scholarly journals Identification and Pathogenicity of Fungal Pathogens Associated with Stem-End Rot of Avocado in California

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
M. Twizeyimana ◽  
H. Förster ◽  
V. McDonald ◽  
D. H. Wang ◽  
J. E. Adaskaveg ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Southern California ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Pathogenicity Test ◽  
Avocado Fruit ◽  
Low Humidity ◽  
Neofusicoccum Luteum

Stem-end rot of harvested avocado fruit commonly occurs wherever the crop is cultivated. Multiple fungal species have been described as causal agents. To determine the causal pathogens of stem-end rot in California, fungal isolations were conducted from symptomatic fruit, and fungi were identified by morphological and molecular techniques. In 2010 and 2011, a total of 177 isolates were recovered from 290 avocado fruit collected from seven orchards in one of the major avocado growing areas in Southern California. The majority of isolates was identified as Neofusicoccum luteum (65%), with the remainder either as Colletotrichum gloeosporioides (33%) or Phomopsis sp. (2%). In a pathogenicity test, N. luteum caused significantly (P < 0.05) more severe stem-end rot than either C. gloeosporioides or Phomopsis sp. No significant (P > 0.05) differences in stem-end rot severity were observed between inoculations with N. luteum isolated from fruit stem-end rot and N. luteum or N. parvum isolated from branch cankers. This confirms that stem-end rot of avocado can be initiated by fungi causing branch cankers. Although low humidity and rainfall during much of the growing and harvest seasons in California are considered unfavorable conditions for the development of avocado stem-end rot, the identification of the causal pathogens is of value when decays have to be managed during outbreaks, and it stresses the importance of managing branch cankers.

scholarly journals Identification of New Fungal Pathogens of Coast Live Oak in California

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1025-1036 ◽  
Author(s):  
Shannon Colleen Lynch ◽  
Paul J. Zambino ◽  
Joey Sal Mayorquin ◽  
Danny Ho Wang ◽  
Akif Eskalen
Keyword(s):  
Fungal Pathogens ◽  
Southern California ◽  
Phylogenetic Analyses ◽  
Ribosomal Subunit ◽  
Complete Sequence ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Live Oak ◽  
Unknown Species ◽  
One Year

A decline of coast live oak (Quercus agrifolia) has been observed throughout southern California. In this study, the identity and pathogenicity of non-Botryosphaeriaceae fungal species consistently recovered from necrotic tissues of branch and bleeding trunk canker samples from these locations were assessed. Species were identified morphologically and by comparison of the complete sequence of the internal transcribed spacer (ITS) of the ribosomal DNA to sequences available in GenBank. Phylogenetic analyses were then conducted using ITS and partial sequences of the β-tubulin and mitochondrial small ribosomal subunit genes for unknown species. Fungi recovered and identified included Fusarium solani, Phaeoacremonium mortoniae, Diatrypella verrucaeformis, and a fungus described herein as Cryptosporiopsis querciphila sp. nov. One-year-old coast live oak seedlings were wound inoculated under controlled conditions to test pathogenicity of the fungal species. Each fungal species was successfully reisolated from necrotic tissue at 70 and 100% for P. mortoniae and all other species, and xylem necrosis was significantly different between all treatments and controls (P < 0.0001 at α = 0.05). Isolates of F. solani were the most aggressive tested. These species represent new records of fungal pathogens of coast live oak in California. Results from the pathogenicity test suggest that these fungi play a role in the decline of southern California coast live oak trees.

scholarly journals The Use of Galleria mellonella Larvae to Identify Novel Antimicrobial Agents against Fungal Species of Medical Interest

2018 ◽  
Vol 4 (3) ◽  
pp. 113 ◽  
Author(s):  
Kevin Kavanagh ◽  
Gerard Sheehan
Keyword(s):  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Galleria Mellonella ◽  
Fungal Infections ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Antifungal Drugs ◽  
Immune Priming ◽  
Greater Wax Moth

