Diaporthe seed decay of soybean [Glycine max (L.) Merr.] is endemic in the United States, but new fungi are involved

Plant Disease ◽  
2020 ◽  
Author(s):  
Kristina Petrovic ◽  
Demetra Skaltsas ◽  
Lisa Castlebury ◽  
Brian Kontz ◽  
Tom Allen ◽  
...  

Diaporthe seed decay can compromise seed quality in soybean [Glycine max (L.) Merr.] in the warm and humid production areas of the United States during crop maturation. In the current study, 45 isolates of Diaporthe were recovered from seed sampled from soybean fields affected by Diaporthe-associated diseases in eight U.S. states in 2017. The isolates obtained belonged to 10 species of Diaporthe based on morphology and phylogenetic analyses of the internal transcribed spacer, the partial translation elongation factor 1-alpha, and beta-tubulin gene sequences. The associated species included D. aspalathi, D. caulivora, D. kongii, D. longicolla, D. sojae, D. ueckerae, D. unshiuensis and three novel fungi, D. bacilloides, D. flavescens and D. insulistroma. One isolate each of the 10 species was examined for pathogenicity on seed of cv. ‘Sava’ under controlled conditions. Seven days post-inoculation, significant differences in the percentages of decayed seeds and seedling necrosis were observed among the isolates and the non-inoculated control (p<0.0001). While the isolates of D. bacilloides, D. longicolla, and D. ueckerae caused significantly greater percentage of decayed seeds (p<0.0001), the isolate of D. aspalathi caused the greatest seedling necrosis (p<0.0001) when compared to the non-inoculated control. The observation of new fungi causing Diaporthe seed decay suggests the need for a more comprehensive survey in the U.S. soybean producing areas since members of the genus Diaporthe appear to form a complex that causes seed decay.

2015 ◽  
Vol 105 (7) ◽  
pp. 990-997 ◽  
Author(s):  
Febina M. Mathew ◽  
Kholoud M. Alananbeh ◽  
James G. Jordahl ◽  
Scott M. Meyer ◽  
Lisa A. Castlebury ◽  
...  

Phomopsis stem canker causes yield reductions on sunflower (Helianthus annuus L.) on several continents, including Australia, Europe, and North America. In the United States, Phomopsis stem canker incidence has increased 16-fold in the Northern Great Plains between 2001 and 2012. Although Diaporthe helianthi was assumed to be the sole causal agent in the United States, a newly described species, D. gulyae, was found to be the primary cause of Phomopsis stem canker in Australia. To determine the identity of Diaporthe spp. causing Phomopsis stem canker in the Northern Great Plains, 275 infected stems were collected between 2010 and 2012. Phylogenetic analyses of sequences of the ribosomal DNA internal transcribed spacer region, elongation factor subunit 1-α, and actin gene regions of representative isolates, in comparison with those of type specimens, confirmed two species (D. helianthi and D. gulyae) in the United States. Differences in aggressiveness between the two species were determined using the stem-wound method in the greenhouse; overall, D. helianthi and D. gulyae did not vary significantly (P ≤ 0.05) in their aggressiveness at 10 and 14 days after inoculation. These findings indicate that both Diaporthe spp. have emerged as sunflower pathogens in the United States, and have implications on the management of this disease.


1986 ◽  
Vol 15 (2) ◽  
pp. 75-79
Author(s):  
Robert W. Howell

The rapid increase in importance of soybeans (Glycine max (L.) Merr.) and soybean products in world agriculture is a major phenomenon of the last 50 years. Beginning about 1940 soybean production and use increased rapidly, first in the United States and recently in other parts of the world. Soybean production now ranks near the top of non-cereal sources of calories and protein.


2000 ◽  
Vol 1 (1) ◽  
pp. 32
Author(s):  
R. A. Leitz ◽  
G. L. Hartman ◽  
W. L. Pedersen ◽  
C. D. Nickell

Phytophthora root rot of soybean (Glycine max (L.) Merr.), caused by Phytophthora sojae M. J. Kauffmann & J. W. Gerdemann, has been isolated throughout the soybean-producing regions of the United States. Posted 3 June 2000.


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.


