New Report of Black Leaf Spot Mold (Pseudocercospora fuligena) on Withania somnifera from India

Withania somnifera (family solanaceae) commonly known as ashwagandha and Indian ginseng, originated in India is one of the most powerful medicinal plants for more than 3,000 years (1). It is commercially cultivated for its roots, a natural rich source of glycowithanolides, tannins, potassium nitrate, etc., which are an anti-inflammatory, anti-tumor, anti-oxidant, anti-ulcer, and regulator of the nervous system and sleep (2). During the monsoon of July 2011, black spots on the leaves of infected plants were observed in the ashwagandha growing Lucknow, Raibareilly, and adjoining areas of Uttar Pradesh province with 10 to 20% disease incidence. Early stage of disease were characterized by the presence of light chlorotic spots on both sides of old leaves that later turned into dark black spots resulting in early defoliation. About 27 samples were collected from different locations of the fields for isolation of the causal organism and microscopic studies. Infected leaves were cut into small pieces, surface sterilized with 1% sodium hypochlorite for 1 min, rinsed thrice with sterilized distilled water, and placed onto potato dextrose agar (PDA) plates. After 21 days of dark incubation at 25°C, 8- to 10-mm grayish-brown colonies were observed. Microscopic studies at early and mature stages of infection showed production of conidia in conidiophores. Conidiophores were mostly 5 to 9, few dense pale brown, simple unbranched, septate, geniculate and 14 to 55 × 3 to 5.5 μm. Conidia were subhyline, obclavate to cylindrical, some were straight to slightly curved, multiseptate, base long obconic to long obconically truncate, and 12 to 85 × 3.5 to 5 μm. On the basis of cultural and morphological studies, the pathogen was identified as Pseudocercospora fuligena (3). The pathogen identity was further confirmed at molecular level using universal primers ITS1/ITS4 through PCR (4). An amplification of the expected size (~550 bp) was generated, eluted from agarose gel by QIAquick gel extraction kit (Qiagen), cloned into pGEM-T Easy vector (Promega), sequenced, and deposited in GenBank (Accession No. KF881898). NCBI BLASTn showed 99% identity with P. fuligena (GU214675) strain CPC 12296, isolated from Lycopersicon sp. Pathogenicity test was carried out on 10 plants of W. somnifera cv. Poshita through two approaches, one using mycelia from culture and another using spore suspension from naturally infected leaves. In the first approach, fungal mycelia were applied onto the healthy ashwagandha leaves, whereas in the second approach, infected leaves were washed with distilled water and spore suspension of 106 spores/ml was sprayed on healthy plants. Plants sprayed with sterilized distilled water served as controls. Inoculated plants were placed in a growth chamber at 28°C under 90% humidity for 3 days. After, pots were placed in the glasshouse at 27 ± 2°C with 70 to 80% humidity for 21 days. Initial symptoms appeared on the 7th day while typical symptoms appeared on all the inoculated plants after 12 to 17 days. Control plants remained free of infection. Re-isolation of the pathogen on PDA fulfilled Koch's postulates. Black leaf mold caused by P. fuligena has been reported on tomato (5). This is the first report of black leaf mould caused by P. fuligena on W. somnifera from India. P. fuligena has the potential to reduce yield of W. somnifera. References: (1) Anonymous. Alt. Med Rev. 9:211, 2004. (2) B. D. Basu and K. R. Kirtikar. Indian Medicinal Plants: Plates, vol. 1-4. Bishen Singh Mahendra Pal Singh, Dehradun, India, 1991. (3) T. C. Wang et al. Plant Dis. 79:661, 1995. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (5) S. Yamada. Ann. Phytopathol. Soc. Jpn. 15:13, 1951.

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First Report of Curvularia aeria on Etlingera linguiformis from Nagaland, India

Plant Disease ◽

10.1094/pdis-01-14-0060-pdn ◽

2014 ◽

Vol 98 (11) ◽

pp. 1580-1580 ◽

Cited By ~ 2

Author(s):

C. Kithan ◽

L. Daiho

Keyword(s):