The immune system of insects and the innate immune response of mammals share many similarities and, as a result, insects may be used to assess the virulence of fungal pathogens and give results similar to those from mammals. Larvae of the greater wax moth Galleria mellonella are widely used in this capacity and also for assessing the toxicity and in vivo efficacy of antifungal drugs. G. mellonella larvae are easy to use, inexpensive to purchase and house, and have none of the legal/ethical restrictions that are associated with use of mammals. Larvae may be inoculated by intra-hemocoel injection or by force-feeding. Larvae can be used to assess the in vivo toxicity of antifungal drugs using a variety of cellular, proteomic, and molecular techniques. Larvae have also been used to identify the optimum combinations of antifungal drugs for use in the treatment of recalcitrant fungal infections in mammals. The introduction of foreign material into the hemocoel of larvae can induce an immune priming effect which may operate independently with the activity of the antifungal drug. Procedures to identify this effect and limit its action are required.

scholarly journals Botryosphaeria Tree Fungal Pathogens and Their Diversity

2021 ◽  
Vol 10 (1) ◽  
pp. ACCEPTED
Author(s):  
Wendu A. Darge ◽  
Samuel S. Woldemariam
Keyword(s):  
Fungal Pathogens ◽  
Global Climate ◽  
Its Region ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Nutrient Deficiencies ◽  
Morphological Findings ◽  
Optimal Health ◽  
Molecular Phylogenetic ◽  
Host Tree Species

The genus Botryosphaeria identified in 1863 as saprophytes of dead tissue of woody plants have been described as pathogens of economically important plantation trees in agriculture and native forests. The genus is a species-rich, worldwide distributed occurring on diverse host ranges. Species of the Botryosphaeria are reported as the pathogens of many plantation trees, including species of Acacia, Eucalyptus, and Pinus causing canker and rapid dieback diseases which often end up in death. Botryosphaeria fungal pathogens have cross pathogenicity on different host tree species which enables them important and focus area of research. The taxonomy of Botryosphaeria spp. have been under research, identification of these fungi has generally been based on morphological features of the anamorph that usually seen under the microscope. Characters that are used to classify genera in the Botryosphaeria have mostly relied on the macroscopic features of the ascospores and the conidial features. Currently, molecular techniques such as DNA sequencing involving amplification of ITS region are important for exact identification of the genera to species level. Recent molecular, phylogenetic and morphological findings showed that order Botryosphaeriales is diverse consisting nine families and 33 genera with 23 genera only in the family Botryosphaeriaceae. Botryosphaeria spp. are naturally endophytes associated with tree plants known to cause monocyclic or polycyclic diseases resulting in polyetic epidemics. The factor that makes plants more prone to Botryosphaeria fungal species is assumed to be stress or wounding associated with the host plants. Global climate change driven drought is an important factor that initiate stress resulting in nutrient deficiencies. Botryosphaeria fungal tree diseases can be best managed by ensuring plants are in optimal health through appropriate integration of cultural, silvicultural and fungicidal applications to effectively prevent and control the diseases.

scholarly journals In vitro screening of fungicides and tannins against fungal pathogens of jujube fruits

2016 ◽  
Vol 27 (2) ◽  
pp. 154-161 ◽  
Author(s):  
MZ Hoque ◽  
AM Akanda ◽  
MIH Miah ◽  
MKA Bhuiyan ◽  
MG Miah ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Fungal Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Species ◽  
Plain Water ◽  
Curvularia Lunata ◽  
Mycelium Growth ◽  
Fusarium Semitectum ◽  
Poison Food Technique

