Phyllactinia passiflorae-adenopodae, and Phyllactinia sennae (Erysiphaceae), two new powdery mildew species found in Mexico

Since the first formal description of the unicellular green algae Dunaliella salina, its presence in hypersaline environments worldwide and its physiological responses to different environmental conditions have been studied extensively. Moreover, due to massive carotenoid accumulation by some strains under specific growth conditions, its biotechnological applications have attracted a great deal of scientific interest. In this study, the phylogenetic relationship, growth, and carotenogenesis of a new strain of Dunaliella salina isolated from Maharlu salt lake in Shiraz (latitude 29.26°N, longitude 52.48°E), Iran were investigated. First, a phylogram based on neighbor-joining analysis of the nuclear rDNA ITS (ITS-1 + 5.8 rDNA + ITS-2) sequence data was constructed. The phylogenetic tree showed that the new isolate is part of a major clade containing several strains of D. salina and was designated as D. salina MSI-1. Then, the responses of the new isolate to the initial pH of the culture media and different concentrations of nitrate, NH4+, and citrate were examined. As with other strains of D. salina, growth and carotenogenesis were controlled by the levels of nitrate and NH4+ in the growth media. Low available nitrogen negatively affected growth but enhanced carotenoid accumulation. Insensitivity of carotenogenesis to citrate indicates a minor contribution of cytosolic IPP synthesis to the overall carotenoid production. Despite changes in the initial pH of the culture media over the experimental period, the initial pH had marked effects on the growth and carotenogenesis of the new isolate. These effects, together with the higher cell carotenoid content observed at pH 11.0, await further research. The results confirm that the analysis of the ITS sequences is a reliable basis for determination of the genetic relatedness among strains of the genus Dunaliella, and the search for strains with novel characteristics may have valuable biotechnological applications.

This work presents a reconstruction of the phylogenetic relationships between ten lineages of fescues based on the analysis of nuclear rDNA ITS sequences. Thirty two representatives of most native Western Mediterranean subgenera and sections of Festuca s.l. have been included in this survey in order to establish the evolutionary links between known groups of fescues (subg. Schedonorus, subg. Festuca sect. Festuca and sect. Aulaxyper) and other related Festuca groups that have been poorly studied or that are analyzed here for the first time (subg. Drymanthele, subg. Festuca sect. Subbulbosae, sect. Eskia, sect. Pseudatropis, sect. Scariosae, sect. Pseudoscariosa). Phylogenetic analysis identified two different clades, the “broad-leaved” Festuca and the “fine-leaved” Festuca, using Dactylis, Poa, Deschampsia, Secale, and Brachypodium as outgroups. The “broad-leaved” Festuca clade shows the consecutive sister divergence of the groups: i) the Subbulbosae pro parte clade (some Festuca paniculata s.l. taxa); ii) the Hesperochloa clade (Festuca kingii); iii) the “mixed” clade (incl. sect. Subbulbosae p.p., subg. Drymanthele, sect. Scariosae, and sect. Pseudoscariosa); and iv) the Schedonorus/Lolium clade, subdivided into the “Maghrebian” subclade and the “European + Lolium” subclade. The “fine-leaved” Festuca clade is formed by a paraphyletic assemblage of sectional groups, where sects. Eskia and Pseudatropis are basal to sects. Festuca-Aulaxyper + Vulpia. The closer affinities of Lolium to the European Schedonorus and of Vulpia to Festuca sect. Aulaxyper (”Festuca rubra complex”), stated by previous authors, is confirmed in our analysis. A new nomenclatural combination is proposed (Festuca arundinacea Schreb. subsp. arundinacea var. letourneuxiana (St.-Yves) Torrecilla et Catalán comb. nov.). Communicating Editor: Jeff H. Rettig

Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees of rbcL data show the occurrence of five species of Enteromorpha (E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva (U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide.

Bayesian inference analyses of nuclear LSU rDNA sequences showed Verrucariales and Eurotiales to form the sistergroup of Mycocaliciales. A more detailed analysis of ITS rDNA sequences showed Sphinctrinaceae to be embedded in Mycocaliciaceae. Mycocaliciales contain two major lineages. Intron occurrence and phylogeny was partly congruent with the ITS‐based phylogeny. Chaenothecopsis is paraphyletic with respect to Phaeocalicium, Mycocalicium, Sphinctrina and Stenocybe. Some morphological features traditionally used for characterising Chaenothecopsis and other genera in Mycocaliciales, such as ascus apex structure and stalk anatomy, were found to be homoplasious, while others, such as spore septation, intron distribution and nutritional biology, were consistent with major clades in the analysis. Within the two major clades of Mycocaliciales some subclades are strongly supported and well characterized by anatomical, nutritional and intron features.

