scholarly journals Identification and Pathogenicity of Lasiodiplodia theobromae and Diplodia seriata, the Causal Agents of Bot Canker Disease of Grapevines in Mexico

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 519-529 ◽  
Author(s):  
J. R. Úrbez-Torres ◽  
G. M. Leavitt ◽  
J. C. Guerrero ◽  
J. Guevara ◽  
W. D. Gubler

Perennial cankers and consequent grapevine dieback are a major problem in vineyards of Sonora and Baja California, the most important grape-production areas of Mexico. In order to identify the canker-causing agents, symptomatic arms, cordons, and trunks were collected from 13 and 6 vineyards in Sonora and Baja California, respectively. Two Botryosphaeriaceae spp., Lasiodiplodia theobromae and Diplodia seriata, were isolated frequently from infected wood and identified based on morphological and cultural characters as well as analyses of nucleotide sequences of three genes, the internal transcribed spacer region (ITS1-5.8S-ITS2), a partial sequence of the β-tubulin gene, and part of the translation elongation factor 1-α gene (EF1-α). Although both L. theobromae and D. seriata were isolated from grapevine cankers in Baja California, only L. theobromae was found in vines in the Sonora region. Pathogenicity of both species was verified by inoculation of rooted cuttings and green shoots of Thompson Seedless and Chardonnay cultivars. Isolates of L. theobromae were more virulent, based on the extent of spread in the secondary wood and green tissue, than those of D. seriata. These findings confirm L. theobromae and D. seriata as the causal agents of dieback and canker formation of grapevines in northern Mexico.

Phytotaxa ◽  
2018 ◽  
Vol 364 (2) ◽  
pp. 181 ◽  
Author(s):  
MUNAZZA KIRAN ◽  
JUNAID KHAN ◽  
HASSAN SHER ◽  
DONALD H. PFISTER ◽  
ABDUL NASIR KHALID

A new species, Amanita griseofusca in section Vaginatae is described and illustrated here from Pakistan. Distinguishing characters of the new species include medium-sized basidiomata, greyish brown pileus surface with white to beige, membranous volval remnants present as one (large) to a few (small) warts, close lamellae which are cream colored with a pink tone, striations one third of the total pileus radius, broadly ellipsoidal to ellipsoidal basidiospores and white loose saccate volva turning beige at maturity. Molecular data inferred from partial nuc rDNA internal transcribed spacer region (ITS), partial nuc rDNA larger subunit region (LSU) and partial translation elongation factor 1-alpha (tef1) confirms the novelty of the present taxon.


Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1156-1165 ◽  
Author(s):  
M. A. Bautista-Cruz ◽  
G. Almaguer-Vargas ◽  
S. G. Leyva-Mir ◽  
M. T. Colinas-León ◽  
K. C. Correia ◽  
...  

Persian lime (Citrus latifolia Tan.) is an important and widely cultivated fruit crop in several regions of Mexico. In recent years, severe symptoms of gummosis, stem cankers, and dieback were detected in the Persian lime-producing region in the states of Veracruz and Puebla, Mexico. The aims of this study were to identify the species of Lasiodiplodia associated with these symptoms, determine the distribution of these species, and test their pathogenicity and virulence on Persian lime plants. In 2015, symptomatic samples were collected from 12 commercial Persian lime orchards, and 60 Lasiodiplodia isolates were obtained. Fungal identification of 32 representative isolates was performed using a phylogenetic analysis based on DNA sequence data of the internal transcribed spacer region and part of the translation elongation factor 1-α and β-tubulin genes. Sequence analyses were carried out using the Maximum Likelihood and Bayesian Inference methods. Six Lasiodiplodia species were identified as Lasiodiplodia pseudotheobromae, Lasiodiplodia theobromae, Lasiodiplodia brasiliense, Lasiodiplodia subglobosa, Lasiodiplodia citricola, and Lasiodiplodia iraniensis. All Lasiodiplodia species of this study are reported for the first time in association with Persian lime in Mexico and worldwide. L. pseudotheobromae (46.9% of isolates) was the most frequently isolated species followed by L. theobromae (28.1%) and L. brasiliense (12.5%). Pathogenicity on Persian lime young plants using a mycelial plug inoculation method showed that all identified Lasiodiplodia species were able to cause necrotic lesions and gummosis, but L. subglobosa, L. iraniensis, and L. pseudotheobromae were the most virulent.


Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1378-1384 ◽  
Author(s):  
Fan Wang ◽  
Lina Zhao ◽  
Guohuai Li ◽  
Junbin Huang ◽  
Tom Hsiang

Peach (Prunus persica) is one of the most important and widely grown fruit trees in China; however, perennial gummosis on trunks and branches is a major problem in peach orchards of Hubei Province, one of the most important peach production areas of China. In order to identify the gummosis-causing agents, diseased trunks and branches were collected from 11 peach orchards in Hubei Province. Fungal isolates were obtained from these samples, yielding three species: Botryosphaeria dothidea (anamorph Fusicoccum aesculi), B. rhodina (anamorph Lasiodiplodia theobromae), and B. obtusa (anamorph Diplodia seriata). They were identified based on conidial morphology and cultural characteristics, as well as analyses of nucleotide sequences of three genomic regions: the internal transcribed spacer region, a partial sequence of the β-tubulin gene, and the translation elongation factor 1-α gene. Fusicoccum aesculi was found in all 11 orchards but L. theobromae was found only in Shayang County in the Jingmen region and D. seriata only in Gong'an County in the Jingzhou region. Via artificial inoculation using mycelia on wounded twigs or branches, these three species were all found to be pathogenic, causing dark lesions on the twigs and branches and, sometimes, gum exudation from diseased parts. Isolates of L. theobromae were the most virulent and caused the largest lesions and most copious gummosis, and D. seriata had less gum than the other two species. This report represents the first description of L. theobromae and D. seriata as causal agents of gummosis on peach in China.


2020 ◽  
Vol 11 ◽  
Author(s):  
Indunil C. Senanayake ◽  
Jayarama D. Bhat ◽  
Ratchadawan Cheewangkoon ◽  
Ning Xie

A survey of bambusicolous fungi in Bijiashan Mountain Park, Shenzhen, Guangdong Province, China, revealed several Arthrinium-like taxa from dead sheaths, twigs, and clumps of Bambusa species. Phylogenetic relationships were investigated based on morphology and combined analyses of the internal transcribed spacer region (ITS), large subunit nuclear ribosomal DNA (LSU), beta tubulin (β-tubulin), and translation elongation factor 1-alpha (tef 1-α) gene sequences. Based on morphological characteristics and phylogenetic data, Arthrinium acutiapicum sp. nov. and Arthrinium pseudorasikravindrae sp. nov. are introduced herein with descriptions and illustrations. Additionally, two new locality records of Arthrinium bambusae and Arthrinium guizhouense are described and illustrated.


2021 ◽  
Vol 58 (04) ◽  
pp. 1301-1313
Author(s):  
Imran Ul Haq

Neopestalotiopsis species are known to be involved in plant diseases as associated pathogens. The taxonomic identification of the fungal group Neopestalotiopsisis little bit difficult due to its complex evolutionary history. In the present study, seven fungal isolates were investigated from canker-affected guava plants. The phylogeny for generic placement of these isolates was analyzed to validate them as Neopestalotiopsis genus by phylogenetic signals from the 28S nrRNA region (LSU). Generated morphological data was segregated as new morpho-species of the Neopestalotiopsis genus. Hence, the internal transcribed spacer (ITS), Translation elongation factor 1-α (TEF1-α) and Tubulin (TUB) genic region of these isolates were studied in juxtaposition with morphological data to resolve species limits. Both phylogenetic and morphological data revealed four novel species of the Neopestalotiopsis genus out of seven isolates studied. These Neopestalotiopsis species could be of great significance for further investigation as putative pathogens associated with canker or scabby canker disease in guava.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 754
Author(s):  
Nahid Espargham ◽  
Hamid Mohammadi ◽  
David Gramaje

