The genus Microniphargus (Crustacea, Amphipoda): evidence for three lineages distributed across northwestern Europe and transfer from Niphargidae to Pseudoniphargidae

Microniphargus leruthi Schellenberg, 1934 (Amphipoda: Niphargidae) was first described based on samples collected in Belgium and placed in a monotypic genus within the family Niphargidae. However, some details of its morphology as well as recent phylogenetic studies suggest that Microniphargus may be more closely related to Pseudoniphargus (Amphipoda: Pseudoniphargidae) than to Niphargus. Moreover, M. leruthi ranges over 1,469 km from Ireland to Germany, which is striking since only a few niphargids have confirmed ranges in excess of 200 km. To find out the phylogenetic position of M. leruthi and check whether it may be a complex of cryptic species, we collected material from Ireland, England and Belgium then sequenced fragments of the mitochondrial cytochrome c oxidase subunit 1 gene as well as of the nuclear 28S ribosomal gene. Phylogenetic analyses of both markers confirm that Microniphargus is closer to Pseudoniphargus than to Niphargus, leading us to reallocate Microniphargus to Pseudoniphargidae. We also identify three congruent mito-nuclear lineages present respectively in Ireland, in both Belgium and England, and in England only (with the latter found in sympatry at one location), suggesting that M. leruthi is a complex of at least three species with a putative centre of origin in England.

Drivers of an epic radiation: the role of climate and islands in species diversification and reproductive-mode evolution of Old-World tree frogs

Although large diversifications of species occur unevenly across space and evolutionary lineages, the relative importance of their driving mechanisms, such as climate, ecological opportunity and key innovations, remains poorly understood. Here, we explore the remarkable diversification of rhacophorid frogs, which represent six percent of global amphibian diversity, utilize four distinct reproductive modes, and span a climatically variable area across mainland Asia, associated continental islands, and Africa. Using a complete species-level phylogeny, we find near-constant diversification rates but a highly uneven distribution of species richness. Montane regions on islands and some mainland regions have higher phylogenetic diversity and unique assemblages of taxa; we identify these as cool-wet refugia. Starting from a centre of origin, rhacophorids reached these distant refugia by adapting to new climatic conditions (niche evolution-dominant), especially following the origin of key innovations such as terrestrial reproduction (in the Late Eocene) or by dispersal during periods of favourable climate (niche conservatism-dominant).

The five Urochola spp. used in development of tropical forage cultivars originate from defined subpopulations with differentiated gene pools

Background and Aims: Urochola (syn. Brachiaria, and including some Panicum and Megathyrus) is a genus of tropical and subtropical grasses widely sown as forage to feed ruminants in the tropics. A better understanding of the diversity among Urochola spp. allow us to leverage its varying ploidy levels and genome composition to accelerate its improvement, following the example from other crop genera. Methods: We explored the genetic make-up and population structure in 111 accessions, which comprise the five Urochola species used for the development of commercial cultivars. These accessions are conserved from wild materials from collection sites at their centre of origin in Africa. We used RNA-seq, averaging 40M reads per accession, to generate 1,167,542 stringently selected SNP markers that tentatively encompassed the complete Urochola gene pool used in breeding. Key Results: We identified ten subpopulations, which had no relation with geographical origin and represented ten independent gene pools, and two groups of admixed accessions. Our results support a division in U. decumbens by ploidy, with a diploid subpopulation closely related to U. ruziziensis, and a tetraploid subpopulation closely related to U. brizantha. We observed highly differentiated gene pools in U. brizantha, which were not related with origin or ploidy. Particularly, one U. brizantha subpopulation clustered distant from the other U. brizantha and U. decumbens subpopulations, so likely containing unexplored alleles. We also identified a well-supported subpopulation containing both polyploid U. decumbens and U. brizantha accessions; this was the only group containing more than one species and tentatively constitutes an independent "mixed" gene pool for both species. We observed two gene pools in U. humidicola. One subpopulation, "humidicola-2", was much less common but likely includes the only known sexual accession in the species. Conclusions: Our results offered a definitive picture of the available diversity in Urochola to inform breeding and resolve questions raised by previous studies. It also allowed us identifying prospective founders to enrich the breeding gene pool and to develop genotyping and genotype-phenotype association mapping experiments.

