Occurrence of Grey Leaf Spot of Sedum erythrostictum Caused by Cercospora cf. pseudokalanchoes in China

Sedum erythrostictum is a perennial herb in the Crassulaceae family, which is a traditional Chinese medicine used for the treatment of hepatitis, dysentery, herpes zoster and swellings. In 2014, a grey leaf spot disease causing significant damage to plants of S. erythrostictum occurred in the Medicinal Herb Garden of Jilin Agricultural University, Jilin Province, China. The fungus mainly infected the leaves. The necrotic lesions on the leaves were circular or elliptical, amphigenous, greyish brown to brown, slightly concave and surrounded by a dark brown distinct margin. The causal agent from symptomatic tissues was identified as Cercospora cf. pseudokalanchoes based on the symptoms, morphological characteristics, molecular identifications and pathogenicity tests. To our knowledge, this is the first formal report of grey leaf spot of S. erythrostictum caused by C. cf. pseudokalanchoes in China.     

First report of leaf spot disease caused by Phoma eupyrena Sacc. on Aloe vera from Madhya Pradesh,India

A leaf spot disease caused by Phoma eupyrena Sacc. on Aloe vera was reported from Madhya Pradesh, India. Disease symptoms were observed as irregular to elongated, sunken lesion on both leaf surfaces which later turns creamish brown with maroon margin. The fungal colonies were whitish or light pale to dark grey colour. The pycnidia were glabrous and solitary, papillate, and indistinctly uniostiolate averages 100–260 μm in diameter. Conidia were ellipsoidal, 4.5–7.5 × 2.5–3.75 μm in size, with two large guttules. To the best of our knowledge, this is the first report of P. eupyrena causing leaf spot disease on A. vera in India.     

Identification of Alternaria tenuissima causing brown leaf spot on Paris polyphylla var. chinensis in China

Severe brown leaf spot disease was observed on Paris polyphylla var. chinensis in Sichuan Province, China, in 2017 and 2018. The initial symptoms were many light‐brown small spots with necrotic centres, round or irregular in shape, becoming dark brown, gradually enlarging and eventually coalescing, causing extensive leaf senescence. A fungus was isolated from diseased leaves showing typical symptoms of brown leaf spot. The isolates were cultured on potato sucrose agar, and their morphological characteristics of the causal pathogen were observed under a light microscope. Pathogenicity tests revealed that this fungus was the causal pathogen of the disease. Molecular analyses of the sequences of the ribosomal DNA internal transcribed spacer (ITS) region, translation elongation factor 1‐alpha (TEF) and the RNA polymerase II second largest subunit (RBP2) gene were conducted to confirm the identity of the pathogen. The multi‐gene phylogeny indicated that the causal agent was Alternaria tenuissima. To our knowledge, this is the first report of A. tenuissima causing brown leaf sports on P. polyphylla var. chinensis in China.     

Chlorolepiota indica sp. nov.—A new species from India

A new species Chlorolepiota indica is reported from Patiala in Punjab, India. The fungus is characterized by convex brown pileus covered by concentrically arranged brown scales with yellow tinge around the umbo. The stipe of the fruiting body is cream to pale yellow, pinkish to reddish brown near the pileus, and yellowish to dark grey brown towards the base.     

First report of leaf spot disease caused by Corynespora torulosa MCC-1368 on cotton plant from India

In present study, the leaf spot disease of cotton plant emerged in the North Maharashtra region of India was reported. The fungal phytopathogen associated with inducing the leaf spot disease symptoms was isolated and characterised. The isolated fungus was identified as Corynespora torulosa (Deposition accession number, MCC-1368; Genbank accession no. MF462072) based on morphological and cultural characteristics and molecular analysis of ITS region. The pathogenicity of fungal phytopathogen was verified by Koch’s postulates. To our knowledge, this is the first report of incidence of leaf spot disease caused by Corynespora torulosa on cotton plant.     

