Myrothecium roridum Leaf Spot and Stem Canker on Watermelon in the Southern Great Plains: Possible Factors for Its Outbreak

2012 ◽  
Vol 13 (1) ◽  
pp. 47 ◽  
Author(s):  
Benny D. Bruton ◽  
Wayne W. Fish
Keyword(s):  
Great Plains ◽  
Leaf Spot ◽  
Natural Infection ◽  
Stem Canker ◽  
Differential Resistance ◽  
Fruit Rot ◽  
Wide Range ◽  
Myrothecium Roridum ◽  
High Level ◽  
Physical Features

In 2010, a foliar and stem-lesion disease was observed for the first time in Oklahoma causing moderate to severe defoliation. Using microscopic examination, the physical features of the fungus were consistent with Myrothecium roridum. There was a wide range of susceptibility among watermelon cultivars in the field indicating a moderately high level of resistance to Myrothecium leaf spot in some cultivars. In greenhouse inoculation experiments, cantaloupe, honeydew, cucumber, squash, and watermelon were all susceptible to the fungus with cantaloupe and honeydew being the most susceptible and watermelon the most resistant. Furthermore, greenhouse inoculations supported the field observations as differential resistance was exhibited among the watermelon cultivars as well as the cucurbit types. Although cantaloupe was most susceptible to the foliar phase of this disease, watermelon was most susceptible to the fruit-rot phase. Natural infection of watermelon fruit has never been reported. Accepted for publication 15 December 2011. Published 30 January 2012.

Didymella bryoniae. [Descriptions of Fungi and Bacteria].

1972 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Natural Infection ◽  
Seed Transmission ◽  
Stem Canker ◽  
Fruit Rot ◽  
Didymella Bryoniae ◽  
Gummy Stem Blight ◽  
Water Splash ◽  
Characteristic Features

Abstract A description is provided for Didymella bryoniae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Cucurbits (Bryonia, Colocynthis, Cucumis, Cucurbita, Luffa, Momordica and Trichosanthes). DISEASE: Gummy stem blight of Cucurbitaceae, showing a variety of symptoms which are referred to as leaf spot, stem canker, vine wilt and black fruit rot. Lesions on leaves and fruit usually begin as spreading water-soaked areas; in the former these may have a chlorotic halo, become light brown and irregular in outline, leaves can be destroyed. On fruit, dark cracked sunken lesions form, beneath which an extensive rot is found. In the field the first symptoms may be plant collapse where sunken, girdling cankers lead to total loss. Infection also occurs on seedlings. The main characteristic features are the gummy exudate on stem and fruit lesions and the abundant pycnidia followed by perithecia, GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 450, ed. 2, 1970). Records not yet mapped are: Brunei, Mexico, Netherlands, Pitcairn Islands, Republic of Ireland, Salvador. TRANSMISSION: Through conidia by water splash and aerially by ascospores which, in glasshouses in England, had a diurnal periodicity with a peak at 1800-2000 hr (46, 825; 48, 672); and in USA occurred mostly at night (50, 2621). Both spore types may serve as primary inoculum and between-crop survival is an important factor in the epidemiology. Reports on seed transmission are conflicting in cucumber, although seed could be inoculated successfully, no evidence for natural infection was found (48, 322). In the glasshouse transmission by pruning knives has been demonstrated (46, 825).

Colletotrichum capsici. [Descriptions of Fungi and Bacteria].

1971 ◽  
Author(s):  
J. E. M. Mordue
Keyword(s):  
Capsicum Annuum ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Fruit Rot ◽  
Southern Europe ◽  
Seedling Blight ◽  
Plant Debris ◽  
Colletotrichum Capsici ◽  
Wide Range ◽  
Extensive Growth

Abstract A description is provided for Colletotrichum capsici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Capsicum annuum, C. frutescens, Aristolochia, Cicer, cotton, Eggplant, jute, tomato, turmeric and many others from a wide range of families. DISEASE: Dieback, stem break, anthracnose, leaf spot, seedling blight, fruit rot (dieback of young fruits and ripe rot). GEOGRAPHICAL DISTRIBUTION: Tropics and subtropics of Africa, Asia, America and Australasia; has been recorded occasionally in Southern Europe. TRANSMISSION: Seed-borne; persists in decayed fruits and other plant debris from which conidia are dispersed locally by water and air currents. No extensive growth in soil reported.

Phytophthora cactorum. [Descriptions of Fungi and Bacteria].

