Determining the Sources of Primary and Secondary Inoculum and Seasonal Inoculum Dynamics of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Fruit rot of deciduous holly, caused by species of the genera Alternaria, Colletotrichum, Diaporthe, and Epicoccum, is affecting plant production in Midwestern and Eastern U.S. nurseries. To determine the sources of inoculum, dormant twigs and mummified fruit were collected, and leaf spot development was monitored throughout the season from three Ohio nurseries over two consecutive years. Mummified fruit was the main source of primary inoculum for species of Alternaria and Epicoccum, whereas mummified fruit and bark were equally important for species of Colletotrichum and Diaporthe. Brown, irregular leaf spots developed in the summer, and disease incidence and severity increased along with leaf and fruit development. Coalesced leaf spots eventually resulted in early plant defoliation. When tested for their pathogenicity on fruit, leaf spot isolates were able to infect wounded mature fruit and induce rot symptoms, which indicated that leaf spots could serve as a source of secondary inoculum for fruit infections. In addition, spore traps were used to monitor seasonal inoculum abundance in the nurseries. Fruit rot pathogens were captured by the spore traps throughout the season, with peak dissemination occurring during flowering. In this study, we also attempted to understand the role of environmental factors on leaf spot development. Although leaf spot incidence and severity were negatively correlated to mean maximum, minimum and average temperature, a decrease in temperature also coincided with leaf senescence. The role of temperature on leaf spot development should be further studied to fully interpret these results.

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Investigations on the Timing of Fruit Infection by Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽

10.1094/pdis-06-18-0973-re ◽

2019 ◽

Vol 103 (2) ◽

pp. 308-314 ◽

Cited By ~ 2

Author(s):

Shan Lin ◽

Francesca Peduto Hand

Keyword(s):

Disease Incidence ◽

Fruit Rot ◽

Host Susceptibility ◽

Plant Production ◽

Mature Fruit ◽

Flower Bud ◽

Fungal Isolation ◽

Susceptibility To Infection ◽

First Case ◽

Fruit Maturity

Fruit rot of deciduous holly is an emerging fungal disease that is affecting plant production across midwestern and eastern U.S. nurseries. To determine the growth stage(s) of host susceptibility to infection by the major pathogens associated with the disease, Alternaria alternata and Diaporthe ilicicola, and minor pathogens such as Colletotrichum fioriniae and Epicoccum nigrum, we conducted two sets of experiments over two consecutive seasons. In the first case we monitored the presence of the pathogens as well as disease progression in a commercial nursery under natural conditions by collecting plant tissues from the flower bud stage until fruit maturity. The target pathogens were consistently isolated from asymptomatic samples at all stages of fruit development and from symptomatic samples at fruit maturity across the 2 years of collection. A significant increase in fungal isolation frequency, primarily species of Alternaria and Colletotrichum, was observed right after flowering, but fruit rot symptoms only developed on mature fruit. In the second case we artificially inoculated containerized plants maintained outdoor at our research farm with individual or combined pathogens at different fruit developmental stages, and we assessed disease incidence on mature fruit to determine the time of host susceptibility to infection and, indirectly, whether pathogens in the fungal complex carry out latent infections. D. ilicicola could cause latent infection on deciduous holly fruit when inoculated at the full bloom and petal fall stages, and all inoculations made on wounded mature fruit resulted in fruit rot. These findings suggest that flowering represents a critical period to manage D. ilicicola infections and that mature fruit should be protected from any injury to avoid disease. In both experiments a negative correlation between disease incidence and temperature was found; however, the decrease in temperature also coincided with fruit ripening. The effects of temperature and changes in physiological properties of the fruit during maturation on disease development should be further investigated to fully interpret these findings.