Geographical distribution and species diagnostics of the Carboniferous and Permian genus Gzheloceras (Cephalopoda: Nautiloidea)

The article is devoted to an attempt to trace the ways of distribution of Late Paleozoic nautilids Gzheloceras Ruzhencev et Shimansky, 1954. The genus Gzheloceras Ruzhencev et Shimansky (Cephalopoda: Nautiloidea) includes a large number of species from Carboniferous and Permian sediments. Representatives of the genus Gzheloceras were distributed mainly in the northern hemisphere. They inhabited the warm epicontinental seas of the northern and north-western periphery of the Palaeo-Tethys. Species of the genus Gzheloceras differ from each other by insignificant differences in the position of the siphuncle, the details of the surface ornamentation, less often in the form of suture and the shape of the cross section of the whorls. The form of the conch and a transverse ornamentation indicate a nectobenthic lifestyle of the genus Gzheloceras. The centre of origin of the genus is the waters on the place of modern Kazakhstan. In the Serpukhovian or Early Bashkirian, representatives of the genus Gzheloceras, apparently, dispersed into the Urals. The genus Gzheloceras flourished in the Early Permian of the Urals.

Phytophthora austrocedri.

Phytophthora austrocedri is a soil and water-borne oomycete pathogen of woody species residing within the Cupressaceae. Its centre of origin is unknown. It was first reported causing widespread dieback and mortality of Austrocedrus chilensis in southern Argentina in 2007 and subsequently reported causing extensive dieback and mortality of Juniperus communis in northern Britain. The pathogen is considered to be invasive in both regions due to the clonal nature of the populations and recently observed disease epidemics. In addition to the two established wider-environment epidemics in Argentina and Britain, P. austrocedri has been isolated from a young Juniperus horizontalis growing in a plant nursery in Germany and from an ornamental Cupressus sempervirens located in a public park in northern Iran. P. austrocedri infects phloem in the roots and stem bases of affected hosts, with aerial infections also reported on J. communis in Britain. Natural spread is likely to occur via movement in water and soil, and possibly via animal and/or human activity. The presence of water courses and areas of standing water are likely to favour pathogen spread at a site. In Britain, DNA of P. austrocedri has been confirmed as present in traded plants of various Cupressaceae species, including those imported from continental Europe. The pathogen is a regulated pest in the plant trade in the UK.

Phytophthora austrocedri.

Phytophthora austrocedri is a soil and water-borne oomycete pathogen of woody species residing within the Cupressaceae. Its centre of origin is unknown. It was first reported causing widespread dieback and mortality of Austrocedrus chilensis in southern Argentina in 2007 and subsequently reported causing extensive dieback and mortality of Juniperus communis in northern Britain. The pathogen is considered to be invasive in both regions due to the clonal nature of the populations and recently observed disease epidemics. In addition to the two established wider-environment epidemics in Argentina and Britain, P. austrocedri has been isolated from a young Juniperus horizontalis growing in a plant nursery in Germany and from an ornamental Cupressus sempervirens located in a public park in northern Iran. P. austrocedri infects phloem in the roots and stem bases of affected hosts, with aerial infections also reported on J. communis in Britain. Natural spread is likely to occur via movement in water and soil, and possibly via animal and/or human activity. The presence of water courses and areas of standing water are likely to favour pathogen spread at a site. In Britain, DNA of P. austrocedri has been confirmed as present in traded plants of various Cupressaceae species, including those imported from continental Europe. The pathogen is a regulated pest in the plant trade in the UK.