The aim of this study to identify the effective fungicides for controlling major leaf and fruit diseases of Jujube caused by different fungal pathogens. An in vitro experiment was undertaken to screen ten fungicides and two Tannins against six important fungal pathogens of Jujube fruits which were Alternaria alternata, Colletotrichum gloeosporioides, Curvularia lunata, Lasiodiplodia theobromae, Fusarium semitectum and Pestalotiopsis palmarum. Fungicides were Conza 5 EC (Hexaconazole), Folicur 250 EC (Tebuconazole) and Potent 250 EC (Propiconazole), Bavistin DF (Carbendazim), Kasumin 2% liquid (Kasugamycin), Rovral 50 WP (Iprodine), Matco 72 WP (Mancozeb 64% + Metalaxyl 8%), Geneb 80 WP (Mancozeb), Emivit 50 WP (Copper oxychloride) and Evavit 80 WG (Sulphur 80 WG). And two tannins were Chestnut Tannin and Quabracho Tannin. Plain water was used as control. Poison food technique was followed to conduct the experiment. Both Tannins did not show satisfactory inhibition of mycelial growth of any of the six fungal pathogens. The effectiveness of fungicides varied greatly with fungal species. The most effective fungicides were Folicur 250 EC followed by Potent 250 EC, Rovral 50 WP, Conza 5 WP and Bavistin DF. Folicur 250 EC caused 89.52% inhibition of mycelium growth of A. alternata and 100% growth inhibition in other five fungi. In addition, Potent 250 EC inhibited growth of L. theobromae, C. lunata, F. semitectum and P. palmarum by 100% and that of C. gloeosporioides by 91.79%. Complete growth inhibition of F. semitectum and P. palmarum was achieved with Bavistin DF. Furthermore, Conza 5 EC caused 100% growth inhibition in C. lunata and more than 90% in L. theobromae and F. semitectum.Progressive Agriculture 27 (2): 154-161, 2016

scholarly journals Molecular characterization of fungi associated with stored soybean (Glycine max L) seeds

2020 ◽  
Vol 36 (2) ◽  
pp. 27-32
Author(s):  
C.G. Ikechi-Nwogu ◽  
F.C. Okene
Keyword(s):  
Fungal Pathogens ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Local Alignment ◽  
Post Harvest ◽  
High Quality Protein ◽  
Search Tool ◽  
Food And Feed ◽  
Glycine Max L

Soybean is an important legume that has high quality protein and oil for food and feed. Despite the importance of this legume, the crop is affected by several post-harvest diseases caused by fungi. A study was carried out to identify the fungal species associated with the seeds of soybean using molecular techniques. The DNA of the isolate, was molecularly characterized using Internal Transcribed Spacer 1 (ITS-1) molecular marker. The isolate DNA sequence, was aligned using the Basic Local Alignment Search Tool for nucleotide (BLASTN) 2.8.0 version of the National Center for Biotechnology Information (NCBI) database. The results showed that the isolate sequence was 98% identical to Diaporthe spp. Voucher VP51, 98% identical to Diaporthe schini isolate L5N71 and 98% identical to Diaporthe schini strain B125. These findings showed that Diaporthe spp. is one of the causal fungal pathogens of post-harvest diseases of soybean seeds. It is anticipated that these results will provide information on culturing Diaporthe species also provide the basis for further study to show their antibiotic and anti-cancerous, enzymes and secondary metabolites producing ability. Keywords: Soybean, Diaporthe schini and RBCL marker

scholarly journals Anthracnose and leaf spot diseases of Aloe vera L. from Bangladesh

2013 ◽  
Vol 22 (2) ◽  
pp. 103-108
Author(s):  
Anita Rani Shutrodhar ◽  
Shamim Shamsi
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Flavus ◽  
Leaf Spot ◽  
Colletotrichum Gloeosporioides ◽  
Aloe Vera ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Diseased Leaf ◽  
Leaf Spots ◽  
Nigrospora Oryzae

Characteristic symptoms of anthracnose and leaf spot were recorded from diseased leaf samples of Aloe vera L. A total of 8 fungal species, namely Alternaria pluriseptata (Karst. & Har.) Jorstad, Aspergillus flavus Link, Aspergillus niger Van Tieghem, Cladosporium oxysporum Berk. & Curt., Colletotrichum gloeosporioides (Penz.) Sacc., Nigrospora oryzae (Berk. & Br.) Petch, Penicillium sp. and Pestalotiopsis guepinii (Desm.) Stay. were found to be associated with healthy and diseased leaf samples. In addition to above 8 fungi, Curvularia brachyospora Boedijn, Epicoccum purpurascens Ehrenb. ex Schlecht and Sclerotium sp. were also associated with diseased leaf samples of the plant. The prevalence of the fungi ranged 1.43 - 13.35% on healthy leaves and 1.43 - 62.16% on infected leaves. The frequency of C. gloeosporioides was the maximum and that of Aspergillus and Penicillium was the lowest. Pathogenicity test revealed that C. gloeosporioides causes anthracnose and E. purpurascens and P. guepinii cause leaf spots of A. vera. Dhaka Univ. J. Biol. Sci. 22(2): 103-108, 2013 (July)

scholarly journals Spore Trapping and Pathogenicity of Fungi in the Botryosphaeriaceae and Diaporthaceae Associated with Avocado Branch Canker in California

