scholarly journals First Report of Stem Rot of Huangjing (Polygonatum sibiricum) Caused by Sclerotium rolfsii

Plant Disease ◽  
2020 ◽  
Author(s):  
Qingqun Tan ◽  
Dailin Zhao ◽  
Xuehui Yang ◽  
Na Wang ◽  
Haiyong. He
Keyword(s):  
Biological Activities ◽  
Sclerotium Rolfsii ◽  
Pcr Amplification ◽  
Fungal Species ◽  
Its Sequences ◽  
Stem Rot ◽  
First Report ◽  
Athelia Rolfsii ◽  
Microscopic Field ◽  
Alignment Analysis

Huangjing (Polygonatum sibiricum) is a medicinal plant widely distributed in China, Japan, and Korea. The dried rhizome of Huangjing has been reported to have many pharmacological applications and biological activities, such as antioxidants, immunity enhancement, anti-fatigue, anti-osteoporosis, and anti-aging activity (Cui et al., 2018). In June 2018, we observed some wilted Huangjing plants in commercial plantings in Shuicheng, Guizhou, China (26.22 N, 104.76 E). Symptoms began as moderate to severe wilting of stems and necrosis of leaves, followed by the death of plants. The collar rot appeared on the stem near to the soil. When incubated at 28°C and 100% relative humidity (RH) for 8 to 10 days, the infected stem produced brown sclerotia. We picked the sclerotia and cultured them on potato dextrose agar (PDA) supplemented with 50 μg/ml of streptomycin. The hyphal tips generated by the sclerotia was isolated under microscopic field and transferred to the fresh PDA. Three isolates (HJ-1, HJ-6 and HJ-10) came from the hyphal tips formed the typical clamp connection structure at 6-7 days post-incubation and the sclerotia of them were white and the late ones turned dark brown. The matured sclerotia were globular, 1.5 to 3.3 mm (avg. 2.2) in diameter. The morphologic observation revealed that three isolates were consistent with Athelia rolfsii (Paul et al., 2017). To further confirm the fungal species, the ribosomal internal transcribed spacer (ITS) sequences were amplified and sequenced. Primers and PCR amplification were referenced as previously described (Paul et al., 2017). The sequences were compared to type sequences in GenBank. The ITS sequences (GenBank accession MT478452, MT949696 and MT949697) of the isolates (HJ-10, HJ-1 and HJ-6) were 99% identical with strain 13M-0091 (GenBank accession KT222898) of A. rolfsii, respectively (Paul et al., 2017). A maximum likelihood tree was constructed using MEGA-X version 10.1.6 (Kumar et al., 2018) based on the ITS sequences of the three strains (HJ-10, HJ-1 and HJ-6) and that of Athelia spp. previously deposited in GenBank (Paul et al., 2017). Phylogenetic analysis showed that the isolates (HJ-10, HJ-1 and HJ-6) belong to the A. rolfsii clade. Based on morphology and DNA sequencing, the isolates (HJ-10, HJ-1 and HJ-6) were identified as A. rolfsii. To verify pathogenicity, Huangjing seedlings were inoculated with colonized agar discs of the isolates. Additional Huangjing plants inoculated with uncolonized agar discs were used as the control. After inoculation, Huangjing seedlings were moved to the inoculation chamber under high humidity and 28°C for 3 days and then transferred to a greenhouse. The typical wilting symptoms appeared 8 days after inoculation and were similar to those observed in the field, while control plants remained symptomless. The causing agents were isolated from the lesions and the ITS sequences of them were sequenced again. The alignment analysis of the ITS sequences showed the causing agents are consistent with the original isolates. These studies fulfilled Koch’s postulates. To our knowledge, this is the first report of A. rolfsii causing stem rot on Huangjing.

scholarly journals First Report of Root Rot on kiwifruits Caused by Athelia rolfsii in Hefei, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Qianwen Liu ◽  
Hanyang Wang ◽  
Wenpeng Song ◽  
Jiuming Yu ◽  
Lu Huang ◽  
...  
Keyword(s):  
Root Rot ◽  
Phylogenetic Analyses ◽  
Infected Plant ◽  
Sclerotium Rolfsii ◽  
Soil Surface ◽  
Its Sequences ◽  
Control Group ◽  
First Report ◽  
Athelia Rolfsii ◽  
Significant Difference