Leaf Surface ◽

Agricultural Research ◽

Disease Incidence ◽

Indian Agricultural Research Institute ◽

Mountain Range ◽

Pathogenicity Test ◽

Distilled Water ◽

Conidial Suspension ◽

First Report ◽

Initial Symptoms

Etlingera linguiformis (Roxb.) R.M.Sm. of Zingiberaceae family is an important indigenous medicinal and aromatic plant of Nagaland, India, that grows well in warm climates with loamy soil rich in humus (1). The plant rhizome has medicinal benefits in treating sore throats, stomachache, rheumatism, and respiratory complaints, while its essential oil is used in perfumery. A severe disease incidence of leaf blight was observed on the foliar portion of E. linguiformis at the Patkai mountain range of northeast India in September 2012. Initial symptoms of the disease are small brown water soaked flecks appearing on the upper leaf surface with diameter ranging from 0.5 to 3 cm, which later coalesced to form dark brown lesions with a well-defined border. Lesions often merged to form large necrotic areas, covering more than 90% of the leaf surface, which contributed to plant death. The disease significantly reduces the number of functional leaves. As disease progresses, stems and rhizomes were also affected, reducing quality and yield. The diseased leaf tissues were surface sterilized with 0.2% sodium hypochlorite for 2 min followed by rinsing in sterile distilled water and transferred into potato dextrose agar (PDA) medium. After 3 days, the growing tips of the mycelium were transferred to PDA slants and incubated at 25 ± 2°C until conidia formation. Fungal colonies on PDA were dark gray to dark brown, usually zonate; stromata regularly and abundantly formed in culture. Conidia were straight to curved, ellipsoidal, 3-septate, rarely 4-septate, middle cells broad and darker than other two end cells, middle septum not median, smooth, 18 to 32 × 8 to 16 μm (mean 25.15 × 12.10 μm). Conidiophores were terminal and lateral on hyphae and stromata, simple or branched, straight or flexuous, often geniculate, septate, pale brown to brown, smooth, and up to 800 μm thick (2,3). Pathogen identification was performed by the Indian Type Culture Collection, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi (ITCC Accession No. 7895.10). Further molecular identity of the pathogen was confirmed as Curvularia aeria by PCR amplification and sequencing of the internal transcribed spacer (ITS) regions of the ribosomal DNA by using primers ITS4 and ITS5 (4). The sequence was submitted to GenBank (Accession No. MTCC11875). BLAST analysis of the fungal sequence showed 100% nucleotide similarity with Cochliobolus lunatus and Curvularia aeria. Pathogenicity tests were performed by spraying with an aqueous conidial suspension (1 × 106 conidia /ml) on leaves of three healthy Etlingera plants. Three plants sprayed with sterile distilled water served as controls. The first foliar lesions developed on leaves 7 days after inoculation and after 10 to 12 days, 80% of the leaves were severely infected. Control plants remained healthy. The inoculated leaves developed similar blight symptoms to those observed on naturally infected leaves. C. aeria was re-isolated from the inoculated leaves, thus fulfilling Koch's postulates. The pathogenicity test was repeated twice. To our knowledge, this is the first report of the presence of C. aeria on E. linguiformis. References: (1) M. H. Arafat et al. Pharm. J. 16:33, 2013. (2) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (3) K. J. Martin and P. T. Rygiewicz. BMC Microbiol. 5:28, 2005. (4) C. V. Suberamanian. Proc. Indian Acad. Sci. 38:27, 1955.

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First Report of Wilt of Rubber Tree Caused by Chalaropsis thielavioides in China

Plant Disease ◽

10.1094/pdis-09-20-2066-pdn ◽

2020 ◽

Author(s):

Xue Li ◽

Jie Li ◽

Hua Yong Bai ◽

Kecheng Xu ◽

Ruiqi Zhang ◽

...

Keyword(s):

