scholarly journals First Report of Rust Caused by Puccinia carthami on Safflower in Oman

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 208-208 ◽  
Author(s):  
M. L. Deadman ◽  
A. M. Al Sadi ◽  
S. Al Jahdhami ◽  
M. C. Aime

Safflower (Carthamus tinctorius L.) is a minor, but culturally important crop in Oman; the dried flowers produce a pigment used in facial ornamentation. Although Oman is not a commercial producer of safflower, the region is a center of diversity and a source of genetic material for breeding programs. Production of oil from safflower has potential in Oman, where plant growth is prolific. In April 2004, leaf samples showing rust symptoms were collected from Mudhaibi, 100 km south of Muscat. Chestnut brown pustules covered both sides of the leaves, but not the stems, and yielded urediniospores and teliospores typical of the pathogen. Urediniospores were globose, 25 μm in diameter with three germ pores. Two-celled teliospores were chestnut brown, minutely verrucose, with a single, depressed germ pore in each cell. The pathogen was identified as Puccinia carthami Corda (voucher specimen deposited in the U.S. National Fungus Collections, BPI863557; nuclear ribosomal large subunit DNA voucher sequence deposited in GenBank, Accession No. AY787782). On the basis of phylogenetic analyses, the rust from Oman belongs to a complex of closely related Puccinia spp. that infects members of the Cardueae. Elsewhere, in addition to leaf infections, P. carthami causes foot and root disease of safflower (1) with teliospores surviving in the soil and on seed to initiate new infections. Germplasm is now being collected and will be screened for variation in response to rust infection. Reference: (1) M. L. Schuster et al. Phytopathology 42:211, 1952.

2005 ◽  
Vol 187 (10) ◽  
pp. 3311-3318 ◽  
Author(s):  
Ramy K. Aziz ◽  
Robert A. Edwards ◽  
William W. Taylor ◽  
Donald E. Low ◽  
Allison McGeer ◽  
...  

ABSTRACT The recrudescence of severe invasive group A streptococcal (GAS) diseases has been associated with relatively few strains, including the M1T1 subclone that has shown an unprecedented global spread and prevalence and high virulence in susceptible hosts. To understand its unusual epidemiology, we aimed to identify unique genomic features that differentiate it from the fully sequenced M1 SF370 strain. We constructed DNA microarrays from an M1T1 shotgun library and, using differential hybridization, we found that both M1 strains are 95% identical and that the 5% unique M1T1 clone sequences more closely resemble sequences found in the M3 strain, which is also associated with severe disease. Careful analysis of these unique sequences revealed three unique prophages that we named M1T1.X, M1T1.Y, and M1T1.Z. While M1T1.Y is similar to phage 370.3 of the M1-SF370 strain, M1T1.X and M1T1.Z are novel and encode the toxins SpeA2 and Sda1, respectively. The genomes of these prophages are highly mosaic, with different segments being related to distinct streptococcal phages, suggesting that GAS phages continue to exchange genetic material. Bioinformatic and phylogenetic analyses revealed a highly conserved open reading frame (ORF) adjacent to the toxins in 18 of the 21 toxin-carrying GAS prophages. We named this ORF paratox, determined its allelic distribution among different phages, and found linkage disequilibrium between particular paratox alleles and specific toxin genes, suggesting that they may move as a single cassette. Based on the conservation of paratox and other genes flanking the toxins, we propose a recombination-based model for toxin dissemination among prophages. We also provide evidence that a minor population of the M1T1 clonal isolates have exchanged their virulence module on phage M1T1.Y, replacing it with a different module identical to that found on a related M3 phage. Taken together, the data demonstrate that mosaicism of the GAS prophages has contributed to the emergence and diversification of the M1T1 subclone.


IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takamichi Orihara ◽  
Rosanne Healy ◽  
Adriana Corrales ◽  
Matthew E. Smith

ABSTRACTAmong many convergently evolved sequestrate fungal genera in Boletaceae (Boletales, Basidiomycota), the genus Octaviania is the most diverse. We recently collected many specimens of Octaviania subg. Octaviania, including several undescribed taxa, from Japan and the Americas. Here we describe two new species in subgenus Octaviania, O. tenuipes and O. tomentosa, from temperate to subtropical evergreen Fagaceae forests in Japan based on morphological observation and robust multilocus phylogenetic analyses (nrDNA ITS and partial large subunit [LSU], translation elongation factor 1-α gene [TEF1] and the largest subunit of RNA polymerase II gene [RPB1]). Based on specimens from the Americas as well as studies of the holotype, we also taxonomically re-evaluate O. asterosperma var. potteri. Our analysis suggests that O. asterosperma var. potteri is a distinct taxon within the subgenus Octaviania so we recognize this as O. potteri stat. nov. We unexpectedly collected O. potteri specimens from geographically widespread sites in the USA, Japan and Colombia. This is the first verified report of Octaviania from the South American continent. Our molecular analyses also revealed that the RPB1 sequence of one O. tenuipes specimen was identical to that of a closely related species, O. japonimontana, and that one O. potteri specimen from Minnesota had an RPB1 sequence of an unknown species of O. subg. Octaviania. Additionally, one O. japonimontana specimen had an unusually divergent TEF1 sequence. Gene-tree comparison and phylogenetic network analysis of the multilocus dataset suggest that these heterogenous sequences are most likely the result of previous inter- and intra-specific hybridization. We hypothesize that frequent hybridization events in Octaviania may have promoted the high genetic and species diversity found within the genus.


