scholarly journals First report of Anthracnose on Cinnamomun burmannii Caused by Colletotrichum scovillei in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Jingyu Li ◽  
Shiqiang Xu ◽  
Yu Mei ◽  
Shike Cai ◽  
Xiaofeng Zhou ◽  
...  
Keyword(s):  
Mangifera Indica ◽  
Guangdong Province ◽  
Likelihood Method ◽  
Conidial Suspension ◽  
Tree Leaves ◽  
First Report ◽  
Rdna Its ◽  
Colletotrichum Scovillei ◽  
The Central Nervous System ◽  
Almost All

Mei Pian tree belongs to a new physiological type of Cinnamomun burmannii discovered in the eastern part of the Guangdong province in China in 1987 (Chen et al. 2011). Although the external morphology of Mei Pian tree is similar to Cinnamomun burmannii, the leaves of Mei Pian tree, known as an important traditional Chinese medicine, are rich in natural D-borneol, which protects the heart, brain, and other organs, regulates the central nervous system, and promotes the absorption of other drugs (Yang et al. 2020; Fu et al. 2020). In April 2020, we found that the yield and quality of Mei Pian tree leaves were seriously threatened by anthracnose. Approximately, 40 - 60% of trees were infected in Pingyuan County, Meizhou City, Guangdong Province (N24°28'31.13", E115°50'50.02"). Small circular black spots were initially observed on infected leaves, and spots continued to grow and developed chlorotic margins and concentric rings with sunken areas. As the disease progressed, multiple spots were observed on almost all leaves. Four symptomatic leaves were collected and used for pathogen isolation. The areas of symptomatic and healthy-appearing leaf tissues at the margin of spots were surface-sterilized with 0.5% NaClO for 2 minutes and 70% alcohol for 30 seconds. The sterilized leaves were washed three times with sterile water, air dried, plated on potato dextrose agar (PDA) medium, and incubated at 28°C for 4 days in the dark. A total of six single-spored isolates were obtained and named from MPS-1 to MPS-6, respectively. Among those isolates, MPS-2, MPS-5, and MPS-6 were identical when cultured on PDA plate. The colonies were white to pale gray with dense aerial mycelia, and the reverse side of the colonies was light reddish brown. Conidia were cylindrical and measured 9.0 to 14.0 μm in length and 3.0 to 4.5 μm in width (n = 35). For molecular identification, the primers ITS1/ITS4, GDF/GDR , CHS-79F/CHS-345R, ACT-512F/ACT-783R and T1/Bt2b were used to amplify the partial regions of rDNA-ITS, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase(CHS1), actin (ACT) and β-tubulin (TUB2), respectively, from the genomic DNA extracted from fresh mycelia of MPS-2 (Damm et al. 2012). The resulting sequences were deposited in GenBank with accession numbers of MW091490, MW125584, MW125585, MW125586 and MW125587, respectively. The phylogenetic tree was generated by the maximum likelihood method of the MEGA 7 software using a concatenated alignment of ITS, GADPH, CHS1, ACT and TUB2 sequences. According to both morphological and sequence analyses, MPS-2 was identified as Colletotrichum scovillei (Damm et al. 2012, 2020). Pathogenicity tests were performed by inoculating healthy Mei Pian tree leaves with 5 mm PDA plugs containing actively growing mycelium of MPS-2 and wound-inoculated by spraying MPS-2 conidial suspension (106 conidia ml-1). Controls were inoculated only with sterile PDA plugs and ddH2O. All inoculated plants were maintained in a moist chamber (RH greater than 90%) at 25 °C, with an 8-h photoperiod under T5 LED lights. All inoculated leaves developed symptoms similar to those on naturally infected leaves after 5 days, but leaves on control plants remained asymptomatic. The fungus on the inoculated plants was identical in morphology to that found on the original sample collected in the field, thus fulfilling Koch’s postulates. In previous studies, Colletotrichum scovillei also caused anthracnose on banana (Musa spp. AAA group), pepper (Capsicum annuum), and mango (Mangifera indica L.) in China (Zhou et al. 2016; Zhao et al. 2016; Qin et al. 2019). To our knowledge, this is the first report of Colletotrichum scovillei causing anthracnose on Cinnamomun burmannii in China and worldwide. The identification of C. scovillei as the causal agent of the observed anthracnose on C. burmannii is critical to the prevention and control of this disease in the future.

scholarly journals First Report of Berkeleyomyces basicola Causing Black Root Rot on Lisianthus (Eustoma grandiflorum) in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Yishuo Huang ◽  
Xuewen Xie ◽  
Yanxia Shi ◽  
A LI CHAI ◽  
Lei Li ◽  
...  
Keyword(s):  
Root Rot ◽  
Mangifera Indica ◽  
Large Subunit ◽  
Morphological Characteristics ◽  
Internal Transcribed Spacers ◽  
Likelihood Method ◽  
Conidial Suspension ◽  
Eustoma Grandiflorum ◽  
Black Root Rot ◽  
First Report