Rubber Tree ◽

Morphological Characteristics ◽

Spore Suspension ◽

Malt Extract ◽

Pathogenicity Test ◽

Distilled Water ◽

Ceratocystis Fimbriata ◽

First Report ◽

Mould Fungus ◽

Its Sequence Analysis

Rubber tree (Hevea brasiliensis (Willd. ex Adr. Juss) Müll. Arg.) is used for the extraction of natural rubber and is an economically and socially important estate crop commodity in many Asian countries such as Indonesia, Malaysia, Thailand, India, Sri Lanka, China and several countries in Africa (Pu et al, 2007). Xishuangbanna City and Wenshan City are the main rubber cultivation areas in Yunnan Province, China. In November 2012, rubber tree showing typical wilt symptoms (Fig. 1 A) and vascular stains (Fig. 1 B) were found in Mengla County, Xishuangbanna City. This disease was destructive in these trees and plant wilt death rate reached 5%. The diseased wood pieces (0.5cm long) from trunk of rubber was surface disinfected with 75% ethanol for 30s and 0.1% mercuric chloride (HgCl2) for 2min, rinsed three times with sterile distilled water, plated onto malt extract agar medium (MEA), and incubated at 28℃. After 7 days, fungal-like filaments were growing from the diseased trunk. Six cultures from 6 rubber trunk were obtained and incubated on MEA at 28℃, after 7 days to observe the cultural features. The mycelium of each culture was white initially on MEA, and then became dark green. Cylindrical endoconidia apices rounded, non-septate, smooth, single or borne in chains (8.9 to 23.6 × 3.81 to 6.3μm) (Fig. 1 C). Chlamydospores (Fig. 1 D) were abundant, thick walled, smooth, forming singly or in chains (11.1 to 19.2 × 9.4 to 12.0μm). The mould fungus was identifed as Chalaropsis based on morphology (Paulin-Mahady et al. 2002). PCR amplification was carried out for 3 isolates, using rDNA internal transcribed spacer (ITS) primer pairs ITS1F and ITS4 (Thorpe et al. 2005). The nucleotide sequences were deposited in the GenBank data base and used in a Blast search of GenBank. Blast analysis of sequenced isolates XJm8-2-6, XJm8-2 and XJm10-2-6 (accessions KJ511486, KJ511487, KJ511489 respectively) had 99% identity to Ch. thielavioides strains hy (KF356186) and C1630 (AF275491). Thus the pathogen was identified as Ch. thielavioides based on morphological characteristics and rDNA-ITS sequence analysis. Pathogenicity test of the isolate (XJm8-2) was conducted on five 1-year-old rubber seedlings. The soil of 5 rubber seedlings was inoculated by drenching with 40 ml spore suspension (106 spores / ml). Five control seedlings were inoculated with 40 ml of sterile distilled water. All the seedlings were maintained in a controlled greenhouse at 25°C and watered weekly. After inoculated 6 weeks, all the seedlings with spore suspension produced wilt symptoms, as disease progressed, inoculated leaves withered (Fig. 1 E) and vascular stains (Fig. 1 F) by 4 months. While control seedlings inoculated with sterile distilled water remained healthy. The pathogen re-isolated from all inoculated symptomatic trunk was identical to the isolates by morphology and ITS analysis. But no pathogen was isolated from the control seedlings. The pathogenicity assay showed that Ch. thielavioides was pathogenic to rubber trees. Blight caused on rubber tree by Ceratocystis fimbriata previously in Brazil (Valdetaro et al. 2015), and wilt by Ch. thielavioides was not reported. The asexual states of most species in Ceratocystis are “chalara” or “thielaviopsis” (de Beer et al. 2014). To our knowledge, this is the first report of this fungus causing wilt of rubber in China. The spread of this disease may pose a threat to rubber production in China.

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First report of Penicillium olsonii causing postharvest fruit rot on tomato in Serbia

Plant Disease ◽

10.1094/pdis-02-21-0323-pdn ◽

2021 ◽

Author(s):

Svetlana Živković ◽

Danijela Ristić ◽

Stefan Stošić

Keyword(s):

Fruit Rot ◽

Morphological Identification ◽

Malt Extract ◽

Pathogenicity Test ◽

Distilled Water ◽

Total Production ◽

Academic Press ◽

First Report ◽

Initial Symptoms ◽

The Republic

Tomato (Solanum lycopersicum, L.) is one of the most important vegetable crop in Serbia, with a total production of 111,639 t in 2019 (Statistical Office of the Republic of Serbia). In July 2020, six tomatoes (cv. Balkan) with symptoms of fruit rot were collected from market in Belgrade, Serbia. The incidence of disease was about 2%, and the symptomatic samples were stored for 10 days after harvest. The initial symptoms on fruits were small circular, slightly sunken and water-soaked spots with white mycelia, that progressively expanded into larger grey lesions following the occurrence of sporulation. Isolations were conducted from one spot/fruit. Small pieces (2 to 3 mm2) from the margins of lesions were surface sterilized for 1 min in 1% NaOCl, washed twice with sterile distilled water, and cultivated on potato dextrose agar (PDA) at 25°C. The isolation frequency of Penicillium-like colonies was 100%. In total, six monosporic isolates were obtained and two isolates (SZ-20-6 and SZ-20-7) were selected as representative for morphological and molecular identification, and pathogenicity test. Morphological characteristics of both isolates were observed after growth on malt extract agar (MEA) for 7 days at 25ºC. On MEA, mycelia were white and colonies turned greyish-green with abundant sporulation. On the reverse sides colonies were pale yellow. The mean colony diameter on MEA for isolate SZ-20-6 was 25 ± 1.2 mm and 26 ± 1.0 mm for isolate SZ-20-7. The colony texture was velvety, without exudates and pigmentation. The conidiophores of both isolates were terverticillate, unbranched; phialides were flask shaped with a short neck, and conidia were smooth, greenish and subglobose to ellipsoidal. The conidial diameter for isolate SZ-20-6 was 3 to 4 × 2.5 to 3 µm, and for isolate SZ-20-7 was 3.5 to 4 × 2.5 to 3.5 µm (n =50). Based on these characteristics, isolates were identified as Penicillium olsonii (Pitt 1979). To confirm the morphological identification, genomic DNA was extracted from isolates (SZ-20-6 and SZ-20-7), and the rDNA ITS region and partial β-tubulin gene (BenA) were amplified using the primers ITS1/ITS4 (White et al. 1990) and Bt2a/Bt2b (Glass and Donaldson 1995), respectively. All sequences showed 99 to 100% similarity to P. olsonii and were deposited in GenBank (ITS, MW130235 and MW130236; BenA, MW145147 and MW145148). In multilocus phylogenetic analysis (ITS+BenA), isolates from this study clustered together with other P. olsonii sequences with 100% bootstrap support. To complete Koch's postulates, asymptomatic fruits of tomato cv. Balkan (five fruits per isolate) were superficially sterilized with 70% ethanol, wounded with a sterile needle and inoculated with 10 μl of a spore suspension (1 × 106 spores/ml). Five control fruits were inoculated with 10 μl of sterile distilled water. The experiment was repeated twice. After 7 days of incubation in a moisture chamber at 25°C, typical grey lesions developed on inoculated fruits. The control fruits remained symptomless. The isolates recovered from symptomatic fruits showed the same morphological features as the original isolates. P. olsonii was previously reported on tomato fruit only in Canada (Chatterton et al. 2012) and Pakistan (Anjum et al. 2018). To our knowledge, this is the first report of P. olsonii causing postharvest fruit rot on tomato in Serbia, and in Europe, as well. Therefore, it is essential to monitor spreading of P. olsonii on tomato and other crops in storages, and develop efficient disease management strategies. References: Anjum, N. et al. 2018. Plant Dis. 102:451. Chatterton, S., et al. 2012. Can. J. Plant Pathol. 34:524. Glass, N. L. and Donaldson, G. C. 1995. Appl. Environ. Microbiol. 61:1323. Pitt, J. I. 1979. The Genus Penicillium and its Teleomorophic States Eupenicillium and Talaromyces. Academic Press, London, U.K. Statistical Office of the Republic of Serbia. https://www.stat.gov.rs/en-US/ White, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Funding: This research was financed by the Ministry of Education, Science and Technical Development of the Republic of Serbia, grant 451-03-68/2020-14/200010.

