Environmental predictors of the occurrence of exotic <Emphasis Type="Italic">Hydrilla verticillata</Emphasis> (L.f.) Royle and native <Emphasis Type="Italic">Egeria najas</Emphasis> Planch. in a sub-tropical river floodplain: the Upper River Paraná, Brazil

The Upper River Paraná Floodplain System comprises the rivers Ivinheima, Baía and Paraná, which with their associated waterbodies form three subsystems, each showing individual characteristics. Hydrilla verticillata recently invaded the Upper Paraná Floodplain, while Egeria najas is the native most abundant submersed macrophyte. A large flood-pulse, during January–March 2007, abruptly reduced macrophyte stands in many areas to near-zero and dispersed propagules over the entire floodplain. From April 2007 to April 2008, we conducted three surveys sampling for the presence–absence of H. verticillata and E. najas and environmental variables aiming to answer: (1) How rapid is the colonization–regeneration process for both species? (2) Which habitats seem to be more susceptible to their colonization? (3) Which environmental factors can best predict their occurrence? Neither H. verticillata nor E. najas colonized the Ivinheima subsystem. In the Baía subsystem, E. najas had only two occurrences while H. verticillata was not present. In the Paraná subsystem, E. najas predominantly occurred in river channels, but it was also common in floodplain lakes. In April 2007, it was found in 13% of the sites in the Paraná subsystem, increasing to 30% in November 2007 and reaching 34% in April 2008. H. verticillata did not successfully colonize floodplain lakes of the Paraná subsystem. In channels, it had 34% occurrence in April 2007, increasing to 62% in November 2007 and remaining at 62% in April 2008. The role of environmental variables in predicting species occurrence changed depending upon the scale of the analysis. Considering the whole Upper Paraná floodplain, water transparency followed by electrical conductivity were the strongest predictors for both species. Colonization by submersed plants seems improbable in the Ivinheima subsystem owing to its low water transparency besides frequent localized floods; in the Baía subsystem, it seems inhibited by transparency and low alkalinity. Considering just the Paraná subsystem, the proportion of organic matter in sediment, ten times higher in floodplain lakes than in channels, was the best predictor for H. verticillata occurrence (also related to water pH and transparency), while E. najas was only significantly explained by transparency.     

Centromeric and non-centromeric satellite DNA organisation differs in holocentric <Emphasis Type="Italic">Rhynchospora</Emphasis> species

Satellite DNA repeats (or satDNA) are fast-evolving sequences usually associated with condensed heterochromatin. To test whether the chromosomal organisation of centromeric and non-centromeric satDNA differs in species with holocentric chromosomes, we identified and characterised the major satDNA families in the holocentric Cyperaceae species Rhynchospora ciliata (2n = 10), R. globosa (2n = 50) and R. tenuis (2n = 2x = 4 and 2n = 4x = 8). While conserved centromeric repeats (present in R. ciliata and R. tenuis) revealed linear signals at both chromatids, non-centromeric, species-specific satDNAs formed distinct clusters along the chromosomes. Colocalisation of both repeat types resulted in a ladder-like hybridisation pattern at mitotic chromosomes. In interphase, the centromeric satDNA was dispersed while non-centromeric satDNA clustered and partly colocalised to chromocentres. Despite the banding-like hybridisation patterns of the clustered satDNA, the identification of chromosome pairs was impaired due to the irregular hybridisation patterns of the homologues in R. tenuis and R. ciliata. These differences are probably caused by restricted or impaired meiotic recombination as reported for R. tenuis, or alternatively by complex chromosome rearrangements or unequal condensation of homologous metaphase chromosomes. Thus, holocentricity influences the chromosomal organisation leading to differences in the distribution patterns and condensation dynamics of centromeric and non-centromeric satDNA.     