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First Report of Botrytis cinerea Causing Leaf Spot on Strawberry in Florida

Plant Disease ◽

10.1094/pdis-05-21-1082-pdn ◽

2021 ◽

Author(s):

Marcus Vinicius Marin ◽

Natalia A. Peres

Keyword(s):

Botrytis Cinerea ◽

Leaf Spot ◽

Fungicide Resistance ◽

Disease Incidence ◽

Deionized Water ◽

Fruit Rot ◽

Tween 20 ◽

Isolation Medium ◽

First Report ◽

Leaf Spots

During the 2020-2021 Florida strawberry season (October to April), strawberry (Fragaria × ananassa) plants showing leaf spots were observed on samples submitted to the Diagnostic Clinic at the University of Florida’s Gulf Coast Research and Education Center. Disease incidence was up to 5% and observed on four different farms in Plant City, FL on cultivars SensationTM Florida127 and Florida Brilliance. All the samples were submitted early in the season (November) and shared the same nursery source in California. Symptoms consisted of circular or irregular lesions with purple or brown halos, eventually developing leaf blight with sporulation at the center on advanced lesions. Diseased tissues (0.5 mm2) were surface disinfested with 10% bleach solution for 90 s, rinsed twice in sterile deionized water, and plated on general isolation medium (Amiri et al. 2018). Plates were incubated at 25°C and a 12-h photoperiod. A fungus producing white mycelia with sparse sporulation of Botrytis-like spores was consistently isolated. Isolates were single-spored and grown on HA medium to induce sporulation (Leroch et al. 2013). Three isolates (20-291, 20-293, and 20-295) were selected for identification and pathogenicity assays. Resulting cultures on HA had profuse sporulation resembling gray mold. Conidia (n=50) were round to ellipsoid ranging from 9 to 14.6 μm long (Avg=10.8, SD=1.3) and 6.3 to 9.5 μm wide (Avg=7.7, Sd=0.7). No sclerotia formation was observed on GI and HA medium. Based on morphology, the pathogen was tentatively identified as Botrytis cinerea (Hong et al. 2001; Jarvis 1977). DNA was extracted from the same three isolates using the FastDNA kit (MP Biomedicals, Solon, OH), and the heat shock protein (HSP60), RNA polymerase II-binding (RPB2), and glyceraldehyde 3-phosphate dehydrogenase (G3PDH) genes were amplified (Staats et al. 2004). Sequences were deposited in GenBank (accession nos. MZ288746 - MZ288754). BLASTn searches revealed that isolates were 100% identical to B. cinerea reported causing leaf spot on strawberry in California; accession numbers MK919494 (HSP60, 996/996 bp), MK919495 (RPB2, 1131/1131 bp), and MK919496 (G3PDH, 877/877 bp). To test for pathogenicity, four one-month-old plants of 'Florida Brilliance' were used per isolate and control treatment. Spores were harvested from two-week-old cultures grown on HA medium, and the suspension adjusted to 106 spores/mL in a solution of 0.1% of Tween 20. Plants were spray inoculated until run-off and kept inside clear plastic boxes for 48 h. Control plants were sprayed with sterile deionized water. Afterward, plants were kept in a misting table in the greenhouse with a water regime of 3 s every 10 min during the day. Disease incidence was evaluated weekly, and the experiment repeated once. Two weeks after inoculation, leaf spots were observed in all inoculated plants, while controls remained healthy. Fungi morphologically identical to the original isolates were re-isolated from the diseased tissues. To our knowledge, this is the first report of B. cinerea causing leaf spot on strawberry in Florida. This disease was recently reported in California (Mansouripour and Holmes 2020), which is where the transplants originated from. Considering the disease was observed early in the Florida season, it is likely that it was introduced with transplants from the nursery. This pathogen is also the causal agent of Botrytis fruit rot, which is considered a major disease of strawberry, and a previous study has shown that populations resistant to multiple fungicides are introduced with transplants (Mertely et al. 2018, Oliveira et al. 2018). While Botrytis leaf spot is currently considered rare and of minor significance (Mansouripour and Holmes 2020), it could contribute to the spread of fungicide resistance to from nursery to strawberry fruit production fields. Efforts should be implemented to monitor its occurrence and spread considering the high variability and fungicide resistance profile of this pathogen.