Lisianthus (Eustoma grandiflorum (Raf.) Shinn.) is an important ornamental plant ranking in the top 10 cut flowers worldwide (Xiao et al., 2018). In 2020 and 2021, black root rot was found as a major disease limiting lisianthus production in Yunnan Province, China. Black root rot was first observed in early July 2020 on lisianthus grown in a commercial flower-production plantation, with nearly 60% plants infected. Symptoms appeared as coalescing necrotic lesions leading to black discoloration of the roots. Root damage induced by disease resulted in insufficient water and nutrient uptake by the plant, causing stunting and whole-plant wilting. The pathogen could not infect the intact endodermis, and vascular tissues below the discolored cortical tissue remained healthy. Symptomatic roots were surface sterilized using 1% NaClO for 1 min, rinsed three times in sterile water, placed onto potato dextrose agar (PDA), and incubated at 25°C for 7 days in the dark. The morphological characteristics were basically consistent: the colonies were white to gray in color, and the conidiophores were colorless to brown, solitary or clustered. Conidia were single-celled, colorless, rod-shaped, and obtuse at both ends. Chlamydospores were dark brown, clustered or solitary. The morphological characteristics of the pathogen were similar to those of Berkeleyomyces basicola (Berk. & Broome) W.J. Nel, Z.W. de Beer, T.A. Duong & M.J. Wingf. (Nakane et al. 2019). DNA was extracted from mycelia of representative isolate TB using the Plant Genomic DNA Kit (Tiangen, Beijing, China). The internal transcribed spacers (ITS), DNA replication licensing factor (MCM7), ribosomal large subunit (LSU), and 60S ribosomal protein RPL10 (60S) regions were amplified with primer pairs ITS1/ITS4 (Groenewald et al. 2013), MCM7-for/MCM7-rev, LR0R/LR5, and 60S-506F/60S-908R, respectively (Nel et al. 2018). Phylogenetic analysis of multiple genes (Bakhshi et al. 2018) was conducted with the maximum likelihood method using MEGA7. The sequences of our isolate (TB) and three published sequences of B. basicola were clustered into one clade with a 100% bootstrapping value. The accession numbers of B. basicola reference sequences are MF952423 (ITS), MF967079 (MCM7), MF948658 (LSU), and MF967072 (60S) of isolate CMW6714; MF952428 (ITS), MF967088 (MCM7), MF948661 (LSU), and MF967073 (60S) of isolate CMW25440; MF952429 (ITS), MF967102 (MCM7), MF948659 (LSU), and MF967075 (60S) of isolate CMW49352. The sequences of TB have been deposited in GenBank with accession numbers MZ351733 for ITS, MZ695817 for MCM7, MZ695816 for LSU, and MZ695815 for the 60S region. To verify the pathogenicity of the fungus, inoculations were performed on ten 2-month-old potted lisianthus plants by dipping the roots into a conidial suspension (105 spores/ml) for 2 h. Ten plants were mock inoculated with distilled water as a control. Symptoms of black root rot were observed 30 days after inoculation, whereas the control roots remained healthy. The causal fungus has a host range of over 230 species and is a destructive pathogen of many crops and ornamental plants, including cotton (Gossypium barbadense L.), tobacco (Nicotiana tabacum L.) and mango (Mangifera indica L.) (Shukla et al. 2021; Toksoz and Rothrock 2009). This is the first report worldwide of B. basicola infecting lisianthus. This discovery is of great importance for Chinese flower growers because this fungus is well established in the observed area, and effective measures are needed to manage this disease.

scholarly journals First Report of Leaf Blight of Rice Caused by Cochliobolus lunatus in China

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 686-686 ◽  
Author(s):  
L. M. Liu ◽  
S. W. Huang ◽  
L. Wang ◽  
E. Q. Hou ◽  
D. F. Xiao
Keyword(s):  
Leaf Blight ◽  
Green Water ◽  
Tween 20 ◽  
Curvularia Lunata ◽  
Conidial Suspension ◽  
First Report ◽  
Rice Plants ◽  
Rdna Its ◽  
Cochliobolus Lunatus ◽  
Wide Range