Kiwifruits (Actinidia ssp.), known as “King of vitamin C”, have been wildly cultivated. In August 2020, about 15% of A. deliciosa (cv. Xuxiang) and A. macrosperma (rootstock) plants displayed symptoms typical of root rot at a farm in Hefei (117°25′E, 31°86′N), Anhui Province of China (Fig.1 a-b). Symptoms first appeared at the root and stem junction which were covered by cottony white mycelium during warm and humid summer. Then, the infected tissues were rotted, and subsequently the whole plant withered. Tan to brown sclerotia were observed on the basal stem epidermis and soil surface surrounding the stem (Fig.1 c-d). Infected plant tissues and sclerotia were collected for isolating the fungal pathogen. The samples were surface sterilized in 70% alcohol for 30 s, followed by 2% sodium hypochlorite for 3 min, washed five times with sterile double-distilled water (ddH2O), dried, placed on potato dextrose agar, and incubated at 25 °C in the dark. In total, twelve fungal isolates were obtained. The mycelia of all the isolates were white with a fluffy appearance (Fig.1 e). Sclerotia formed after 7 days were initially white (Fig.1 f) and gradually turned to dark brown (Fig.1 g) measuring 0.67 to 2.03 mm in diameter (mean = 1.367 ± 0.16 mm; n = 30). Hyphae were hyaline, septate. Some cells possessed multiple nuclei (Fig.1 h) and clamp connections (Fig.1 i). No spores were observed. For species-level identification, ITS1/ITS4 and EF1-983F/EF1-2218R primers were used to amplify the internal transcribed spacer regions (ITS) and translation elongation factor-1 alpha regions (TEF-1α), respectively (White et al. 1990; Rehner & Buckley 2005). Based on ITS and TEF-1α sequence analyses, all 12 isolates were categorized into two groups, group one including isolates NC-1 and NC-6~10 and group two containing NC-2~5 and NC-11~12. The length of ITS sequences for NC-1 (MW311079) was 684bp and 99% to 100% similar to Athelia rolfsii (MN610007.1, MN258360.1). Similarly, ITS sequences for NC-2 (MW311080) were 99% to 100% similar to A. rolfsii (MH858139.1; MN872304.1). Also, TEF-1α sequences of NC-1 (MW322687) and NC-2 (MW322688) were 96% to 99% similar to sequences of A. rolfsii (MN702794.1, GU187681.1, MN702789.1). Based on morphology and phylogenetic analyses (Fig.1 j&k), the isolates NC-1 and NC-2 were identified as Athelia rolfsii (anamorph Sclerotium rolfsii) (Mordue. 1974; Punja. 1985). To fulfill Koch’s postulates, ten sclerotia of NC-1 were incorporated into the soil near stems of healthy Xuxiang plants (Fig.2 a). Similar treatments were also used for plants of A. macrosperma or A. arguta (Fig.2 g&m). Each control group had the same number of plants (n=3) for inoculating with ddH2O. The plants were kept in an incubator with a relative humidity of 80% and temperature of 28°C with 16/8 hours light/dark photoperiod. After twenty days, the pathogen-inoculated plants developed similar symptoms of root rot observed in the field (Fig.2 b-d, h-j, n-o). Similarly, four days after inoculation with sclerotia, leaves developed water-soaked lesions (Fig.2 e, k&p). No significant difference in pathogenicity was observed between NC-1 and NC-2. Non-inoculated control plants remained disease-free (Fig.2 f, l&q). The pathogenicity experiments were repeated three times. The pathogen was re-isolated from infected tissues and sclerotia, and isolates were confirmed as A. rolfsii by the ITS sequences. A. rolfsii has been reported to cause root rot in kiwifruit in the USA (Raabe. 1988). To our knowledge, this is the first report A. rolfsii causing root rot on kiwifruits in China.