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First Report of a Leaf Spot Disease of Bells-of-Ireland (Moluccella laevis) Caused by Cercospora apii in California

Plant Disease ◽

10.1094/pdis.2003.87.2.203a ◽

2003 ◽

Vol 87 (2) ◽

pp. 203-203

Author(s):

S. T. Koike ◽

S. A. Tjosvold ◽

J. Z. Groenewald ◽

P. W. Crous

Keyword(s):

Leaf Spot ◽

Sequence Data ◽

Disease Incidence ◽

Leaf Spot Disease ◽

Conidial Suspension ◽

Internal Transcribed Spacer Region ◽

First Report ◽

Spot Disease ◽

Leaf Spots ◽

Initial Symptoms

Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant that is field planted in coastal California (Santa Cruz County) for commercial cutflower production. In 2001, a new leaf spot disease was found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were surveyed during this time had at least 50% disease. Initial symptoms consisted of gray-green leaf spots. Spots were generally oval in shape, often delimited by the major leaf veins, and later turned tan. Lesions were apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported on leaves of M. laevis in Turkey (1). However, sequence data obtained from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and AY156919) indicated there were no base pair differences between the bells-of-Ireland isolates from California, our own reference isolates of C. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the plants in a dew chamber for 24 h, and maintaining them in a greenhouse (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots that were identical to those observed in the field. C. apii was again associated with all leaf spots. Control plants, which were treated with water, did not develop any symptoms. The test was repeated and the results were similar. To our knowledge this is the first report of C. apii as a pathogen of bells-of-Ireland in California. Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell University Press, Ithaca, New York, 1954.

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Diversity and occurrence of major diseases of vegetables and fruit crops during spring season at Aanbukhaireni rural municipality of Tanahun district, Nepal

Journal of Agriculture and Natural Resources ◽

10.3126/janr.v2i1.26043 ◽

2019 ◽

Vol 2 (1) ◽

pp. 60-74

Author(s):

Subash Subedi ◽

Sheela Koirala ◽

Saraswati Neupane

Keyword(s):

Leaf Spot ◽

Control Measure ◽

Disease Incidence ◽

Fruit Rot ◽

Spring Season ◽

Cercospora Leaf Spot ◽

Survey Period ◽

Rural Municipality ◽

Vegetables And Fruits ◽

Leaf Curl

A survey has been conducted to assess the diversity and occurrence of major vegetables and fruits cultivated in Aanbukhaireni rural municipality of Tanahun district, Nepal during spring season of 2019.The surveyed areas were Satrasayaphant, Baradiphant and Dumridanda villages of ward no 1, Yeklephant, Markichowk and Pateni villages of ward no2 , Gaadapani village of ward no 3, Saakhar village of ward no 4 and Ghummaune village of ward no. 5. The surveyed area consists of upper tropical and sub tropical climate. The total no of farmers field selected for the survey was 34, 32, 24, 17 and 21 from ward no 1,2,3,4 and 5 respectively.The major vegetables cultivated during survey period in the surveyed area were bean, bitter-gourd, brinjal, chilli, cowpea, cucumber, okra, pumpkin, sponge-gourd, tomato, snake-gourd and bottle-gourd. Similarly, the fruits found in the region were banana, papaya, grapes, mango, litchi, peach, guava, lemon, mandarin orange etc. The major diseases of vegetables noticed were early blight, late blight, cercospora leaf spot, powdery mildew, downey mildew, fruit rot, bacterial wilt, bacterial spot, leaf curl and mosaic. In case of fruits, sigatoka leaf spot, panama wilt, black rot, algal leaf spot, canker, root rot, foot rot, sooty mold, red rust, anthracnose, rust, mosaic, alternaria leaf spot, downey mildew and leaf curl were the major diseases. The higher disease incidence (70%) and severity (48%) in vegetables were recorded in ward no 2 where as the lower incidence (45.2%) and severity (37.71%) were found in ward no 4. Similarly, the higher fruit disease incidence (70.24%) and severity (51.27%) in ward no 1 followed by ward no 2 with disease incidence and severity of 66.79% and 45.14% respectively. The reasons for those results are low educational level, lack of best bet technology, no proper irrigation and fertilizer, unavailability of pesticides for controlling the diseases. This study will be useful to identify the major diseases of vegetables and fruits of terai and inner terai region of Nepal and applying control measure, looking for the best possible solutions.

