scholarly journals A Survey of Trunk Disease Pathogens within Citrus Trees in Iran

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 ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2483-2491 ◽  
Author(s):  
Diego Olmo ◽  
Josep Armengol ◽  
Maela León ◽  
David Gramaje

In this study, 31 almond orchards with trees showing severe decline symptoms were surveyed from 2009 to 2014 on the island of Mallorca (Spain). In all, 45 Botryosphaeriaceae isolates were collected and characterized based on phenotypical features and comparisons of DNA sequence data of the nuclear ribosomal DNA-internal transcribed spacer region and elongation factor 1-α gene. Five species were identified as Diplodia olivarum, D. seriata, Neofusicoccum luteum, N. mediterraneum, and N. parvum. Pathogenicity tests were performed on four cultivars (‘Pons’, ‘Vivot’, ‘Jordi’, and ‘Ferragnes’) under field conditions for two consecutive years (2013 to 2014), and confirmed that all five species cause canker and dieback of almond, with Neofusicoccum spp. more virulent than Diplodia spp. in both years. Jordi was less sensitive to fungal infection in 2013. First reports from almond in Spain include N. mediterraneum and N. luteum.


Plant Disease ◽  
2021 ◽  
Author(s):  
Terry Torres-Cruz ◽  
Briana Whitaker ◽  
Robert Proctor ◽  
Kirk Broders ◽  
Imane Laraba ◽  
...  

Species within Fusarium are of global agricultural, medical, and food/feed safety concern and have been extensively characterized. However, accurate identification of species is challenging and usually requires DNA sequence data. FUSARIUM-ID (http://isolate.fusariumdb.org/) is a publicly available database designed to support the identification of Fusarium species using sequences of multiple phylogenetically informative loci, especially the highly informative ~680 bp 5' portion of the translation elongation factor 1-alpha (TEF1) gene that has been adopted as the primary barcoding locus in the genus. However, FUSARIUM-ID v.1.0 and 2.0 had several limitations, including inconsistent metadata annotation for the archived sequences and poor representation of some species complexes and marker loci. Here, we present FUSARIUM-ID v.3.0, which provides the following improvements: (i) additional and updated annotation of metadata for isolates associated with each sequence, (ii) expanded taxon representation in the TEF1 sequence database, (iii) availability of the sequence database as a downloadable file to enable local BLAST queries, and (iv) a tutorial file for users to perform local BLAST searches using either freely-available software, such as SequenceServer, BLAST+ executable in the command line, and Galaxy, or the proprietary Geneious software. FUSARIUM-ID will be updated on a regular basis by archiving sequences of TEF1 and other loci from newly identified species and greater in-depth sampling of currently recognized species.


2010 ◽  
Vol 100 (12) ◽  
pp. 1340-1351 ◽  
Author(s):  
Juan Moral ◽  
Concepción Muñoz-Díez ◽  
Nazaret González ◽  
Antonio Trapero ◽  
Themis J. Michailides

Species in the family Botryosphaeriaceae are common pathogens causing fruit rot and dieback of many woody plants. In this study, 150 Botryosphaeriaceae isolates were collected from olive and other hosts in Spain and California. Representative isolates of each type were characterized based on morphological features and comparisons of DNA sequence data of three regions: internal transcribed spacer 5.8S, β-tubulin, and elongation factor. Three main species were identified as Neofusicoccum mediterraneum, causing dieback of branches of olive and pistachio; Diplodia seriata, causing decay of ripe fruit and dieback of olive branches; and Botryosphaeria dothidea, causing dalmatian disease on unripe olive fruit in Spain. Moreover, the sexual stage of this last species was also found attacking olive branches in California. In pathogenicity tests using unripe fruit and branches of olive, D. seriata isolates were the least aggressive on the fruit and branches while N. mediterraneum isolates were the most aggressive on both tissues. Isolates of B. dothidea which cause dalmatian disease on fruit were not pathogenic on branches and only weakly aggressive on fruit. These results, together with the close association between the presence of dalmatian disease symptoms and the wound created by the olive fly (Bactrocera oleae), suggest that the fly is essential for the initiation of the disease on fruit. Isolates recovered from dalmatian disease symptoms had an optimum of 26°C for mycelial growth and 30°C for conidial germination, suggesting that the pathogen is well adapted to high summer temperatures. In contrast, the range of water activity in the medium for growth of dalmatian isolates was 0.93 to 1 MPa, which was similar to that for the majority of fungi. This study resolved long-standing questions of identity and pathogenicity of species within the family Botryosphaeriaceae attacking olive trees in Spain and California.


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.


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.


Phytotaxa ◽  
2016 ◽  
Vol 260 (2) ◽  
pp. 101 ◽  
Author(s):  
CHANG SUN KIM ◽  
JONG WON JO ◽  
YOUNG-NAM KWAG ◽  
GI-HO SUNG ◽  
JAE-GU HAN ◽  
...  

