scholarly journals Factors Affecting Development of Alternaria Leaf Spot of Asalio Caused By Alternaria Alternata And Identification of Pathogen

2021 ◽  
Author(s):  
Poonam Kumari ◽  
Amit Trivedi ◽  
Akansha Deora ◽  
Neelam Geat ◽  
Lokesh Kumar
Keyword(s):  
Molecular Identification ◽  
Alternaria Alternata ◽  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Inoculum Concentration ◽  
Factors Affecting ◽  
Significant Difference ◽  
Its Regions ◽  
Polymerase Chain ◽  
Effect Of Age

Abstract The present study was on management of Alternaria leaf spot caused by Alternaria alternata in Asalio. The disease was found to be very severe in all Asalio growing areas causing heavy destruction. The main aim of this investigation was to find out effect of age of the host, inoculum density in Alternaria leaf spot disease development and molecular identification of pathogen. The result shows that the susceptibility in Asalio increased with increase in age on inoculatios of A. alternata. Maximum disease was obtained in the plants ageing 40 DAS with PDI 55.60 per cent. Among the variously examined levels of inoculum concentrations. The two lower concentrations 1 × 101 and 1 × 102 conidia ml-1 exhibited significant difference in the PDI (20.00 and 31.20 respectively) within each other. 1 × 103 and 1 × 104 conidia ml-1 inoculum levels were found to be significantly at par to each other with PDI (39.20 and 40.80 respectively). 1 × 103 conidia ml-1 inoculum concentration was optimum for causing highest level of disease. After inoculation of inoculum 1 × 103 conidia ml-1, typical leaf spot symptoms were observed on the leaves of Asalio plants. Disease severity according to the scale was 39.20%. For molecular identification, 650 bp internal transcribed spacer (ITS) regions (ITS1, 5.8s and ITS2) were amplified through polymerase chain reaction (PCR). The nucleotide sequences from ITS regions of the isolates were submitted to NCBI with GenBank accession numbers MA585375.

scholarly journals First Report of Alternaria Leaf Spot of Almond Caused by Species in the Alternaria alternata Complex in California

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 558-558 ◽  
Author(s):  
B. L. Teviotdale ◽  
M. Viveros ◽  
B. Pryor ◽  
J. E. Adaskaveg
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Prunus Dulcis ◽  
Leaf Spot Disease ◽  
Yield Losses ◽  
Mature Leaves ◽  
Branching Chains ◽  
Paper Towels ◽  
Industry Conference

A new leaf spot disease of almond (Prunus dulcis [Mill.] D. Webb) was observed in California in the late 1980s and was first associated with severe defoliation in the mid-1990s (1). Orchards in areas with frequent summer dews, high humidity, and little air movement sustained severe defoliation, resulting in yield losses often exceeding 50%. Symptoms occur only on leaf blades in late spring and summer. Lesions develop as small, circular, tan spots 1 to 3 mm in diameter that may enlarge to 5 to 20 mm in size. Semicircular lesions frequently develop along the leaf margins and tips. The centers of mature lesions become black with fungal sporulation. The fungi isolated from the margins of sporulating and non-sporulating lesions were identified as three species in the Alternaria alternata complex: A. alternata, A. arborescens, and A. tenuissima (2,3). Cultures grown in the dark on potato dextrose (PDA) or potato-carrot agar are grayish white to olivacious green in the former two species and dark gray and wooly in the latter species. On 5% PDA, cultures of all three species produced catenulate dictyospores that were granular to punctate (-verrucose), pale yellowish to brown or black, and had visible apical and basal pores. Conidial morphology depended on chain position; apical conidia ranged from ovoid to ellipsoid, whereas basal conidia were elliptical to obclavate. Average conidial dimensions of A. alternata and A. arborescens ranged from 20 to 28 × 8 to 10 μm. Conidia of A. alternata were produced in acropetal succession in branching chains on single, short suberect conidiophores. A. arborescens produced conidia similarly but mostly in dichotomously branching chains on short to long conidiophores. Average conidial dimensions of A. tenuissima ranged from 20 to 34 × 8 to 12 μm and they were produced in simple chains with one or two branches forming occasionally. In preliminary studies, the optimum temperature for mycelial growth on PDA for all three species ranged from 24 to 28°C. Fifty mature leaves on each of four 7- or 8-year-old almond cv. Butte trees were inoculated at 2- to 3-week intervals from mid-spring through summer in 1999 and 2000. Leaves were sprayed with aqueous suspensions containing 105 conidia per milliliter for one isolate each of A. alternata and A. arborescens and two isolates of A. tenuissima or with sterile distilled water. The shoots were covered for 72 h with plastic-lined brown paper bags containing wet paper towels. Leaves were examined for infection after 7 and 14 days. All isolates were pathogenic and produced non-sporulating lesions similar to those observed in natural infections. No symptoms were observed on noninoculated control plants. Disease incidence was low (<15%) until late June 1999 and July 2000. Inoculations in summer produced increasingly more infections, reaching incidences of 40 to 52% in September 1999 and 18 to 80% in August 2000. References: (1) J. E. Adaskaveg. 1994. Pages 5–7 in Proceedings of the 22nd Annual Almond Industry Conference. 1994. (2) J. Rotem. 1994. The genus Alternaria. Biology, Epidemiology, and Pathogenicity. APS Press, St. Paul, MN. (3) E. G. Simmons. Mycotaxon 70:325–369, 1999.

