No abstract

Accurate species delimitation is important as species are a fundamental unit in ecological, evolutionary and conservation biology research. In lichenized fungi, species delimitation has been difficult due to a lack of taxonomically important characteristics and due to the limits of traditional, morphology‐based species concepts. In this study we reassess the current taxonomy of the Parmotrema perforatum group, which recognizes six closely related species divided into three species pairs, each pair comprising one apotheciate (sexual) and one sorediate (asexual) species. Each pair is further characterized by a distinct combination of secondary metabolites. It was hypothesized that the three apotheciate species are reproductively isolated sibling species and that each sorediate species evolved once from the chemically identical apotheciate species. In this study, species boundaries were re‐examined using an integrative approach incorporating morphological, chemical and molecular sequence data to delimit species boundaries. Phylogenetic trees were inferred from a seven‐locus DNA sequence dataset using concatenated gene tree and coalescent‐based species‐tree inference methods. Furthermore, we employed a multi‐species coalescent method to validate candidate species. Micromorphological measurements of conidia were found to be congruent with phylogenetic clusters. Each approach that we applied to the P. perforatum group consistently recovered four of the currently circumscribed species (P. perforatum, P. hypotropum, P. subrigidum and P. louisianae), whereas P. preperforatum and P. hypoleucinum were consistently combined and are thus interpreted as conspecific.

New ring-trisubstituted propyl cyanophenylpropenoates, RPhCH=C(CN)CO2C3H7 (where R is 2-bromo-3-hydroxy-4-methoxy, 5-bromo-2,3-dimethoxy, 5-bromo-2,4-dimethoxy, 6-bromo-3,4-dimethoxy, 2-chloro-3,4-dimetoxy, 5-chloro-2,3-dimetoxy, 4-bromo-2,6-difluoro, 3-chloro-2,6-difluoro, 4-chloro-2,6-difluoro) were prepared by the piperidine catalyzed Knoevenagel condensation of ring-trisubstituted benzaldehydes and propyl cyanoacetate and characterized by CHN elemental analysis, IR, 1H and 13C-NMR. The propenoates formed copolymers with styrene in solution with radical initiation (ABCN) at 70°C. The copolymers were characterized by nitrogen elemental analysis, IR, 1H and 13C-NMR, DSC. Decomposition of the copolymers in nitrogen (TGA) occurred in two steps, first in the 200-500ºC range with residue (4.2 -8.1% wt.), which then decomposed in the 500-800ºC range.