First Report of Myrothecium roridum Causing Leaf Spot on Anthurium andraeanum in China

A new severe disease on Anthurium andraeanum Lind. was observed in the summer of 2011 in Beijing, China. The fungus was isolated from symptomatic leaves, and its pathogenicity was confirmed. Based on the morphological characteristics and molecular analysis, the pathogen was identified as Myrothecium roridum Tode ex Fr. This is the first report of M. roridum causing leaf spot on A. andraeanum in China.     

Response of mulberry accessions to major foliar diseases in temperate conditions of Jammu and Kashmir,India

Thirty-three indigenous and 24 exotic mulberry accessions belonging to five Morus spp. originated from seven countries distributed in temperate and tropical climates were observed for their response to two major foliar diseases during 2010 and 2011 under temperate conditions of Jammu and Kashmir, India. Leaf spot and powdery mildew severity (Percent Disease Index (PDI)) ranged from 0.00 to 74.90% and 0.00 to 59.85%, respectively. Indigenous and exotic accessions responded similarly to leaf spot, but varied too much to powdery mildew. Irrespective of origin, response in ascending order of PDI for leaf spot is M. multicaulis, M. indica, M. alba, M. kayayama and M. bombycis and for powdery mildew is M. multicaulis, M. kayayama, M. bombycis M. alba and M. indica. Among indigenous accessions, Brentul Kashmir offered highest resistance to both the diseases. Nadigam offered maximum resistance only to leaf spot followed by Himachal local; while Chinarpati followed by Mysore local only for powdery mildew. Among exotic accessions, Ichinose offered maximum resistance to both the diseases followed by Kokusou-21 and Tagowase.     

First Report of Anthracnose Disease on Jatropha curcas Caused by Colletotrichum gloeosporioides in Korea

In the summers of 2010 and 2011, an anthracnose disease was observed on the Jatropha curcas L. grown at the research field of Gyeongsangnam‐do Agricultural Research and Extension Services, South Korea. The symptoms included the appearance of dark brown spots on the leaf and fruit and the mummification of the fruit. The causal fungus formed grey to dark grey colony on potato dextrose agar. Conidia were single celled, ovoid or oblong, and 8–15 × 3–5 μm in size while seta was dark brown, cone‐shaped and 25–46 × 2–6 μm in size. The optimum temperature for growth was approximately 30°C. On the basis of mycological characteristics, pathogenicity test and molecular identification using internal transcribed spacer rDNA sequence, the fungus was identified as Colletotrichum gloeosporioides. To our knowledge, this is the first report of an anthracnose caused by C. gloeosporioides on J. curcas plant in Korea.     

Identification and Characterization of Paraphoma chrysanthemicola Causing Leaf Spot Disease on Atractylodes japonica in China

Atractylodes japonica is a perennial herb in Compositae family, which is used for stomach disorders as a traditional Chinese medicine (Guo et al. 2006 ). In 2013, a leaf spot disease was first observed on plants of A. japonica in a production field of Fushun County, Liaoning Province, China. The disease had a speckled appearance initially. Lesions with grey–white centre and brown margin gradually developed and enlarged. Eventually, infections usually caused yellowing of the leaves and premature defoliation. The causal agent of infection on plants was identified as Paraphoma chrysanthemicola based on morphological and cultural characteristics, pathogenicity tests and phylogenetic analysis. To our knowledge, this is the first report of a leaf spot disease on A. japonica caused by P. chrysanthemicola in China.     

Zonate Leaf Spot of Prunus mandshurica Caused by Hinomyces pruni in Korea

Zonate leaf spots and severe defoliation were observed on Manchurian apricot (Prunus mandshurica) growing in a humid location in Korea from 2011 through 2013. The main symptoms included greyish green to brownish grey and zonate leaf spots without border lines, which mostly led to premature defoliation. The morphological characteristics of the causal agent were consistent with Hinomyces pruni. Identification was supported by analysing the sequence of the internal transcribed spacer region of ribosomal DNA from an isolate. The pathogenicity of the isolate was confirmed by artificial inoculation. This is the first report of zonate leaf spot caused by H. pruni on Manchurian apricot globally as well as in Korea.     