Norway maple leaves bearing powdery mildew were collected from one location in the fall of 2003 and four locations (as much as 1.5 km apart) in the fall of 2005 in Buffalo, NY. No powdery mildew was observed on leaves collected from sugar maples (Acer saccharum) that were present in the vicinity of affected Norway maples at two locations. Trees were located along streets and in yards. Diseased leaves were present throughout tree crowns but lower leaves were more commonly affected. White mycelium was present in irregular, discrete, scattered spots only on the upper surface of leaves and on both sides of wings of samaras. Typically, <10% of the upper leaf area bore visible mycelium. Cleistothecia were present singly or in groups on the mycelium. Morphology of cleistothecia on leaves collected each year, including simple and bifid appendages with uncinate to circinate apices, was sufficient to identify the pathogen to the genus Sawadaea (1). Other characteristics were not sufficiently distinct to make an identification of S. bicornis or S. tulasnei (1), each a European species found on Acer spp. However, a sample from 2003 was supplied by the authors for use in a study of phylogeny of the genus (2) that served as a first report of the species in the United States. Analysis of nuclear rDNA ITS sequence of this specimen (GenBank Accession No. AB193390) placed the sample in a clade with S. tulasnei specimens from Europe. In the same study, powdery mildew samples from Acer spp. in Ohio and Montreal, Canada also were placed in this clade. Thus, occurrence of S. tulasnei in North America is confirmed. S. bicornis was recently identified (based on morphology) on Norway maple in the western United States (3). Specimens from Buffalo, NY have been deposited in the U.S. National Fungus Collections (BPI 871210).

The genus Elymus L. sensu lato includes Roegneria, Elymus, Hystrix, Sitanion and Kengyilia, and they are very important group in the tribe Triticeae. However, the phylogenetic relationships and taxonomic status of them are still in dispute. The ITS sequences were obtained and analyzed for their phylogenetic relationships by using Maximum Parsimony (MP) and Bayesian Inference (BI) methods. The main results were as follows: (1) Most species in Roegneria, Elymus and Sitanion were clustered in the St clade with diploid St genome species, and it was difficult to distinguish the species in Roegneria and Elymus; (2) The polyploid species with St genomes in the St clade were divided into three groups, which suggests that there exists differentiation of St genome in polyploids; (3) Most species of Kengyilia have only P-type of clone and clustered with diploid Agropyron species, which may suggest that Kengyilia is a valid genus; (4) Hy. patula, the type species of Hystrix was clustered with species of Elymus, while Hy. duthiei ssp. duthiei, Hy. duthiei ssp. longearistata, Hy. coreana and Hy. komarovii were grouped with diploid Psathyrostachys species. It indicated that Hy. patula is distinct related to other Hystrix species, and it is reasonable to treat Hystrix patula as Elymus hystrix and other species in Hystrix should be transferred to Leymus; (5) The "clones bias" in ITS sequences are widespread in the allopolyploid species.

The identification of two Atlantic kelp species, Laminaria longicruris and L. saccharina, has been controversial. In order to know if these two species are conspecific, plastid‐encoded RuBisCo spacer and nuclear rDNA ITS sequences were analyzed from twelve individuals of L. longicruris, five of L. saccharina, from Connecticut and Nova Scotia. Four individuals of L. digitata from the above coasts were also analyzed as reference in this study. All RuBisCo spacer sequences from L. longicruris and L. saccharina were exactly identical except for one individual with three different nucleotides. Zero to five different nucleotides of ITS sequences, inculding four polymorphic sites, were found in two species. However, their RuBisCo spacer and ITS sequences are quite different from those of L. digitata. These results strongly suggest that L. saccharina (L.) Lamour. 1813 is conspecific with L. longicruris De La Pylaie 1824 and the different local populations, despite various morphotypes, may be genetically very similar.

Study of the Evolutionary Relationships among Limonium Species (Plumbaginaceae) Using Nuclear and Cytoplasmic Molecular Markers

