Species delimitation in Ceratozamia (Zamiaceae) from Southwestern Mexico, in light of reproductive and climatic diversification
Por:
Martinez-Dominguez, Lili, Nicolalde-Morejon, Fernando, Vergara-Silva, Francisco, Guevara, Roger, Gernandt, David S., Stevenson, Dennis Wm
Publicada:
1 jun 2023
Ahead of Print:
1 dic 2022
Categoría:
Ecology, evolution, behavior and systematics
Resumen:
Multidisciplinary taxonomic studies have enhanced the delimitation of
species within complex taxonomic groups. In the cycad genus Ceratozamia,
the taxonomy is still not fully resolved for the several species
complexes that have been proposed. Five Ceratozamia species occur in
geographic proximity in the Soconusco region of southwestern Mexico.
Because of similarity and variable morphology across these species,
their taxonomy is a source of confusion. Based on integrative taxonomy,
including morphological (qualitative and quantitative), ecological, and
molecular data, we aimed to diagnose the species from the Soconusco
region. We carried out extensive field sampling, collecting 225
individuals from a total of 12 populations, and reviewed one hundred
herbarium specimens to evaluate whether the species are diagnosable. We
carried out morphometric analyses at the population level on vegetative
and reproductive characters and present the first analyses of phenotypic
variability of pollen and ovulate strobili in neotropical cycads.
Additionally, we evaluated the influence of climatic factors on
morphological variation. Morphological characters of ovulate strobili
were correlated with climatic conditions. In contrast, there was no
significant correlation between the morphology of pollen strobili and
the environment. In the pollen strobili, we found fixed characters that
allow for the identification of the species. The haplotype networks
displayed several groups of related haplotypes, which in some species
corresponded to mixed population clusters. We detected a discordance
between phenotypic and genetic evidence. The integration of evidence
offers grounded views for clarifying species boundaries and outlining
the differences among species, which we incorporated into a taxonomic
key. In general, the mixed relations within this group of species may be
due to historical hybridization events favored by common phenology and
sharing of biotic pollination vectors. Finally, based on our results, we
discuss the use of morphology for species delimitation and inference of
evolutionary relationships in cycads.
Filiaciones:
Martinez-Dominguez, Lili:
Univ Nacl Autonoma Mexico, Inst Biol, Posgrad Ciencias Biol, 3er Circuito Exterior,Ciudad Univ, Coyoacan 04510, Cdmx, Mexico
Univ Nacl Autonoma Mexico, Inst Biol, Lab Teoria Evolut & Hist Ciencia, 3er Circuito Exterior,Ciudad Univ, Coyoacan 04510, Cdmx, Mexico
Nicolalde-Morejon, Fernando:
Univ Veracruzana, Inst Invest Biol, Lab Taxon Integrat, Xalapa 91190, Veracruz, Mexico
Vergara-Silva, Francisco:
Univ Nacl Autonoma Mexico, Inst Biol, Lab Teoria Evolut & Hist Ciencia, 3er Circuito Exterior,Ciudad Univ, Coyoacan 04510, Cdmx, Mexico
Guevara, Roger:
Inst Ecol AC, Red Biol Evolut, Carretera Antigua Coatepec 351, Xalapa 91070, Veracruz, Mexico
Gernandt, David S.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Bot, 3er Circuito Exterior,Ciudad Univ, Coyoacan 04510, Cdmx, Mexico
Stevenson, Dennis Wm:
New York Bot Garden, Bronx, NY 10458 USA
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