2019 ◽  
Vol 15 ◽  
pp. 117693431988994
Author(s):  
Shulin Zhang ◽  
Yaling Cai ◽  
Jinggong Guo ◽  
Kun Li ◽  
Renhai Peng ◽  
...  

Determining the genetic rearrangement and domestication footprints in Gossypium hirsutum cultivars and primitive race genotypes are essential for effective gene conservation efforts and the development of advanced breeding molecular markers for marker-assisted breeding. In this study, 94 accessions representing the 7 primitive races of G hirsutum, along with 9 G hirsutum and 12 Gossypium barbadense cultivated accessions were evaluated. The genotyping-by-sequencing (GBS) approach was employed and 146 558 single nucleotide polymorphisms (SNP) were generated. Distinct SNP signatures were identified through the combination of selection scans and association analyses. Phylogenetic analyses were also conducted, and we concluded that the Latifolium, Richmondi, and Marie-Galante race accessions were more genetically related to the G hirsutum cultivars and tend to cluster together. Fifty-four outlier SNP loci were identified by selection-scan analysis, and 3 SNPs were located in genes related to the processes of plant responding to stress conditions and confirmed through further genome-wide signals of marker-phenotype association analysis, which indicate a clear selection signature for such trait. These results identified useful candidate gene locus for cotton breeding programs.


2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.


2012 ◽  
Vol 25 (6) ◽  
pp. 418 ◽  
Author(s):  
Roy E. Halling ◽  
Mitchell Nuhn ◽  
Todd Osmundson ◽  
Nigel Fechner ◽  
James M. Trappe ◽  
...  

Harrya is described as a new genus of Boletaceae to accommodate Boletus chromapes, a pink-capped bolete with a finely scabrous stipe adorned with pink scabers, a chrome yellow base and a reddish-brown spore deposit. Phylogenetic analyses of large-subunit rDNA and translation elongation factor 1α confirmed Harrya as a unique generic lineage with two species, one of which is newly described (H. atriceps). Some Chinese taxa were recently placed in a separate genus, Zangia, supported by both morphology and molecular data. Multiple accessions from Queensland, Australia, support the synonymy of at least three species in a separate Australian clade in the new genus, Australopilus. The truffle-like Royoungia is also supported as a separate lineage in this clade of boletes. Even though it lacks stipe characters, it possesses the deep, bright yellow to orange pigments in the peridium. Additional collections from Zambia and Thailand represent independent lineages of uncertain phylogenetic placement in the Chromapes complex, but sampling is insufficient for formal description of new species. Specimens from Java referable to Tylopilus pernanus appear to be a sister group of the Harrya lineage.


Phytotaxa ◽  
2017 ◽  
Vol 312 (1) ◽  
pp. 111
Author(s):  
HUAN-DI ZHENG ◽  
WEN-YING ZHUANG

A new species, namely Chlorociboria herbicola, is discovered on herbaceous stems in central China. Morphologically, the new fungus is distinctive by the combination of light blue-green apothecia, rectangular cells in ectal excipulum, and elongate-ellipsoidal ascospores with rounded ends. Phylogenetic analyses of the internal transcribed spacer and large subunit of nuclear ribosomal DNA sequences confirm its ascription in Chlorociboria and distinction from the known species of the genus.


1998 ◽  
Vol 76 (9) ◽  
pp. 1570-1583 ◽  
Author(s):  
W Gams ◽  
K O'Donnell ◽  
H -J Schroers ◽  
M Christensen