本文就核rDNA (nrDNA)的ITS区序列在植物系统与进化研究中的应用进行了讨论。nrDNA是植物系统发育研究中广泛应用的重要核基因片段。5.8S rDNA把nrDNA的内转录间隔区分为ITS1和ITS2两部分。被子植物中ITS1的长度为165~298 bp，ITS2的长度为177~266 bp；裸子植物中ITS片段较长，且其长度变化主要由ITS1的长度变异所致。由于ITS序列变异较快，能够提供较丰富的变异位点和信息位点，已成为被子植物较低分类阶元的系统发育和分类研究中的重要分子标记，为探讨多倍体复合体网状进化关系，异源多倍体的起源提供了重要的系统学信息。 The application of nuclear rDNA ITS sequences in plant phylogeny and evolution analysis was discussed in this paper. Nuclear rDNA is an important nuclear gene fragment, which had been widely used in phylogenetic studies. The internal transcribed spacer of nuclear rDNA was divided into ITS1 and ITS2 by 5.8S rDNA. The length of ITS1 ranges from 165 bp to 298 bp in angiosperms, and the length of ITS2 ranges from 177 bp to 266 bp. ITS sequence is relatively longer in gymnosperms. It much depends on the length of ITS1. As mutate quickly, ITS sequences are capable of providing many variable sites and informative sites, which has become an important molecular marker in plant systematic development and classification researches within low-order angiosperm categories. AT the same time, it can prove important systematic information for exploring polyploidy reticulate evolution and allopolyploid origins.

A B S T R A C T In addition to biochemical, physiological and morphological analysis, molecular studies provide additional information for establishing phylogenetic relationships amo ng different species and strains of the genus Dunaliella. In the present study, based on neighbor - joining analysis of the nuclear rDNA ITS sequence, a novel strain of the green algae Dunaliella viridis was identified from Maharlu salt lake in Shiraz, Iran . The phylogenetic tree shows that the new strain is part of a clade containing several strains of D. viridis. The new strain was designated Dunaliella viridis MSV-1 and submitted to the GenBank under the accession number HQ864830. The optimum salinity for MSV-1 growth is between 1.0 to 1.5 M NaCl and does not turn red up to 4.5 M NaCl, confirming identity of the isolated strain. With respect to growth response to copper toxicity, increase in Cu 2+ concentration from 1 to 30 µM, caused progressive increase in cell number ml -1 of culture over time, whereas reduction in cell number occurred at 100 and 200 µM Cu +2 . Nano copper (colloidal copper with 40 nm dimensions) showed less toxicity compared to the ionic form. Cell number ml -1 of culture did not change up to 200 µM nano copper but decreased at 500 µM. In conclusion, the analysis of the ITS sequence is a reliable basis for establishing evolutionary relationships among species and strains of the genus Dunaliella and due to rapid growth at 1.5 M NaCl and high cell density, D. viridis MSV-1 is a good candidate for biofuel production from microalgae.

The morphologically uniform species Gonium pectorale is a colonial green flagellate of worldwide distribution. The affinities of 25 isolates from 18 sites on five continents were assessed by both DNA sequence comparisons and sexual compatibility. Complete sequences were obtained (i) for the internal transcribed spacer ITS-1 and ITS-2 regions of ribosomal DNA and (ii) for each of three single-copy spliceosomal introns, two in a small G protein and one in the actin gene. ITS sequences appeared to homogenize sufficiently rapidly to behave as a single copy gene. Intron sequence differences between isolates in this species reached nucleotide substitution saturation, while ITS sequences did not. Parsimony and evolutionary distance analysis of the two types of DNA data gave essentially the same tree conformation. By all these criteria, the group of G. pectorale isolates fell into two main clades, A and B. Clade A, with isolates from four continents, was comprised of four subclades of quite closely related isolates, plus one strain of ambiguous affinity. Clade B was comprised of two subclades represented by South African and South American isolates, respectively; thus, only subclades of clade B showed geographical localization. With respect to mating, all isolates except one homothallic strain and one apparently sterile strain fell into either one or the other of two mating types. Pairings in all possible combinations revealed that isolates from the same site formed abundant zygotes, which germinated to produce new, sexually active organisms. Zygotes were also formed in many pairings of other combinations, including crosses of clade A with clade B organisms, but none of the latter produced viable germlings. The ability to mate and produce viable progeny that were themselves capable of sexual reproduction was restricted to members of subclades established on the basis of DNA sequence similarities. Thus, the grades of difference in both nuclear intron sequences and rDNA ITS sequences paralleled those observed in the sexual analysis.

This study represents a nuclear rDNA ITS-based phylogenetic analyses of a greater sampling of the Old WorldAstragalus compared to our previous work (212 vs. 134 taxa). Phylogenetic relationships among 212 species (213 accessions) of the Old WorldAstragalus, including newly segregated monotypic genusPodlechiella, the two aneuploid New WorldAstragalus, and five related genera, were inferred from analyses of nuclear rDNA ITS sequences using maximum parsimony. A total of 658 nucleotide sites and four binary characters for indels were analyzed. The results of phylogenetic analyses suggest sect.Phyllolobium, comprising mostly the Chinese species, is placed outside of the so-calledAstragalus s. str. and is a well-supported monophyletic group. The monotypic annual segregate genusThlaspidium (≡Astragalus sect.Thlaspidium, A. thlaspi), is clearly nested withinAstragalus s. str. Among the many sections analyzed here, only sects.Cenanthrum, Caraganella, Eremophysa, Incani, Laxiflori, andLotidium are strongly supported as monophyletic. Our analysis, in agreement with previous studies, shows that the North American euploidAstragalus species are scattered throughout the Old World groups of the genus.