Phylogeny and historical biogeography analysis support Caucasian and Mediterranean centres of origin of key holoparasitic Orobancheae (Orobanchaceae) lineages

The extensive diversity of the tribe Orobancheae, the most species-rich lineage of holoparasitic Orobanchaceae, is concentrated in the Caucasus and Mediterranean regions of the Old World. This extant diversity has inspired hypotheses that these regions are also centres of origin of its key lineages, however the ability to test hypotheses has been limited by a lack of sampling and phylogenetic information about the species, especially in the Caucasus region. First, we assessed the phylogenetic relationships of several poorly known, problematic, or newly described species and host-races of four genera of Orobancheae occurring in the Caucasus region–Cistanche, Phelypaea, Phelipanche and Orobanche–using nuclear ribosomal (ITS) and plastid (trnL–trnF) sequence data. Then we applied a probablistic dispersal-extinction-cladogenesis model of historical biogeography across a more inclusive clade of holoparasites, to explicitly test hypotheses of Orobancheae diversification and historical biogeography shifts. In sum, we sampled 548 sequences (including 196 newly generated) from 13 genera, 140 species, and 175 taxa across 44 countries. We find that the Western Asia (particularly the Caucasus) and the Mediterranean are the centre of origin for large clades of holoparasitic Orobancheae within the last 6 million years. In the Caucasus, the centres of diversity are composed both of long-branch taxa and shallow, recently diversified clades, while Orobancheae diversity in the Mediterranean appears to represent mainly recent diversification.

Multiple genes confer anthracnose resistance in French bean accessions of Garhwal Himalayas

The Indian Himalayan region is very rich in the genetic variability of French bean and therefore considered as the secondary centre of origin of French bean. Though, a good diversity of French bean is present in Uttarakhand hills of Western Himalaya but it is almost unexplored yet. Unfortunately, French bean is attacked by some of the phytopathogens those cause heavy crop losses. Colletotrichum lindemuthianu (Sacc. & Magnus) Scrib is one of the sever pathogens that causes anthracnose disease in French bean worldwide. Identification or development of a resistant variety/cultivar is an environmentally safe approach. Diversity analysis of anthracnose resistant loci in common bean is important to identify new sources of resistance gene(s). So the study was designed with the objectives to collect and screen the local accessions of French bean from Garhwal hills for anthracnose resistance. A total of 100 accessions were collected from 6 different districts of Garhwal region of Uttarakhand and all were screened for anthracnose resistance. For this, 13 SCAR (Sequence cleaved amplified region) primers specific to anthracnose resistance were used in this study. Results revealed a high level of genetic diversity within the population for anthracnose resistance loci. Gene diversity ranged from 0.354 to 0.499 with a mean of 0.457. Pair wise genetic distance ranged from 0 to 2.236. The accessions were also screened for anthracnose resistance under field and polyhouse conditions. There was a moderate correlation (R = 0.56) between field trial and trial under controlled condition. Thirteen of these accessions possessing two genes (Co-10 and Co-42) showed complete resistance for anthracnose disease under field and polyhouse conditions. The anthracnose resistant accessions may further be used in future breeding programmes to develop new and more resistant varieties of French bean against anthracnose disease.

Biogeography of Iberian Ants (Hymenoptera: Formicidae)

Ants are highly diverse in the Iberian Peninsula (IP), both in species richness (299 cited species) and in number of endemic species (72). The Iberian ant fauna is one of the richest in the broader Mediterranean region, it is similar to the Balkan Peninsula but lower than Greece or Israel, when species richness is controlled by the surface area. In this first general study on the biogeography of Iberian ants, we propose seven chorological categories for grouping thems. Moreover, we also propose eight biogeographic refugium areas, based on the criteria of “refugia-within-refugium” in the IP. We analysed species richness, occurrence and endemism in all these refugium areas, which we found to be significantly different as far as ant similarity was concerned. Finally, we collected published evidence of biological traits, molecular phylogenies, fossil deposits and geological processes to be able to infer the most probable centre of origin and dispersal routes followed for the most noteworthy ants in the IP. As a result, we have divided the Iberian myrmecofauna into four biogeographical groups: relict, Asian-IP disjunct, Baetic-Rifan and Alpine. To sum up, our results support biogeography as being a significant factor for determining the current structure of ant communities, especially in the very complex and heterogenous IP. Moreover, the taxonomic diversity and distribution patterns we describe in this study highlight the utility of Iberian ants for understanding the complex evolutionary history and biogeography of the Iberian Peninsula.