Guignardia citricarpa a Cause of Black Spot on Mango Foliage in Florida1

A strain of Guignardia citricarpa Kiely was isolated from infected mango (Mangifera indica L.) leaves. The morphological and physiological characteristics of perithecia and ascospores were identical with those described for G. citricarpa. Inoculated leaves developed lesions 7 to 10 days after ascospore germination. Young lesions appeared as minute, sunken, blackish depressions on upper and lower leaf surfaces. Mature lesions were roughly circular ranging from 1 to 2 mm in diameter. The fungus was consistently reisolated from the lesions which appeared on the leaves, arising from inoculation. Benomyl at 1.7 g/l provided control of black spot.     

Identification of Fungal Species Associated with Cladode Spot of Prickly Pear and Their Sensitivity to Chitosan

México is the most important producer of prickly pear (Opuntia ficus‐indica) in the world. There are several fungal diseases that can have a negative impact on their yields. In this study, there was a widespread fungal richness on cladodes spot of prickly pears from México. A total of 41 fungi isolates were obtained from cladodes spot; 11 of them were morphologically different. According to the pathogenicity test, seven isolates caused lesions on cladodes. The morphological and molecular identification evidenced the isolation of Colletotrichum gloeosporioides, Alternaria alternata, Fusarium lunatum, Curvularia lunata. All these species caused similar symptoms of circular cladodes spot. However, it is noticeable that some lesions showed perforation and detachment of affected tissues by Fusarium lunatum. To our knowledge, this is the first report of the Fusarium lunatum as phytopathogenic fungus of cladodes of prickly pear. The chitosan inhibited the mycelium growth in the seven isolates of phytopathogenic fungi. Chitosan applications diminished the disease incidence caused by C. gloeosporioies and F. lunatum in 40 and 100%, respectively. Likewise, the lesion severity index in cladodes decreased. There are no previous reports about the application of chitosan on cladodes of prickly pears for the control of phytopathogenic fungi. Therefore, this research could contribute to improve the strategies for the management of diseases in prickly pear.     

Effect of Zinc on the Development of Brown Spot in Rice

Brown spot, caused by the fungus Bipolaris oryzae, is one of the most destructive diseases of rice. This study investigated the effect of zinc rates on the development of brown spot in rice. Rice plants (cv. ‘Metica‐1′) were grown in hydroponic culture amended with Zn rates (applied as ZnSO₄^.7H₂O) of 0, 0.5, 1, 2 and 4 μm and inoculated with B. oryzae. The foliar concentration of Zn was determined. Leaf samples were assessed for disease severity, and then, area under brown spot progress curve (AUBSPC) was calculated. The relationship between Zn concentrations on leaf tissues and the rates of this micronutrient was best described by a positive linear regression model, while the relationship between the Zn rates and the AUBSPC was best described with a positive quadratic regression model. The correlation between Zn concentrations on leaf tissues and AUBSPC was positive and significant (r = 0.68, P < 0.05). The results from this study showed that high foliar concentration of Zn was associated with increasing rice susceptibility to brown spot.     

The Association Between Leaf Malondialdehyde and Lignin Content and Resistance to Spot Blotch in Wheat

Spot blotch (causative pathogen Bipolaris sorokiniana (Sacc.) Shoem) is a common disease of wheat in the Eastern Gangetic Plains region of India. The association of leaf malondialdehyde and lignin contents with the severity of spot blotch disease was studied using a correlation analysis based on a population of recombinant inbred lines bred from the cross cvs. Yangmai 6 (resistant) × Sonalika (susceptible). The material was field‐tested over two consecutive years and inoculated artificially with a highly virulent strain of the pathogen. Disease severity was assessed at three growth stages around and after anthesis. Leaf lignin content tended to be higher in the more resistant RILs, while the opposite was the case for leaf malondialdehyde content. Lesion size showed a positive correlation with disease severity and leaf malondialdehyde content, while disease severity and leaf lignin content were negatively correlated with one another, as were leaf malondialdehyde and leaf lignin content. Leaf malondialdehyde and/or leaf lignin content could be informative as markers for selection for higher levels of resistance against spot blotch in wheat.     

