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Sample records for black rot disease

  1. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

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    Lincon Rafael da Silva

    2015-06-01

    Full Text Available This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots. Each plot consisted of three planting lines 2.5 m long (six plants/line, spaced 1.0 m apart, for a total area of 7.5 m². Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS, and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha and Cindy (19.95 and 23.56 t/ha being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot.

  2. