scholarly journals Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata

2005 ◽  
Vol 95 (5) ◽  
pp. 512-518 ◽  
Author(s):  
T. L. Peever ◽  
L. Carpenter-Boggs ◽  
L. W. Timmer ◽  
L. M. Carris ◽  
A. Bhatia

Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata.

2000 ◽  
Vol 90 (7) ◽  
pp. 762-768 ◽  
Author(s):  
A. Masunaka ◽  
A. Tanaka ◽  
T. Tsuge ◽  
T. L. Peever ◽  
L. W. Timmer ◽  
...  

The tangerine pathotype of Alternaria alternata produces a host-selective toxin (HST), known as ACT-toxin, and causes Alternaria brown spot disease of citrus. The structure of ACT-toxin is closely related to AK- and AF-toxins, which are HSTs produced by the Japanese pear and strawberry pathotypes of A. alternata, respectively. AC-, AK-, and AF-toxins are chemically similar and share a 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid moiety. Two genes controlling AK-toxin biosynthesis (AKT1 and AKT2) were recently cloned from the Japanese pear pathotype of A. alternata. Portions of these genes were used as heterologous probes in Southern blots, that detected homologs in 13 isolates of A. alternata tangerine pathotype from Minneola tangelo in Florida. Partial sequencing of the homologs in one of these isolates demonstrated high sequence similarity to AKT1 (89.8%) and to AKT2 (90.7%). AKT homologs were not detected in nine isolates of A. alternata from rough lemon, six isolates of nonpathogenic A. alternata, and one isolate of A. citri that causes citrus black rot. The presence of homologs in the Minneola isolates and not in the rough lemon isolates, nonpathogens or black rot isolates, correlates perfectly to pathogenicity on Iyo tangerine and ACT-toxin production. Functionality of the homologs was demonstrated by detection of transcripts using reverse transcription-polymerase chain reaction (RT-PCR) in total RNA of the tangerine pathotype of A. alternata. The high sequence similarity of AKT and AKT homologs in the tangerine patho-type, combined with the structural similarity of AK-toxin and ACT-toxin, may indicate that these homologs are involved in the biosynthesis of the decatrienoic acid moiety of ACT-toxin.


1999 ◽  
Vol 47 (5) ◽  
pp. 499 ◽  
Author(s):  
S. Brown ◽  
G. Rouse ◽  
P. Hutchings ◽  
D. Colgan

DNA sequence data from for histone H3 (34 species), U2 snRNA (34 species) and two segments (D1 and D9–10 expansion regions) of 28S rDNA (28 and 26 species, respectively) have been collected to investigate the relationships of polychaetes. Representatives of all of the major morphologically identified clades were used, as well as members of the Sipuncula, Echiura, Turbellaria, Clitellata and Siboglinidae (formerly the phyla Pogonophora and Vestimentifera). Maximum parsimony analyses of the separate data sets gave conflicting results and none conformed closely to previous results based on morphology. Instead each data set provided corroboration of a few of the morphological groupings, usually pairing, though inconsistently, members of the same family. Higher groupings proposed on morphological grounds were rarely recovered. Maximum parsimony analysis of the combined data, excluding areas of uncertain alignment, recovered some morphological groupings such as Cirratulidae, Terebellidae, scale worms and eunicimorphs, and did not significantly contradict others. However, some expected groupings were not recovered. Surprisingly, the fanworms (Sabellidae and Serpulidae) were not shown as sister taxa, and monophyly of Phyllodocida, a morphologically well corroborated clade, required four more steps than most parsimonious trees. Aciculata was not seen in our analyses, although it was the most strongly supported large clade in Rouse and Fauchald (1997, Cladistics and polychaetes. Zoologica Scripta 26, 138–204). Trees constrained to show Aciculata as monophyletic were 18 steps longer than the most parsimonious trees. If trees are rooted on sipunculans rather than the nematode, Aciculata is nearly recovered, being rendered paraphyletic by the inclusion of the sister-pair of Oweniidae and Chaetopteridae. As suggested by some recent morphological and molecular analyses, Siboglinidae and Clitellata may well have sister groups among polychaetes. The morphologically aberrant Sternaspidae are closest to members of Terebellida in the present analyses, supporting the placement of Rouse and Fauchald. Interesting results deserving further assessment concern the placement of Chaetopteridae, Oweniidae and Sipuncula.


MycoKeys ◽  
2018 ◽  
Vol 43 ◽  
pp. 59-74 ◽  
Author(s):  
Ye-Ming Zhou ◽  
Jun-Rui Zhi ◽  
Mao Ye ◽  
Zhi-Yuan Zhang ◽  
Wen-Bo Yue ◽  
...  

A new species of entomopathogenic fungi,Lecanicilliumcauligalbarum, was discovered from a survey of invertebrate-associated fungi in the Yao Ren National Forest Mountain Park in China. The synnemata of this species emerged from the corpse of a stemborer (Lepidoptera), which was hidden amongst pieces of wood on the forest floor. It differs from morphologically similarLecanicilliumspecies mainly in its short conidiogenous cells and ellipsoid to ovoid and aseptate conidia. Phylogenetic analysis of a combined data set comprising ITS,SSU,LSU,TEF,RPB1andRPB2sequence data supported the inclusion ofL.cauligalbarumin theLecanicilliumgenus and its recognition as a distinct species.