Linkage mapping in prairie cordgrass (<Emphasis Type="Italic">Spartina pectinata</Emphasis> Link) using genotyping-by-sequencing

Prairie cordgrass (Spartina pectinata Link) is a polyploid Chloridoid grass with tetraploid (2n = 40), hexaploid (2n = 60), and octoploid (2n = 80) cytotypes and is a potential dedicated energy crop with promising yields in marginal environments. Efforts to breed prairie cordgrass are currently hampered by the lack of a linkage map, the lack of a Chloridoid reference genome, and the lack of information on inheritance patterns (disomic versus polysomic). Genotyping-by-sequencing (GBS) was applied to a population of 85 progenies from a reciprocal cross of heterozygous tetraploid parents. A total of 26,418 SNPs were discovered, with a distribution of allele frequencies suggesting disomic inheritance. A filtered set of 3034 single-dose, high-coverage SNPs was used for pseudo-testcross mapping with 63 progenies, resulting in two parental maps of 20 linkage groups containing 1522 and 1016 SNPs and a nearly 1:1 ratio of coupling to repulsion phase linkages, again suggesting disomic inheritance. Genomic contigs from tef, another Chloridoid grass, were used as a bridge to associate genetic markers in prairie cordgrass with unique positions in the sorghum genome, providing a glimpse into synteny between Chloridoids and other grasses. GBS enabled rapid generation of a linkage map that will aid in future breeding and genomics efforts in prairie cordgrass.     

Geographic patterns of genetic variation in nuclear and chloroplast genomes of two related oaks (<Emphasis Type="Italic">Quercus aliena</Emphasis> and <Emphasis Type="Italic">Q. serrata</Emphasis>) in Japan: implications for seed and seedling transfer

In this study, we assessed geographic patterns of genetic variations in nuclear and chloroplast genomes of two related native oaks in Japan, Quercus aliena and Q. serrata, in order to facilitate development of genetic guidelines for transfer of planting stocks for each species. A total of 12 populations of Q. aliena and 44 populations of Q. serrata were analyzed in this study. Genotyping of nuclear microsatellites in Q. aliena was done with only nine populations (n = 212) due to limited numbers of individuals in two populations, while all 12 populations (n = 89) were used in sequencing chloroplast DNA (cpDNA). In Q. serrata, 43 populations (n = 1032) were genotyped by nuclear microsatellite markers, while cpDNA of 44 populations (n = 350) was sequenced. As anticipated, geographic patterns detected in the variations of Q. aliena’s nuclear genome and its chloroplast haplotype distribution clearly distinguished northern and southern groups of populations. However, those of Q. serrata were inconsistent. The geographic distribution of its chloroplast haplotypes tends to show the predicted differentiation between northern and southern lineages, but geographic signals in the genetic structure of its nuclear microsatellites are weak. Therefore, treating northern and southern regions of Japan as genetically distinct transferrable zones for planting stocks is highly warranted for Q. aliena. For Q. serrata, the strong NE-SW geographic structure of cpDNA should be considered.     

Phylogenetic Diversity and In Vitro Susceptibility Profiles of Human Pathogenic Members of the <Emphasis Type="Italic">Fusarium fujikuroi</Emphasis> Species Complex Isolated from South India

Availability of molecular methods, gene sequencing, and phylogenetic species recognition have led to rare fungi being recognized as opportunistic pathogens. Fungal keratitis and onychomycosis are fairly common mycoses in the tropics, especially among outdoor workers and enthusiasts. The frequently isolated etiological agents belong to genera Candida, Aspergillus, and Fusarium. Within the genus Fusarium, known to be recalcitrant to prolonged antifungal treatment and associated with poor outcome, members of the Fusarium solani species complex are reported to be most common, followed by members of the Fusarium oxysporum SC and the Fusarium fujikuroi SC (FFSC). Morphological differentiation among the various members is ineffective most times. In the present study, we describe different species of the FFSC isolated from clinical specimen in south India. All twelve isolates were characterized up to species level by nucleic acid sequencing and phylogenetic analysis. The molecular targets chosen were partial regions of the internal transcribed spacer rDNA region, the panfungal marker and translation elongation factor-1α gene, the marker of choice for Fusarium speciation. Phylogenetic analysis was executed using the Molecular Evolutionary Genetics Analysis software (MEGA7). In vitro susceptibility testing against amphotericin B, voriconazole, posaconazole, natamycin, and caspofungin diacetate was performed following the CLSI M38-A2 guidelines for broth microdilution method. The twelve isolates of the FFSC were F. verticillioides (n = 4), F. sacchari (n = 3), F. proliferatum (n = 2), F. thapsinum (n = 1), F. andiyazi (n = 1), and F. pseudocircinatum (n = 1). To the best of our knowledge, this is the first report of F. andiyazi from India and of F. pseudocircinatum as a human pathogen worldwide. Natamycin and voriconazole were found to be most active agents followed by amphotericin B. Elderly outdoor workers figured more among the patients and must be recommended protective eye wear.     

