362
(Table 13.4; and Soldati et al. 2013) reinforce the presence of introgressant hybrids
into these populations since hybridization can lead to an increase in genetic diversity at population level (Donoso et al. 2004; Hoffmann and Agro 2011).
13.2.3.4 Delimitation of Hybrid Zones of C. balansae and C. saltensis
in the Yungas
The abundance of samples with mixed ancestry in both C. balansae and C. saltensis
corroborated the existence of hybrid contact zones in the Yungas. These hybrid
zones exist in areas of sympatry as well as at intermediate elevations where C. balansae and C. saltensis co-occur. To display altitude ranges of hybrid contact zones, we
addressed the altitudinal distribution of genetic clusters from AFLP at sample level.
In Fig. 13.4b, each sample is represented by a horizontal colored bar; the extension
of the color in each bar indicates the probability of belonging to the inferred genetic
cluster in that sample. In addition, it was addressed the altitudinal distribution of
ribotypes showing the correspondence between ribotype assignment and the altitude where the sample was obtained (Fig. 13.4d). The geographic locations of
hybrid zones are depicted as hatched areas on the maps (Fig. 13.4a, c). Hatched
areas on the first map included all populations with ancestry in more than one species, from Bayesian clustering analyses of AFLP markers (Fig. 13.4a). Hatched
areas on the second map included the populations that showed ITS ribotypes from
distinct species (Fig. 13.4c); each circle in this map represents the ribotype of a
sample; populations of hybrid origin display ribotypes encoded with different color;
multicolored circles represent samples harboring intragenomic polymorphism.
The changes in the frequencies of AFLP markers and ITS ribotypes were strongly
congruent along the Yungas and strata elevation. Intermediate genotypes displayed
ancestry in both species at sympatric areas that occurred in the Calilegua National
Park and the San Andrés farm (Fig. 13.4a, c). Moreover, increasing proportions of
ancestry admixture occur towards altitude ranges approximately from 820 to 1100 m
asl (Pintascayo and Acambuco localities) (Fig. 13.4b, d). Additionally, pure populations of C. saltensis were genetically identified towards increasing altitudes of the
MR. Meanwhile, pure populations of C. balansae were widely represented in the
PR, in accordance with vegetation strata described for the Yungas (Fig. 13.4b, d)
(Brown et al. 2001; Zapater et al. 2004; Malizia et al. 2006). In addition, genetically
pure samples of either C. balansae or C. saltensis were found together with hybrids
and introgressant forms between these species in Calilegua National Park, San
Andrés, and Pintascayo localities.
We did not find any genetically pure sample of C. balansae in the Acambuco
population; it is worth mentioning that an accession of C. saltensis was reported in
Tarija (South of Bolivia) at 22° 16’ S, 64° 30’ W, and 1100 m asl (James C. Solomon
collector, No.10066, herbaria LPB and MO; http://www.tropicos.org), not far from
locality of Acambuco. The existence of C. saltensis nearby may explain the presence of introgressant forms of C. balansae in Acambuco population.
N. Zelener et al.
(Table 13.4; and Soldati et al. 2013) reinforce the presence of introgressant hybrids
into these populations since hybridization can lead to an increase in genetic diversity at population level (Donoso et al. 2004; Hoffmann and Agro 2011).
13.2.3.4 Delimitation of Hybrid Zones of C. balansae and C. saltensis
in the Yungas
The abundance of samples with mixed ancestry in both C. balansae and C. saltensis
corroborated the existence of hybrid contact zones in the Yungas. These hybrid
zones exist in areas of sympatry as well as at intermediate elevations where C. balansae and C. saltensis co-occur. To display altitude ranges of hybrid contact zones, we
addressed the altitudinal distribution of genetic clusters from AFLP at sample level.
In Fig. 13.4b, each sample is represented by a horizontal colored bar; the extension
of the color in each bar indicates the probability of belonging to the inferred genetic
cluster in that sample. In addition, it was addressed the altitudinal distribution of
ribotypes showing the correspondence between ribotype assignment and the altitude where the sample was obtained (Fig. 13.4d). The geographic locations of
hybrid zones are depicted as hatched areas on the maps (Fig. 13.4a, c). Hatched
areas on the first map included all populations with ancestry in more than one species, from Bayesian clustering analyses of AFLP markers (Fig. 13.4a). Hatched
areas on the second map included the populations that showed ITS ribotypes from
distinct species (Fig. 13.4c); each circle in this map represents the ribotype of a
sample; populations of hybrid origin display ribotypes encoded with different color;
multicolored circles represent samples harboring intragenomic polymorphism.
The changes in the frequencies of AFLP markers and ITS ribotypes were strongly
congruent along the Yungas and strata elevation. Intermediate genotypes displayed
ancestry in both species at sympatric areas that occurred in the Calilegua National
Park and the San Andrés farm (Fig. 13.4a, c). Moreover, increasing proportions of
ancestry admixture occur towards altitude ranges approximately from 820 to 1100 m
asl (Pintascayo and Acambuco localities) (Fig. 13.4b, d). Additionally, pure populations of C. saltensis were genetically identified towards increasing altitudes of the
MR. Meanwhile, pure populations of C. balansae were widely represented in the
PR, in accordance with vegetation strata described for the Yungas (Fig. 13.4b, d)
(Brown et al. 2001; Zapater et al. 2004; Malizia et al. 2006). In addition, genetically
pure samples of either C. balansae or C. saltensis were found together with hybrids
and introgressant forms between these species in Calilegua National Park, San
Andrés, and Pintascayo localities.
We did not find any genetically pure sample of C. balansae in the Acambuco
population; it is worth mentioning that an accession of C. saltensis was reported in
Tarija (South of Bolivia) at 22° 16’ S, 64° 30’ W, and 1100 m asl (James C. Solomon
collector, No.10066, herbaria LPB and MO; http://www.tropicos.org), not far from
locality of Acambuco. The existence of C. saltensis nearby may explain the presence of introgressant forms of C. balansae in Acambuco population.
N. Zelener et al.