Citrus trees with cankers and dieback symptoms were observed in Bushehr (Bushehr province, Iran). Isolations were made from diseased cankers and branches. Recovered fungal isolates were identified using cultural and morphological characteristics, as well as comparisons of DNA sequence data of the nuclear ribosomal DNA-internal transcribed spacer region, translation elongation factor 1α, β-tubulin, and actin gene regions. Dothiorella viticola, Lasiodiplodia theobromae, Neoscytalidium hyalinum, Phaeoacremonium (P.) parasiticum, P. italicum, P. iranianum, P. rubrigenum, P. minimum, P. croatiense, P. fraxinopensylvanicum, Phaeoacremonium sp., Cadophora luteo-olivacea, Biscogniauxia (B.) mediterranea, Colletotrichum gloeosporioides, C. boninense, Peyronellaea (Pa.) pinodella, Stilbocrea (S.) walteri, and several isolates of Phoma, Pestalotiopsis, and Fusarium species were obtained from diseased trees. The pathogenicity tests were conducted by artificial inoculation of excised shoots of healthy acid lime trees (Citrus aurantifolia) under controlled conditions. Lasiodiplodia theobromae was the most virulent and caused the longest lesions within 40 days of inoculation. According to literature reviews, this is the first report of L. theobromae and N. hyalinum on citrus in Iran. Additionally, we report several Phaeoacremonium species, S. walteri, Pa. pinodella and C. luteo-olivacea on citrus trees for the first time in the world.


Plant Disease ◽  
2020 ◽  
Author(s):  
Swarnalatha Moparthi ◽  
Mary Eileen Burrows ◽  
Josephine Mgbechi-Ezeri ◽  
Bright Agindotan

Root rot caused by Fusarium species is a major problem in the pulse growing regions of Montana. Fusarium isolates (n=112) were obtained from seeds and/or roots of chickpea, dry pea, and lentil. Isolates were identified by comparing the sequences of the internal transcribed spacer region and the translation elongation factor 1-α in Fusarium-ID database. Fusarium avenaceum was the most abundant species (28%), followed by F. acuminatum (21%), F. poae (13%), F. oxysporum (8%), F. culmorum (6%), F. redolens (6%), F. sporotrichioides (6%), F. solani (4%), F. graminearum (2%), F. torulosum (2%) and F. tricinctum (0.9%). The aggressiveness of a subset of 50 isolates that represent various sources of isolation was tested on three pulse crops and two cereal crops. Nonparametric analysis of variance conducted on ranks of disease severity indicated that F. avenaceum and F. solani isolates were highly aggressive on pea and chickpea. In lentil, F. avenaceum and F. culmorum were highly aggressive. In barley, F. avenaceum, F. solani, F. culmorum, and F. graminearum were highly aggressive. In wheat, F. avenaceum, F. graminearum, and F. culmorum were highly aggressive. Two F. avenaceum isolates were highly aggressive across all the crops tested and found to be cross pathogenic. One isolate of F. culmorum and an isolate of F. graminearum obtained from chickpea and lentil seed were highly aggressive on barley and wheat. The results indicate that multiple Fusarium spp. from seeds and roots can cause root rot on both pulse and cereal crops. Rotating these crops may still lead to an increase in inoculum levels, making crop rotation limited in efficacy as a disease management strategy.