1966 ◽  
Author(s):  
G. M. Waterhouse
Keyword(s):  
Geographical Distribution ◽  
Stem Canker ◽  
Fruit Trees ◽  
Crown Rot ◽  
Fruit Rot ◽  
Infested Soil ◽  
Apple Orchards ◽  
Phytophthora Cactorum ◽  
Collar Rot ◽  
Wide Range

Abstract A description is provided for Phytophthora cactorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a very wide range of host plants embracing 54 families (particularly Rosaceae) and over 150 genera (Nienhaus, 1960; Rangaswami, 1962) including ash, beech, cherry, conifers, apple, pear, apricot, strawberry, cucurbits, eggplant, cacti, gooseberry, rhododendron, lilac, ginseng, rhubarb, avocado, birch, maple and oak. DISEASES: Damping-off of seedlings including ash, beech, cherry and conifers; fruit rot of apple, pear, apricot, strawberry (leather rot), cucurbits and eggplant; leaf and stem rot of cacti, gooseberry, rhododendron, lilac, ginseng and rhubarb; collar rot and crown rot of apple and other fruit trees stem canker of avocado, birch, maple and oak; root rots in general. GEOGRAPHICAL DISTRIBUTION: Widespread in tempetate areas (CMI Map 280). TRANSMISSION: Soil-borne. Widely distributed in soils of apple orchards affected with collar rot (35: 685; 37: 132). Strawberry fruit in unmulched beds and wind-fall apples and pears on the ground frequently become infected by contact with infested soil (4: 101; 35: 685) where the pathogen may occur to a depth of 50 cm and persist for as long as 15 yr. in ploughland previously under apple orchards (42: 75). This has been partially explained by the irregular germination of oospores which require a dormant period (Blackwell, 1943; Legge, 1952). Apple fruit and gooseberry shoot infection are most frequent on lower branches subject to rain-splash which carry zoospores (41: 49). Long periods of rain, heavy dews, fog and high soil moisture favour the spread of the pathogen (39: 250; 45, 2553; 22: 30-31; 42: 391).

scholarly journals First Report of a Leaf Spot and Stem Canker Caused by Myrothecium roridum on Watermelon in the United States

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 342-342 ◽  
Author(s):  
K. W. Seebold ◽  
D. B. Langston ◽  
R. C. Kemerait ◽  
J. E. Hudgins
Keyword(s):  
United States ◽  
Leaf Spot ◽  
Citrullus Lanatus ◽  
Stem Canker ◽  
The United States ◽  
Tween 20 ◽  
Conidial Suspension ◽  
American Phytopathological Society ◽  
Leaf Spots ◽  
Myrothecium Roridum

Myrothecium roridum Tode:Fr, pathogenic to a number of cucurbit species, causes fruit rots, cankers on crowns and stems, and leaf spots. Hosts include cantaloupe and honeydew (Cucurbita melo) and cucumber (Cucumis sativus) (1,3). In June 2004, following a period of heavy rainfall, numerous round-to-oblong, brown lesions with concentric rings were observed on leaves of watermelon (Citrullus lanatus) cv. Desert King at the Blackshank Farm in Tifton, GA. Disease was localized in the field and severity was low (<5% of leaf area affected). No symptoms were observed on fruit. Sections of tissue were removed from the margin between healthy and diseased tissue and plated on acidified, 25% potato dextrose agar (aPDA). A small plug of agar and mycelium were removed from colonies that emerged from lesions and were transferred to aPDA. Isolated colonies were characterized by a white, floccose mycelium with concentric, dark green-to-black rings of sporodochia bearing viscid masses of conidia. Conidia were cylindrical with rounded ends and measured 6 to 8 × 1.5 to 2.5 μm. The features of the fungus were consistent with the description of Myrothecium roridum (1,2). Pathogenicity tests were conducted in a temperature-controlled greenhouse. Twenty-five watermelon plants (cv. Desert King) were inoculated with a conidial suspension of M. roridum (5 × 105 conidia per ml) plus 0.1% vol/vol Tween 20. Inoculum was applied on leaves and stems until runoff with a hand-held mister, and plants were placed in a dew chamber for 72 h. Ten plants were sprayed with sterile, distilled water to serve as controls. Inoculated and noninoculated control plants were removed from the dew chamber and maintained at 25 to 28°C. Symptoms appeared 8 days after inoculation and were characterized by round, dark lesions with concentric rings; noninoculated plants were symptomless. Sections of symptomatic tissue were plated, and M. roridum was reisolated. Although M. roridum is a common pathogen of melons and cucumber, to our knowledge, this is the first field report of a leaf spot caused by M. roridum on watermelon in the United States. No further occurrences of the disease on watermelon have been observed in Georgia since the initial discovery of M. roridum in 2004; however, losses could be potentially severe if widespread infection of fruit were to occur. References: (1) B. D. Bruton. Crater Rot. Pages 49–50 in: Compendium of Cucurbit Diseases. T. A. Zitter et al., eds. The American Phytopathological Society, St. Paul, MN, 1996. (2) M. B. Ellis. Page 552 in: Dematiaceous Hyphomycetes. CAB International, Wallingford, UK, 1971. (3) D. F. Farr et al. Page 809 in: Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.