Leaf-streak symptoms were observed on rice (Oryza sativa L.) starting at the booting stage through harvest in Zhejiang Province, China, in 2012. Based on Fuyang County, only 15% of the rice fields were estimated to show these symptoms. However, incidence could be 40 to 80% when the rice got infected. Typical symptoms started as green water-soaked streaks from the tip or edge of leaf blades, similar to bacterial leaf blight caused by Xanthomonas oryzae. Infected leaves turned yellow, then eventually became wilted and dry. No bacterial streaming was observed and no bacteria were isolated. Pieces of infected leaf tissue were surface sterilized using 0.1% (v/v) mercuric chloride, rinsed with sterilized water, then placed on water agar (WA). After 2 or 3 days on WA at 28°C, only fungal growth was observed from surface sterilized tissues. Fungi were isolated, purified by single spore separation process, and subcultured to potato dextrose agar (PDA) plates. Growing on PDA, the surface of the colony was circular, fluffy, and shiny velvety-black, whereas the under surface was dark Prussian blue. Conidiophores were single or fascicled, brown to dark brown, rarely branched, multiseptate, and straight or often geniculate near the apex. Conidia were brown, smooth, fusiform, geniculate or hook-shaped, 17.5 to 28.5 × 8.5 to 14.0 μm, and 3-septate, with the third cell from the base larger and darker than the others. Molecular identification was performed by analysis of the rDNA internal transcribed spacer region (ITS1-5.8S-ITS2). The rDNA-ITS region was amplified with primer pair ITS1 and ITS4 (5), sequenced, and deposited in GenBank (Accession No. KC462186). The sequence of rDNA-ITS (KC462186) showed 100% identity with Cochliobolus lunatus R.R. Nelson & Haasis (JN943422) after BLAST. Based on the results of morphological and molecular analyses, the fungus isolated from infected leaves was identified as C. lunatus (anamorph: Curvularia lunata (Wakk.) Boedijn) (3). Pathogenicity tests were conducted three times by spraying a conidial suspension (1 × 105 spores/ml) with 0.1% (v/v) Tween 20 on 12 healthy rice plants at late tillering stage. The same number of the healthy rice plants sprayed with sterilized water with 0.1% (v/v) Tween 20 were used as control. All plants were kept at 30°C and 75 to 85% relative humidity (RH) under a 12-h light/dark rotation. About 5 to 7 days after inoculation, green water-soaked streaks began to appear on inoculated plants. From 7 to 14 days after inoculation, the lesions developed quickly and the leaves began to wilt. After 14 days, inoculated plants showed symptoms similar to those originally observed in the field, while control plants (sprayed with sterilized water) remained healthy. C. lunatus was re-isolated from all inoculated plants, and re-identified by the same methods (morphological and molecular methods) as described above, thereby satisfying Koch's postulates, and confirming C. lunatus as the cause of the disease. C. lunatus is a pathogen of a wide range of plants and is common in paddy environments. It was reported as one of the causal agents of black kernel of rice (4) and rice spikelet rot disease (SRD) (1,2). The level of incidence observed in the affected fields suggest that this disease could potentially cause major losses under favorable weather conditions if susceptible cultivars are grown. To our knowledge, this is the first report of C. lunatus causing leaf blight of rice in China. References: (1) S. W. Huang et al. Crop Prot. 30:1, 2011. (2) S. W. Huang et al. Crop Prot. 30:10, 2011. (3) D. S. Manamgoda et al. Fungal Divers. 51:3. (4) S. H. Ou. Rice diseases [M]. CABI, 1985. (5) T. J. White et al. PCR Protocols: a Guide to Methods and Application. Academic Press, San Diego, CA, 1990.

scholarly journals First Report of Epicoccum layuense Causing Leaf Brown Spot on Camellia oleifera in Hefei, China

Plant Disease ◽  
2022 ◽  
Author(s):  
Xiang Xie ◽  
Shiqiang Zhang ◽  
Qingjie Yu ◽  
Xinye Li ◽  
Yongsheng Liu ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Brown Spot ◽  
Likelihood Method ◽  
Leaf Spot Disease ◽  
Original Strain ◽  
Conidial Suspension ◽  
Camellia Oleifera ◽  
Sterile Water ◽  
Beta Tubulin ◽  
First Report

Camellia oleifera, a major tree species for producing edible oil, is originated in China. Its oil is also called ‘‘eastern olive oil’’ with high economic value due to richness in a variety of healthy fatty acids (Lin et al. 218). However, leaves are susceptible to leaf spot disease (Zhu et al. 2014). In May 2021, we found circular to irregular reddish-brown lesions, 4-11 mm in diameter, near the leaf veins or leaf edges on 30%-50% leaves of 1/3 oil tea trees in a garden of Hefei City, Anhui Province, China (East longitude 117.27, North latitude 31.86) (Figure S1 A). To isolate the causal agents, symptomatic leaves were cut from the junction of diseased and healthy tissues (5X5 mm) and treated with 70 % alcohol for 30 secs and 1 % NaClO for 5 min, and subsequently inoculated onto PDA medium for culture. After 3 days, hyphal tips were transferred to PDA. Eventually, five isolates were obtained. Then the isolates were cultured on PDA at 25°C for 7 days and the mycelia appeared yellow with a white edge and secreted a large amount of orange-red material to the PDA (Figure S1 B and C). Twenty days later, the mycelium appeared reddish-brown, and sub-circular (3-10 mm) raised white or yellow mycelium was commonly seen on the Petri dish, and black particles were occasionally seen. Meanwhile, the colonies on the PDA produced abundant conidia. Microscopy revealed that conidia were globular to pyriform, dark, verrucose, and multicellular with 14.2 to 25.3 μm (=19.34 μm, n = 30) diameter (Figure S1 D). The morphological characteristics of mycelial and conidia from these isolates are similar to that of Epicoccum layuense (Chen et al.2020). To further determine the species classification of the isolates, DNA was extracted from 7-day-old mycelia cultures and the PCR-amplified fragments were sequenced for internal transcribed spacer (ITS), beta-tubulin and 28S large subunit ribosomal RNA (LSU) gene regions ITS1/ITS4, Bt2a/Bt2b and LR0R/LR5, followed by sequencing and molecular phylogenetic analysis of the sequences analysis (White et al. 1990; Glass and Donaldson 1995; Vilgalys and Hester 1990). Sequence analysis revealed that ITS, beta-tubulin, and LSU divided these isolates into two groups. The isolates AAU-NCY1 and AAU-NCY2, representing the first group (AAU-NCY1 and AAU-NCY5) and the second group (AAU-NCY2, AAU-NCY3 and AAU-NCY4), respectively, were used for further studies. Based on BLASTn analysis, the ITS sequences of AAU-NCY1 (MZ477250) and AAU-NCY2 (MZ477251) showed 100 and 99.6% identity with E. layuense accessions MN396393 and KY742108, respectively. And, the beta-tubulin sequences (MZ552310; MZ552311) showed 99.03 and 99.35% identity with E. layuense accessions MN397247 and MN397248, respectively. Consistently, their LSU (MZ477254; MZ477255) showed 99.88 and 99.77% identity with E. layuense accessions MN328724 and MN396395, respectively. Phylogenetic trees were built by maximum likelihood method (1,000 replicates) using MEGA v.6.0 based on the concatenated sequences of ITS, beta-tubulin and LSU (Figure S2). Phylogenetic tree analysis confirmed that AAU-NCY1 and AAU-NCY2 are closely clustered with E. layuense stains (Figure S2). To test the pathogenicity, conidial suspension of AAU-NCY2 (106 spores/mL) was prepared and sterile water was used as the control. Twelve healthy leaves (six for each treatment) on C. oleifera tree were punched with sterile needle (0.8-1mm), the sterile water or spore suspension was added dropwise at the pinhole respectively (Figure S1 E and F). The experiment was repeated three times. By ten-day post inoculation, the leaves infected by the conidia gradually developed reddish-brown necrotic spots that were similar to those observed in the garden, while the control leaves remained asymptomatic (Figure S1 G and H). DNA sequences derived from the strain re-isolated from the infected leaves was identical to that of the original strain. E. layuense has been reported to cause leaf spot on C. sinensis (Chen et al. 2020), and similar pathogenic phenotypes were reported on Weigela florida (Tian et al. 2021) and Prunus x yedoensis Matsumura in Korea ( Han et al. 2021). To our knowledge, this is the first report of E. layuense causing leaf spot on C. oleifera in Hefei, China.

