scholarly journals Farklı Konukçu Bitkilerden Toplanan Ökse Otu (Viscum album L.) Ekstraktlarının Bazı Bitki Patojeni Bakteriler Üzerine Etkisi

Author(s):  
Sabriye Belgüzar ◽  
Bahadır Şin ◽  
Zeliha Eroğlu ◽  
İzzet Kadıoğlu ◽  
Yusuf Yanar

In this study, antibacterial effects of semi-parasitic plant common mistletoe (Viscum album L.), collected from different woody host, extracts on the tomato bacterial cancer and wilt disease agent Clavibacter michiganensis subsp. michiganensis, pepper and tomato bacterial leaf spot disease agent Xanthomonas axonopodis pv. vesicatoria and tomato bacterial leaf spot disease agent Pseudomonas syringae pv.tomato were determined. The common mistletoe collected from pine, pear, acacia and mahaleb trees. The leaves and stems water extracts of common mistletoe were added to Nutrinet agar medium before autoclaving at the final concentrations of 1%, 2.5%, 5% and 10%. The bacterial concentration was adjusted to 108 cfu/ml with spectrophotometer to within an 0.2 at 600 nm. Then, 100 µl of bacterial inoculums were spread over the extracts amended media plates. As a control group, pathogens were plated on the unamended media. The study was established in 3 repetitions and repeated 2 times. At the end of the incubation period, bacteria growing on all treated petri dishes were collected and their density was measured in a spectrophotometer. Based on the results of the study, 1% and 2.5% concentration of the extracts obtained from leaves and stems of common mistletoe collected from different trees were not effective on the bacteria tested, while 5% and 10% concentration of them inhibited the bacterial growth completely (100%). Also, it was observed that there wasn’t difference on the pathogens on the basis of the host where mistletoe was collected. According to the results of this study conducted under in vitro conditions, in vivo studies should be carried out with the common mistletoe extract, which is effective on the bacterial pathogens.

2016 ◽  
Vol 10 (11) ◽  
pp. 238-245 ◽  
Author(s):  
Amos Chilagane Luseko ◽  
Nchimbi-Msolla Susan ◽  
Mbogo Kusolwa Paul ◽  
Gabriel Porch Timothy ◽  
Miryam Serrato Diaz Luz ◽  
...  

Plant Disease ◽  
2020 ◽  
Author(s):  
JiangTao Peng ◽  
Yao Chen ◽  
Guo ying Zhou ◽  
Jun Ang Liu

Dalbergia odorifera T. Chen is a national second-grade protected and one of the four famous trees in China, with high medicinal and economic value. Leaf spot disease in this plant can cause the leaves to dry up, perforate or even fall off, which affects the growth and development, and also has a great influence on its products. In May 2019, the leaf spot of Dalbergia odorifera T. Chen was found and observed in Chengmai County (N19°40′, E110°0′), Hainan Province, China, and the symptomatic leaves were brought back to the laboratory for research; According to our survey at that time, the incidence of the disease was between 10% and 15%. A sterile stainless-steel scalpel was used to cut the tissues at the junction of the leaf lesions and placed on a clean bench, soaked in alcohol (75 %) for 30 s, and rinsed thrice with sterile water. Then it was inserted obliquely onto lactic acid-containing potato dextrose agar (PDA) and incubated at 28 °C for 5 days. The growing prominent colonies were singled out and re-inoculated on PDA and SNA plates. Preliminary identification was based on morphological characteristics, followed by molecular identification of strains by evaluating genes for translation elongation factor-1α(TEF-1α), beta-tubulin, mitochondrial small subunit (mtSSU)( Duan et al. 2019; Cao et al.2019; Stenglein et al.2010), and histone H3 (Jacobs, et al. 2010) . Through morphological observation, the isolate was identified as Fusarium fujikuroi. At the initial stage of growth on PDA, the strain produced a large number of white hyphae, followed by pink and purple-brown hyphae in the center of the colony which spread to the surrounding area. The microspores were abundant, colorless, elliptic or clavate, without septum or at 1-2 septate, and the size was about 3.3 to 13.5 × 1.2 to 3.2 µm. After nine days of culturing on SNA medium, few, large conidia were observed, typically sickle-like, with 3-4 septa with a size of about 20 to 40.2 × 2.3 to 4.4 μm. The identity of the strains was determined by comparing the gene sequences of TEF-1α, mtSSU, beta-tubulin and histone H3 by NCBI BLAST. The results showed that TEF-1 α (MN958396), mtSSU (MN958394), β - tubulin (MN958395), and histone H3 (MN958397) from the target strain (jxht0302) had 100% sequence homology with F. fujikuroi (GenBank, accession numbers KF604040.1, MF984420.1, XM023575231.1, and MF356523.1 respectively). Next, the infection of D. odorifera T. Chen seedlings with and without injury was studied using a fungus block, with PDA as a control. Two days after inoculation with injury, obvious lesions were observed on the leaves, which appeared at least 5 days post- inoculation without injury, with no lesions in the control group. F. fujikuroi could be re-isolated from the leaves with lesions, but not from the control group. F. fujikuroi causes Black Rot of Macleaya cordata and maize ear rot (Yull et al.2019; Duan et al. 2019). As far as we know, this is the first report of F. fujikuroi causing leaf spot disease of D. odorifera T. Chen. Given the importance of D. odorifera T. Chen products, this disease needs more attention to tackle it.


