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Jacobs-Venter A, Laraba I, Geiser DM, Busman M, Vaughan MM, Proctor RH, McCormick SP, O'Donnell K. Molecular systematics of two sister clades, the Fusarium concolor and F. babinda species complexes, and the discovery of a novel microcycle macroconidium-producing species from South Africa. Mycologia 2018; 110:1189-1204. [PMID: 30522417 DOI: 10.1080/00275514.2018.1526619] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Multilocus DNA sequence data were used to investigate species identity and diversity in two sister clades, the Fusarium concolor (FCOSC) and F. babinda species complexes. Of the 109 isolates analyzed, only 4 were received correctly identified to species and these included 1/46 F. concolor, 1/31 F. babinda, and 2/3 F. anguioides. The majority of the F. concolor and F. babinda isolates were received as F. polyphialidicum, which is a heterotypic synonym of the former species. Previously documented from South America, Africa, Europe, and Australia, our data show that F. concolor is also present in North America. The present study expands the known distribution of F. babinda in Australia to Asia, Europe, and North America. The molecular phylogenetic results support the recognition of a novel Fusarium species within the FCOSC, which is described and illustrated here as F. austroafricanum, sp. nov. It was isolated as an endophyte of kikuyu grass associated with a putative mycotoxicosis of cattle and from plant debris in soil in South Africa. Fusarium austroafricanum is most similar morphologically to F. concolor and F. babinda but differs from the latter two species in producing (i) much longer macroconidia in which the apical cell is blunt to slightly papillate and the basal cell is only slightly notched and (ii) macroconidia via microcycle conidiation on water agar. BLASTn searches of the whole genome sequence of F. austroafricanum NRRL 53441 were conducted to predict mycotoxin potential, using genes known to be essential for the synthesis of several mycotoxins and biologically active metabolites. Based on the presence of intact gene clusters that confer the ability to synthesize mycotoxins and pigments, we analyzed cracked corn kernel cultures of F. austroafricanum via liquid chromatography-mass spectrometry (LC-MS) but failed to detect these metabolites in vitro.
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Affiliation(s)
- Adriaana Jacobs-Venter
- a Biosystematics Unit, Plant Health and Protection, Agricultural Research Council , Pretoria , 0001 South Africa
| | - Imane Laraba
- b Laboratoire de phytopathologie et de biologie moléculaire, département de botanique, Ecole Nationale Supérieure Agronomique , Algiers , Algeria
| | - David M Geiser
- c Department of Plant Pathology and Environmental Microbiology , Pennsylvania State University, University Park , Pennsylvania 16802
| | - Mark Busman
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Martha M Vaughan
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Robert H Proctor
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Susan P McCormick
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
| | - Kerry O'Donnell
- d Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture , Peoria , Illinois 60604-3999
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Lawrence DP, Travadon R, Baumgartner K. Diversity of Diaporthe species associated with wood cankers of fruit and nut crops in northern California. Mycologia 2015; 107:926-40. [PMID: 26240309 DOI: 10.3852/14-353] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 06/23/2015] [Indexed: 11/10/2022]
Abstract
Diaporthe ampelina, causal agent of Phomopsis cane and leaf spot of grapevine (Vitis vinifera L.) is isolated frequently from grapevine wood cankers, causing Phomopsis dieback. The latter disease is associated with four other Diaporthe species, three of which also are reported from hosts other than grape. To better understand the role of this Diaporthe community in Phomopsis dieback of grapevine and the potential for infection routes among alternate hosts, 76 Diaporthe isolates were recovered from wood cankers of cultivated grape, pear, apricot, almond and the wild host willow in four California counties. Isolates were characterized morphologically and assigned to species based on multigene sequence analyses. This study identified eight Diaporthe species from grapevine and one novel taxon from willow, D. benedicti. We report the first findings of D. australafricana and D. novem in North America. Our findings also expand the host ranges of D. ambigua to apricot and willow, D. australafricana to almond and willow, D. chamaeropis to grapevine and willow, D. foeniculina to willow and D. novem to almond. The generalists D. ambigua and D. eres were the most genetically diverse species, based on high nucleotide and haplotypic diversity, followed by the grapevine specialist D. ampelina. Analyses based on multilocus linkage disequilibrium could not reject the hypothesis of random mating for D. ambigua, which is further supported by relatively high haplotypic diversity, reports of both mating types and reports of successful matings in vitro. Pathogenicity assays revealed that D. ampelina was the most pathogenic species to grapevine wood.
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Affiliation(s)
- Daniel P Lawrence
- Department of Plant Pathology, University of California, Davis, California 95616
| | - Renaud Travadon
- Department of Plant Pathology, University of California, Davis, California 95616
| | - Kendra Baumgartner
- United States Department of Agriculture, Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, California 95616
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