Global and regional drivers of abundance patterns in the hart's tongue fern complex (Aspleniaceae).

BACKGROUND AND AIMS: The hart's tongue fern (HTF) complex is a monophyletic group composed of five geographically segregated members with divergent abundance patterns across its broad geographic range. We postulated hierarchical systems of environmental controls in which climatic and land-use change drive abundance patterns at the global scale, while various ecological conditions function as finer scale determinants that further increase geographic disparities at regional to local scales. METHODS: After quantifying the abundance patterns of the HTF complex, we estimated their correlations with global climate and land-use dynamics. Regional determinants were assessed using boosted regression tree models with 18 potential ecological variables. Moreover, we investigated long-term population trends in the USA to understand the interplay of climate change and anthropogenic activities on a temporal scale. KEY RESULTS: Latitudinal climate shifts drove latitudinal abundance gradients, and regionally different levels of land-use change resulted in global geographic disparities in population abundance. At a regional scale, population isolation, which accounts for rescue effects, played an important role, particularly in Europe and East Asia where several hot spots occurred. Furthermore, the variables most strongly influencing abundance patterns greatly differed by region: precipitation seasonality in Europe; spatial heterogeneity of temperature and precipitation in East Asia; and magnitudes of past climate change, temperature seasonality and edaphic conditions in North America. In the USA, protected populations showed increasing trends compared with unprotected populations at the same latitude, highlighting the critical role of habitat protection in conservation measures. CONCLUSIONS: Geographic disparities in the abundance patterns of the HTF complex were determined by hierarchical systems of environmental controls, wherein climatic and land-use dynamics act globally but are modulated by various regional and local determinants operating at increasingly finer scales. We highlighted that fern conservation must be tailored to particular geographic contexts and environmental conditions by incorporating a better understanding of the dynamics acting at different spatiotemporal scales.

The complete plastome sequence of Monstera deliciosa (Araceae), an ornamental foliage plant.

In the current study, we sequenced the complete plastome of Monstera deliciosa Liebm. (1849), an attractive foliage plant. The total length of the plastome of M. deliciosa is 163,499 bp and it consists of three distinct regions: a large single-copy (90,092 bp), a small single-copy (21,737 bp), and a pair of inverted repeats (IRs, 25,835 bp). The overall GC content is 36.2%, and the genome contains 110 functional genes, excluding pseudogenes. These functional genes encompass 77 protein-coding genes, 29 transfer RNA genes, and four ribosomal RNA genes. Notably, both the infA and rpl23 genes have been identified as pseudogenes. Phylogenetic analysis based on 14 representative plastomes from seven subfamilies indicates that Monsteroideae is monophyletic and sister to Pothoideae. Furthermore, M. deliciosa and M. adansonii were shown to share a recent common ancestor, the finding for which is supported by a strong bootstrap value. The sequenced plastome of M. deliciosa can serve as a valuable resource for establishing phylogenetic relationships and enhancing species identification within the genus Monstera. In addition, it can facilitate investigations into the genetic characteristics of this plant.

Comparative plastomes and phylogenetic analysis of seven Korean endemic Saussurea (Asteraceae).

BACKGROUND: Saussurea is one of the most species-rich genera in the Cardueae, Asteraceae. There are approximately 40 Saussurea species distributed in Korea, with nearly 40% of them endemics. Infrageneric relationships remain uncertain due to insufficient resolutions and low statistical support. In this study, we sequenced the plastid genomes of five Korean endemic Saussurea (S. albifolia, S. calcicola, S. diamantica, S. grandicapitula, and S. seoulensis), and comparative analyses including two other endemics (S. chabyoungsanica and S. polylepis) were conducted. RESULTS: The plastomes of Korean endemics were highly conserved in gene content, order, and numbers. Exceptionally, S. diamantica had mitochondrial DNA sequences including two tRNAs in SSC region. There were no significant differences of the type and numbers of SSRs among the seven Korean endemics except in S. seoulensis. Nine mutation hotspots with high nucleotide diversity value (Pi > 0.0033) were identified, and phylogenetic analysis suggested that those Korean endemic species most likely evolved several times from diverse lineages within the genus. Moreover, molecular dating estimated that the Korean endemic species diverged since the late Miocene. CONCLUSIONS: This study provides insight into understanding the plastome evolution and evolutionary relationships of highly complex species of Saussurea in Korean peninsula.

The complete chloroplast genome sequence of Asplenium komarovii Akasawa, a rare fern in South Korea.

We sequenced the complete chloroplast genome of Asplenium komarovii Akasawa (syn: Asplenium scolopendrium L. subsp. japonicum (Komarov) Rasbach, Reichstein & Viane), which is designated as a rare species in South Korea. The complete chloroplast genome is 149,393 bp in total length and comprised of the following regions: large single copy (82,464 bp), small single copy (21,345 bp), and a pair of inverted repeats (22,792 bp). The overall GC content is 40.9% and the genome encoded a total of 115 genes, including 84 protein-coding, 27 transfer RNA, and 4 ribosomal RNA genes. Phylogenetic analysis based on 21 representative chloroplast genomes of the suborder Aspleniineae (and one outgroup) indicates that Aspleniaceae is monophyletic and sister to Diplaziopsidaceae, with Rhadidosoraceae as the basal group in this three family clade. Asplenium komarovii is sister to A. nidus and A. prolongatum with strong bootstrap support. The chloroplast genome of A. komarovii will be useful in establishing its relationships within the A. scolopendrium complex, which is currently unresolved.