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First Report of Leaf Spot of Spinach Caused by Pleospora betae in Spain

Plant Disease ◽

10.1094/pdis-04-14-0367-pdn ◽

2014 ◽

Vol 98 (11) ◽

pp. 1583-1583 ◽

Cited By ~ 4

Author(s):

D. D. M. Bassimba ◽

J. L. Mira ◽

A. Vicent

Keyword(s):

Leaf Spot ◽

Spinacia Oleracea ◽

Disease Incidence ◽

Control Measures ◽

Conidial Suspension ◽

First Report ◽

Leaf Spots ◽

Plastic Bags ◽

Swiss Chard ◽

Spinach Leaves

The production of spinach (Spinacia oleracea L.) in Spain has increased 50% since 2009, mainly due to the commercialization of fresh-cut spinach leaves packaged in modified atmosphere containers. In October 2012, light brown leaf spots 1 to 2 cm in diameter with dark concentric rings were observed in a commercial spinach production area in Valencia Province, Spain. The initial outbreak comprised an area of about 3 ha with a 20% disease incidence. Symptomatic leaves from spinach cv. Apollo were collected in the affected area and were surface disinfected with 0.5% NaOCl for 2 min. Small fragments from lesions were placed onto potato dextrose agar (PDA) amended with 0.5 g streptomycin sulfate/liter. Fungal colonies developed after 3 days of incubation at 23°C from about 90% of the infected tissues plated. Isolates were transferred to oatmeal agar (OA) (1) and water agar (WA) amended with autoclaved pea seeds (2). Plates were incubated for 30 days at 24°C with 13 h of fluorescent light and 11 h of dark for morphological examination. Colonies were olivaceous grey in OA and pycnidia developed in WA were globose to subglobose, olivaceous black, and 100 to 200 μm in diameter. Conidia were globose to ellipsoidal, hyaline, aseptate, and 3.8 to 7.7 × 2.4 to 3.9 μm. Swollen cells were observed. Isolates showed a positive reaction to NaOH (1). Partial 18S, ITS1, 5.8S, ITS2, and partial 28S ribosomal RNA (rRNA) regions were amplified using the primers ITS1 and ITS4 (4) and sequenced from DNA extracted from the isolate designated as IVIA-V004 (GenBank Accession No. KF321782). The sequence had 100% identity (e-value 0.0) with that of Pleospora betae (Berl.) Nevod. (syn. Phoma betae A.B. Frank) representative strain CBS 523.66 (1). Pathogenicity tests were performed twice by inoculating 4-month-old plants of spinach cv. Apollo, table beet (Beta vulgaris L.) cv. Detroit, and Swiss chard (B. vulgaris subsp. cicla) cv. Verde de Penca Blanca. Plants were inoculated by spraying a conidial suspension of isolate IVIA-V004 (10 ml/plant, 105 conidia/ml water) using a manual pressure sprayer. Plants were immediately covered with black plastic bags and incubated in a growth chamber at 23°C. In each experiment, four plants of each host were inoculated with the fungus and four additional plants sprayed with sterile distilled water were used as controls. Plastic bags were removed after 48 h and leaf spots similar to those observed in affected spinach plants in the field were visible on all spinach, table beets, and Swiss chard plants 3 to 5 days after inoculation. No symptoms were observed on control plants. Fungal colonies morphologically identified as P. betae were re-isolated from leaf lesions on inoculated plants, but not from asymptomatic leaves of control plants. To our knowledge, this is the first report of leaf spot caused by P. betae on spinach in Spain, where it was previously described affecting sugar beet (3). The disease reduces the quality of spinach leaves and proper control measures should be implemented. References: (1) G. H. Boerema et al. Phoma Identification Manual, Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing, Wallingford, UK, 2004. (2) O. D. Dhingra and J. B. Sinclair. Basic Plant Pathology Methods, 2nd ed. CRC Press, Boca Raton, FL, 1995. (3) P. Melgarejo et al. Patógenos de Plantas Descritos en España. MARM-SEF, Madrid, 2010. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

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Alternaria citri. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400242 ◽

1970 ◽

Author(s):

M. B. Ellis

Keyword(s):