Occurrence and distribution of multiple antibiotic-resistant <Emphasis Type="Italic">Enterococcus</Emphasis> and <Emphasis Type="Italic">Lactobacillus</Emphasis> spp. from Indian poultry: in vivo transferability of their erythromycin,tetracycline and vancomycin resistance

The objective of this study was to determine the occurrence and distribution of antibiotic resistant (AR) lactic acid bacteria (LAB) in Indian poultry. LAB from poultry farm feces (n = 21) and samples from slaughter houses comprising chicken intestine (n = 46), raw meat (n = 23), and sanitary water (n = 4) were evaluated and compared with those from organic chicken (OC) collected from nearby villages. Screening studies showed 5–7 log units higher erythromycin (ER), tetracycline (TC) and vancomycin (VAN) resistant LAB from conventional poultry chicken (CC) compared to OC. Molecular characterization of isolated cultures (n = 32) with repetitive-PCR profiling and 16S rRNA gene sequencing revealed their taxonomical status as Enterococcus faecium (n = 16), Enterococcus durans (n = 2), Lactobacillus plantarum (n = 10), Lactobacillus pentosus (n = 1) and Lactobacillus salivarius (n = 3). The isolates were found to harbor erm(B), msr(C), msr(A/B), tet(M), tet(L) and tet(K) genes associated with Tn916 and Tn917 family transposons. Expression studies through real-time PCR revealed antibiotic-induced expression of the identified AR genes. In vitro and in vivo conjugational studies revealed transfer of ER and TC resistant (ER^R and TC^R) genes with transfer frequencies of 10^?7 and 10^?4 transconjugants recipient^?1, respectively. Although no known VAN resistance (VAN^R) genes were detected, high phenotypic resistance was observed and was transferable to the recipient. From a public health point of view, this study reports Indian poultry as a major source of high levels of AR bacteria contaminating the food chain and the environment. Thus, urgent and determined strategies are needed to control the spread of multiple AR bacteria.     

Molecular Epidemiology of Trypanosomatids and <Emphasis Type="Italic">Trypanosoma cruzi</Emphasis> in Primates from Peru

We determined the prevalence rate and risk of infection of Trypanosoma cruzi and other trypanosomatids in Peruvian non-human primates (NHPs) in the wild (n = 126) and in different captive conditions (n = 183). Blood samples were collected on filter paper, FTA cards, or EDTA tubes and tested using a nested PCR protocol targeting the 24Sα rRNA gene. Main risk factors associated with trypanosomatid and T. cruzi infection were genus and the human–animal context (wild vs captive animals). Wild NHPs had higher prevalence of both trypanosomatids (64.3 vs 27.9%, P < 0.001) and T. cruzi (8.7 vs 3.3%, P = 0.057), compared to captive NHPs, suggesting that parasite transmission in NHPs occurs more actively in the sylvatic cycle. In terms of primate family, Pitheciidae had the highest trypanosomatid prevalence (20/22, 90.9%) and Cebidae had the highest T. cruzi prevalence (15/117, 12.8%). T. cruzi and trypanosomatids are common in Peruvian NHPs and could pose a health risk to human and animals that has not been properly studied.     

Description of Freshwater Bacterial Assemblages from the Upper Paraná River Floodpulse System,Brazil

Bacteria were identified from a large, seasonally flooded river (Paraná River, Brazil) and two floodplain habitats that were part of the same river system yet very different in nature: clearwater Garças Lagoon and the highly humic waters of Patos Lagoon. Bacterioplankton were collected during mid-summer (Jan. 2002) from water samples (2 l) filtered first through a 1.2-μm filter then a 0.2-μm membrane filter representing the particle-attached and free-living sub-communities, respectively. DNA was extracted from filters and purified and a 16S rRNA clone library established for each habitat. Over 300 clones were sequenced and checked for similarity to existing 16S sequences in GenBank using the BLAST algorithm with default parameters. Further classification of clones was done using a species “backbone” attachment followed by parsimony analysis. The majority (85%) of sequences, referred to here as operational taxonomic units (OTUs), were most similar to uncultured bacterium 16S sequences. OTUs from each Proteobacteria sub-phylum (α, β, γ, δ, ?) were present in the Upper Paraná River system, as well as members of the Bacteroidetes. The microbial assemblage from Patos Lagoon was least like other samples in that it had no Firmicutes present and was dominated by Actinobacteria. Verrucomicrobia OTUs were only found in the free-living assemblage. This study documents the presence of globally distributed phyla in Upper Paraná River and taxa unique to habitat and particle attachment.     

