scholarly journals A Morphological and Molecular Analysis of a Bloom of the Filamentous Green Alga Pithophora

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 760
Author(s):  
Blia Lor ◽  
Merry Zohn ◽  
Marcus J. Meade ◽  
A. Bruce Cahoon ◽  
Kalina M. Manoylov

Filamentous representatives of Cladophorales (Chlorophyta) are major contributors to algal biomass of littoral communities. In the present study, community analysis of a reported bloom in the Ogeechee River in Georgia provided an opportunity to combine morphological and genetic analyses with ecological information related to an understudied nuisance alga. A polyphasic approach of incorporating genotypic and phenotypic methods led to the identification of the algal community as Pithophora roettleri (Roth) Wittrock. Morphological analysis showed a monospecific community based on the average length and diameter of the heterosporous intercalary and terminal akinetes, along with the diameter of the principal filaments. Single-gene and concatenated-gene phylogenetic analyses of the LSU (28S rRNA) and SSU (18S rRNA) markers further confirmed this species identification. In this study, we conducted a morphological treatment of P. roettleri, produced 17 novel gene sequences, and produced a new, schematic diagram illustrating the four steps of the asexual reproduction of an intercalary akinete. Morphological characteristics, like the position and shape of akinetes documented here, and the availability of genetic sequences can improve identification and further ecological understanding of filamentous green algae. Flowing mats of P. roettleri, like those observed in this study, can lower light availability for other biota and structurally alter the habitat.

Phytotaxa ◽  
2020 ◽  
Vol 474 (3) ◽  
pp. 218-234
Author(s):  
YI-JYUN CHEN ◽  
RUVISHIKA S. JAYAWARDENA ◽  
CHITRABHANU S. BHUNJUN ◽  
DULANJALEE L. HARISHCHANDRA ◽  
KEVIN D. HYDE

A cercosporoid fungus associated with leaf lesions of Dypsis lutenscens (Arecaceae) was observed in Chiang Rai, Thailand. This study describes the new species Pseudocercospora dypsidis based on morphological characteristics and phylogenetic analyses from three gene regions, ITS, TEF-1α, and ACT. Single gene analyses are generally insufficient for identification of Pseudocercospora species, or for segregation of other genera in the Pseudocercospora complex. A list is provided of all Pseudocercospora species known from Thailand and the need to confirm their identifications by a polyphasic approach is stressed.


2019 ◽  
Author(s):  
Angie M. Macias ◽  
David M. Geiser ◽  
Jason E. Stajich ◽  
Piotr Łukasik ◽  
Claudio Veloso ◽  
...  

AbstractThe fungal genus Massospora (Zoopagomycota: Entomophthorales) includes more than a dozen obligate, sexually transmissible pathogenic species that infect cicadas (Hemiptera) worldwide. At least two species are known to produce psychoactive compounds during infection, which has garnered considerable interest for this enigmatic genus. As with many Entomophthorales, the evolutionary relationships and host associations of Massospora spp. are not well understood. The acquisition of M. diceroproctae from Arizona, M. tettigatis from Chile, and M. platypediae from California and Colorado provided an opportunity to conduct molecular phylogenetic analyses and morphological studies to investigate if these fungi represent a monophyletic group and delimit species boundaries. In a three-locus phylogenetic analysis including the D1–D2 domains of the nuclear 28S rRNA gene (28S), elongation factor 1 alpha-like (EFL), and beta-tubulin (BTUB), Massospora was resolved in a strongly supported monophyletic group containing four well-supported genealogically exclusive lineages, based on two of three methods of phylogenetic inference. There was incongruence among the single-gene trees: two methods of phylogenetic inference recovered trees with either the same topology as the 3-gene concatenated tree (EFL), or a basal polytomy (28S, BTUB). Massospora levispora and M. platypediae isolates formed a single lineage in all analyses and are synonymized here as M. levispora. Massospora diceroproctae was sister to M. cicadina in all three single-gene trees and on an extremely long branch relative to the other Massospora, and even the outgroup taxa, which may reflect an accelerated rate of molecular evolution and/or incomplete taxa sampling. The results of the morphological study presented here indicate that spore measurements may not be phylogenetically or diagnostically informative. Despite recent advances in understanding the ecology of Massospora, much about its host range and diversity remains unexplored. The emerging phylogenetic framework can provide a foundation for exploring co-evolutionary relationships with cicada hosts and the evolution of behavior-altering compounds.


Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2825-2842 ◽  
Author(s):  
Clemen J. Oliveira ◽  
Sergei A. Subbotin ◽  
Sergio Álvarez-Ortega ◽  
Johan Desaeger ◽  
Janete A. Brito ◽  
...  

