Do we have different varieties in Acer velutinum (Sapindaceae): Morphological and molecular studies

Abstract

The genus Acer L. has about 156 species which are distributed in Asia, Europe, Northern Africa and North America. The species of Acer show extensive morphological and molecular diversity and the species that co-occur may hybridize; therefore, sometimes the species delimitation turns out to be difficult. Eight Acer (maple) species have been reported in Iran. The velvet maple—Acer velutinum Boiss (1846: 28)—is one of the largest maples in the world and the most frequent maple species in Iran. Morphologically speaking, two varieties have been cited for this species. Due to the extensive morphological variability, however, the researchers encounter difficulty delimiting these two varieties. Against this backdrop, the present study was performed with the aim to delimit two varieties of Acer velutinum by using both morphological and molecular approaches. It also aimed to proffer data on the genetic diversity of this species in the country. Nighty-four plant specimens of A. velutinum were randomly collected within 14 geographical populations at four provinces in Hyrcanian forests of Iran. The PsbA-trnHGUG intergenic spacer sequence of cp-DNA and the ISSR molecular markers along with the morphometric analysis and image analysis of the leaf shape were used. The numerical and phylogenetic analyses of the tree specimens from the presumed varieties of A. velutinum—based on morphology, image analysis of leaf shape, ISSR and cp-DNA—did not delimit these varieties; hence, A. velutinum was considered to have a high level of intergrading morphological variability. The population genetic study revealed significant molecular differences among the studied populations. The STRUCTURE plot and gene flow analysis (Nm), nevertheless, revealed some degree of shared alleles among the populations. The Mantel tests demonstrated significant correlation between the geographical and genetic distance of the studied populations; it further signaled the fact that the gene flow occurred mainly between the coterminous populations.

Infra-specific variation of Acer cappadocicum (Sapindaceae): morphological and molecular approaches

“…In a similar study carried on the sympatric varieties of Acer velutinum in north of Iran, the observed genetic variability was reported due to the high gene flow or the introgression between these varieties with high leaf morphological diversity (Siahkolaee et al 2017).…”

“…In addition, DNA sequences like ITS (Internal transcribed spacer) and chloroplast DNA have been used in determining intraspecific variation in Acer species like A. pictum Thunb., A. velutinum Boiss., and A. campestre L. (Grimm and Thomas 2014;Siahkolaee et al 2017). Ideally, species should not be proposed or rejected solely based on descriptive (non-numeric) morphology; any taxonomic reassessment should be complemented by genetic evidence (diagnostic sequences, DNA fingerprinting, and population-genetic analyses) (Grimm and Thomas 2014).…”

Micro-morphology and molecular investigations in some Carduus species in Iran

“…Species identification and differentiation is an important task for systematic and evolutionary studies. This may be difficult in the genera with overlapping morphological characters among the species, and in those genera that encounter inter-specific hybridization as well as ancient-historic introgression events (SIAHKOLAEE et al 2017).…”

Species relationship and genetic diversity in some Iranian Lamium L. species using ISSR markers

“…Genetic diversity is an important element in the survival of population, because it has a positive influence on the adaptation of species in the presence of fluctuating biological and abiotic factors (Vrijenhoek 1994). ISSR (Inter-simple sequence repeats) molecular markers are stable, highly reproducible, easy to work and are known to be useful in various biological investigations such as, species delimitation, genetic diversity analysis, population structure, breeding programs and conservation management (Shahi-Gharahlar et al 2011;Sheidai et al 2014;Koohdar et al 2015;Minaeifar et al 2016;Nikzat-Siahkolaee et al 2017;Tabaripour et al 2018 ).There are many studies which have been mainly focused on the taxonomy, phylogeny, nutlet micromorphology, cytology, anatomy, trichome and pollen morphology of Lamium species (Mill 1982;Mennema 1989;Abu-Asab and Cantino 1994;Özdemir 2009, 2011;Bendiksby et al 2011a, b;Celep et al 2011Celep et al , 2014Krawczyk et al 2013Krawczyk et al , 2014Atalaya et al 2016 a, b). However, genetic diversity of Lamium species have been reported in only a few studies (Wąsowicz et al 2011;Stojanova et al 2013;Azimishad et al 2018), also genetic structure, ecological adaptation, and intra-and inter-specific differentiation along with morphometric studies on Lamium of Iran have not been investigated yet.…”