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 329-332 ◽  
Author(s):  
Akif Eskalen ◽  
Ben Faber ◽  
Mary Bianchi
Keyword(s):  
Fungal Species ◽  
Vascular Lesion ◽  
Summer Season ◽  
High Density ◽  
Pathogenicity Test ◽  
Spore Trap ◽  
Avocado Fruit ◽  
Spore Trapping ◽  
Precipitation Events ◽  
Branch Canker

Avocado branch canker in California is caused by a complex of fungal species in the families Botryosphaeriaceae and Diaporthaceae. As the popularity of avocado fruit increases, California growers are under pressure to increase their productivity in order to compete with imports. One way to increase production is through high-density planting, which entails intense canopy management, possibly leaving the trees vulnerable to infection through pruning wounds. A spore trap study was undertaken to determine the seasonal spore discharge of Botryosphaeriaceous and Diaporthaceous fungi. Based on colony counts, the highest population of Botryosphaeriaceous fungi (68%) occurred during or soon after precipitation events, which coincided with the winter months of December, January, and February. The spring and fall seasons had lower numbers of spores trapped (at 13 and 17%, respectively), with few spores trapped in the summer season. For members of the Diaporthaceae family, spores trapped were almost evenly split between winter and fall seasons (50 and 49%, respectively), with few to no spores trapped in the spring and summer seasons. A pathogenicity test of six fungi of Botryosphaeriaceae and one fungus of Diaporthaceae was conducted in the greenhouse. Internal plant vascular lesion lengths resulting from inoculation with any of the seven fungal species differed significantly from the noninoculated control. These studies suggest that pruning during the drier parts of the year would minimize infection by fungi in the Botryosphaeriaceae and Diaporthaceae families.

scholarly journals Dieback and decline pathogens of olive trees in South Africa

2020 ◽  
Vol 45 (1) ◽  
pp. 196-220
Author(s):  
C.F.J. Spies ◽  
L. Mostert ◽  
A. Carlucci ◽  
P. Moyo ◽  
W.J. van Jaarsveld ◽  
...  
Keyword(s):  
South Africa ◽  
New Species ◽  
Fungal Pathogens ◽  
Fungal Species ◽  
Molecular Techniques ◽  
White Rot ◽  
Western Cape ◽  
Production Region ◽  
Wild Olive ◽  
Olive Trees

Trunk disease fungal pathogens reduce olive production globally by causing cankers, dieback, and other decline-related symptoms on olive trees. Very few fungi have been reported in association with olive dieback and decline in South Africa. Many of the fungal species reported from symptomatic olive trees in other countries have broad host ranges and are known to occur on other woody host plants in the Western Cape province, the main olive production region of South Africa. This survey investigated the diversity of fungi and symptoms associated with olive dieback and decline in South Africa. Isolations were made from internal wood symptoms of 145 European and 42 wild olive trees sampled in 10 and 9 districts, respectively. A total of 99 taxa were identified among 440 fungal isolates using combinations of morphological and molecular techniques. A new species of Pseudophaeomoniella, P. globosa, had the highest incidence, being recovered from 42.8 % of European and 54.8 % of wild olive samples. This species was recovered from 9 of the 10 districts where European olive trees were sampled and from all districts where wild olive trees were sampled. Members of the Phaeomoniellales (mainly P. globosa ) were the most prevalent fungi in five of the seven symptom types considered, the only exceptions being twig dieback, where members of the Botryosphaeriaceae were more common, and soft/white rot where only Basidiomycota were recovered. Several of the species identified are known as pathogens of olives or other woody crops either in South Africa or elsewhere in the world, including species of Neofusicoccum, Phaeoacremonium, and Pleurostoma richardsiae. However, 81 of the 99 taxa identified have not previously been recorded on olive trees and have unknown interactions with this host. These taxa include one new genus and several putative new species, of which four are formally described as Celerioriella umnquma sp. nov., Pseudophaeomoniella globosa sp. nov., Vredendaliella oleae gen. & sp. nov., and Xenocylindrosporium margaritarum sp. nov.