2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
T. M. Hardig ◽  
C. K. Anttila ◽  
S. J. Brunsfeld

The genus Salix has proven a fertile taxon for a host of evolutionary and ecological studies, yet much work remains in the development of a definitive phylogenetic context for those studies. We performed phylogenetic analyses, using both maximum likelihood and maximum parsimony techniques, of chloroplast-encoded matK and nuclear-encoded ribosomal DNA (rDNA) gene sequences, gathered from specimens deemed representative of the existing subgeneric classification, with the objective of identifying and elaborating the phylogenetic relationships within Salix. Comparisons between the two phylogenetic hypotheses indicate a high degree of polyphyly in the matK-based phylogeny. This we attribute to the effects of hybridization, introgression, and lineage sorting. Comparisons with previous molecule-based phylogenetic hypotheses indicate a fair degree of congruence and all are unanimous in placing Chosenia arbutifolia within the genus Salix. The phylogenetic analysis of our ITS data set has produced results that generally support the most-recent infrageneric classification.


Phytotaxa ◽  
2013 ◽  
Vol 146 (1) ◽  
pp. 1 ◽  
Author(s):  
PETER B. HEENAN ◽  
ROB D. SMISSEN

The generic taxonomy of the Nothofagaceae is revised. We present a new phylogenetic analysis of morphological characters and map these characters onto a recently published phylogenetic tree obtained from DNA sequence data. Results of these and previous analyses strongly support the monophyly of four clades of Nothofagaceae that are currently treated as subgenera of Nothofagus. The four clades of Nothofagaceae are robust and well-supported, with deep stem divergences, have evolutionary equivalence with other genera of Fagales, and can be circumscribed with morphological characters. We argue that these morphological and molecular differences are sufficient for the four clades of Nothofagaceae to be recognised at the primary rank of genus, and that this classification will be more informative and efficient than the currently circumscribed Nothofagus with four subgenera.        Nothofagus is recircumscribed to include five species from southern South America, Lophozonia and Trisyngyne are reinstated, and the new genus Fuscospora is described. Fuscospora and Lophozonia, with six and seven species respectively, occur in New Zealand, southern South America and Australia. Trisyngyne comprises 25 species from New Caledonia, Papua New Guinea and Indonesia. New combinations are provided where necessary in each of these genera.


PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0150366 ◽  
Author(s):  
Chao Hu ◽  
Huaizhen Tian ◽  
Hongqing Li ◽  
Aiqun Hu ◽  
Fuwu Xing ◽  
...  

Zootaxa ◽  
2009 ◽  
Vol 1991 (1) ◽  
pp. 28-42 ◽  
Author(s):  
T. HEATH OGDEN ◽  
JONATHAN T. OSBORNE ◽  
LUKE M. JACOBUS ◽  
MICHAEL F. WHITING

This study represents the first combined molecular and morphological analysis for the mayfly family Ephemerellidae (Ephemeroptera), with a focus on the relationships of genera and species groups of the subfamily Ephemerellinae. The phylogeny was constructed based on DNA sequence data from 3 nuclear (18S rDNA, 28S rDNA, histone H3) and 2 mitochondrial (12S rDNA, 16S rDNA) genes, and 23 morphological characters. Taxon sampling for Ephemerellidae included exemplars from all 25 extant genus groups and additional representatives from those genera with the highest diversity. Ephemerellidae appears to consist of three major clades. Ephemerella, the largest genus of Ephemerellidae, and Serratella were not supported as monophyletic, and each had representatives in two of the three major clades. However, the genera Drunella and Cincticostella were supported as monophyletic. Lineages strongly supported as monophyletic include a grouping of the Timpanoginae genera Timpanoga, Dannella, Dentatella and Eurylophella, and groupings of the Ephemerellinae genera Torleya, Hyrtanella and Crinitella and the genera Kangella, Uracanthella and Teloganopsis. The placement of the Timpanoginae genus Attenella fell within Ephemerellinae, based on molecular and combined data, but it grouped with other Timpanoginae based on morphological data alone. Further study and analysis of Ephemerellidae morphology is needed, and classification should be revised, if it is to reflect phylogenetic relationships.


Phytotaxa ◽  
2015 ◽  
Vol 204 (4) ◽  
pp. 253 ◽  
Author(s):  
YONG-YU SU ◽  
YI-LANG HUANG ◽  
LI-JUN CHEN ◽  
PEI-WEN ZHANG ◽  
Zhong-Jian Liu ◽  
...  

A new orchid species, Liparis wenshanensis, discovered in Yunnan, China is described and illustrated in this study based on morphological and molecular analyses. A detailed comparison between the newly discovered orchid and other members of the genus, Liparis, was conducted. The new plant is characterized by the combination of the following features: a long rachis with 45 to 55 flowers; white sepals, petals and column; a greenish lip with a purplish center; strongly recurved and revolute dorsal sepals and petals; strongly recurved, oblong lateral sepals; a cordate lip that is strongly deflexed below the middle, with a two-lobed apex and a two-lobed callus at the base; an arcuate column with a lamella extending along the center almost to the stigma, and with a pair of broad wings toward the apex. These features distinguish the new orchid from all other known species of Liparis. We proceeded to a phylogenetic analysis to ascertain the systematic position of this enigmatic species. Molecular analyses based on nuclear ribosomal ITS and plastid matK DNA sequence data supports the recognition of L. wenshanensis as a distinct species.


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