scholarly journals First Report of Dieback of Camellia azalea Caused by Glomerella cingulata f. sp. camelliae in Guangdong, China

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1583-1583 ◽  
Author(s):  
S. Sun ◽  
J. Wang ◽  
H. Zhao ◽  
M. Zhang ◽  
C. Shu ◽  
...  
Keyword(s):  
Average Rate ◽  
Morphological Characteristics ◽  
Guangdong Province ◽  
Middle Part ◽  
Individual Plant ◽  
Conidial Suspension ◽  
Glomerella Cingulata ◽  
Single Spore ◽  
First Report ◽  
Necrotic Spots

Camellia azalea Wei (Theaceae) is a critically endangered species with high ornamental value in China. Its wild individual plants, less than 1,000, are only found in Yangchun, Guangdong Province, China. Since 2010, a severe dieback on C. azalea has been observed in several commercial plantations in Foshan, Guangdong Province, during the process of artificial propagation. The infection started from the middle portion of the new shoots, where necrosis spots developed and expanded to girdle the stems. Consequently, the shoots died and became brown in color. Later, the necrotic spots turned pale gray, and many small, black fruiting bodies emerged. In the end, more than half of the dead shoots broke off from the necrotic spots. Generally, about 10 to 20% new shoots were infected for one individual plant. Although the older branches with leaves were not infected and showed no symptoms, the dieback of crown outer layer greatly reduced the ornamental value of the plants and the sale price went down. Another part of the plants that is often infected is the stalk, resulting in the drop of fruits. By using routine isolation methods and single-spore purification technique, 18 single-conidial isolates with similar colony morphology were obtained from five diseased plants. The cultures of single-conidial isolates grew at an average rate of 6.8 mm per day on PDA at 28°C. The central part of colony became gray-green with age, and acervuli formed on the medium after incubation for 7 to 10 days. Conidia, round at both ends, were 13.65 to 18.3 × 3.61 to 5.92 μm (avg. = 16.1 ± 1.6 × 4.8 ± 0.8 μm, n = 50) in size. After culturing for 50 to 60 days, perithecia matured. Ascopores were hyaline, straight, aseptate, and 10.02 to 13.77 × 3.27 to 4.45 μm (avg. = 12.2 ± 1.1 × 3.9 ± 0.4 μm, n = 50) in size. The cultural and morphological characteristics of these isolates are consistent with the description of Glomerella cingulata f. sp. camelliae (1). The sequences (GenBank Accession Nos. KJ668576, KJ668577, KJ676642, KJ689374, KJ689375, and KJ689376) of ITS, GPDH, GS, actin, β-tubulin, and CAL regions of three representative isolates are identical and share 99, 99, 100, 99, 100, and 100% identity with those of the type specimen of G. cingulata f. sp. camelliae ICMP 10643 (JX010224, JX009908, JX010119, JX009540, JX010436, and JX009630), respectively (2). Twenty randomly selected shoots with young leaves on the top of them, detached from different trees, were scratched in the middle part with a fine scalpel to generate a 5-mm-long wound, 50 μl conidial suspension (1 × 105 conidia ml−1) was then dropped onto the wound for inoculation. The control shoots were inoculated with the same volume of sterile distilled water. All inoculated shoots were placed into an intelligent artificial climate incubator with 12-h photoperiod and 100% relative humidity at 28 ± 1°C. Each treatment replicated on five shoots, and the tests were repeated twice. Symptoms resembling those in the field were observed on all conidia-inoculated shoots after 10 to 14 days, and control shoots were asymptomatic. The same fungus G. cingulata f. sp. camelliae was consistently re-isolated from the diseased shoots, fulfilling Koch's postulates. G. cingulata f. sp. camelliae has been reported on other species of Camellia outside China, but this is the first report in China where the species is endemic and endangered (1,2). References: (1) J. S. W. Dickens et al. Plant Pathol. 38:75, 1989. (2) B. Weir et al. Stud Mycol. 73:115, 2012.