scholarly journals Identification and Pathogenicity of Fungal Pathogens Associated with Stem End Rots of Avocado Fruits in Kenya

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
E. K. Wanjiku ◽  
J. W. Waceke ◽  
B. W. Wanjala ◽  
J. N. Mbaka
Keyword(s):  
Household Income ◽  
Fungal Pathogens ◽  
Significant Contribution ◽  
Management Strategies ◽  
Molecular Techniques ◽  
Pathogenicity Test ◽  
Neofusicoccum Parvum ◽  
Fungal Isolates ◽  
Postharvest Loss ◽  
Major Pathogens

Losses associated with stem end rot (SER) of avocado fruits have been reported in all avocado growing regions of the world. In Kenya, mature avocado fruits present SER symptoms during storage and marketing, but the disease causal agent(s) has not been established. This study aimed to identify the fungal pathogen(s) associated with avocado SER in Kenya and evaluate its pathogenicity. Fungal isolates were collected from symptomatic avocado fruits from randomly selected orchards and major markets within Murang'a County, a major avocado growing region in Kenya, between September 2017 and March 2018. A total of 207 and 125 fungal isolates, recovered from orchards and major markets, respectively, were identified morphologically and further confirmed by molecular techniques. The identified isolates were Lasiodiplodia theobromae (39.8%), Neofusicoccum parvum (24.4%), Nectria pseudotrichia (18.4%), Fusarium solani (7.2%), F. oxysporum (5.1%), F. equiseti (3.9%), and Geotricum candidum (1.2%). Geotricum candidum was exclusively recovered from fruits from the market. In the pathogenicity test, L. theobromae, N. parvum, and N. pseudotrichia caused the most severe SER symptoms. Consequently, they were considered to be the major pathogens of SER of avocado fruits in Kenya. To our knowledge, this is the first report of SER pathogen of avocado fruits in Kenya. Given the significant contribution of avocado fruits to household income and foreign exchange in Kenya, this information is significant to further develop management strategies of postharvest loss of avocado fruits in Kenya.

scholarly journals Identification and Characterizations of Pathogenic Fungal Species Associated with Symptoms of Cassava Anthracnose in Ivory Coast

2019 ◽  
pp. 1-9
Author(s):  
Ehui Kouadio Jean Nestor ◽  
Toure Howélé Michaëlle Andrée Célestine ◽  
Kouame Koffi Gaston ◽  
Abo Kouabenan ◽  
Kone Daouda
Keyword(s):  
Ivory Coast ◽  
Fungal Pathogens ◽  
Plant Disease ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Species ◽  
Economic Importance ◽  
Scientific Interest ◽  
Apical Buds ◽  
Great Economic Importance ◽  
Fusarium Sp

Cassava anthracnose is a plant disease that affects cassava stems, petioles and fruits. The aim of this study was to analyze the diversity of cassava anthracnose symptoms in Ivory Coast and then to identify and characterize the associated fungal genera. Surveys were carried out in all agricultural zones of the country from July to November, in 2014, 2015, 2016 and 2017. Infected samples consisting of stems cut with a small number of superficial cankers (0.3%), distorted stems (25.77%), and necrotic stems and petioles (65.18%) were collected. Also, withered and dried apical buds (8.76%) were harvested. Fungal pathogens derived from samples were Colletotrichum gloeosporioides (35.08%), Fusarium sp. (27.19%) and Botrytis sp. (19.73%) genera and undetermined strains (17.98%). Genera were characterized by morphological and microscopic characteristics. Parasitic pressure increased to 80 and 100% respectively for Botrytis sp. genus and Colletotrichum gloeosporioides and Fusarium sp genera. Fungal genera have caused lesions on stem and petioles in green house with diameters sizes 46, 71 and 72 mm respectively for genera Botrytis sp, Fusarium sp and Colletotrichum gloeosporioides. Aggressiveness index of Botrytis sp. genus was 3 and 4 respectively for Colletotrichum gloeosporioides and Fusarium sp. genera. The mycoflora of cassava aerial organs alteration, linked to the symptoms of anthracnose, is composed of genera of great economic importance and scientific interest.

Sign in / Sign up

Export Citation Format

Share Document