MycoKeys ◽  
2018 ◽  
Vol 35 ◽  
pp. 1-25 ◽  
Author(s):  
Yu Pei Tan ◽  
Pedro W. Crous ◽  
Roger G. Shivas

Several unidentified specimens of Curvularia deposited in the Queensland Plant Pathology Herbarium were re-examined. Phylogenetic analyses based on sequence data of the internal transcribed spacer region, partial fragments of the glyceraldehyde-3-phosphate dehydrogenase and the translation elongation factor 1-α genes, supported the introduction of 13 novel Curvularia species. Eight of the species described, namely, C.beasleyi sp. nov., C.beerburrumensis sp. nov., C.eragrosticola sp. nov., C.kenpeggii sp. nov., C.mebaldsii sp. nov., C.petersonii sp. nov., C.platzii sp. nov. and C.warraberensis sp. nov., were isolated from grasses (Poaceae) exotic to Australia. Only two species, C.lamingtonensis sp. nov. and C.sporobolicola sp. nov., were described from native Australian grasses. Two species were described from hosts in other families, namely, C.coatesiae sp. nov. from Litchichinensis (Sapindaceae) and C.colbranii sp. nov. from Crinumzeylanicum (Amaryllidaceae). Curvulariareesii sp. nov. was described from an isolate obtained from an air sample. Furthermore, DNA sequences from ex-type cultures supported the generic placement of C.neoindica and the transfer of Drechsleraboeremae to Curvularia.


Plant Disease ◽  
2020 ◽  
Author(s):  
Gonzalo A Díaz ◽  
Juan Pablo Zoffoli ◽  
Enrique Ferrada ◽  
Mauricio A. Lolas

Dieback symptoms associated with fungal trunk pathogens cause significant economic losses to kiwifruit and other woody fruit trees worldwide. This study represents the first attempt to identify and characterize the fungal trunk pathogens associated with cordon dieback disease of kiwifruit in central Chile. Field surveys were conducted throughout the main kiwifruit-growing regions in central Chile to determine the incidence and to characterize the fungal trunk pathogens associated with cordon dieback of kiwifruit cv. Hayward through morphological, molecular and pathogenicity studies. A total of 250 cordon samples were collected, and the isolations were performed on acidified potato dextrose agar (2%, APDA) plus antibiotics and Igepal. The incidence of kiwifruit cordon dieback ranged between 5 and 85% in all surveyed areas in central Chile. A total of 246 isolates were isolated and identified using culture and morphological features as belonging to three fungal taxa. Diaporthaceae spp. (Diaporthe ambigua and D. australafricana; n=133 isolates), Botryosphaeriaceae spp. (Diplodia seriata and Neofusicoccum parvum; n=89 isolates) and Ploettnerulaceae spp. (Cadophora luteo-olivacea and C. malorum; n=24 isolates) were identified using phylogenetics studies of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) of the rDNA, part of the β-tubulin gene (tub2) and part of the translation elongation factor 1-α gene (tef1-α). Isolates of N. parvum and Di. seriata were the most virulent, causing internal brown lesion and dieback symptoms in attached green shoots, attached lignified canes and young inoculated kiwifruits. This report is the first to describe Di. seriata and C. luteo-olivacea associated with kiwifruit cordon dieback in Chile and presents the first description of N. parvum causing kiwifruit dieback worldwide.


Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 853
Author(s):  
Alina S. Puig ◽  
Mike C. Winterstein

Mango (Mangifera indica) is an economically significant crop, and is affected by dieback in nearly all commercial production areas. Due to the wide range of organisms previously associated with these disease symptoms in Florida, isolations and pathogenicity tests were carried out to determine the causal organism. The pathogen was identified as Neofusicoccum batangarum based on genetic sequences from three loci (internal transcribed spacer of the rDNA (ITS), β-tubulin (BT), and translation elongation factor 1-α (EF)), recommended for members of the Botryosphaeriaceae family. Possible infection routes were determined by inoculating wounded and unwounded stems with N. batangarum. Trees wounded prior to pathogen inoculation developed larger lesions (5.85 cm ± 1.51) than unwounded trees (0.51 cm ± 0.48), p < 0.0003. In addition, lesions only developed at a small number of inoculation sites in the absence of wounds (14.3%), compared to 93% when stems were wounded. No necrosis was observed in the negative controls. This study provides molecular data on N. batangarum, and evidence of its role causing mango dieback in Florida.


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