Unlike most phialide-producing fungi that liberate a multiplicity of conidia from each conidiogenous cell, only single conidia are formed on phialide-like conidiogenous cells in Aphanocladium, Verticimonosporium, and some species of Sibirina. A group of isolates obtained from soil of native Artemisia tridentata (sagebrush) grassland in Wyoming and from desert soil in Iraq is compared with these genera and classified as a fourth genus, Stanjemonium, honouring Stanley J. Hughes. Phylogenetic analyses of partial nuclear small- (18S) and large-subunit (28S) rDNA sequences indicate that Stanjemonium spp. form a monophyletic group with Emericellopsis. Sequences from the nuclear 18S and 28S rDNA were too conserved to resolve morphological species of Stanjemonium; however, phylogenetic analysis of b-tubulin and translation elongation factor 1a gene exons and introns resolved all species distinguished morphologically. Numerous conidiogenous cells or denticles are scattered along the cells of aerial hyphae in Aphanocladium and Stanjemonium spp., very rapidly collapsing into denticles in the former, somewhat more persistent and leaving broad scars in the latter. In Cladobotryum-Sibirina and Verticimonosporium spp., conidiogenous cells are discrete in terminal and intercalary whorls; phialides of the latter taxon are particularly swollen. The taxonomy of Aphanocladium is not yet resolved. Two species are recognized in Verticimonosporium. Three new species of Stanjemonium are described, and one new combination from Aphanocladium is proposed, along with one new species of Cladobotryum.Key words: Aphanocladium, Cladobotryum, conidiogenesis, hyphomycetes, molecular phylogeny, phialide, Stanjemonium, systematics, Verticimonosporium.


2018 ◽  
Vol 19 (3) ◽  
pp. 258-264
Author(s):  
David H. Gent ◽  
Briana J. Claassen ◽  
Megan C. Twomey ◽  
Sierra N. Wolfenbarger

Powdery mildew (caused by Podosphaera macularis) is one of the most important diseases of hop in the western United States. Strains of the fungus virulent on cultivars possessing the resistance factor termed R6 and the cultivar Cascade have become widespread in the Pacific Northwestern United States, the primary hop producing region in the country, rendering most cultivars grown susceptible to the disease at some level. In an effort to identify potential sources of resistance in extant germplasm, 136 male accessions of hop contained in the U.S. Department of Agriculture collection were screened under controlled conditions. Iterative inoculations with three isolates of P. macularis with varying race identified 23 (16.9%) accessions with apparent resistance to all known races of the pathogen present in the Pacific Northwest. Of the 23 accessions, 12 were resistant when inoculated with three additional isolates obtained from Europe that possess novel virulences. The nature of resistance in these individuals is unclear but does not appear to be based on known R genes. Identification of possible novel sources of resistance to powdery mildew will be useful to hop breeding programs in the western United States and elsewhere.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1531
Author(s):  
Xu Lu ◽  
Haisheng Yuan

Species in the genus Tomentella are distributed throughout the temperate and tropical regions worldwide, but few studies associated with the taxonomy and phylogeny of this genus had been reported from Northwest China. In this paper, molecular phylogenetic analyses of the nuclear ribosomal ITS (internal transcribed spacer: ITS1-5.8S-ITS2) and LSU (large subunit: 28S) sequences combined with morphological characteristics identified three new species from Xinjiang Autonomous Region in Northwest China, which were named T. aurantispora, T. kanasensis, and T. schrenkiana. Similar macromorphological and anatomical characteristics are shared by these new species: arachnoid basidiocarps; byssoid sterile margins; utriform basidia with a clamp connection at the base; the absence of rhizomorphs and cystidia; and slightly thick-walled, subglobose to globose basidiospores. Among these new species, the color of the hymenophoral surface, the size of the basidiospores, and some other features can be used for species delimitation. The new species and closely related species in the phylogenetic tree were discussed, and a key to the identified species of Tomentella from China was provided.


2021 ◽  
Vol 117 (1) ◽  
pp. 1
Author(s):  
Pooran GOLKAR ◽  
Esmaeil HAMZEH ◽  
Seyed Ali Mohammad MIRMOHAMMADY MAIBODY

<p>Improvement of elite safflower genotypes for drought-tolerance is hampered by a deficiency of effective selection criteria. The present study evaluated 100 genotypes of safflower in terms of their drought tolerance over a period of three years (2016–2018) under both non-stress and drought-stress conditions. The eight drought-tolerance indices of tolerance index (TOL), mean productivity (MP), geometric mean productivity (GMP), stress susceptibility index (SSI), stress tolerance index (STI), yield stability index (YSI), drought resistance index (DI), and harmonic mean (HARM) were calculated based on seed yield under drought (Y<sub>s</sub>) and non-drought (Y<sub>p</sub>) conditions. A high genetic variation was found in drought tolerance among the genotypes studied. The MP, GMP, and STI indices were able to discriminate between tolerant and drought-sensitive genotypes. Plots of the first and second principal components identified drought-tolerant genotypes averaged over the three study years. Cluster analysis divided the genotypes into three distinct groups using the drought tolerance indices. Ultimately, eight genotypes (namely, G<sub>3</sub>, G<sub>11</sub>, G<sub>13</sub>, G<sub>24</sub>, G<sub>33</sub>, G<sub>47</sub>, G<sub>58</sub>, and G<sub>61</sub>) from different origins were detected as more tolerant to drought stress suitable for use in safflower breeding programs in drought-affected areas. The most tolerant and susceptible genotypes could be exploited to produce mapping populations for drought tolerance breeding programs in safflower.</p>


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