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First Report of Hyphodermella rosae Causing Dry Fruit Rot Disease on Plum in Iran

Plant Disease ◽

10.1094/pdis-10-11-0825 ◽

2012 ◽

Vol 96 (8) ◽

pp. 1228-1228 ◽

Cited By ~ 1

Author(s):

M. Sayari ◽

V. Babaeizad ◽

M. A. T. Ghanbari ◽

H. Rahimian ◽

B. Borhani ◽

...

Keyword(s):

Sour Cherry ◽

Fruit Rot ◽

Pathogenicity Test ◽

Mazandaran Province ◽

Causal Organism ◽

Potato Dextrose Broth ◽

First Report ◽

Initial Symptoms ◽

Fruit Samples ◽

Dry Fruit

Plum (Prunus domestica) and peach (P. persica) are widely grown, often in alternate rows with citrus, in the Mazandaran Province of Iran. In June 2011, a dry fruit rot of plum was observed in several production regions in Mazandaran Province (35°47′N, 50°34′E). Initial symptoms at pit-hardening stage appeared as dark brown, circular, necrotic spots from 2 to 5 cm in diameter. They later developed into a dry fruit rot. Severe symptoms occurred during June and July when warm weather (temperature around 28°C) and high relative humidity (RH) (>85%) were present. Marketable yield losses reached 50% to almost 100% in many orchards. To isolate the causal organism, symptomatic fruits were surface disinfested for 1 min in 0.5% active chlorine, washed thoroughly with sterile distilled water, and segments were plated on potato dextrose agar (PDA) amended with 50 mg/liter of streptomycin sulfate and incubated at 25°C for 3 days. The fungus Hyphodermella rosae (Bresadola) Nakasone was consistently isolated (37 isolates from 79 samples) and identified on the basis of morphological characteristics on PDA. Basidiomata were effuse, resupinate, 15 × 10 mm, crustaceous, tubercules small with apical bristles, and light orange to grayish orange. Subhymenium was up to 30 μm thick, composed of vertically arranged, short-celled, nonagglutinated hyphae; subhymenial hyphae were 3 to 4 μm in diameter. Basidiospores were ellipsoid, 7.5 to 8.5 × 4.5 to 5.5 μm (100 determination), and their cell walls were thin, hyaline, and smooth (1). Genomic DNA was extracted from mycelium with a DNA extraction kit (Qiagen, Hilden, Germany) according to the manufacturer's directions and grown on potato dextrose broth for 4 days at 28°C. The rDNA region was amplified with the primers ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) and ITS5 (5′- GGAAGTAAAAGTCGTAACAA-3′) (4) and the PCR product was sequenced. Nucleotide BLAST analysis of the amplified 627-bp fragment confirmed a 99% similarity with the sequence of H. rosae (GenBank Accession No. JN593086). A pathogenicity test was conducted with isolate MA4099 by placing 5-day-old mycelial plugs grown on PDA at the surface of healthy fruit (n = 6) incubated under >85% RH at 25°C for at least 4 days until the appearance of symptoms, which were similar to those displayed under orchard conditions. Control fruits, inoculated with blocks of PDA plugs, remained intact and symptomless. Reisolation from inoculated fruit samples consistently yielded the inoculated fungus, completing Koch's postulates. The genus Hyphodermella has been reported to be causing wood rot on apricot (2) and sweet and sour cherry (3). To our knowledge, this is the first report of H. rosae causing dry fruit rot on a stone fruit species in the world. References: (1) K. K. Nakasone. Mycologie, 29:231, 2008. (2) J. M. Ogawa et al. Diseases of Apricot (Prunus armeniaca L.). The American Phytopathological Society, St. Paul, MN, 2003. (3) J. K. Uyemoto et al. Diseases of Sweet Cherry (Prunus avium L.) and Sour Cherry (P. cerasus L.). IS-MPMInet, http://www.ismpminet.org/resources/common/comment/cherry.asp , accessed June 2012. (4) T. J. White et al. Page: 315 in: PCR Protocols: A Guide to Methods and Application. M.A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