1993 ◽  
Vol 21 (1) ◽  
pp. 75-78 ◽  
Author(s):  
A. R. Wasnikar ◽  
S. K. Khatik ◽  
M. L. Nayak ◽  
S. K. Vishwakarma ◽  
L. K. Punekar

Plant Disease ◽  
2021 ◽  
Author(s):  
Lei Li ◽  
Yishuo Huang ◽  
Yanxia Shi ◽  
A LI CHAI ◽  
Xuewen Xie ◽  
...  

Coriander (Coriandrum sativum L.) or Chinese parsley is a culinary herb with multiple medicinal effects that are widely used in cooking and traditional medicine. From September to November 2019, symptoms were observed in 2-month-old coriander plants from coriander fields in Lanzhou and Wenzhou, China. The disease developed rapidly under cold and wet climatic conditions, and the infection rate was almost 80% in open coriander fields. Typical symptoms on leaves included small, water-soaked blotches and irregular brown spots surrounding haloes; as the disease progressed, the spots coalesced into necrotic areas. Symptomatic leaf tissue was surface sterilized, macerated in sterile distilled water, and cultured on nutrient agar plates at 28 °C for 48 h (Koike and Bull, 2006). After incubation, six bacterial colonies, which were individually isolated from collected samples from two different areas, were selected for further study. Colonies on NA plate were small, round, raised, white to cream-colored, and had smooth margins. All bacterial isolates were gram-negative, rod-shaped and nonfluorescent on King's B medium. The bacteria were positive for levan production, Tween 80 hydrolysis, and tobacco hypersensitivity but negative for oxidase, potato slice rot test, arginine dihydrolase, ice nucleation activity, indole production and H2S production. The suspension of representative isolate for inoculating of plants was obtained from single colony on King's B medium for 2-3 days at 28 °C. DNA was extracted from bacterial suspensions of YS2003200102 cultured in 20 ml of King’s B medium broth at 28 °C for 1 day. Extraction was performed with a TIANamp Bacterial DNA Kit (TIANGEN, China) according to the manufacturer’s recommendations. The pathogen was confirmed by amplification and sequencing of the glyceraldehyde-3-phosphate dehydrogenase A (gapA) gene, the citrate synthase (gltA) gene, the DNA gyrase B (gyrB) gene and the RNA polymerase sigma factor 70 (rpoD) gene using gapA-For/gapA-Rev, gltA-For/gltA-Rev, gyrB-For/gryB-Rev, rpoD-For/rpoD-Rev primers, respectively (Popović et al., 2019). The sequences of the PCR products were deposited in GenBank with accession numbers MZ681931 (gapA), MZ681932 (gltA), MZ681933 (gyrB), and MZ681934 (rpoD). Phylogenetic analysis of multiple genes (Xu and Miller, 2013) was conducted with the maximum likelihood method using MEGA7. The sequences of our isolates and ten published sequences of P. syringae pv. coriandricola were clustered into one clade with a 100% confidence level. To confirm the pathogenicity of isolate YS2003200102, 2-month-old healthy coriander plants were inoculated by spraying the leaves with a bacterial suspension (108 CFU ml−1) at 28 °C incubation temperature and 70% relative humidity condition, and sterile distilled water was applied as a negative control treatment (Cazorla et al. 2005). Three replicates were conducted for every isolate, and each replicate included 6 coriander plants. After twelve days, only the inoculated leaves with bacterial suspension showed bacterial leaf spot resembling those observed on naturally infected coriander leaves. Cultures re-isolated from symptomatic leaves showed the same morphological characteristics and molecular traits as those initially isolated from infected leaves in the field. This bacterium was previously reported causing leaf spot of coriander in India and Spain (Gupta et al. 2013; Cazorla et al. 2005). To our knowledge, this is the first report of P. syringae pv. coriandricola causing leaf spot disease on coriander in China. Studies are needed on strategies to manage P. syringae pv. coriandricola in crops, because its prevalence may cause yield loss on coriander in China.


Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1207-1207 ◽  
Author(s):  
N. A. Cintas ◽  
C. T. Bull ◽  
S. T. Koike ◽  
H. Bouzar

In 1998, a new disease was detected on 3-week-old commercial broccolini (Brassica oleracea L. var. botrytis × B. alboglabra) transplants in a Salinas Valley, Monterey County, CA greenhouse. Initial symptoms were small (2 to 4 mm diameter) circular to angular, water-soaked spots. As the disease progressed, spots remained relatively small, but turned tan to brown. When diseased tissues were macerated and streaked on King's medium B, a blue-green fluorescent pseudomonad was consistently isolated. Strains were levan positive, oxidase negative, and arginine dihydrolase negative. Strains did not rot potato slices, but induced a hypersensitive reaction on tobacco (Nicotiana tabacum L. ‘Turk’). Fatty acid methyl ester analysis (MIS-TSBA, version 4.10, MIDI Inc., Newark, DE) indicated that strains had a high similarity index (0.82 or higher) to Pseudomonas syringae, and GN (version 3.50, Biolog, Inc., Hayward, CA) profiles also identified strains as P. syringae. The bacterium associated with the disease, therefore, was identified as P. syringae van Hall. Pathogenicity was demonstrated by growing inoculum in nutrient broth shake cultures for 48 h, misting the broth cultures (1×106 CFU/ml) onto broccolini (cv. Aspabrock), and subjecting the plants to 48 h of high humidity. Control plants were misted with sterile nutrient broth. After 4 to 5 days in a greenhouse, leaf spot symptoms developed on all inoculated broccolini plants, and reisolated strains were characterized and found to be P. syringae. Control plants remained symptomless. The results of two sets of pathogenicity tests were the same. Repetitive sequence-based polymerase chain reaction using the BOXA1R primer resulted in identical banding patterns for the broccolini pathogen and for known isolates of P. syringae pv. maculicola from crucifers. In host range testing, P. syringae pv. maculicolawas pathogenic to broccolini plants. The broccolini isolates and P. syringae pv. maculicola isolates had the same pathogenicity results when crucifers and tomatoes were tested as hosts; broccoli and cauliflower (B. oleracea var. botrytis) were infected, and tomato results were variable. These tests suggest that the broccolini pathogen is the bacterial leaf spot pathogen, Pseudomonas syringae pv. maculicola, that occurs on broccoli and cauliflower transplants (1). To our knowledge, this is the first report of this pathogen causing a disease on commercially grown broccolini. Reference: (1) S. T. Koike et al. Plant Dis. 82:727, 1998.


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