A New Leaf Spot Disease of Calotropis gigantean Caused by Alternaria alternata in Rajasthan, India

2009 ◽  
Vol 10 (1) ◽  
pp. 45
Author(s):  
Satish K. Sain ◽  
H. N. Gour ◽  
P. Sharma ◽  
P. N. Chowdhry
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
First Record ◽  
Leaf Spot Disease ◽  
Koch’S Postulates ◽  
Calotropis Gigantea ◽  
Spot Disease ◽  
Koch's Postulates

Madar (Calotropis gigantea) is a medicinally important wild shrub native to India. The seed floss is used for furniture stuffing and the bark for nets and twine. In early 2005, we observed a leaf spot epidemic of madar growing on wasteland sites near the Sikar district of Rajasthan, India. Koch's Postulates were completed. This is the first record of the disease from the Sikar district of the Rajasthan state of India. Accepted for publication 6 February 2009. Published 31 March 2009.

scholarly journals Leaf Spot Disease Caused by Alternaria alternata on Rehmannia glutinosa in China

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 3059-3059
Author(s):  
Jia-fang Du ◽  
Wen-kai Nian ◽  
Zhang-jin Zhou ◽  
Tao Dou ◽  
Guo-hong Song ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Rehmannia Glutinosa ◽  
Spot Disease

scholarly journals Molecular identification of fungal pathogens associated with leaf spot disease of date palms (Phoenix dactylifera)

All Life ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 587-597
Author(s):  
Hamed Al-Nadabi ◽  
Sajeewa S. N. Maharachchikumbura ◽  
Zameta S. Al-Gahaffi ◽  
Ahmed S. Al-Hasani ◽  
Rethinasamy Velazhahan ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Leaf Spot ◽  
Fungal Pathogens ◽  
Phoenix Dactylifera ◽  
Leaf Spot Disease ◽  
Date Palms ◽  
Spot Disease

Screening Groundnut (Arachis hypogeae) Genotypes for Resistance to Early and Late Leaf Spot Diseases

2019 ◽  
pp. 1-9
Author(s):  
M. S. Alidu ◽  
S. Abukari ◽  
M. Abudulai
Keyword(s):  
Leaf Spot ◽  
Agricultural Research ◽  
Block Design ◽  
Northern Region ◽  
Limiting Factors ◽  
Leaf Spot Disease ◽  
Cercospora Arachidicola ◽  
Late Leaf Spot ◽  
Arachis Hypogaea L ◽  
Significant Difference