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First Report of Foliar Blight Caused by Phytophthora capsici on Citrus reticulata Blanco cv. Nian Ju in Guangdong, China

Plant Disease ◽

10.1094/pdis-09-13-0951-pdn ◽

2014 ◽

Vol 98 (6) ◽

pp. 845-845

Author(s):

B. P. Cheng ◽

L. M. Lu ◽

A. T. Peng ◽

X. B. Song ◽

J. F. Ling ◽

...

Keyword(s):

Phytophthora Capsici ◽

Morphological Characteristics ◽

Broad Host Range ◽

Pathogenicity Test ◽

Citrus Reticulata ◽

Causal Organism ◽

First Report ◽

Citrus Reticulata Blanco ◽

Foliar Blight ◽

Initial Symptoms

Citrus reticulata Blanco cv. Nian Ju, an important ornamental plant, is traditionally displayed during the Chinese Spring Festival because its golden fruits are a symbol of auspiciousness. In the spring of 2012, foliar blight was observed on 10 to 30% of the Nian Ju plants at four nurseries in Yangjiang, Guangdong Province, China. Initial symptoms appeared as brown to black foliar lesions, followed by expansion of spots into blight. Some young branches also had necrosis. During frequent rainfall and prolonged wet periods at 22°C to 30°C, white and dense mycelia and sporangia were observed on the infected seedlings. To isolate the causal organism, leaves and stems were cut into sections. Each section included some partial lesion and adjacent asymptomatic tissues. They were surface-disinfested in 1% sodium hypochlorite for 60 s, rinsed three times with sterile water, and placed on V8 juice agar (V8A) at 25°C. After 3 days, 10 isolates were obtained and purified by single-zoospore method. These isolates were identified to species level by sequencing the rRNA internal transcribed spacer (ITS) region. Four representative isolates had an identical ITS sequence (GenBank Accession No. KF750568), which had 99% homology with Phytophthora capsici sequences in GenBank. In addition, all recovered isolates were identical in morphological characteristics. They produced caducous, papillate, and ovoid to ellipsoid sporangia (Length × width = 46.2 ± 7.7 × 23.6 ± 11.3 μm), often with a tapered base. The average length of pedicels was 33.3 ± 4.5 μm. All isolates are A2 mating type. They produced gametangia when paired with an A1 tester of P. capsici isolated from pepper on V8A. Plerotic oospores were 25.3 ± 2.1 μm in diameter. Amphigynous antheridia were 13.6 ± 2.8 μm long and 11.2 ± 0.9 μm wide. Oogonia were 27.4 ± 3.2 μm in diameter. To determine the pathogenicity, three 3-year-old potted C. reticulata cv. Nian Ju plants were sprayed with 20 ml of zoospore suspension from one representative isolate at 105 per ml. Two control plants were sprayed with 20 ml distilled water. All plants were then maintained at 90% relative humidity at 25°C with a 12-h photoperiod. Symptoms similar to those observed in the nurseries developed on all inoculated plants but not on any control plants after 10 days. The pathogenicity test was repeated once and similar results were obtained. P. capsici was recovered from all inoculated plants and resultant isolates had identical morphology to that of the isolates used for inoculation. P. capsici has a relatively broad host range including pumpkins, cucumbers, peppers, beans, squashes, and spinach (1,2). To our knowledge, this is the first report of foliar blight of C. reticulata cv. Nian Ju caused by P. capsici. This study indicates that P. capsici is potentially an important pathogen of C. reticulata cv. Nian Ju plants and further investigations into its epidemiology and development of site-specific integrated management programs for this new disease are warranted. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. American Phytopathological Society, St. Paul, MN, 1996. (2) D. Tian and M. Babadoost. Plant Dis. 88:485. 2004.

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First record of Colletotrichum alienum Causing postharvest Anthracnose disease of mango fruit in China

Plant Disease ◽

10.1094/pdis-09-20-2074-pdn ◽

2021 ◽

Author(s):

Tanvir Ahmad ◽

Jingjing Wang ◽

Yongquan Zheng ◽

Ankwasa Edgar Mugizi ◽

Anam Moosa ◽

...

