Genome Constitution of the <i>Dryopteris atrata</i> Complex (Dryopteridaceae)

Abstract

We analyzed molecular phylogenetically using two low-copy nuclear markers (AK1 and Esterase) and plastid ndhF DNA sequence in the Dryopteris atrata complex. According to nuclear allele constitution and plastid ndhF sequence, apogamous species of the D. atrata complex seemed to be of hybrid origin. The genome constitution of the D. atrata complex showed that apogamous fern species which produce regularly shaped spores can maintain genome constitution if it is of hybrid origin between apogamous species and sexual species. Otherwise, sterile hybrids will be going to hybrid collapse because they cannot prevent genetic segregation.

Two new Dryopteris taxa originated from distantly related congeners in China

“…Scales from six species mainly discussed were observed and photographed under the Olympus SZX16 (DP73) and Nikon SMZ1500 (Camera Head DS‐Fi2) stereomicroscopes. A total of 25 morphological features (Table 1) were extracted from specimens (including images) and species descriptions from previous studies (Wu & Lu, 2000; Wu & al., 2013; Hori & al., 2018a). For phylogenetic analyses, four samples of the two potential new taxa, along with 14 species, including those possibly more closely related to the new taxa, and those representing the main branches within Dryopteris sect.…”

“…Consequently, they are classified at the section level as members of the section represented by their parents. However, an increasing number of hybrid‐origin taxa have been discovered originating from distantly related sections (e.g., Hori & al., 2018a,b,c). These hybrids possess characteristics from both sections represented by their parents.…”

“…For these taxa, the section‐level classification often lacks consensus. They are either not assigned to any specific section or placed in a section without clear justification, sometimes even being placed in the section of the paternal parent (e.g., Hori & al., 2018a). This made the affected section being non‐monophyletic in the trees of plastid phylogenetic relationships.…”

“…Variae . Although previous studies have already shown that some species may have originated through hybridization between members of different sections (Hori & al., 2018a,b,c,d), the proper classification of such species has not been addressed extensively in previous discussions. In this study, we provide suggestions for the section‐level classification of these taxa based on both phylogenetic and morphological evidence.…”

Allelic Variation of the <i>Athyrium christensenianum</i> Complex (Athyriaceae)

“…Plastid rbcL was used as the maternally inherited cpDNA marker (Gastony andYatskievych, 1992, Hori et al 2018a), and AK1 was used as the biparentally inherited nrDNA marker (Hori et al 2018a). PCR-SSCP was used to determine allelic variations at the nuclear locus for each individual, according to the method described by Hori et al (2019). Further, electrophoresis was performed using gels containing 2% glycerol at 15 C for 16 h at 300 V for AK1, followed by silver stain-ing.…”