Penetration by Botryosphaeriaceae species in avocado,guava and persimmon fruit during postharvest

Botryosphaeriaceae species have a wide host range and a worldwide distribution. These fungal species can colonize several plant organs, such as the trunk, leaves and fruit. Some Botryosphaeriaceae species cause important diseases on persimmon, avocado and guava fruit. However, there is a lack of information regarding the mechanisms of penetration by Botryosphaeriaceae species on these tropical and subtropical fruits. This study aimed to better understand the mechanisms involved in fungal penetration, host specificity and aggressiveness of Botryosphaeria dothidea, Lasiodiplodia pseudotheobromae and Neofusicoccum parvum on avocado (Persea americana), guava (Psidium guajava) and persimmon (Diospyros kaki) fruit. Scanning electron microscopy (SEM) image analysis showed that in avocado fruit, the three studied Botryosphaeriaceae species penetrated through lenticels. In guava fruit, penetration through stomata was verified for Botryosphaeria dothidea and Neofusicoccum parvum. In persimmon fruit, an appressoria-like structure was observed for B. dothidea, which suggests direct penetration. Disease incidence in wounded fruit was 24% higher than in non-wounded fruit. L. pseudotheobromae and N. parvum showed differences in aggressiveness in guava fruit. The longest incubation period was observed for N. parvum inoculated on guava, with an average of 4.5 days, and the shortest incubation period was verified for B. dothidea inoculated on avocado, with an average of 2.8 days. The area under the disease progress curve (AUDPC) did not differ between Botryosphaeriaceae species on avocado, whereas on guava and persimmon fruit, the AUDPC was lower for B. dothidea. The information regarding penetration mechanisms and aggressiveness is important to improve postharvest disease control strategies.     

Characterization of Colletotrichum orchidophilum,the agent of black spot disease of vanilla

Black spot symptoms were reported on vanilla plants in Reunion Island in 2011. They have repeatedly reduced annual pod production by 10% to 30%. The disease is characterized by dark spots that appear in slight depressions on flowers, pods, leaves and stems. The spots then develop into broad clearly depressed necrotic plaques. Morphological and molecular analyses, as well as pathogenicity tests, identified the fungus Colletotrichum orchidophilum (Ascomycota) as the causal agent of the disease. Inoculation tests in controlled conditions confirmed that the two C. orchidophilum strains isolated from fruit lesions are pathogenic on the leaves and fruits of Vanilla planifolia (accessions CR0001 and CR0020). However, these strains induced symptoms only when the epidermis of leaves and fruits had been punctured by a needle. In the absence of injury, no symptom appeared. Colletotrichum arxii and Fusarium proliferatum (Ascomycota) are fungal species that are also frequently isolated from black spot lesions. However, they are not pathogenic to vanilla. This is the first report of C. orchidophilum in Reunion Island. It is also the first demonstration of C. orchidophilum's pathogenicity to an orchid. Simple preventive control measures were proposed to reduce the incidence of black spot disease in vanilla plots.     

Symbiotic Fungal Flora in Leaf Galls Induced by <Emphasis Type="BoldItalic">Illiciomyia yukawai</Emphasis> (Diptera: Cecidomyiidae) and in Its Mycangia

We investigated the association between a gall midge, Illiciomyia yukawai, and its symbiotic fungi on Japanese star anise, Illicium anisatum. The number of fungal species isolated from the galls increased with development of the galls, whereas those from the leaves showed a different trend. Botryosphaeria dothidea was dominant in the galls from June to October, and after that Phomopsis sp. 1, Colletotrichum sp., and Pestalotiopsis sp. became dominant. Although B. dothidea was not isolated from the leaves, it was detected from mycangia (abdominal sternite VII) of egg-laying adults at a high isolation frequency (>90%). However, B. dothidea was not isolated from mycangia of adults emerging from galls that were enclosed by plastic bags. This indicates that I. yukawai is closely associated with B. dothidea and that its newly emerged adults do not take the fungus into mycangia directly from the galls where they had developed. Also, the fungus from the fungal layers of ambrosia galls has less ability to propagate on artificial media despite the presence of its mycelial mass in mature galls.     