Thirty-four Lycoperdon specimens from Korea were examined with the internal transcribed spacer (ITS) region of ribosomal DNA sequence data. The result of the ITS sequences phylogenetic analysis indicated that the Korean specimens represented nine different species. To confirm the taxonomic position of these species, we conducted an intensive morphological investigation, and additional phylogenetic investigation of the protein coding regions RNA polymerase subunit II (RPB2) and translation elongation factor 1-alpha (TEF1). We discovered two new species (L. albiperidium and L. subperlatum) and one (L. ericaeum) newly discovered in Korea. Lycoperdon albiperidium is closely related to L. ericaeum based on ITS, RPB2 and TEF1 sequence data, but these species were distinguishable by morphological characteristics, especially the shape of the basidiocarps, the diameter of the eucapillitial threads and the size of the basidospores. Lycoperdon subperlatum is quite similar to the European and American L. perlatum based on morphological characteristics. However, L. subperlatum is clearly distinct from European and American L. perlatum based on ITS, RPB2 and TEF1 sequence data, and somewhat differs from them in macro- and microscopic characteristics. Based on morphological characteristics, L. ericaeum is related to L. subumbrinum and L. lividum but it is distinguishable by the presence of fragile, eucapillitial threads, the diameters of the threads and ITS sequences. Here, we describe four Lycoperdon species collected in Korea.


Phytotaxa ◽  
2020 ◽  
Vol 437 (1) ◽  
pp. 14-22
Author(s):  
YUAN S. LIU ◽  
JIAN-KUI (JACK) LIU ◽  
PHONGEUN SYSOUPHANTHONG ◽  
KEVIN D. HYDE ◽  
SAISAMORN LUMYONG

Xanthagaricus siamensis, a new species in the family Agaricaceae, was discovered in northern Thailand and is here introduced based on its morphological features and molecular data. It is characterized by small to medium-sized basidiomata, a convex to plano-convex with depressed center pileus when mature, the presence of greyish orange to violet-brown fibrillose squamules on the pileus, lamellae that start out white, change to pinkish white when damaged, then change to dull green with age. Additionally, the annulus is fugacious, and the pileipellis is recognized as a cutis which morphologically distinguishes it from all other known Xanthagaricus. Phylogenetic analysis of the internal transcribed spacer region (ITS) and the large subunit of the nuclear ribosomal DNA (nrLSU) sequence data indicated that the three specimens of X. siamensis form a distinct lineage within Xanthagaricus, and they formed a well-supported clade representing the genus Xanthagaricus. Detailed illustrations of macro- and micro-morphological characteristics and descriptions are provided, as well as other relevant molecular evidence.


Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Carmen Berlanas ◽  
Sonia Ojeda ◽  
Beatriz López-Manzanares ◽  
Marcos Andrés-Sodupe ◽  
Rebeca Bujanda ◽  
...  

In this study, 3,426 grafted grapevines ready to be planted from 15 grapevine nursery fields in Northern Spain were inspected from 2016 to 2018 for black-foot causing pathogens. In all, 1,427 isolates of black-foot pathogens were collected from the asymptomatic inner tissues of surface sterilized secondary roots and characterized based on morphological features and DNA sequence data of the nuclear ribosomal DNA-internal transcribed spacer region, histone H3, translation elongation factor 1-alpha and β-tubulin genes. Eleven species belonging to the genera Dactylonectria, Ilyonectria, Neonectria, and Thelonectria were identified, including Dactylonectria alcacerensis, D. macrodidyma, D. novozelandica, D. pauciseptata, D. torresensis, Ilyonectria liriodendri, I. pseudodestructans, I. robusta, Neonectria quercicola, Neonectria sp. 1, and Thelonectria olida. In addition, two species are newly described, namely D. riojana and I. vivaria. Twenty-four isolates representing 13 black-foot species were inoculated onto grapevine seedlings cultivar ‘Tempranillo’. The pathogenicity tests detected diversity in virulence among fungal species and between isolates within each species. The most virulent species was D. novozelandica isolate BV-0760, followed by D. alcacerensis isolate BV-1240 and I. vivaria sp. nov. isolate BV-2305. This study improves our knowledge on the etiology and virulence of black-foot disease pathogens, and opens up new perspectives in the study of the endophytic phase of these pathogens in grapevines.


Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 727-738 ◽  
Author(s):  
Yongyan Chen ◽  
Qixing Zhou ◽  
Stephen E. Strelkov ◽  
Sheau-Fang Hwang

Canola (Brassica napus) is one of the most economically important oilseed crops in Canada. Fusarium seedling blight is a root disease with the potential to cause severe yield reductions in canola. Fusarium spp. are commonly isolated root pathogens from fields in Alberta. Fusarium infection can also cause root rot in adult plants. In this study, 128 isolates identified as Fusarium spp. were recovered from field soils in central Alberta and from the roots of diseased canola plants with typical Fusarium seedling blight symptoms. Six species of Fusarium were identified, with Fusarium acuminatum as the predominant species (57 of 128 isolates, 44.5%). Phylogenetic analyses based on the translation elongation factor 1-α and the internal transcribed spacer sequence data were used for evaluation of genetic variations, and also used for Fusarium spp. identification in combination with morphological characteristics and polymerase chain reaction-based analyses. Based on disease ratings in pathogenicity tests, six isolates of F. avenaceum showed high aggressiveness on canola. Also, the aggressiveness varied within all Fusarium spp. No correlation was observed between aggressiveness and the geographic origin of the isolates.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4300 ◽  
Author(s):  
Ian Drake ◽  
James F. White Jr ◽  
Faith C. Belanger

The grass Ammophila breviligulata (American beachgrass) is known to host an endophyte of the genus Epichloë. Based on morphological characteristics it was originally identified as Acremonium typhinum var. ammophilae and is currently designated as Epichloë typhina var. ammophilae. However, the Epichloë species has not previously been identified based on DNA sequence data. Based on phylogenetic placement of beta-tubulin and translation elongation factor 1-alpha DNA sequences the endophyte is identified as a member of E. amarillans rather than E. typhina.


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