scholarly journals First report of Nigrospora sphaerica causing fruit dried-shrink disease in Akebia trifoliata from China

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiujing Hong ◽  
Shijia Chen ◽  
linchao Wang ◽  
Bo Liu ◽  
Yuruo Yang ◽  
...  
Keyword(s):  
Elongation Factor ◽  
Morphological Characteristics ◽  
Its Region ◽  
Average Diameter ◽  
Ethanol Solution ◽  
Likelihood Method ◽  
Conidial Suspension ◽  
Multiple Sequence ◽  
First Report ◽  
Pure Cultures

Akebia trifoliata, a recently domesticated horticultural crop, produces delicious fruits containing multiple nutritional metabolites and has been widely used as medicinal herb in China. In June 2020, symptoms of dried-shrink disease were first observed on fruits of A. trifoliata grown in Zhangjiajie, China (110.2°E, 29.4°N) with an incidence about 10%. The infected fruits were shrunken, colored in dark brown, and withered to death (Figure S1A, B). The symptomatic fruits tissues (6 × 6 mm) were excised from three individual plants, surface-disinfested in 1% NaOCl for 30s and 70% ethanol solution for 45s, washed, dried, and plated on potato dextrose agar (PDA) containing 50 mg/L streptomycin sulfate in the dark, and incubated at 25℃ for 3 days. Subsequently, hyphal tips were transferred to PDA to obtain pure cultures. After 7 days, five pure cultures were obtained, including two identical to previously reported Colletotrichum gloeosporioides causing leaf anthracnose in A. trifoliata (Pan et al. 2020) and three unknown isolates (ZJJ-C1-1, ZJJ-C1-2, and ZJJ-C1-3). The mycelia of ZJJ-C1-1, ZJJ-C1-2 and ZJJ-C1-3 were white, and formed colonies of approximate 70 mm (diameter) in size at 25℃ after 7 days on potato sucrose agar (PSA) plates (Figure S1C). After 25 days, conidia were formed, solitary, globose, black, shiny, smooth, and 16-21 μm in size (average diameter = 18.22 ± 1.00 μm, n = 20) (Figure S1D). These morphological characteristics were similar to those of N. sphaerica previously reported (Li et al. 2018). To identify species of ZJJ-C1-1, ZJJ-C1-2 and ZJJ-C1-3, the internal transcribed spacer (ITS) region, β-tubulin (TUB2), and the translation elongation factor 1-alpha (TEF1-α) were amplified using primer pairs including ITS1/ITS4 (Vilgalys and Hester 1990), Bt-2a/Bt-2b (Glass and Donaldson 1995), and EF1-728F/EF-2 (Zhou et al. 2015), respectively. Multiple sequence analyses showed no nucleotide difference was detected among genes tested except ITS that placed three isolates into two groups (Figure S2). BLAST analyses determined that ZJJ-C1-1, ZJJ-C1-2 and ZJJ-C1-3 had 99.73% to N. sphaerica strains LC2705 (KY019479), 100% to LC7294 (KY019397), and 99.79-100% to LC7294 (KX985932) or LC7294 (KX985932) based on sequences of TUB2 (MW252168, MW269660, MW269661), TEF-1α (MW252169, MW269662, MW269663), and ITS (MW250235, MW250236, MW192897), respectively. These indicated three isolates belong to the same species of N. sphaerica. Based on a combined dataset of ITS, TUB2 and TEF-1α sequences, a phylogenetic tree was constructed using Maximum likelihood method through IQ-TREE (Minh et al. 2020) and confirmed that three isolates were N. sphaerica (Figure S2). Further, pathogenicity tests were performed. Briefly, healthy unwounded fruits were surface-disinfected in 0.1% NaOCl for 30s, washed, dried and needling-wounded. Then, three fruits were inoculated with 10 μl of conidial suspension (1 × 106 conidia/ml) derived from three individual isolates, with another three fruits sprayed with 10 μl sterilized water as control. The treated fruits were incubated at 25℃ in 90% humidity. After 15 days, all the three fruits inoculated with conidia displayed typical dried-shrink symptoms as those observed in the farm field (Figure S1E). The decayed tissues with mycelium and spores could be observed on the skin or vertical split of the infected fruits after 15 days’ inoculation (Figure S1F-H). Comparably, in the three control fruits, there were no dried-shrink-related symptoms displayed. The experiment was repeated twice. The re-isolated pathogens were identical to N. sphaerica determined by sequencing the ITS, TUB2 and TEF-1α. Previous reports showed N. sphaerica could cause postharvest rot disease in kiwifruits (Li et al. 2018). To our knowledge, this is the first report of N. sphaerica causing fruits dried-shrink disease in A. trifoliata in China.