Molecular analysis reveals hidden diversity in <Emphasis Type="Italic">Zungaro</Emphasis> (Siluriformes: Pimelodidade): a genus of giant South American catfish

The genus Zungaro contains some of the largest catfish in South America. Two valid species are currently recognized: Zungaro jahu, inhabiting the Paraná and Paraguay basins, and Zungaro zungaro, occurring in the Amazonas and Orinoco basins. Analysing Zungaro specimens from the Amazonas, Orinoco, Paraguay and Paraná basins, based on the sequencing of COI and D-loop, we found at least three MOTUs, indicating the existence of hidden diversity within this fish group. Considering the ecological and economic values of this fish, our results are surely welcomed for its conservation, disclosing new findings on its diversity and pointing out the necessity for a detailed taxonomic revision.     

Molecular cytogenetic characterization of <Emphasis Type="Italic">Triticum timopheevii</Emphasis> chromosomes provides new insight on genome evolution of <Emphasis Type="Italic">T. zhukovskyi</Emphasis>

Triticum timopheevii (2n = 4x = 28, GGA^tA^t) is a tetraploid wheat formerly cultivated in western Georgia. The natural allopolyploid Triticum zhukovskyi is a hexaploid taxon originated from hybridization of T. timopheevii with cultivated einkorn T. monococcum (2n = 2x = 14, A^mA^m). Karyotypically T. timopheevii and T. zhukovskyi differ from other tetraploid and hexaploid wheats and were assigned to the section Timopheevii of the genus Triticum L. Triticum timopheevii and T. zhukovskyi are resistant to many fungal diseases and therefore could potentially be utilized for wheat improvement. We were aiming to precisely identify all T. timopheevii chromosomes and to trace the evolution of T. zhukovskyi. For this, we developed a set of molecular cytogenetic landmarks based on eleven DNA probes. Each chromosome can now be characterized by two to eight probes. The pTa-535 sequence allows the identification of all A^t-genome chromosomes, whereas G-genome and some A^t-genome chromosomes can be identified using (GAA/CTT) _n and pSc119.2 probes. The probes pAesp_SAT86, pAs1, Spelt-1, Spelt-52 and 5S and 45S rDNA can be applied as additional markers to discriminate particular chromosomes or chromosomal regions. The distribution of (GAA/CTT) _n , pTa-535 and pSc119.2 DNA probes on T. timopheevii chromosomes is distinct from other tetraploid wheats and can therefore be used to track individual chromosomes in introgression programs. Our study confirms the origin of T. zhukovskyi from hybridization of T. timopheevii with T. monococcum; however, we show that the emergence was accompanied by changes involving mostly A^t-genome chromosomes. This may be due to the presence of two closely related A-genomes in the T. zhukovskyi karyotype.     

Karyo-taxonomic study of the genus<Emphasis Type="Italic">Pseudolysimachion</Emphasis> (<Emphasis Type="Italic">Scrophulariaceae</Emphasis>) in the Czech Republic and Slovakia

Flow cytometry was used to determine ploidy levels in the Czech and Slovak taxa of the genusPseudolysimachion (W.D.J. Koch)Opiz (=Veronica auct. p.p.,Scrophulariaceae). In total, 123 populations from the Czech Republic, Slovakia, Ukraine (one locality), Austria (one locality) and Hungary (one locality) were analyzed. InP. maritimum (L.)Á. Löve etD. Löve andP. spicatum (L.)Opiz, two cytotypes were found: diploid (2n=2x=34) and tetraploid (2n=4x=68). In both species the tetraploid cytotype predominated (P. maritimum: 41 tetraploid populations out of 45;P. spicatum: 57 tetraploid populations out of 58). The two cytotypes ofP. maritimum have no taxonomic significance because ploidy level is not obviously correlated with morphology, distribution pattern or ecology. Tetraploid populations ofP. spicatum belong to two morphologically different subspecies, subsp.spicatum and subsp.fischeri Trávní?ek. The diploid cytotype (one population only) should be provisionally classified as a third subspecies ofP. spicatum, which is morphologically similar to the Asian subsp.porphyrianum (Pavlov)Trávní?ek. Only diploid plants (2n=2x=34) ofP. orchideum (Crantz)Wraber were found; all 13 populations that were analyzed belong toP. orchideum s.str. One diploid population sample ofP. spurium subsp.foliosum (Waldst. etKit.)Holub (2n=2x=34) and one tetraploid sample ofP. incanum subsp.pallens (Host)Trávní?ek (2n=4x=68) were also analyzed. In addition, three tetraploid populations of hybrid origin were investigated:P. maritimum ×P. spicatum subsp.spicatum (one population) andP. maritimum ×P. spurium subsp.foliosum (two populations). While hybrid plants ofP. maritimum ×P. spicatum arose from tetraploid parental species, plants ofP. maritimum ×P. spurium probably resulted from a cross between tetraploidP. maritimum and diploidP. spurium. The putative origin and evolutionary importance of polyploids in thePseudolysimachion are discussed.     