Molecular Evidence for the Association of Tomato leaf curl Gujarat virus with a Leaf Curl Disease of Phaseolus vulgaris L.

A leaf curl disease with symptoms typical of begomoviruses was observed in bean (Phaseolus vulgaris) at the Main Research Farm of the Indian Institute of Pulses Research, Kanpur, India. Infected plants had severe distortion of leaves and the plants were unproductive. PCR indicated the involvement of French bean leaf curl virus (JQ866297), a recently described Begomovirus, and Tomato leaf curl Gujarat virus (ToLCGV). The full‐length genome of ToLCGV associated with leaf curl disease of bean was 2757 nucleotides long and had maximum identity (97–98%) with seven isolates of ToLCGV (AY234383, AF449999, EU573714, GQ994098, AY190290, FR819708, AF413671) and is designated as Tomato leaf curl Gujarat virus‐(IN:Knp:Bean:2013) (KF440686). To the best of our knowledge, this is the first record of ToLCGV infecting a leguminous host, P. vulgaris.     

Euphorbia cotinifolia (Euphorbiaceae): a promising alternative for leaf cutting ant Atta cephalotes (Hymenoptera: Formicidae) control

Field observations indicate that Euphorbia cotinifolia escapes attack by leaf cutting ants, which are the largest generalist herbivores of the Neotropics. We used controlled bioassays to evaluate the effect of E. cotinifolia on the foraging of the Atta cephalotes ant. In a free-choice trial, to five colonies were offered Mangifera indica leaves with a 10% aqueous E. cotinifolia extract, leaves with distilled water and untreated leaves. The carrying time and leaf area consumed were determined over a five-hour period. The effect of E. cotinifolia on the development of the symbiotic fungus on three sets of five colonies fed the leaves of this plant were compared to the controls fed M. indica and oat flakes, and the effect of the addition of extracts on the culture medium used for the symbiotic fungus isolation was evaluated. Euphorbia leaf consumption was lower than that of the other diets; its consumption as the exclusive foraging resource significantly affected the symbiotic fungus, resulting in changes in colour and texture and an 83.57% decrease in volume that occasionally caused 100% mortality. Although the aqueous extract of E. cotinifolia is not a phagodeterrent for foraging workers, it is evident that E. cotinifolia is not a preferred resource for A. cephalotes due to the negative effect on the growth and viability of the symbiotic fungus.     

<i>Aspergillus tubingensis</i> Causes Leaf Spot of Cotton (<i>Gossypium hirsutum</i> L.) in Pakistan

Cotton (Gossypium hirsutum L.) is a key fiber crop of great commercial importance. Numerous phytopathogens decimate crop production by causing various diseases. During July-August 2018, leaf spot symptoms were recurrently observed on cotton leaves in Rahim Yar Khan, Pakistan and adjacent areas. Infected leaf samples were collected and plated on potato dextrose agar (PDA) media. Causal agent of cotton leaf spot was isolated, characterized and identified as Aspergillus tubingensis based on morphological and microscopic observations. Conclusive identification of pathogen was done on the comparative molecular analysis of CaM and β-tubulin gene sequences. BLAST analysis of both sequenced genes showed 99% similarity with A. tubingensis. Koch’s postulates were followed to confirm the pathogenicity of the isolated fungus. Healthy plants were inoculated with fungus and similar disease symptoms were observed. Fungus was re-isolated and identified to be identical to the inoculated fungus. To our knowledge, this is the first report describing the involvement of A. tubingensis in causing leaf spot disease of cotton in Pakistan and around the world.