, substrate inoculum
(artificial greenhouse substrate vs forest soil) cultivation techniques and forest management seem to be important factors in determining mycorrhizal development and
diversity in raulí.
It is also interesting to mention that, in natural ecosystems, there is a high level
of similarity in the EcM fungal communities associated with different Nothofagus
species (Fernández et al. 2013, 2015; Nouhra et al. 2013; Truong et al. 2019;
Barroetaveña et al. 2019; Fioroni 2020). In fact, it has been recently described that
one of these common species (Ruhlandiella patagonica, Fig. 3.5b; Kraisitudomsook
et al. 2019) might improve plant growth in recently established N. obliqua seedlings
(Fioroni 2020). This information is relevant because it gives us clues regarding the
fungal species that could be used for simultaneous inoculation of different
Nothofagus species during their cultivation in the nursery.
P. Marchelli et al.
seedlings transplanted to the nursery soil had lower colonization rates than those
that remained growing in the greenhouse, which was probably related to transplant
stress and changes in the environmental conditions. However, these seedlings had
higher EcM richness (six species) with respect to those that were in the greenhouse
(two species), indicating that after being exposed to a natural soil inoculum they
were colonized by other fungi. These results indicated that mycorrhization of
N. alpina occurs spontaneously under the standard protocols generally used in local
nurseries, and that the abundance and diversity of EcM in domesticated raulí seedlings depends on the cultivation technique (Fernández et al. 2013).
In order to obtain information regarding the colonization dynamics of EcM in
N. alpina outside the greenhouse, the abundance and diversity of EcM in plants of
different age (seedlings, young plants and adults) naturally established in the native
forest, and in young specimens cultivated in the nursery and then implanted in the
same forest (10-year-old provenance trial), were analysed (Fernández et al. 2015).
This study was conducted in a forest located in the Lake Lácar basin (Lanín National
Park). All the specimens were highly colonized by EcM (>90%). The highest colonization values corresponded to the adults and the lowest to the seedlings. A total of
25 fungal species were identified (Fig. 3.5a), being most of them Basidiomycetes
(88%). Richness and diversity of EcM were higher in adults and young specimens
than in seedlings and were also higher in cultivated specimens growing in the native
forest for 10 years than in naturally established plants. This indicates that the passage of the plants through the nursery in addition to the management practices associated with the establishment of the provenance trial (i.e. fences against livestock,
understory removed before plantation, removal of fallen branches and trees) might
influence EcM fungal communities in N. alpina roots. Additionally, the associated
changes are still evident even several years after the trial establishment. It was also
observed that the number of fungal species forming EcM in specimens located in
the forest was significantly higher than in nursery seedlings. Besides, the composition of EcM fungal communities was completely different, and no common fungal
species was found between the native forest (Fernández et al. 2015) and the nursery
(Fernández et al. 2013). According to these findings, plant age, substrate inoculum
(artificial greenhouse substrate vs forest soil) cultivation techniques and forest management seem to be important factors in determining mycorrhizal development and
diversity in raulí.
It is also interesting to mention that, in natural ecosystems, there is a high level
of similarity in the EcM fungal communities associated with different Nothofagus
species (Fernández et al. 2013, 2015; Nouhra et al. 2013; Truong et al. 2019;
Barroetaveña et al. 2019; Fioroni 2020). In fact, it has been recently described that
one of these common species (Ruhlandiella patagonica, Fig. 3.5b; Kraisitudomsook
et al. 2019) might improve plant growth in recently established N. obliqua seedlings
(Fioroni 2020). This information is relevant because it gives us clues regarding the
fungal species that could be used for simultaneous inoculation of different
Nothofagus species during their cultivation in the nursery.
P. Marchelli et al.