Genetic differentiation in the polyploid complex of <Emphasis Type="Italic">Suaeda corniculata</Emphasis> (C.A. Mey.) Bunge in Eastern Siberia

Data on differentiation of the polyploid complex of Suaeda corniculata (C.A. Mey.) Bunge in East Siberia based on variability of morphological characteristics, karyological analysis, and genetic polymorphism in inter simple sequence repeat (ISSR) markers were given for the first time. It was established that the samples studied belonged to three cytotypes: diploids (2n = 2x = 18), tetraploids (2n = 4x = 36) and hexaploids (2n = 6x = 54). The analysis of variability of morphological characteristics by the method of principal coordinates showed division of the samples into three separate groups. On the basis of morphological and molecular-genetic methods, a genetically differentiated diploid population was revealed in Yakutia.     

Selection of Potential Probiotic <Emphasis Type="Italic">Lactobacillus</Emphasis> with Inhibitory Activity Against <Emphasis Type="Italic">Salmonella</Emphasis> and Fecal Coliform Bacteria

Three hundred and sixty presumptive lactic acid bacteria (LAB) isolated from pregnant sows, newborn, suckling, and weaned piglets were preliminarily screened for anti-Salmonella activity. Fifty-eight isolates consisting of Lactobacillus reuteri (n = 32), Lactobacillus salivarius (n = 10), Lactobacillus mucosae (n = 8), Lactobacillus johnsonii (n = 5), and Lactobacillus crispatus (n = 3) were selected and further characterized for probiotic properties including production of antimicrobial substances, acid and bile tolerance, and cell adherence to Caco-2 cells. Eight isolates including Lact. johnsonii LJ202 and Lact. reuteri LR108 were identified as potential probiotics. LJ202 was selected for further use in co-culture studies of two-bacterial and multiple-bacterial species to examine its inhibitory activity against Salmonella enterica serovar Enteritidis DMST7106 (SE7106). Co-culture of LJ202 and SE7106 showed that LJ202 could completely inhibit the growth of SE7106 in 10 h of co-culture. In co-culture of multiple-bacterial species, culturable fecal bacteria from pig feces were used as representative of multiple-bacterial species. The study was performed to examine whether interactions among multiple-bacterial species would influence antagonistic activity of LJ202 against SE7106 and fecal coliform bacteria. Co-culture of SE7106 with different combinations of fecal bacteria and probiotic (LJ202 and LR108) or non-probiotic (Lact. mucosae LM303) strains revealed that the growth of SE7106 was completely inhibited either in the presence or in the absence of probiotic strains. Intriguingly, LJ202 exhibited notable inhibitory activity against fecal coliform bacteria while LR108 did not. Taken together, the results of co-culture studies suggested that LJ202 is a good probiotic candidate for further study its inhibitory effects against pathogen infections in pigs.     