scholarly journals First Report of Phomopsis longicolla Causing Stem Canker of Eggplant in Guangdong, China

Plant Disease ◽  
2014 ◽  
Vol 98 (3) ◽  
pp. 426-426 ◽  
Author(s):  
C. Shu ◽  
J. Chen ◽  
H. Huang ◽  
Y. He ◽  
E. Zhou
Keyword(s):  
Disease Incidence ◽  
Guangdong Province ◽  
Stem Canker ◽  
Universal Primers ◽  
Distilled Water ◽  
Conidial Suspension ◽  
Phomopsis Longicolla ◽  
Fungal Isolation ◽  
First Report ◽  
Absorbent Cotton

Eggplant (Solanum melongena L.) is an economically important vegetable crop worldwide. In August 2012, severe stem cankers were observed on eggplant at the early stage of maturation in several fields in Guangdong Province, China. Diseased plants raised cankers on the stems and branches, which resulted in wilting and stunting. No symptoms developed on eggplant fruit. Disease incidence was as high as 40% within affected fields. By using routine fungal-isolation methods and single-spore purification technique, five single-conidial isolates were obtained from each diseased stem. Colonies were grayish-white, circular, and got yellow pigmentation when placed in acidified potato dextrose agar (PDA) in an incubator at pH 4.5 and 25°C with a 12-h photoperiod. Stromata were black, large, and spreading in a concentric pattern. Conidiomata were pycnidial, and the pycnidia were round, oblate, triangular or irregular, and unilocular. Conidiophores were colorless, separated, dichotomous, and 10.0 to 18.0 × 1.5 to 2.0 μm. Alpha conidia were single-celled, ellipsoidal to fusiform, guttulate, and 6.0 to 8.0 × 2.0 to 2.5 μm. Beta conidia, produced on oat meal agar in 2 weeks at 25°C in the dark, were filiform, hamate, and 16.0 to 28.0 × 0.7 to 1.0 μm. Based on these morphological characters, the fungus was identified as Phomopsis longicolla Hobbs (1). The ITS-rDNA sequence (GenBank Accession No. KC886605) of the isolate EPPL1 of this fungus (P. longicolla EPPL1) was obtained by using universal primers ITS5/ITS4 (1). BLAST searches showed a 98% homology with the sequence of the ITS region of rDNA of P. longicolla. Phylogenetic analysis showed that P. longicolla EPPL1 clustered with P. longicolla SYJM15 and formed a distinct clade distantly related to P. vexans PV3 (GU373630), a well-known pathogen of eggplant. Digestion of PCR-amplified DNA with Alu I yielded two restriction fragments of sizes consistent with those reported for P. longicolla (2). Pathogenicity tests were performed on 30-day-old plants of cv. Yuefengzihongqie grown in a plastic pot (1 liter) in a greenhouse by using mycelial plugs and conidial suspensions of isolate EPPL1 as inocula. A mycelial plug (4 mm in diameter) from a 7-day-old PDA culture was placed on stems of both wounded and non-wounded plants and covered with sterile absorbent cotton moistened with sterile distilled water. Both wounded and non-wounded plants were inoculated with 0.5 ml of conidial suspension (1 × 106 conidia ml–1) dropped onto sterile absorbent cotton covering the stems. Control assays were performed with agar plugs and sterile distilled water only. Inoculated plants were placed in a greenhouse with a 12-h photoperiod at 28°C. Each treatment was replicated on five plants, and the test was repeated. Twenty-five days after inoculation, both wounded and non-wounded plants inoculated with either method showed raised cankers at the points of inoculation and canker lesions similar to those observed in the field expanded up and down the stems to reach lengths of 15 to 30 mm. Later, sparse, small, black pycnidia formed on the surface of the lesions. The inoculated plants exhibited stunting and premature senescence compared to controls. P. longicolla was re-isolated from the infected stems of inoculated plants. Control plants were asymptomatic. To our knowledge, this is the first report of P. longicolla causing stem canker in eggplant in Guangdong, China. Considering the economic importance of eggplant in Guangdong Province and throughout the world, further study of phomopsis stem canker of eggplant is warranted. References: (1) T. W. Hobbs et al. Mycologia 77:535, 1985. (2) A. W. Zhang et al. Plant Dis. 81:1143, 1997.

scholarly journals First Report of Colletotrichum acutatum Associated with Stem Blight of Blueberry Plants in China

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 422-422 ◽  
Author(s):  
C.-N. Xu ◽  
Z.-S. Zhou ◽  
Y.-X. Wu ◽  
F.-M. Chi ◽  
Z.-R. Ji ◽  
...  
Keyword(s):  
Vaccinium Corymbosum ◽  
Colletotrichum Acutatum ◽  
Post Inoculation ◽  
Pathogenicity Test ◽  
Distilled Water ◽  
Conidial Suspension ◽  
First Report ◽  
Rdna Its ◽  
Its Sequence Analysis ◽  
Species Specific