Geographical Distribution ◽

Leaf Spot ◽

Nutrient Balance ◽

Fruit Rot ◽

Black Rot ◽

Mature Fruit ◽

Limited Distribution ◽

Rough Lemon ◽

Leaf Drop ◽

Necrotic Spots

Abstract A description is provided for Alternaria citri. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Citrus spp. DISEASES: Black rot of oranges; fruit rot of lemons and tangerines, leaf spot of rough lemon and Emperor mandarin. Probably found in general on Citrus spp., especially fruit. Internal decay in oranges begins near the styler end. There is no external sign of this but infected fruit tend to colour prematurely and some may drop. The condition may be aggravated by weather and host nutrient balance. On lemons a soft, central rot occurs in mature fruit, beginning at the button and spreading to the axis. The rind becomes translucent before the rot appears on the surface. There is also an end rot in which the external spread is almost as extensive as that inside the fruit. On leaves of rough lemon circular or irregular necrotic spots with concentric zoning are produced. A general chlorosis, curling and leaf drop follow. GEOGRAPHICAL DISTRIBUTION: The fruit rotting form is widespread although other forms may be of more limited distribution. TRANSMISSION: Presumably air-borne but no dispersal studies appear to have been reported.

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Mangrove Dieback and Leaf Disease in Sonneratia apetala and Sonneratia caseolaris in Vietnam

Forests ◽

10.3390/f12091273 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1273 ◽

Cited By ~ 1

Author(s):

Huong Thi Thuy Nguyen ◽

Giles E. St. J. Hardy ◽

Tuat Van Le ◽

Huy Quoc Nguyen ◽

Duc Hoang Le ◽

...

Keyword(s):

Leaf Spot ◽

Fungal Pathogens ◽

Survival Rates ◽

Tree Decline ◽

Mangrove Restoration ◽

Sonneratia Caseolaris ◽

Leaf Spots ◽

Black Leaf Spot ◽

Stem Lesions

Even though survival rates for mangrove restoration in Vietnam have often been low, there is no information on fungal pathogens associated with mangrove decline in Vietnam. Therefore, this research was undertaken to assess the overall health of mangrove afforestation in Thanh Hoa Province and fungal pathogens associated with tree decline. From a survey of 4800 Sonneratia trees, the incidence of disorders was in the order of pink leaf spot > shoot dieback > black leaf spot for S. caseolaris and black leaf spot > shoot dieback > pink leaf spot for S. apetala. Approximately 12% of S. caseolaris trees had both pink leaf spot and shoot dieback, while only 2% of S. apetala trees had black leaf spot and shoot dieback. Stem and leaf samples were taken from symptomatic trees and fungi were cultured in vitro. From ITS4 and ITS5 analysis, four main fungal genera causing leaf spots and shoot dieback on the two Sonneratia species were identified. The most frequently isolated fungal taxa were Curvularia aff. tsudae (from black leaf spot),Neopestalotiopsis sp.1 (from stem dieback), Pestalotiopsis sp.1 (from pink leaf spot), and Pestalotiopsis sp.4a (from black leaf spot). The pathogenicity of the four isolates was assessed by under-bark inoculation of S. apetala and S. caseolaris seedlings in a nursery in Thai Binh Province. All isolates caused stem lesions, and Neopestalotiopsis sp.1 was the most pathogenic. Thus, investigation of fungal pathogens and their impact on mangrove health should be extended to other afforestation projects in the region, and options for disease management need to be developed for mangrove nurseries.

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Identification and Characterization of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽

10.1094/pdis-02-18-0372-re ◽

2018 ◽

Vol 102 (12) ◽

pp. 2430-2445 ◽

Cited By ~ 4

Author(s):

Shan Lin ◽

Nancy J. Taylor ◽

Francesca Peduto Hand

Keyword(s):

Fungal Pathogens ◽

Disease Incidence ◽

Phylogenetic Analyses ◽

Management Strategies ◽

Morphological Characterization ◽

Fruit Rot ◽

Economic Losses ◽

Yield Reduction ◽

Inoculum Concentration ◽

Fruit Samples

Cut branches of deciduous holly (Ilex spp. L.) harboring colorful berries are traditionally used as ornaments in holiday decorations. Since 2012, a fruit rot of unspecified cause has resulted in significant yield reduction and economic losses across Midwestern and Eastern U.S. nurseries. In this study, symptomatic fruit samples collected from nine different locations over five years were analyzed, and several fungal species were isolated. A combination of morphological characterization, multilocus phylogenetic analyses, and pathogenicity assays revealed that Alternaria alternata and Diaporthe ilicicola sp. nov. were the primary pathogens associated with symptomatic fruit. Other fungi including A. arborescens, Colletotrichum fioriniae, C. nymphaeae, Epicoccum nigrum, and species in the D. eres species complex appeared to be minor pathogens in this disease complex. In detached fruit pathogenicity assays testing the role of wounding and inoculum concentration on disease development, disease incidence and severity increased when fruit was wounded and inoculated with a higher inoculum concentration. These findings indicate that management strategies that can protect fruit from injury or reduce inoculum may lower disease levels in the field. This research established the basis for further studies on this emerging disease and the design of research-based management strategies. To our knowledge, it also represents the first report of species of Alternaria, Colletotrichum, Diaporthe, and Epicoccum causing fruit rot of deciduous holly.