scholarly journals LATE BLIGHT RESISTANCE OF WILD POTATO SPECIES UNDER FIELD CONDITIONS IN THE NORTHWEST OF RUSSIA

2020 ◽  
Vol 180 (4) ◽  
pp. 159-169 ◽  
Author(s):  
N. M. Zoteyeva
Keyword(s):  
Late Blight ◽  
Natural Infection ◽  
Late Blight Resistance ◽  
Field Resistance ◽  
Wild Potato ◽  
Wild Potato Species ◽  
Potato Species ◽  
Wide Range ◽  
Foliar Resistance ◽  
High Level

Background. Despite the great efforts made by breeders, late blight remains a paramount cause of significant potato harvest losses. Introgression of various resistance genes from wild Solanum L. species is the main method to increase the resistance in potato cultivars. Field resistance is considered to be more durable than those induced by the action of single R genes. To this end, resistance sources should be selected from а wide range of species under severe natural infection.Material and methods. As the material for evaluation, 1141 accessions of 99 wild potato species belonging to 15 taxonomic series according to the system of J. Hawkes were used. Each accession was assessed for 3–5 years. A 1–9 point scale was employed to score the damage of plants every week starting from the first symptoms of the disease, where 9 meant the absence of any symptoms, and 1 the entirely damaged plant. The plants scoring 6 to 9 points were considered resistant.Results and conclusions. As a result of the long-term field observations, wild potato species, represented in the current evaluation by numerous accessions, were characterized for foliar resistance to late blight; individual introductions resistant to late blight were also identified. Some of those studied in the 1980s showed high resistance in the end of the 1990s through the 2000s. The highest percentage of resistant accessions/species was identified among the species with areas of distribution in Mexico. A group of Central American species and large part of species with areas of distribution in South America expressed high level of interspecific polymorphism in foliar resistance to late blight.

scholarly journals First report of leaf spot caused by Colletotrichum siamense on Salix matsudana in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Meng-Yu Zhang ◽  
Yuan-Zhi Si ◽  
Yue Ju ◽  
De-Wei Li ◽  
Li-Hua Zhu
Keyword(s):  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Conidial Suspension ◽  
Individual Tree ◽  
First Report ◽  
Spot Disease ◽  
Wide Range ◽  
Colletotrichum Siamense ◽  
Salix Matsudana ◽  
High Level