An anthracnose disease was observed on stems of high-bush blueberry plants (Vaccinium corymbosum L.) in Liaoning Province, China in 2012. The typical symptoms consist of sudden wilting and dieback of stems during the growing season. Dark brown lesions originate from infected buds and kill portions of the stems. Lesions have grayish white centers, with the necrotic areas becoming 6 to 8 cm in length. Disinfected stem pieces were placed on potato dextrose agar (PDA) and incubated at 28°C for 5 to 7 days, after which the emerging colonies were transferred to fresh PDA. All isolates initially produced white growth, but turned pink after 7 days before becoming blackish green. The average colony diameter was 65.5 to 75.0 mm after 7 days. Conidia were aseptate, hyaline, fusiform to ellipsoid, 8.5 to 16.5 × 2.5 to 4.0 μm in size and single celled with two to seven oil globules. Setae were not found on the acervuli. These characteristics matched published descriptions of Colletotrichum acutatum (1) (teleomorph Glomerella acutata). Pathogenicity test was confirmed in 15 2-year-old healthy potted plants of cv. Berkeley. Stems of 10 plants were punctured with flamed needles and sprayed with 5 ml of conidial suspension (106 conidia per ml in sterile distilled water) of isolate LNSW1. Five control plants were inoculated with sterile distilled water. Seven days after inoculation, eight of the 10 blueberry plants exhibited stem lesions, leaf chlorosis, followed by branch dieback 15 days post-inoculation. The symptoms were similar to those observed on diseased plants in the field, and no lesions were observed on control plants. The pathogen was reisolated from the margin of lesions and identified by colony growth characteristics on PDA. PCR amplification of one isolate (LNSW1) was carried out by utilizing the universal rDNA-ITS primer pair ITS1/ITS4. The sequence (557 bp) of isolate LNSW1 (GenBank Accession No. JX392857) showed 99% identity to G. acutata (AB443950) and C. acutatum (AJ749672) in a BLAST search. An approximately 490-bp fragment was amplified from LNSW1 by the species-specific primer pair CaInt2/ITS4 (2). The pathogen was identified as G. acutata (asexual stage: C. acutatum J.H. Simmonds) on the basis of morphological characters, rDNA-ITS sequence analysis, and a PCR product with species-specific primers. To our knowledge, this is the first report of C. acutatum in high-bush blueberry plants in China. References: (1) C. Lei et al. Fungal Diversity 12:183, 2009. (2) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996

scholarly journals First Report of Gray Leaf Spot of Mango (Mangifera indica) Caused by Pestalotiopsis mangiferae in Taiwan

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1684-1684 ◽  
Author(s):  
Y. Ko ◽  
K. S. Yao ◽  
C. Y. Chen ◽  
C. H. Lin
Keyword(s):  
Leaf Spot ◽  
Mangifera Indica ◽  
Gray Leaf Spot ◽  
Leaf Spot Disease ◽  
Continuous Exposure ◽  
Conidial Suspension ◽  
Tropical Fruit ◽  
First Report ◽  
Spot Disease ◽  
Initial Symptoms

Mango (Mangifera indica L.; family Anacardiaceae) is one of the world's most important fruit crops and is widely grown in tropical and subtropical regions. Since 2001, a leaf spot disease was found in mango orchards of Taiwan. Now, the disease was observed throughout (approximately 21,000 ha) Taiwan in moderate to severe form, thus affecting the general health of mango trees and orchards. Initial symptoms were small, yellow-to-brown spots on leaves. Later, the irregularly shaped spots, ranging from a few millimeters to a few centimeters in diameter, turned white to gray and coalesced to form larger gray patches. Lesions had slightly raised dark margins. On mature lesions, numerous black acervuli, measuring 290 to 328 μm in diameter, developed on the gray necrotic areas. Single conidial isolates of the fungus were identified morphologically as Pestalotiopsis mangiferae (Henn.) Steyaert (2,3) and were consistently isolated from the diseased mango leaves on acidified (0.06% lactic acid) potato dextrose agar (PDA) medium incubated at 25 ± 1°C. Initially, the fungus grew (3 mm per day) on PDA as a white, chalky colony that subsequently turned gray after 2 weeks. Acervuli developed in culture after continuous exposure to light for 9 to 12 days at 20 to 30°C. Abundant conidia oozed from the acervulus as a creamy mass. The conidia (17.6 to 25.4 μm long and 4.8 to 7.1 μm wide) were fusiform and usually straight to slightly curved with four septa. Three median cells were olivaceous and larger than the hyaline apical and basal cells. The apical cells bore three (rarely four) cylindrical appendages. Pathogenicity tests were conducted with either 3-day-old mycelial discs or conidial suspension (105 conidia per ml) obtained from 8- to 10-day-old cultures. Four leaves on each of 10 trees were inoculated. Before inoculation, the leaves were washed with a mild detergent, rinsed with tap water, and then surface sterilized with 70% ethanol. Leaves were wounded with a needle and exposed to either a 5-mm mycelial disc or 0.2 ml of the spore suspension. The inoculated areas were wrapped with cotton pads saturated with sterile water and the leaves were covered with polyethylene bags for 3 days to maintain high relative humidity. Wounded leaves inoculated with PDA discs alone served as controls. The symptoms described above were observed on all inoculated leaves, whereas uninoculated leaves remained completely free from symptoms. Reisolation from the inoculated leaves consistently yielded P. mangiferae, thus fulfilling Koch's postulates. Gray leaf spot is a common disease of mangos in the tropics and is widely distributed in Africa and Asia (1–3); however, to our knowledge, this is the first report of gray leaf spot disease affecting mango in Taiwan. References: (1) T. K. Lim and K. C. Khoo. Diseases and Disorders of Mango in Malaysia. Tropical Press. Malaysia, 1985. (2) J. E. M. Mordue. No. 676 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Surrey, England, 1980. (3) R. C. Ploetz et al. Compendium of Tropical Fruit Diseases. The American Phytopathological Society. St. Paul, MN, 1994.