2019 ◽  
Vol 5 (4) ◽  
pp. eaav3875 ◽  
Author(s):  
J. Luque ◽  
R. M. Feldmann ◽  
O. Vernygora ◽  
C. E. Schweitzer ◽  
C. B. Cameron ◽  
...  

Evolutionary origins of novel forms are often obscure because early and transitional fossils tend to be rare, poorly preserved, or lack proper phylogenetic contexts. We describe a new, exceptionally preserved enigmatic crab from the mid-Cretaceous of Colombia and the United States, whose completeness illuminates the early disparity of the group and the origins of novel forms. Its large and unprotected compound eyes, small fusiform body, and leg-like mouthparts suggest larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical “crab-like” body plan since the Early Cretaceous. These parallel morphological transformations may be associated with repeated invasions of novel environments, including the pelagic/necto-benthic zone in this pedomorphic chimera crab.


2019 ◽  
Vol 10 (2) ◽  
pp. 155-170
Author(s):  
Tobechi Onyenali ◽  
Victor Olowe ◽  
Thomas Fabunmi ◽  
Adeniyi Soretire

2012 ◽  
Vol 24 (5) ◽  
pp. 903-910 ◽  
Author(s):  
Yogesh Chander ◽  
Alexander Primus ◽  
Simone Oliveira ◽  
Connie J. Gebhart

Since 2007, outbreaks of severe bloody diarrhea and hemorrhagic colitis have been reported in the United States and Canada. Though the primary causative agent of swine dysentery is Brachyspira hyodysenteriae, which is strongly hemolytic, the current report describes the isolation of a novel strongly hemolytic Brachyspira sp. This novel Brachyspira sp. was identified from clinical submissions at the Minnesota Veterinary Diagnostic Laboratory, and 40 of such isolates were obtained from 22 clinical submissions representing 5 states. Isolates were confirmed to be different from any known Brachyspira sp. on the basis of phylogenetic analysis of nucleotide sequences of nox and 16S ribosomal RNA (rRNA) genes. Phylogenetic analyses grouped all isolates into 2 clades (clades I and II), and grouping patterns were similar for both nox and 16S rRNA gene sequence analyses. Phenotypically, all isolates were indole and hippurate negative, and enzymatic profiling indicated 2 types of profiles, irrespective of the phylogenetic grouping, differing only in the production of β-glucosidase. The results suggest that a potentially virulent new species of Brachyspira sp., provisionally named “ Brachyspira hampsonii ”, is circulating among swine herds in the United States.


2016 ◽  
Vol 54 (11) ◽  
pp. 2813-2819 ◽  
Author(s):  
Kerry O'Donnell ◽  
Deanna A. Sutton ◽  
Nathan Wiederhold ◽  
Vincent A. R. G. Robert ◽  
Pedro W. Crous ◽  
...  

Multilocus DNA sequence data were used to assess the genetic diversity and evolutionary relationships of 67Fusariumstrains from veterinary sources, most of which were from the United States. Molecular phylogenetic analyses revealed that the strains comprised 23 phylogenetically distinct species, all but two of which were previously known to infect humans, distributed among eight species complexes. The majority of the veterinary isolates (47/67 = 70.1%) were nested within theFusarium solanispecies complex (FSSC), and these included 8 phylospecies and 33 unique 3-locus sequence types (STs). Three of the FSSC species (Fusarium falciforme,Fusarium keratoplasticum, andFusariumsp. FSSC 12) accounted for four-fifths of the veterinary strains (38/47) and STs (27/33) within this clade. Most of theF. falciformestrains (12/15) were recovered from equine keratitis infections; however, strains ofF. keratoplasticumandFusariumsp. FSSC 12 were mostly (25/27) isolated from marine vertebrates and invertebrates. Our sampling suggests that theFusarium incarnatum-equisetispecies complex (FIESC), with eight mycoses-associated species, may represent the second most important clade of veterinary relevance withinFusarium. Six of the multilocus STs within the FSSC (3+4-eee, 1-b, 12-a, 12-b, 12-f, and 12-h) and one each within the FIESC (1-a) and theFusarium oxysporumspecies complex (ST-33) were widespread geographically, including three STs with transoceanic disjunctions. In conclusion, fusaria associated with veterinary mycoses are phylogenetically diverse and typically can only be identified to the species level using DNA sequence data from portions of one or more informative genes.


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