Salix matsudana Koidz. (Chinese willow) is an important landscaping tree species widely grown in China (Zhang et al. 2017). In October 2019, a characteristic leaf spot disease of S. matsudana was found on the campus of Nanjing Forestry University. Most 25-year-old S. matsudana trees (13 out of 21, approximately 62%) on campus showed the leaf spot disease. On average, 70% of the leaves per individual tree were affected by this disease. Foliar symptoms began as dark brown, irregular spots and the centers were gray-white, gradually enlarging with time. Leaf spot symptomatic leaves were collected from three infected S. matsudana trees (10 leaves/tree), and small infected tissues (3–4 mm2) were surface-sterilized in 75% ethanol for 30 s, 1% NaClO for 90 s, rinsed in ddH2O, dried on sterilized filter paper, and plated on potato dextrose agar (PDA), and then incubated at 25°C. Three isolates (NHY1-1, NHY1-2, and NHY1-3) of the same fungus were obtained in 85% of the samples and deposited in China's Forestry Culture Collection Center (NHY1-1: cfcc55354, NHY1-2: cfcc55355, NHY1-3: cfcc55359). The colonies of three isolates were white, but the reverse side was grayish-white. The conidia of NHY1-1 were one-celled, straight, subcylindrical, hyaline, 14.4 ± 0.9 × 5.4 ± 0.4 µm (n = 50), with a rounded end. Conidiophores were hyaline to pale brown, septate, and branched. Appressoria were one-celled, ellipsoidal, brown or dark brown, thick-walled, 8.0 ± 0.9 × 5.9 ± 0.5 µm (n = 50). The conidia and appressoria of the other two isolates weralmost identical to NHY1-1. The morphological characters of the three isolates were matched with those of the Colletotrichum gloeosporioides complex (Weir et al. 2012). For accurate identification, the DNA of the three isolates was extracted. The internal transcribed spacer region (ITS), actin (ACT), calmodulin (CAL), chitin synthase (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), superoxide dismutase (SOD2), and β-tubulin 2 (TUB2) genes were amplified using the primer pairs ITS1/ITS4, ACT-512F/ACT-783R, CL1C/CL2C, CHS-79F/CHS-345R, GDF1/GDR1, SODglo2-F/SODglo2-R, and Bt2a/Bt2b, respectively (Weir et al. 2012). The sequences were deposited in GenBank [Accession Nos. MW784679 and MW808959 to MW808964 for NHY1-1; MW784726 and MW808965 to MW808970 for NHY1-2; MW784729 and MW808971 to MW808976 for NHY1-3]. A BLAST search of GenBank showed that ITS, ACT, CAL, GAPDH, SOD2, and TUB2 sequences of the three isolates were identical to Colletotrichum siamense at a high level (>99%), and CHS-1 sequences of three isolates were consistent with Colletotrichum fructicola at a high level (>99%). A maximum likelihood and Bayesian posterior probability analyses using IQtree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences (ITS, ACT, CAL, CHS-1, GAPDH, SOD2, and TUB2) placed NHY1-1, NHY1-2, and NHY1-3 in the clade of C. siamense with high bootstrap support values (ML/BI = 93/1). The pathogenicity of three isolates were tested on potted 2-yr-old seedlings (50-cm tall) of S. matsudana, which were grown in a greenhouse. Healthy leaves were wounded with a sterile needle and then inoculated with 10 µL of conidial suspension (106 conidia/mL). Controls were treated with ddH2O (Zhu et al. 2019). In total, 12 seedlings were inoculated including controls. Three seedlings/isolate and 10 leaves/seedling were used for each treatment. The plants were covered with plastic bags after inoculation and sterilized H2O was sprayed into the bags twice/day to maintain humidity and kept in a greenhouse at the day/night temperatures at 25 ± 2 / 16 ± 2°C. Within 7 days, all the inoculated points showed lesions similar to those observed in field, whereas controls were asymptomatic. The infection rate of each of the three isolates is 100%. C. siamense was re-isolated from the lesions, whereas no fungus was isolated from control leaves. The diseases caused by C. siamense often occur in tropical and subtropical regions of China, with a wide range of hosts, such as Hevea brasiliensis and Coffea arabica, etc. (Cao et al. 2019; Liu et al. 2018). This is the first report of C. siamense causing leaf spot of S. matsudana in China and the world. These data will help to develop effective strategies for managing this newly emerging disease.

The way of value of Correlation of genomic DNA microsatellite loci and live weight of Chukchi reindeer

2020 ◽  
pp. 27-32
Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova
Keyword(s):  
Microsatellite Markers ◽  
Agricultural Production ◽  
Live Weight ◽  
Biodiversity Loss ◽  
Tribal Community ◽  
High Germination ◽  
Wide Range ◽  
The Mean ◽  
High Level ◽  
Dna Microsatellite

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.

COVID-19 Outbreak Prediction with Machine Learning

2020 ◽  
Author(s):  
Sina Faizollahzadeh Ardabili ◽  
Amir Mosavi ◽  
Pedram Ghamisi ◽  
Filip Ferdinand ◽  
Annamaria R. Varkonyi-Koczy ◽  
...  
Keyword(s):  
Machine Learning ◽  
Prediction Models ◽  
Fuzzy Inference ◽  
Control Measures ◽  
Future Research ◽  
Complex Nature ◽  
Inference System ◽  
Wide Range ◽  
Standard Models ◽  
High Level

Several outbreak prediction models for COVID-19 are being used by officials around the world to make informed-decisions and enforce relevant control measures. Among the standard models for COVID-19 global pandemic prediction, simple epidemiological and statistical models have received more attention by authorities, and they are popular in the media. Due to a high level of uncertainty and lack of essential data, standard models have shown low accuracy for long-term prediction. Although the literature includes several attempts to address this issue, the essential generalization and robustness abilities of existing models needs to be improved. This paper presents a comparative analysis of machine learning and soft computing models to predict the COVID-19 outbreak as an alternative to SIR and SEIR models. Among a wide range of machine learning models investigated, two models showed promising results (i.e., multi-layered perceptron, MLP, and adaptive network-based fuzzy inference system, ANFIS). Based on the results reported here, and due to the highly complex nature of the COVID-19 outbreak and variation in its behavior from nation-to-nation, this study suggests machine learning as an effective tool to model the outbreak. This paper provides an initial benchmarking to demonstrate the potential of machine learning for future research. Paper further suggests that real novelty in outbreak prediction can be realized through integrating machine learning and SEIR models.