Two Florida populations of foliar nematodes were collected from strawberries originating from Cashiers, North Carolina (USA) located west from Willard, the type locality of Aphelenchoides besseyi. Both nematodes were cultured on Monilinia fructicola and identified using morphological characteristics and molecular assays as Aphelenchoides besseyi and Aphelenchoides pseudogoodeyi sp. n., a herein described new species related to Aphelenchoides goodeyi belonging to the Group of Aphelenchoides exhibiting stellate tails. The morphological and biological characters of Florida A. besseyi fit those of the original description of this species. A. pseudogoodeyi sp. n., which was initially misidentified as Aphelenchoides fujianensis, differed from the type population of the latter species from China because it was without males, and females lacked a functional spermatheca, whereas type A. fujianensis is an amphimictic species. Phylogenetic analyses using near full-length 18S ribosomal RNA (rRNA), the D2-D3 expansion fragments of 28S rRNA, and partial COI gene sequences indicated that A. besseyi is a species complex. A. pseudogoodeyi sp. n. grouped in different clades from those of the type A. fujianensis, instead merging with populations identified of ‘A. fujianensis’ from Brazil and other countries, suggesting that the latter are conspecific and incorrectly identified. The Florida A. besseyi infected strawberry and gerbera daisy, but not soybean and alfalfa. A. pseudogoodeyi sp. n. is mainly mycetophagous. Localized inoculation of 300 specimens applied with filter paper adhering to the blade of the soybean leaves resulted in nematode penetration into the mesophyll with subsequent development of lesions limited to the inoculated area of the blade.


2021 ◽  
Vol 95 ◽  
Author(s):  
B. Neov ◽  
G.P. Vasileva ◽  
G. Radoslavov ◽  
P. Hristov ◽  
D.T.J. Littlewood ◽  
...  

Abstract The aim of the study is to test a hypothesis for the phylogenetic relationships among mammalian hymenolepidid tapeworms, based on partial (D1–D3) nuclear 28S ribosomal RNA (rRNA) genes, by estimating new molecular phylogenies for the group based on partial mitochondrial cytochrome c oxidase I (COI) and nuclear 18S rRNA genes, as well as a combined analysis using all three genes. New sequences of COI and 18S rRNA genes were obtained for Coronacanthus integrus, C. magnihamatus, C. omissus, C. vassilevi, Ditestolepis diaphana, Lineolepis scutigera, Spasskylepis ovaluteri, Staphylocystis tiara, S. furcata, S. uncinata, Vaucherilepis trichophorus and Neoskrjabinolepis sp. The phylogenetic analyses confirmed the major clades identified by Haukisalmi et al. (Zoologica Scripta 39: 631–641, 2010): Ditestolepis clade, Hymenolepis clade, Rodentolepis clade and Arostrilepis clade. While the Ditestolepis clade is associated with soricids, the structure of the other three clades suggests multiple evolutionary events of host switching between shrews and rodents. Two of the present analyses (18S rRNA and COI genes) show that the basal relationships of the four mammalian clades are branching at the same polytomy with several hymenolepidids from birds (both terrestrial and aquatic). This may indicate a rapid radiation of the group, with multiple events of colonizations of mammalian hosts by avian parasites.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 202
Author(s):  
Jianghua Chen ◽  
Zihang Zhu ◽  
Yanping Fu ◽  
Jiasen Cheng ◽  
Jiatao Xie ◽  
...  

Considering the huge economic loss caused by postharvest diseases, the identification and prevention of citrus postharvest diseases is vital to the citrus industry. In 2018, 16 decayed citrus fruit from four citrus varieties—Satsuma mandarin (Citrus unshiu), Ponkan (Citrus reticulata Blanco cv. Ponkan), Nanfeng mandarin (Citrus reticulata cv. nanfengmiju), and Sugar orange (Citrus reticulata Blanco)—showing soft rot and sogginess on their surfaces and covered with white mycelia were collected from storage rooms in seven provinces. The pathogens were isolated and the pathogenicity of the isolates was tested. The fungal strains were identified as Lasiodiplodia pseudotheobromae based on their morphological characteristics and phylogenetic analyses using the internal transcribed spacer regions (ITS), translation elongation factor 1-α gene (TEF), and beta-tubulin (TUB) gene sequences. The strains could infect wounded citrus fruit and cause decay within two days post inoculation, but could not infect unwounded fruit. To our knowledge, this is the first report of citrus fruit decay caused by L. pseudotheobromae in China.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 559
Author(s):  
Hao Li ◽  
Fang-Fang Liu ◽  
Li-Qing Fu ◽  
Ze Liu ◽  
Wen-Ting Zhang ◽  
...  

Insect C-type lectins (CTLs) play vital roles in modulating humoral and cellular immune responses. The oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae) is a migratory pest that causes significant economic loss in agriculture. CTLs have not yet been systematically identified in M. separata. In this study, we first constructed a transcriptome of M. separata larvae, generating a total of 45,888 unigenes with an average length of 910 bp. Unigenes were functionally annotated in six databases: NR, GO, KEGG, Pfam, eggNOG, and Swiss-Prot. Unigenes were enriched in functional pathways, such as those of signal transduction, endocrine system, cellular community, and immune system. Thirty-five unigenes encoding C-type lectins were identified, including CTL-S1~CTL-S6 (single CRD) and IML-1~IML-29 (dual CRD). Phylogenetic analyses showed dramatic lineage-specific expansions of IMLs. Sequence alignment and structural modeling identified potential ligand-interacting residues. Real-time qPCR revealed that CTL-Ss mainly express in eggs and early stage larvae, while IMLs mainly express in mid-late-stage larvae, pupae, and adults. In naïve larvae, hemocytes, fat body, and epidermis are the major tissues that express CTLs. In larvae challenged by Escherichia coli, Staphylococcus aureus, or Beauveria bassiana, the expression of different CTLs was stimulated in hemocytes, fat body and midgut. The present study will help further explore functions of M. separata CTLs.