The recent occurrence,establishment and potential impact of <Emphasis Type="Italic">Geophagus proximus</Emphasis> (Cichlidae: Perciformes) in the Tietê River reservoirs: an Amazonian fish species introduced in the Paraná Basin (Brazil)

The introduction of allochthonous fish species happens constantly in large bodies of freshwater, like as the reservoirs of Paraná Basin, located in Brazilian southeast, representing a threat for local biodiversity. The fish species Plagioscion squamosissimus and Cichla ocellaris were introduced from the 1970s in several water bodies of this basin and had successfully established themselves in all six reservoirs located in the middle and lower Tietê River (SP, Brazil), particularly. After six decades from the first recorded species introduction, this hydrographic system remains open to the invasion of further fish species, owing to widespread fish-farming activity and by the channels opened between this system and other reservoirs and river basin. This study was an effort to confirm the Geophagus proximus occurrence in the six Tietê River reservoirs, verifying the actual introduction status and analyzing its potential environmental impacts on local species by the analysis of the population structure (abundance, body dimensions and feeding habits). By the results, this species was confirmed in the Ibitinga, Nova Avanhandava and Três Irmãos reservoirs. The abundance and feeding analysis shows, respectively, it is successfully established in the Três Irmãos reservoir with the same feeding habitats of local species, such as Geophagus brasiliensis. It was further shown to be very likely that G. proximus would spread throughout the reservoir system of the middle and lower Tietê River, in the manner of P. squamosissimus and C. ocellaris, and the competition pressure for food resources between G. proximus and the local species which represents a potential environmental impact system. These scientific evidences fortifies the knowledge basin for the implantation of a fish management system, to control and reduce the abundance of the invader and to prevent its becoming established in all the Tietê River Basin, avoiding the disastrous consequences for the native species of Paraná River Basin.     

Growth dynamics of juvenile loggerhead sea turtles undergoing an ontogenetic habitat shift

Ontogenetic niche theory predicts that individuals may undergo one or more changes in habitat or diet throughout their lifetime to maintain optimal growth rates, or to optimize trade-offs between mortality risk and growth. We combine skeletochronological and stable nitrogen isotope (δ¹⁵N) analyses of sea turtle humeri (n = 61) to characterize the growth dynamics of juvenile loggerhead sea turtles (Caretta caretta) during an oceanic-to-neritic ontogenetic shift. The primary objective of this study was to determine how ontogenetic niche theory extends to sea turtles, and to individuals with different patterns of resource use (discrete shifters, n = 23; facultative shifters n = 14; non-shifters, n = 24). Mean growth rates peaked at the start of the ontogenetic shift (based on change in δ¹⁵N values), but returned to pre-shift levels within 2 years. Turtles generally only experienced 1 year of relatively high growth, but the timing of peak growth relative to the start of an ontogenetic shift varied among individuals (before, n = 14; during, n = 12; after, n = 8). Furthermore, no reduction in growth preceded the transition, as is predicted by ontogenetic niche theory. Annual growth rates were similar between non-transitioning turtles resident in oceanic and neritic habitats and turtles displaying alternative patterns of resource use. These results suggest that factors other than maximization of size-specific growth may more strongly influence the timing of ontogenetic shifts in loggerhead sea turtles, and that alternative patterns of resource use may have limited influence on somatic growth and age at maturation in this species.     

Morpho-Molecular Characterization of Soil Inhabitant Dermatophytes from Ahvaz,Southwest of Iran,a High Occurrence of <Emphasis Type="Italic">Microsporum fulvum</Emphasis>

Occurrence and diversity of dermatophyte mycoflora in 298 soil samples from Ahvaz, Southwest of Iran was investigated by using the hair-baiting technique. The samples were collected during spring (n = 210) and autumn (n = 88) of 2015, and the fungal isolates were identified based on the macro- and micro-morphology of colonies and with further ITS-rDNA RFLP and sequencing. Totally, 60 soil samples (20.1%) were positive for dermatophyte growth whose pH varied from 7.0 to 7.9. The highest (26.6%) and the lowest (14.3%) recovery rates were from the animal resorts and the streets soils samples, respectively. Seasonally, 16.7% of the spring samples and 28.4% of the autumn samples were positive. Based on molecular identification, three species of two genera were identified viz. M. fulvum (n = 57), M. canis (n = 2) and zoophilic Trichophyton interdigitale (n = 1). As a specific goal in the study, differentiation of the species in Microsporum gypseum complex was established by measuring the mean length and width of macroconidia in some strains of M. gypseum, M. fulvum and M. incurvatum. Mean size for macroconidia length and width in three species showed that M. gypseum and M. incurvatum can morphologically be differentiated from M. fulvum but not from each other. M. fulvum was the most abundant species isolated from the soils of Ahvaz; however, to comprehensively specify the distribution pattern of geophilic dermatophytes in the soils of this city further investigations are needed. Identification based on micro-morphometric is not effective for species distinction in M. gypseum complex, while molecular procedures based on sequencing of certain DNA regions are the most reliable and applicable strategies for this purpose.     