CRIMINOLOGICAL FEATURES OF CORRUPTION-RELATED CRIMES IN THE FUEL AND ENERGY COMPLEX

2020 ◽  
pp. 23-27
Author(s):  
Сергей Иванович Вележев ◽  
Антон Михайлович Седогин
Keyword(s):  
Legal Protection ◽  
Criminal Activity ◽  
Criminal Cases ◽  
Law Enforcement Agencies ◽  
Energy Complex ◽  
Significant Damage ◽  
Study Results ◽  
Wide Range ◽  
Illegal Activities ◽  
High Level

В представленной статье авторами рассматриваются вопросы уголовно-правовой охраны топливно-энергетического комплекса Российской Федерации от преступных проявлений, в том числе от коррупционной противоправной деятельности должностных лиц. Такие действия причиняют значительный ущерб нормальному функционированию предприятий топливно-энергетического комплекса. Авторами приводятся результаты исследования некоторых криминологических характеристик должностных лиц, совершивших преступления коррупционного характера. Дан анализ причин и условий, способствующих совершению вышеуказанных противоправных действий. Определена типовая модель преступника для данной категории преступлений и его характеристики: в первую очередь, это высокий уровень компетентности, специальное образование и т. д. Авторами отмечается высокий уровень латентной преступности в данной отрасли. Предложены некоторые пути профилактики данной категории правонарушений. Исследование проводилось на основе анализа конкретных уголовных дел, возбужденных следственными органами по результатам оперативно-розыскной деятельности правоохранительных органов. In the article the authors consider the issues of criminal and legal protection of the fuel and energy complex of the Russian Federation from criminal activity including corrupt illegal practices of officials. The authors cite the results of some criminological characteristics study of the fuel and energy complex staff committed corruption crimes. As a result of these illegal actions significant damage is caused to the normal functioning of the fuel and energy enterprises. Such officials` actions determine not only a wide range of other illegal activities, but also lead to public outcry and discredit the industry as a whole. The analysis of the reasons and conditions contributing to the above illegal actions commission is given. A typical model of a criminal for a given crime category and its characteristics are determined. First of all it is a high level competence, special education, etc. A high level of latent crime in this industry is shown. The study results are presented on the example of specific criminal cases initiated by the investigating authorities based on the results of the operation detection activities of law enforcement agencies. Some ways of preventing this category of offenses are proposed.

Tickets for the Inclusive Museum

2020 ◽  
pp. 390-406
Author(s):  
Magda Nikolaraizi ◽  
Charikleia Kanari ◽  
Marc Marschark
Keyword(s):  
Hard Of Hearing ◽  
Learning Experiences ◽  
Learning Needs ◽  
Participatory Learning ◽  
Maximum Benefit ◽  
Wide Range ◽  
The Right ◽  
Physical Features ◽  
And Behavior

In recent years, museums of various kinds have broadened their mission and made systematic efforts to develop a dynamic role in learning by offering a wide range of less formal experiences for individuals with diverse characteristics, including individuals who are deaf or hard-of-hearing (DHH). Despite the worthwhile efforts, in the case of DHH individuals, museums frequently neglect to consider their unique communication, cognitive, cultural, and learning characteristics, thus limiting their access and opportunities for fully experiencing what museums have to offer. This chapter examines the potential for creating accessible museum environments and methods that reflect an understanding of the diverse communication, cognitive, cultural, and learning needs of DHH visitors, all of which enhance their access and participation in the museum activities. The role of the physical features of museum spaces for the access and behavior of DHH visitors is emphasized, together with attention to exhibition methods and the communication and cognitive challenges that need to be considered so DHH visitors can get the maximum benefit. The chapter emphasizes the right of individuals who are DHH to nonformal learning and analyzes how museums could become more accessible to DHH individuals by designing, from the beginning, participatory learning experiences that address their diverse needs.

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