Clonal distribution,fertility and sex ratios of the moss Plagiomnium affine (Bland.) T.Kop. in forests of contrasting age

Abstract

Six populations of the clonal forest floor moss Plagiomnium affine from forests of different age were screened for genetic variation at 23 allozyme loci, of which nine were polymorphic. Samples consisting of two adjacent unconnected shoots were taken at regular intervals along one transect from each population. A total of 602 shoots was analysed. Almost 80% of the shoots were sterile (i.e. not expressing male or female gender). Sex remained unknown for only 10% of shoots after identification of genets based on electrophoretic data. We identified a mean number of 3.7 fertile clones per population. The mean length of clones along transects in each population ranged between 2 and 3 m. The size distribution within populations was bimodal, with a few dominant clones and a varying number of much smaller clones. The overall sex ratio was slightly female biased at the ramet level, but balanced at the genet level. Forest age was negatively correlated with percentage of sterile shoots and positively correlated with frequency of sporophytes. In both cases correlations were significant only if population 1, which was subject to extreme soil disturbance by badgers, was excluded. We conclude that the effective population size is larger, and the susceptibility to genetic drift is lower, in old forests.     

Description of Bryceella perpusilla n. sp. (Monogononta: Proalidae), a New Rotifer Species from Terrestrial Mosses,with Notes on the Ground Plan of Bryceella Remane, 1929

We here describe the new proalid rotifer species Bryceella perpusilla n. sp. on the basis of light and electron microscopy. The species, certainly representing one of the smallest rotifer and even metazoan species at all, was obtained in January 2008 from terrestrial mosses of North‐west Germany. Bryceella perpusilla n. sp. is distinguished from other species of the genus by the very small size, the slender body outline, the short apical styli, the triangular rostrum, the outward curving, blunt and rod‐shaped toes, the four‐nucleated vitellogermarium, the slender manubria and the caudally directed alulae. With our observations, that can be used for future cladistic analyses of the Proalidae, we are able to define the generic diagnosis of Bryceella more precisely and to give an adapted species key. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Lophodermium pini-mugonis sp. nov. on needles of Pinus mugo from the Alps based on morphological and molecular data

Lophodermium pini-mugonis, collected on needles of Pinus mugo from German Alps, is described as a species new to science. It is characterized by subcuticular ascomata with a wrinkled surface and a somewhat untidy outline, a complex structure of lip cells, and ellipsoidal conidia. An analysis of the internal transcribed spaces of rDNA showed that Lophodermium pini-mugonis is, sister to Lophodermium autumnale and distantly related to other Lophodermium species on pines. The hypothesis of cospeciation of Lophodermium species with members of the Pinaceae is discussed.     

Morphological Studies on Pterophyllum guizhouense sp. nov. and P. astartense Harris from the Late Triassic of Guizhou,China

The morphological characters of Pterophyllum guizhouense sp. nov. were reported and those of P. astartense Harris were supplied and emended. Meanwhile, the significance of cuticle characters chosen in the identification of fossil plants was also discussed.     

Hypnea species (Gigartinales,Rhodophyta) from the southeastern coast of Brazil based on molecular studies complemented with morphological analyses,including descriptions of Hypnea edeniana sp. nov. and H. flava sp. nov.

The red algal genus Hypnea (Gigartinales) has a wide geographical distribution along tropical and subtropical coasts around the world. The relatively simple and plastic morphology, often influenced by the conditions of its habitat, complicates the identification of Hypnea species. Therefore, the number and status of some species remain in doubt. Molecular studies have been performed to supplement traditional studies based on morphology, mainly for Hypnea species occurring in Asia. In the present study, sequence data from the DNA barcode COI-5P for 114 samples from the southeastern coast of Brazil, indicated the occurrence of six taxa. Additionally, sequence data from the UPA and rbcL markers for representatives of each of those taxa confirmed the existence of six different species. After morphological analysis and comparison with sequences available in GenBank, these species were named as follows: H. aspera, H. cervicornis, H. cf. musciformis, H. spinella, and two new species, H. flava Nauer, Cassano & M.C. Oliveira and H. edeniana Nauer, Cassano & M.C. Oliveira. Hypnea cervicornis, often considered as a later synonym of H. spinella, should be considered as a distinct species based on morphology and divergence of the three molecular markers used. Hypnea aspera is a new record for the Atlantic Ocean.     

Ochtodes searlesii sp. nov. (Gigartinales,Rhodophyta), from the Pacific tropical coast of Mexico,based on morphological and molecular evidence

Ochtodes searlesii Mendoza‐González, Mateo‐Cid et Sentíes sp. nov. is described from Michoacán, tropical Mexican Pacific, on the basis of comparative morphology and rbcL sequence analysis. It is distinguished from other Ochtodes species by its erect axes arising from an encrusting base, its small terete fronds, regularly dichotomously branched axes, and obliquely divided zonate tetrasporangia. Phylogenetic analyses showed that three Pacific Mexican samples, from Caletilla, Zapote and La Majahuita (Michoacán), were identical and formed a distinctive and well supported Clade segregated from other species of Ochtodes from Brazil, Cuba, Ecuador, Guadeloupe and Mexico. The Mexican entity is morphologically distinct from other Ochtodes species as well. On this basis we propose a new Ochtodes species.     

Trichodorus petrusalberti n. sp. (Nematoda: Trichodoridae) from Rice with Additional Notes on the Morphology of T. sanniae and T. rinae

A new species in the family Trichodoridae, from the rhizosphere of rice (Oryza sativa L.) in Northern Natal, South Africa, is described and illustrated. Trichodorus petrusalberti n. sp. resembles T. taylori De Waele, Mancini, Roca, and Lamberti, 1982, T. hooperi Loof, 1973, and T. complexus Rahman, Jairajpuri, and Ahmad, 1985, from which it is distinguished by the shape of the spicules. It is distinguished from the former two species by the nonthickened terminal cuticle in the males and by the shape and sclerotization of the vulval-vaginal region in lateral view in the females. Additional morphological details are given for T. sanniae Vermeulen and Heyns, 1985 and T. rinae Vermeulen and Heyns, 1985.     

First description of an euryoecious acanthoecid choanoflagellate species,Enibas tolerabilis gen. et sp. nov. from a salar in the Chilean Andes based on morphological and transcriptomic data

In general, acanthoecid choanoflagellates have been described to occur exclusively in brackish water to marine habitats. Only recently, two studies have proven their existence in inland waters. One of them has shown, that an acanthoecid species from a small lake (near Apia on the island of Upolu, Samoa) is strictly freshwater adapted, not able to tolerate even brackish water. In this study, we present the first euryoecious acanthoecid species, able to live and reproduce in freshwater as well as under hypersaline conditions. The new species, Enibas tolerabilis gen. et sp. nov. was isolated in 2017 from the Salar de Ascotán in the Altiplano at 3750 m a. s. l., Northern Chile. The salinity at the time of sampling was 6 PSU. A series of autecological experiments have revealed a salinity tolerance from freshwater up to 70 PSU. In our phylogenetic analysis, E. tolerabilis gen. et sp. nov. clustered within the family of Acanthoecidae, forming a well-supported sister clade together with two other, environmental choanoflagellate sequences. We erected a new genus, Enibas gen. nov. and described the morphology, molecular biology and autecology for E. tolerabilis gen. et sp. nov. which has a stephanoecid-like lorica morphology. We emphasize that the definition of the genus Stephanoeca, being polyphyletic, is in urgent need of revision as we showed that this morphology is present in both acanthoecid families.