Keyword(s):

Fruit Rot ◽

Post Inoculation ◽

Pathogenicity Test ◽

Distilled Water ◽

Mango Fruit ◽

Causal Organism ◽

Isolation Technique ◽

Anthracnose Disease ◽

Colletotrichum Species ◽

Fruit Surface

Mango (Mangifera indica L.) is one of the world's most significant economic fruit crops, and China is the second-largest producer of mango (Kuhn et al., 2017). Postharvest mango anthracnose is caused by Colletotrichum species and reduce the self-life of mature fruit (Wu et al., 2020). Colletotrichum species also cause postharvest anthracnose and fruit rot disease of Apple, Banana and Avocado (Khodadadi et al., 2020; Vieira et al., 2017; Sharma et al., 2017). In July 2019, mango fruits cv. ‘Jin-Hwang’ were observed at different fruit markets (39°48'42.1"N 116°20'17.0"E) of the Fengtai district, Beijing, China, exhibiting typical symptoms of anthracnose including brown to black lesions in different size (≤ 2 cm) with identified border on the mango fruit surface. Later, the lesions were coalesced and extensively cover the surface area of the fruit. The lesions were also restricted to peel the fruit and pathogen invaded in the fruit pulp. About 30% of mango fruits were affected by anthracnose disease. The margins of lesions from infected mango fruits (n=56) were cut into 2 × 2 mm pieces, surface disinfected with NaClO (2% v/v) for 30 s, rinsed thrice with distilled water for 60s. These pieces were placed on PDA medium and incubated at 25°C for 7 days. Pure culture of fungal isolates was obtained by single spore isolation technique. Initially, the fungal colony was off white, and colony extended with time, turning light gray at the center. The morphological examination revealed that conidia were hyaline, oblong, and unicellular. The conidia were measured from 10 days old culture and dimensions varied from 13.3 to 15.8 µm in length and 4.6 to 6.1 µm in width. For molecular identification, a multi-locus sequence analysis; the Internal Transcribed Spacers (ITS) region, partial actin (ACT) gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene and chitin synthase (CHS-1) gene were amplified by using the primer sets ITS1/4 (White et al. 1990), ACT-512F/ACT-783R (Carbone and Kohn 1999), GDF1/GDR1 (Guerber et al. 2003) and CHS1-79F/CHS-1-354R (Carbone and Kohn 1999) respectively. The partial sequences of MTY21 were deposited to GenBank accessions (MT921666 (ITS), MT936119 (ACT), MT936120 (GAPDH) and MT936118 (CHS-1). All obtained sequences showed 100% similarity with reported sequences of Colletotrichum alienum ICMP.18691 with accessions numbers JX010217 (ITS), JX009580 (ACT), JX010018 (GAPDH) and JX009754 (CHS-1) which represented the isolate MTY21 identified as C. alienum by constructing Maximum Likelihood phylogenetic tree analysis using Mega X (Kumar et al., 2018). For the confirmation of Koch's postulates, the pathogenicity test was conducted on 36 fresh healthy mango fruits for each treatment. Fruits were punctured with the help of a sterilized needle to create 2mm2 wounds and inoculated with 10µL inoculum (107 spores/mL) of MTY21. Control mango fruits were inoculated with 10µL sterilized distilled water and incubated at 25 °C with 90% relative humidity. The lesions appeared at the point of inoculation and gradually spread on the fruit surface after 7 days post inoculation. The symptoms were similar to the symptoms on original fruit specimens. The re-isolated fungus was identified as C. alienum based on morphological and molecular analysis. Mango anthracnose disease caused by several Colletotrichum species has been reported previously on mango in China (Li et al., 2019). Liu et al. (2020) reported C. alienum as the causal organism of anthracnose disease on Aquilaria sinensis in China. C. alienum has been previously reported causing mango anthracnose disease in Mexico (Tovar-Pedraza et al., 2020) To our knowledge, this is the first report of C. alienum causing postharvest anthracnose of mango in China. The prevalence of C. alienum was 30% on mango fruit which reflects the importance of this pathogen as a potential problem of mango fruit in China.

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New Report of a Sweet Basil Leaf Blight Caused by Cochliobolus lunatus in India

Plant Disease ◽

10.1094/pdis-08-14-0841-pdn ◽

2015 ◽

Vol 99 (3) ◽

pp. 419-419 ◽

Cited By ~ 2

Author(s):

A. K. Srivastava ◽

A. Kumar ◽

A. Saroj ◽

S. Singh ◽

R. K. Lal ◽

...