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Silicon-Induced Systemic Defense Responses in Perennial Ryegrass Against Infection by Magnaporthe oryzae

Phytopathology ◽

10.1094/phyto-12-14-0378-r ◽

2015 ◽

Vol 105 (6) ◽

pp. 748-757 ◽

Cited By ~ 39

Author(s):

Alamgir Rahman ◽

Christopher M. Wallis ◽

Wakar Uddin

Keyword(s):

Disease Management ◽

Perennial Ryegrass ◽

Magnaporthe Oryzae ◽

Leaf Spot ◽

Calcium Silicate ◽

Fungal Pathogens ◽

Disease Incidence ◽

Defense Responses ◽

Gray Leaf Spot ◽

Integrated Disease Management

Sustainable integrated disease management for gray leaf spot of perennial ryegrass may involve use of plant defense elicitors with compatible traditional fungicides to reduce disease incidence and severity. Silicon (Si) has previously been identified as a potential inducer or modulator of plant defenses against different fungal pathogens. To this end, perennial ryegrass was inoculated with the causal agent of gray leaf spot, Magnaporthe oryzae, when grown in soil that was nonamended or amended with three different levels of calcium silicate (1, 5, or 10 metric tons [t]/ha). When applied at a rate of 5 t/ha, calcium silicate was found to significantly suppress gray leaf spot in perennial ryegrass, including a significant reduction of disease incidence (39.5%) and disease severity (47.3%). Additional studies observed nonpenetrated papillae or cell-wall appositions harboring callose, phenolic autofluorogens, and lignin-associated polyphenolic compounds in grass grown in the Si-amended soil. Regarding defense-associated enzyme levels, only following infection did grass grown in Si-amended soil exhibit greater activities of peroxidase and polyphenol oxidase than equivalent inoculated control plants. Also following infection with M. oryzae, grass levels of several phenolic acids, including chlorogenic acid and flavonoids, and relative expression levels of genes encoding phenylalanine ammonia lyase (PALa and PALb) and lipoxygenase (LOXa) significantly increased in Si-amended plants compared with that of nonamended control plants. These results suggest that Si-mediated increase of host defense responses to fungal pathogens in perennial ryegrass has a great potential to be part of an effective integrated disease management strategy against gray leaf spot development.

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SEVERITY AND INTENSITY OF FUNGAL DISEASES OF CUCURBIT CROPS OF HAMIRPUR REGION, HP, INDIA

PLANT ARCHIVES ◽

10.51470/plantarchives.2021.v21.no2.025 ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Manu Vineet Sharma ◽

Hem Chander

Keyword(s):

Cucumis Sativus ◽

Disease Severity ◽

Leaf Spot ◽

Fungal Pathogens ◽

Disease Incidence ◽

Fungal Diseases ◽

Lagenaria Siceraria ◽

Coccinia Grandis ◽

Downy Mildews ◽

Powdery Mildews

Cucurbitaceae is the vegetable family enriched with numerous vitamins and minerals. In early rainy season cucurbits are the host of different fungal pathogens. In present study, four fungal diseases dominant on three members of cucurbitaceae family are observed in Bhoranj block of District Hamirpur, lie in lower foot hills of Himachal Pradesh. Four fungal diseases along with host plants are leaf spot of Lagenaria siceraria, downy mildews of Cucumis sativus, powdery mildews of Coccinia grandis and powdery mildews of Cucumis sativus. Among all these diseases, Disease Incidence and Disease Severity of Powdery mildews of Coccinia grandis are most dominant i.e. 40.3±1 and 51.2±1 respectively. Disease Incidence and Disease Severity of Leaf spot of Lagenaria siceraria is least i.e. 12.5±1 and 1.1±1, respectively.

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