First report of Sclerotium rolfsii (=Athelia rolfsii) associated with root rot and leaf spot on clove basil (Ocimum gratissimum L.) in India

2021 ◽  
Author(s):  
Shivannegowda Mahadevakumar ◽  
Yelandur Somaraju Deepika ◽  
Kandikere Ramaiah Sridhar ◽  
Kestur Nagaraj Amruthesh ◽  
Nanjaiah Lakshmidevi
Keyword(s):  
Leaf Spot ◽  
Root Rot ◽  
Sclerotium Rolfsii ◽  
First Report ◽  
Ocimum Gratissimum ◽  
Athelia Rolfsii

scholarly journals First Report of Sclerotium Stem Rot Caused by Athelia rolfsii on Stevia rebaudiana in Southwestern France

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 584 ◽  
Author(s):  
Z. Le Bihan ◽  
J. Gaudin ◽  
F. Robledo-Garcia ◽  
P. Cosson ◽  
C. Hastoy ◽  
...  
Keyword(s):  
Stevia Rebaudiana ◽  
Stem Rot ◽  
First Report ◽  
Athelia Rolfsii

scholarly journals First Report of Passion Fruit Anthracnose Caused by Colletotrichum constrictum

Plant Disease ◽  
2021 ◽  
Author(s):  
Na Wang ◽  
Fumei Chi ◽  
Zhirui Ji ◽  
Zongshan Zhou ◽  
Junxiang Zhang
Keyword(s):  
Sequence Data ◽  
Control Strategies ◽  
Pcr Amplification ◽  
Morphological Characters ◽  
Fungal Species ◽  
Passion Fruit ◽  
Effective Control ◽  
First Report ◽  
Sterile Needle ◽  
Morphologic Data

Passion fruit (Passiflora edulis) is widely cultivated in tropic and subtropic regions. Because of its unique and intense flavour and high acidity, passion fruit juice concentrate is used in making delectable sauces, desserts, candy, ice cream, sherbet, or blending with other fruit juices. Anthracnose of passion fruit is favored by frequent rainfall and average temperatures above 27°C. In August 2018, anthracnose on passion fruit was observed in commercial plantings in Lincang, Yunnan, China (23.88 N, 100.08 E). Symptoms included lesions of oval to irregular shapes with brown to dark brown borders. Infection covered most of the fruit surface with pink-to-dark sporulation as reported by Tarnowski and Ploetz (2010). A conidial mass from an individual sorus observed on an infected fruit was isolated and cultured on potato dextrose agar (PDA) supplemented with 50 μg ml-1 of streptomycin. From a single microscopic field, two monospore isolates were dissected using a sterile needle, subcultured, and referred to as BXG-1 and BXG-2. Morphological characters including conidia colour, size, and shape were similar between the two isolates. Conidia were aseptate and cylindrical with apex and rounded base. Conidial length ranged from 12.3 to 16.1 µm (avg. 13.5) and width ranged from 5.5 to 6.2 µm (avg. 5.7). Morphologic data were consistent with Colletotrichum constrictum (Damm et al., 2012). To further confirm the fungal species, the ribosomal internal transcribed spacer (ITS), partial sequences of actin (ACT), chitin synthase (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and β-tubulin 2 (TUB2) were amplified and sequenced. Primers and PCR amplification were described by Damm et al. (2012). The sequences were compared to type sequences in GenBank. The results showed the ITS (GenBank accession MW828148 and MW828149), ACT (MW855882 and MW855883), CHS-1 (MW855884 and MW855885), GAPDH (MW855886 and MW855887), and TUB2 (MW855888 and MW855889) sequences of the isolates BXG-1 and BXG-2 were 98% identical with sequence data from strain CBS:128504 of C. constrictum. A maximum likelihood tree was constructed using MEGA-X version 10.1.6 (Kumar et al., 2018) based on a combined dataset of the ITS, ACT, CHS-1, GAPDH, and TUB2 sequences of BXG-1 and BXG-2, and those of 18 Colletotrichum spp. previously deposited in GenBank (Damm et al., 2012). The phylogenetic analysis showed that BXG-1 and BXG-2 belong to the C. constrictum clade. Based on morphology and DNA sequencing, BXG-1 and BXG-2 were identified as C. constrictum. To verify pathogenicity, passion fruit were sprayed with a suspension of 1 × 105 conidia ml–1. Control fruit were sprayed with sterilized water. After inoculation, fruit were incubated in an Artificial Climate Box at 27°C and 80% RH. Necrotic symptoms appeared 8 days after inoculation and were similar to those observed on fruit form the field. The pathogen was reisolated from lesions thus fulfilling Koch’s postulates. C. constrictum has been reported to cause anthracnose of citrus from Australia (Wang et al., 2021) and mango from Italy (Ismail et al., 2015). To our knowledge, this is the first report of C. constrictum causing anthracnose on passion fruit worldwide, and these data will provide useful information for developing effective control strategies.