Keyword(s):

Leaf Blight ◽

Control Treatment ◽

Universal Primers ◽

Infected Leaf ◽

Curvularia Lunata ◽

Pathogenicity Test ◽

Distilled Water ◽

Sweet Basil ◽

Cochliobolus Lunatus ◽

Initial Symptoms

Sweet basil (Ocimum basilicum), a member of the Lamiaceae, is used as an ornamental as well as a culinary herb. It is a rich source of the phenolic compound methyl chavicol and is used as a traditional medicinal plant in India, where the crop is grown on ~2,500 ha annually (4). The species is native to India, where it has been cultivated for >5,000 years. During the rainy season, August of 2013, a severe leaf blight was observed on 30- to 45-day-old sweet basil plants in experimental fields (approximately 5 ha) at the CSIR-CIMAP and adjoining areas in Lucknow. Initial symptoms comprised small, irregular, necrotic lesions that coalesced into a leaf blight. Infected parts of the leaves turned black during wet and humid conditions. The incidence of symptoms ranged from 20 to 30%. Infected leaf samples were cut into small pieces and surface-sterilized with 1% sodium hypochlorite for 1 min, followed by two rinses in sterilized, distilled water. The leaf pieces were then blotted dry with sterilized filter paper, placed onto potato dextrose agar (PDA), and incubated at 28°C for 3 to 5 days. Blackish-brown fungal colonies developed. Microscopic examination revealed the presence of brown conidiophores that were cylindrical, septate, unbranched, and straight or geniculate near the apex. Conidia were three-septate, mostly curved at the third cell from the base, which was usually larger and darker than the other cells; intermediate cells were brown or dark brown; terminal cells were subhyaline or pale brown and 16 to 23.5 × 8.5 to 11.5 μm (the average size of 100 conidia was 19.9 × 10.18 μm). On the basis of these characteristics, the fungus was identified as Cochliobolus lunatus (anamorph Curvularia lunata (Wakk.) Boedijin) (1,2). The identification was confirmed by sequencing the internal spacer (ITS) region of ribosomal DNA (rDNA). Genomic DNA was extracted from five fungal isolates, using the 5 Prime Archive Pure DNA Cell/Tissue kit, and subjected to a polymerase chain reaction (PCR) assay with the universal primers ITS1 and ITS4 (5). The amplified product was cloned and sequenced. An NCBI-BLASTn search showed greatest homology (98% similarity) with the ITS sequence of C. lunatus (GenBank Accession No. DQ836800). The sequence was deposited in Genbank (KM272001). A pathogenicity test was carried out using 10, 30-day-old sweet basil (cv. CIM Soumya) plants in pots, by spraying a spore suspension (105 spores/ml) onto the leaves of each plant. Five plants treated similarly with sterilized, distilled water served as a control treatment. The plants were kept at 27 ± 2°C and 85 ± 3% RH for 8 to 10 days. Small, irregular, necrotic lesions appeared after 4 days on all inoculated leaves, while leaves of control plants remained asymptomatic. Fungi re-isolated from inoculated leaves resembled C. lunatus on the basis of microscopic and sequence data, fulfilling Koch's postulates. The fungus was not re-isolated from the control plants. C. guatemalensis has been reported to cause a leaf spot on sweet basil in Korea (3). To our knowledge, this is the first report of a sweet basil leaf blight caused by C. lunatus in India. C. lunatus has the potential to reduce the yield of sweet basil. References: (1) L. M. Liu et al. Plant Dis. 98:686, 2014. (2) D. S. Manamgoda et al. Fungal Divers. 56:131, 2012. (3) J. H. Park et al. Plant Dis. 96:580, 2012. (4) H. A. A. Taie et al. Not. Bot. Hort. Agrobot. Cluj. Napoca 38:119, 2010. (5) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

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First Report of Anthracnose of Papaya (Carica papaya L.) Caused by Colletotrichum siamense in China

Plant Disease ◽

10.1094/pdis-10-20-2154-pdn ◽

2021 ◽

Author(s):

Yujie Zhang ◽

Wenxiu Sun ◽

Ping Ning ◽

Tangxun Guo ◽

SuiPing Huang ◽

...

Keyword(s):

