Population genetic structure and species delimitation in theCryptanthus zonatuscomplex (Bromeliaceae)

Abstract

Morphological variations of individuals and populations of plants have hampered taxonomists from understanding whether such variations are intra- or interspecific. In this research, we study Cryptanthus burle-marxii and C. zonatus, the morphological variations of which overlap, making it difficult to identify them. Both taxa are restricted to the north of the Brazilian Atlantic Forest and are included in the C. zonatus species complex. We applied different methods such as morphological comparison, population genetics using ten nuclear microsatellite markers and ecological niche modelling to study population genetic structure and species delimitation of this species complex. Our analysis revealed that the two genetic clusters were formed possibly because of the presence of a historical geographical barrier in a region called ‘depressão do Abiaí’. The two genetic clusters were concordant with the northern and southern distribution of the complex but incongruent with a morphological variation or current taxonomic delimitation. Thus, we synonymize C. burle-marxii with C. zonatus and re-evaluate its conservation status as endangered.

Assessing the phylogenetic relationship among varieties of Toona ciliata (Meliaceae) in sympatry with chloroplast genomes

“…These varieties are sympatry or partially overlapped in natural geographic distribution in Yunnan Province in China (Zhang, 2018 ), and natural hybridization among them cannot be excluded. However, morphological traits are often continuously distributed or poor for subdivision of intra‐ and interspecific variations (Ferreira et al., 2021 ), which makes it difficult to delimit varieties from morphological traits. Previous genetic studies mainly referred to the T. ciliata complex, without identifying specific varieties.…”

Population Structure and Genetic Diversity of the Toona ciliata (Meliaceae) Complex Assayed with Chloroplast DNA Markers

“…Combining the results from organelle (mtDNA, cpDNA) and nuclear genome (SRAP, SSR, and ITS) markers, we conclude two common patterns regarding the spatial distribution of genetic diversity: (1) The rangewide distribution can be generally divided into western and eastern regions, although the boundaries between them are difficult to delineate. (2) The western region harbors larger genetic diversity than the eastern region. Note that the western region may be further divided into two regions based on mtDNA markers [4].…”

“…Natural hybridization among varieties cannot be excluded, although a few reports on their hybrids are available in the literature. Because leaf and floral traits are often influenced by environmental factors and exhibit continuous variation within and between species [ 2 , 3 ], the delimitation of varieties of T. ciliata based on these traits remains uncertain. There is still debate about the taxonomic status of these varieties [ 4 ].…”