scholarly journals First Report of Stem Rot Caused by Athelia rolfsii on Zamioculcas zamiifolia in Korea

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2965-2965
Author(s):  
Yunhee Seo ◽  
Mi-Jeong Park ◽  
Chang-Gi Back ◽  
Jong-Han Park
Keyword(s):  
Stem Rot ◽  
First Report ◽  
Athelia Rolfsii

scholarly journals First Report of Stem Rot Disease of Miracle Plant (Bryophyllum pinnatum) Caused by Athelia rolfsii in Tripura, India

Plant Disease ◽  
2021 ◽  
pp. PDIS-05-20-1086
Author(s):  
D. Kamil ◽  
A. Bahadur ◽  
P. Debnath ◽  
A. Kumari ◽  
S. P. Choudhary ◽  
...  
Keyword(s):  
Stem Rot ◽  
First Report ◽  
Athelia Rolfsii ◽  
Rot Disease ◽  
Bryophyllum Pinnatum

scholarly journals First report of Athelia rolfsii causing stem rot disease on Vasaka (Justicia adhatoda)

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Deeba Kamil ◽  
Amar Bahadur ◽  
Prasenjit Debnath ◽  
Anjali Kumari ◽  
Shiv Pratap Choudhary ◽  
...  
Keyword(s):  
Stem Rot ◽  
First Report ◽  
Athelia Rolfsii ◽  
Rot Disease ◽  
Justicia Adhatoda

scholarly journals First Report of Sclerotium rolfsii Causing Stem Rot of Luffa cylindrica in Brazil

Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 250 ◽  
Author(s):  
C. Bellé ◽  
R. Moccellin ◽  
P. R. Meneses ◽  
C. G. Neves ◽  
M. Z. Groth ◽  
...  
Keyword(s):  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Luffa Cylindrica ◽  
First Report

scholarly journals Resistance to Athelia rolfsii and Web Blotch in the U.S. Mini-core Collection

2020 ◽  
Vol 47 (1) ◽  
pp. 17-24
Author(s):  
R.S. Bennett ◽  
K.D. Chamberlin
Keyword(s):  
Core Collection ◽  
Sclerotium Rolfsii ◽  
Germplasm Collection ◽  
Stem Rot ◽  
Sources Of Resistance ◽  
Southern Blight ◽  
Mini Core Collection ◽  
Athelia Rolfsii ◽  
Low Levels ◽  
The U.S

ABSTRACT Athelia rolfsii (=Sclerotium rolfsii) is a soilborne fungus that causes the disease commonly known as southern blight, southern stem rot, stem rot, and white mold. Despite the fact that A. rolfsii is one of the most destructive pathogens of peanut, the U.S. germplasm collection has not been evaluated for resistance to this pathogen. Therefore, 71 of the 112 accessions comprising the U.S. peanut mini-core collection were evaluated in the field for resistance to southern blight in 2016 to 2018 in Oklahoma. Moderate to low levels of southern blight were observed, but four accessions—CC125, CC208, CC559, and CC650—had low levels of disease in 2017 and 2018, the most favourable years for A. rolfsii. Ratings for web blotch, a yield-limiting foliar disease in some production areas caused by Didymella arachidicola, were also taken in 2017 and 2018, when outbreaks occurred. Five entries—CC287, CC155, CC149, CC812, and CC559—had between 10% and 20% disease in 2018, a year when over half of the mini-core accessions exhibited between 50% and 93% disease. Because cultivated peanut in the U.S. has a narrow genetic base, these results will be useful to breeders seeking additional sources of resistance to A. rolfsii and web blotch.

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