Carica Papaya ◽

Disease Incidence ◽

Aerial Mycelium ◽

Postharvest Disease ◽

Distilled Water ◽

First Report ◽

Surface Samples ◽

Initial Symptoms ◽

Colletotrichum Siamense ◽

Pathogenicity Tests

Papaya (Carica papaya L.) is a rosaceous plant widely grown in China, which is economically important. Anthracnose caused by Colletotrichum sp. is an important postharvest disease, which severely affects the quality of papaya fruits (Liu et al., 2019). During April 2020, some mature papaya fruits with typical anthracnose symptoms were observed in Fusui, Nanning, Guangxi, China with an average of 30% disease incidence (DI) and over 60% DI in some orchards. Initial symptoms of these papayas appeared as watery lesions, which turned dark brown, sunken, with a conidial mass appearing on the lesions under humid and warm conditions. The disease severity varied among fruits, with some showing tiny light brown spots, and some ripe fruits presenting brownish, rounded, necrotic and depressed lesions over part of their surface. Samples from two papaya plantations (107.54°E, 22.38°N) were collected, and brought to the laboratory. Symptomatic diseased tissues were cut into 5 × 5 mm pieces, surface sterilized with 2% (v/v) sodium hypochlorite for 1 minute, and rinsed three times with sterilized water. The pieces were then placed on potato dextrose agar (PDA). After incubation at 25°C in the dark for one week, colonies with uniform morphology were obtained. The aerial mycelium on PDA was white on top side, and concentric rings of salmon acervuli on the underside. A gelatinous layer of spores was observed on part of PDA plates after 7 days at 28°C. The conidia were elliptical, aseptate and hyaline (Zhang et al., 2020). The length and width of 60 conidia were measured for each of the two representative isolates, MG2-1 and MG3-1, and these averaged 13.10 × 5.11 μm and 14.45 × 5.95 μm. DNA was extracted from mycelia of these two isolates with the DNA secure Plant Kit (TIANGEN, Biotech, China). The internal transcribed spacer (ITS), partial actin (ACT), calmodulin (CAL), chitin synthase (CHS), β-tubulin 2 (TUB2) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) regions were amplified by PCR and sequenced. The sequences were deposited into GenBank with accessions MT904003, MT904004, and MT898650 to MT898659. BLASTN analyses against the GenBank database showed that they all had over 99% identity to the type strain of Colletotrichum siamense isolate ICMP 18642 (GenBank accession numbers JX010278, GQ856775, JX009709, GQ856730, JX010410, JX010019) (Weir et al., 2012). A phylogenetic tree based on the combined ITS, ACT, CAL, CHS, TUB2 and GAPDH sequences using the Neighbor-joining algorithm also showed that the isolates were C. siamense. Pathogenicity tests were conducted on 24 mature, healthy and surface-sterilized papaya fruits. On 12 papaya fruits, three well separated wounded sites were made for inoculation, and for each wounded site, six adjacent pinhole wounds were made in a 5-mm-diameter circular area using a sterilized needle. A 10 µl aliquot of 1 × 106 conidia/ml suspension of each of the isolates (MG2-1 and MG3-1) was inoculated into each wound. For each isolate, there were six replicate fruits. The control fruits were inoculated with sterile distilled water. The same inoculation was applied to 12 non-wound papaya fruits. Fruits were then placed in boxes which were first washed with 75% alcohol and lined with autoclaved filter paper moistened with sterilized distilled water to maintain high humidity. The boxes were then sealed and incubated at 28°C. After 10 days, all the inoculated fruits showed symptoms, while the fruits that were mock inoculated were without symptoms. Koch's postulates were fulfilled by re-isolation of C. siamense from diseased fruits. To our knowledge, this is the first report of C. siamense causing anthracnose of papaya in China. This finding will enable better control of anthracnose disease caused by C. siamense on papaya.

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A Perspective on Withania somnifera Modulating Antitumor Immunity in Targeting Prostate Cancer

Journal of Immunology Research ◽

10.1155/2021/9483433 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Seema Dubey ◽

Manohar Singh ◽

Ariel Nelson ◽

Dev Karan

Keyword(s):

Prostate Cancer ◽

Medicinal Plants ◽

Bioactive Compounds ◽

Antitumor Immunity ◽

Withania Somnifera ◽

Early Stage ◽

Natural Killer Cell Activity ◽

Killer Cell ◽

Cell Activity

Medicinal plants serve as a lead source of bioactive compounds and have been an integral part of day-to-day life in treating various disease conditions since ancient times. Withaferin A (WFA), a bioactive ingredient of Withania somnifera, has been used for health and medicinal purposes for its adaptogenic, anti-inflammatory, and anticancer properties long before the published literature came into existence. Nearly 25% of pharmaceutical drugs are derived from medicinal plants, classified as dietary supplements. The bioactive compounds in these supplements may serve as chemotherapeutic substances competent to inhibit or reverse the process of carcinogenesis. The role of WFA is appreciated to polarize tumor-suppressive Th1-type immune response inducing natural killer cell activity and may provide an opportunity to manipulate the tumor microenvironment at an early stage to inhibit tumor progression. This article signifies the cumulative information about the role of WFA in modulating antitumor immunity and its potential in targeting prostate cancer.

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Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

Innovaciencia Facultad de Ciencias Exactas Físicas y Naturales ◽

10.15649/2346075x.659 ◽

2019 ◽

Vol 7 (1) ◽

pp. 1-9

Author(s):

Bareen Sidqi Shareef Al-Tovi ◽

Raed Abduljabbar Haleem

Keyword(s):

Disease Severity ◽

Root Rot ◽

Field Experiments ◽

Fusarium Species ◽

Test Tube ◽

Spore Suspension ◽

Wheat Crop ◽

Pathogenicity Test ◽

Crown And Root Rot

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

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