scholarly journals First Report of Anthracnose of Mangifera indica Caused by Colletotrichum scovillei in China

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 1043 ◽  
Author(s):  
L. P. Qin ◽  
Y. Zhang ◽  
Q. Su ◽  
Y. L. Chen ◽  
Q. Nong ◽  
...  
Keyword(s):  
Mangifera Indica ◽  
First Report ◽  
Colletotrichum Scovillei

scholarly journals First Report of Blast of Guinea Grass Caused by Pyricularia sp. LS-Group in Japan

Plant Disease ◽  
2009 ◽  
Vol 93 (12) ◽  
pp. 1350-1350 ◽  
Author(s):  
T. Tsukiboshi ◽  
I. Okabe ◽  
K. Sugawara
Keyword(s):  
Phylogenetic Analysis ◽  
Uv Light ◽  
Central Area ◽  
Blast Disease ◽  
Panicum Maximum ◽  
Conidial Suspension ◽  
First Report ◽  
Rdna Its ◽  
Guinea Grass ◽  
Β Tubulin

Guinea grass (Panicum maximum Jacq.) is an important C-4 perennial herbage in the southern part of Japan. In February 2002, a blast disease was found on the grass cultivated on the Okinawa Islands, the southern most region of Japan. Early symptoms appeared as small, round or ellipsoid lesions on leaves. Lesions later expanded to 2 to 5 × 1 to 2 mm and were spindle shaped and grayish white in the central area with dark brown margins. We obtained three single-conidia isolates of a Pyricularia-like fungus from the lesions and deposited them in the NIAS Genebank, Japan as MAFF306662, 306671, and 306672. The isolates were grown under near-UV light on V8 juice agar for 7 days to produce conidia, and guinea grass plants of the seven- to eight-leaf stage grown from seeds in a green house, five plants for each isolate, were inoculated by atomizing them with the conidial suspension of 105 conidia/ml. The same number of plants sprayed with sterilized distilled water served as the control. The experiments were repeated twice. All plants were covered with plastic bags for 24 h at 25°C to maintain high relative humidity. After 7 days, all inoculated plants showed symptoms identical to those observed in the field. Controls remained symptom free. The Pyricularia-like fungus was reisolated from lesions on inoculated leaves. The morphologies of the isolates were observed and described from the colonies grown under the condition described above. Conidiophores were pale brown, emerging singly or in small groups, straight or flexuous, geniculate toward the apex, and 36 to 197 × 2 to 5 μm. Conidia were obpyriform, straight, colorless to pale brown, smooth, and 19 to 30 × 5 to 10 μm with two to three septa. The morphologies were the same as those of the description of the genus Pyricularia. Previously, all Pyricularia isolates from Gramineae had been identified as P. grisea, except for those from rice (3,4). However, a new taxonomy of Pyricularia spp. based on DNA analyses was proposed by Couch and Kohn (1). Only the isolates from Digitaria were classified as P. grisea and those from C-3 grasses classified as P. oryzae. However, the species names for the isolates from the other C-4 grasses were not described. We analyzed the sequences of the rDNA-ITS region (ITS1-5.8s-ITS2) and β-tubulin gene of the isolates from guinea grass following Couch and Kohn (1). The sequences of rDNA-ITS (GenBank Accession No. AB512785) and β-tubulin (AB512786) of the isolate MAFF306672 matched the sequences of those of the Pyricularia sp. LS-group (AB274426 and AB274458, respectively) isolated from Leersia oryzoides. Hirata et al. (2) reclassified Pyricularia isolates from Gramineae by multilocus phylogenetic analysis and showed that non-P. oryzae and non-P. grisea isolates could be classified into two groups of the Pyricularia sp., a LS- and a CE-group, corresponding to those isolated from Leersia spp. and Setaria spp. or Cenchrus spp. of grasses, respectively. Since no Magnaporthe teleomorph was produced by the crossing tests using the isolates, we identified the isolates from guinea grass as the Pyricularia sp. LS-group on the basis of their morphology and the molecular phylogenetic analysis. To our knowledge, this is the first report of blast on guinea grass in Japan. References: (1) B. C. Couch and L. M. Kohn. Mycologia 94:683, 2002. (2) K. Hirata et al. Mycol. Res. 111:799, 2007. (3) K. D. Hyde. Australas. Plant Pathol. 22:73, 1993. (4) R. Sprague. Diseases of Cereals and Grasses in North America. Ronald Press Company, New York, 1950.

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