Plant Disease ◽  
2021 ◽  
pp. PDIS-06-20-1290
Author(s):  
Juliana S. Baggio ◽  
Bruna B. Forcelini ◽  
Nan-Yi Wang ◽  
Rafaela G. Ruschel ◽  
James C. Mertely ◽  
...  

Pestalotiopsis-like species have been reported affecting strawberry worldwide. Recently, severe and unprecedented outbreaks have been reported in Florida commercial fields where leaf, fruit, petiole, crown, and root symptoms were observed, and yield was severely affected. The taxonomic status of the fungus is confusing because it has gone through multiple reclassifications over the years. Morphological characteristics, phylogenetic analyses, and pathogenicity tests were evaluated for strawberry isolates recovered from diseased plants in Florida. Phylogenetic analyses derived from the combined internal transcribed spacer, β-tub, and tef1 regions demonstrated that although there was low genetic diversity among the strawberry isolates, there was a clear separation of the isolates in two groups. The first group included isolates recovered over a period of several years, which was identified as Neopestalotiopsis rosae. Most isolates recovered during the recent outbreaks were genetically different and may belong to a new species. On potato dextrose agar, both groups produced white, circular, and cottony colonies. From the bottom, colonies were white to pale yellow for Neopestalotiopsis sp. and pale luteous to orange for N. rosae. Spores for both groups were five-celled with three median versicolored cells. Mycelial growth and spore production were higher for the new Neopestalotiopsis sp. isolates. Isolates from both groups were pathogenic to strawberry roots and crowns. However, the new Neopestalotiopsis sp. proved more aggressive in fruit and leaf inoculation tests, confirming observations from the recent outbreaks in commercial strawberry fields in Florida.


2008 ◽  
Vol 39 (2) ◽  
pp. 133-154 ◽  
Author(s):  
Alberto Sáez ◽  
Kaoru Maeto ◽  
Alejandro Zaldivar-Riverón ◽  
Sergey Belokobylskij

AbstractThe taxonomy of the Asian genera of the subfamily Betylobraconinae, a small and understudied group within the hymenopteran family Braconidae, is revised. A new genus exclusively from the Asian region, Asiabregma gen. nov., containing three species (A. ryukyuensis sp. nov. (type species, Japan and Malaya), A. makiharai sp. nov. (Japan) and A. sulaensis (van Achterberg), comb. nov. (Indonesia)) is described. One new species of Aulosaphobracon, A. striatus sp. nov. from Vietnam, and one of Facitorus, F. amamioshimus sp. nov. from Japan, are also described. Based on molecular phylogenetic analyses using COI mtDNA and 28S rRNA sequences, the three genera previously placed in the tribe Facitorini, Facitorus, Conobregma and Jannya, together with Asiabregma gen. nov., are transferred to the rogadine tribe Yeliconini.


Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 866-875 ◽  
Author(s):  
Deana L. Baucom ◽  
Marie Romero ◽  
Robert Belfon ◽  
Rebecca Creamer

New species of Undifilum , from locoweeds Astragalus lentiginosus Vitman and Astragalus mollissimus Torr., are described using morphological characteristics and molecular phylogenetic analyses as Undifilum fulvum Baucom & Creamer sp. nov. and Undifilum cinereum Baucom & Creamer sp. nov. Fungi were isolated from dried plants of A. lentiginosus var. araneosus , diphysus , lentiginosus , and wahweapensis collected from Arizona, Oregon, and Utah, USA, and A. mollissimus var. biglovii , earleii , and mollissimus collected from New Mexico, Oklahoma, and Texas, USA. Endophytic fungi from Astragalus locoweeds were compared to Undifilum oxytropis isolates obtained from dried plant material of Oxytropis lamberteii from New Mexico and Oxytropis sericea from Arizona, Colorado, New Mexico, Utah, and Wyoming. Extremely slow growth in vitro was observed for all, and conidia, if present, were ellipsoid with transverse septa. However, in vitro color, growth on four different media, and conidium size differed between fungi from Astragalus spp. and U. oxytropis. Neighbor-joining analyses of internal transcribed spacer (ITS) region and glyceraldehyde-3-phosphate dehydrogenase (GPD) gene sequences revealed that U. fulvum and U. cinereum formed a clade distinct from U. oxytropis. This was supported by neighbor-joining analyses of results generated from random amplified polymorphic DNA (RAPD) fragments using two different primers.


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