Leaves affected by powdery mildew were collected from a Norway maple tree in early October 2007 in Beaver Dam, WI (Dodge County). Diseased leaves were present throughout the crown of this tree, with white mycelium in irregular and often vein-associated spots and often covering as much as 50% of the upper surfaces of leaves. Examination of the lower surfaces revealed necrosis of the areas underlying mycelium. Blades of samaras also bore white mycelium. Chasmothecia were present singly or in groups on the mycelium. Morphology of chasmothecia, including simple and bifid appendages with uncinate to circinate apices, was sufficient to identify the pathogen to the genus Sawadaea (1). Data for nuclear rDNA ITS sequence (546 bp) obtained for a specimen (GenBank Accession No. EU247884) exactly matched sequences for Sawadea tulasnei (GenBank Accession Nos. AB 193363, 478 bp; AB193385, 490 bp; AB193390 and AB193391, 546 bp). This data was 96% similar (528 of 552 nucleotides) to that of another European powdery mildew pathogen, S. bicornis (GenBank Accession No. AB193380), which is also reported to occur on maples in Idaho, Washington, and Wisconsin (2,3). A further survey revealed the same fungus on several additional nearby Norway maples along streets and in yards (including varieties with both darkly colored and variegated leaves), but on these trees very few leaves were affected and usually less than 5% of the upper leaf surfaces bore mycelium. This pathogen was not observed on leaves of either red (A. rubrum) or silver maples (A. saccharinum) examined in the same area. S. tulasnei was previously known in North America only by collections in New York, Ohio, and Montreal, Canada (4), but our observation indicates that the geographic distribution of this pathogen is probably much broader and overlaps with that of S. bicornis. Specimens from Beaver Dam, WI have been deposited in the U.S. National Fungus Collections (BPI 878273).

The taxonomic history of members of the 37-collar-spine group within the genus. Echinostoma has been very confused. We obtained DNA sequence data from the nuclear rDNA ITS1, 5.8S and ITS2 of 7 nominal species belonging to this group, Echinostoma trivolvis (Cort, 1914), E. revolutum (Frölich, 1802), E. caproni Richard, 1964, E. liei Jeyarasasingam et al. 1972, E. paransei Lie & Basch, 1967, two African isolates, E. sp.I and E. sp.II, and of one 28-collar-spined echinostome, E. hortense (Asada, 1926). Five of the eight species were clearly distinguishable using ITS data. Sequences from the remaining three taxa, E. caproni, E. sp.II and E. liei were identical to one another and the group containing these taxa was distant from other 37-collar-spine species on a phylogenetic tree. E. trivolvis and E. paraensei form a second, but less distinct group within the 37-collar-spine group. The resolution obtained using DNA sequencing will assist in the current reclassification of the group. It also provides a model for future work on sibling species.

It has been suggested that southern Africa is the origin of the predominantly herbaceous Apiaceae subfamily Apioideae and that the woody habit is plesiomorphic. We expand previous molecular phylogenetic analyses of the family by considering all but three of the approximately 38 genera native to southern Africa, including all genera whose members, save one, have a woody habit. Representatives of five other genera are included because they may be closely related to these southern African taxa. Chloroplast DNA rps16 intron and/or nuclear rDNA ITS sequences for 154 accessions are analyzed using maximum parsimony, Bayesian, and maximum likelihood methods. Within Apioideae, two major clades hitherto unrecognized in the subfamily are inferred. The monogeneric Lichtensteinia clade is sister group to all other members of the subfamily, whereas the Annesorhiza clade (Annesorhiza, Chamarea, and Itasina) plus Molopospermum (and Astydamia in the ITS trees) are the successive sister group to all Apioideae except Lichtensteinia. Tribe Heteromorpheae is expanded to include Pseudocarum, "Oreofraga" ined., and five genera endemic to Madagascar. The southern African origin of subfamily Apioideae is corroborated (with subsequent migration northward into Eurasia along two dispersal routes), and the positions of the herbaceous Lichtensteinia and Annesorhiza clades within the subfamily suggest, surprisingly, that its ancestor was herbaceous, not woody.