Background for the Study: Groundnut (Arachis hypogaea L.) is an important crop both in subsistence and commercial agriculture in Ghana. Early leaf spot (Cercospora arachidicola) and late leaf spot (Cercosporidium personata) are major limiting factors to groundnut productivity in Ghana. Aim: The objective of the study was to screen groundnut genotypes for resistance to Early and Late leaf spot diseases. Study Design: The treatments were arranged in a randomized complete block design and replicated three (3) times. Place and Duration of Study: The research was conducted from May to December 2013 at the Savanna Agricultural Research Institute experimental site at Nyankpala in the Northern Region. The site lies between latitude 9°25´141 North and longitude 0°58’142 West and an altitude of 183 m. Methodology: The land was done using a tractor and field divided into plots of 2 m x 5 m with 1 m interval between plots. Sowing was done on 3rd June 2013. One seed was planted per hole at a depth of approximately 4 cm. Early and late leaf spot ratings were recorded at 30, 60 and 90 days after planting, using a ten-point scale. At pod maturity, plants from the middle two rows of each plot were hand-harvested and weights of the above ground foliage and underground pods were oven-dried to obtain dry haulm weight and pod yield respectively. Data collected were subjected to analysis of variance using Genstat statistical package (12th edition). Means were separated using the least significant difference at 5%. Results: The were significant differences (P < .001) among the groundnut genotypes in terms of severity for both early and late leaf spot diseases. F-Mix, NC 7, PC 79-79, F-Mix × SINK 24 and NKATIE-SARI had lowest score for both early and late leaf spot diseases. Among the 21 groundnut genotypes, F-Mix recorded the highest pods yield of 1100kg/ha and haulm weight of 5867 kg/ha followed by NC 7 with total pods yield of 900 kg/ha and haulm weight of 5373 kg/ha. PC 79-79 had a total pods yield of 666.7 kg/ha and haulm weight of 4867kg/ha. The pods yield of F-Mix × SINK 24 was 533.3 kg/ha and haulm weight of 4600 kg/ha. NKATIE-SARI recorded pods yield of 500 kg/ha and haulm weight of 4633 kg/ha. Conclusions: From the study, the genotypes F-Mix, NC 7, PC 79-79, F-Mix × SINK 24 and NKATIE-SARI were found to be resistance to both early and late leaf spot disease whereas Chinese, Doumbala, GM 120, GM 324 and ICGV 86015 were susceptible to both diseases.

scholarly journals First Report of Alternaria Alternata Causing Brown Leaf Spot on Apricot (Prunus Armeniaca) in Karbala Province of Iraq

2021 ◽  
Vol 910 (1) ◽  
pp. 012080
Author(s):  
Zeinab L. Hameed ◽  
Adnan A. Lahuf ◽  
Mundher T. Jasim ◽  
Hassan M. Mohsen ◽  
Bahaa J. Kadim ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Causative Factor ◽  
Prunus Armeniaca ◽  
Leaf Spot Disease ◽  
First Report ◽  
Spot Disease ◽  
Brown Leaf Spot ◽  
Rdna Sequencing ◽  
Brown Leaf

Abstract During a survey in season 018, leaf spot symptoms were commonly observed on apricot (Prunus armeniaca) trees in the orchards of Al-Hussainiya district in Karbala Province of Iraq. The symptomatic leaves were gathered, the associated fungus was isolated and characterized relied on its morphological features and ITS-rDNA sequencing. The causative factor was found to be the fungus Alternaria alternata that caused distinguishable leaf spot symptoms on the inoculated leaves of apricot. Based on a review of previous references relatedof this disease in Iraq, this is the first report of the brown leaf spot disease caused by A. alternata in Karbala province of Iraq.

scholarly journals Analysis of virulence and genetic variability of Alternaria alternata associated with leaf spot disease in potato plants in Iran

2018 ◽  
Vol 53 (1) ◽  
Author(s):  
Mehdi Nasr Esfahani
Keyword(s):  
Genetic Variability ◽  
Alternaria Alternata ◽  
Leaf Spot ◽  
Random Amplified Polymorphic Dna ◽  
Management Strategies ◽  
Opportunistic Pathogen ◽  
Leaf Spot Disease ◽  
Plasma Membrane Atpase ◽  
Spot Disease ◽  
Vegetables And Fruits

Leaf spot disease in potato is caused by <em>Alternaria alternata</em> (Fr.) Keissler, an opportunistic pathogen that infests many agricultural crops worldwide in the field and during postharvest storage of vegetables and fruits. <em>Alternaria alternata</em> is associated with leaf spot disease in potato in Iran. Thus, there is a need to investigate the virulence and genetic variability of Iranian <em>A. alternata</em> isolates to facilitate the development of appropriate management strategies. In the present study, we analyzed a total of 28 isolates obtained from the main potato-growing regions of Iran, including the Ardebil, Hamedan, Isfahan, and Fars provinces. The pathogens were characterized based on sequence analysis of the genes encoding glyceraldehyde-3-phosphate dehydrogenase (<em>gpd</em>), plasma membrane ATPase, <em>Alternaria</em> allergen a 1 (Alt a1), calmodulin, and actin. In addition, random amplified polymorphic DNA (RAPD), intersimple sequence repeat (ISSR), and virulence studies were performed. Phylogenetic analysis of the combined dataset indicated that the five representative isolates were grouped with the subcluster comprising <em>A. alternata</em>. RAPD and ISSR analyses clustered the 28 <em>A. alternata</em> isolates into different groups with no correlation with their corresponding geographical origins. Results of the pathogenicity assay indicated that all <em>A. alternata</em> isolates were pathogenic against potato. However, the <em>A. alternata</em> isolates showed high variability in terms of virulence.

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