Assessment of genetic diversity and differentiation of <Emphasis Type="Italic">Liposcelis bostrychophila</Emphasis> (Psocoptera: Liposcelidae) in China using inter-simple sequence repeat (ISSR) fingerprinting

Liposcelis bostrychophila (Psocoptera: Liposcelidae) is a widely distributed pest that can cause considerable economic losses and pose human health risks. Rapid development of insecticide resistance has made L. bostrychophila increasingly difficult to control. To obtain information potentially useful for pest management, genetic diversity and differentiation of L. bostrychophila from five geographic locations in China was studied using inter-simple sequence repeat (ISSR). A total of 104 loci were found by ISSR markers and amplified using 9 selected primers. The percentage of polymorphic bands (PPB) was 91.4%. Shannon’s information index (I) and Nei’s gene diversity (He) indicated high genetic diversity at the species level. Population differentiation (Gst = 0.484) was average in these populations. Analysis of molecular variation (AMOVA) indicated that genetic variation was mainly distributed within populations. Gene flow (Nm = 0.534) was moderate. Cluster analysis showed that genotypes isolated from the same locations displayed higher genetic similarity and permitted the grouping of isolates of L. bostrychophila into three distinct clusters. The correlation between genetic distance and geographic distance was not significant.     

Early characterization of somatic hybrids from symmetric protoplast electrofusion of <Emphasis Type="Italic">Solanum pinnatisectum</Emphasis> Dun. and <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.

Variability of 31 somatic hybrids of Solanum pinnatisectum Dun. with Solanum tuberosum L. for leaf morphology, plant vigor, resistance to Phytophthora infestans, ploidy level, and cytoplasm type was evaluated in vitro. The composition of these somatic hybrids was as follows: [S. pinnatisectum Dun. (2n = 2x = 24; cytoplasmic type Wγ) + S. tuberosum L. (2n = 4x = 48; cytoplasmic type Tß)]. Based on leaf morphology and plant growth vigor, plants were divided into three groups, including plants close to tbr parent with unlobed leaves, small plants with scarcely dissected leaves, and vigorous plants with asymmetrically and pinnately lobed leaves. Nine of the somatic hybrids were found to be highly resistant to P. infestans. Somatic hybrids were either tetraploid or hexaploid, with hexaploids being predominant. The cytoplasm of somatic hybrids was either Tßγ or Wßγ, with Tßγ being more common. Overall, in contrast to leaf morphology and growth vigor, level of resistance to P. infestans was not related to either ploidy level or type of cytoplasm. These findings demonstrate that early in vitro selection of promising hybrids can be useful in breeding programs.     

Time-calibrated phylogenetic trees establish a lag between polyploidisation and diversification in <Emphasis Type="Italic">Nicotiana</Emphasis> (Solanaceae)

We investigate the timing of diversification in allopolyploids of Nicotiana (Solanaceae) utilising sequence data of maternal and paternal origin to look for evidence of a lag phase during which diploidisation took place. Bayesian relaxed clock phylogenetic methods show recent allopolyploids are a result of several unique polyploidisation events, and older allopolyploid sections have undergone subsequent speciation at the polyploid level (i.e. a number of these polyploid species share a singular origin). The independently formed recent polyploid species in the genus all have mean age estimates below 1 million years ago (Ma). Nicotiana section Polydicliae (two species) evolved 1.5 Ma, N. section Repandae (four species) formed 4 Ma, and N. section Suaveolentes (~35 species) is about 6 million years old. A general trend of higher speciation rates in older polyploids is evident, but diversification dramatically increases at approximately 6 Ma (in section Suaveolentes). Nicotiana sect. Suaveolentes has spectacularly radiated to form 35 species in Australia and some Pacific islands following a lag phase of almost 6 million years. Species have filled new ecological niches and undergone extensive diploidisation (e.g. chromosome fusions bringing the ancestral allotetraploid number, n = 24, down to n = 15 and ribosomal loci numbers back to diploid condition). Considering the progenitors of Suaveolentes inhabit South America, this represents the colonisation of Australia by polyploids that have subsequently undergone a recent radiation into new environments. To our knowledge, this study is the first report of a substantial lag phase being investigated below the family level.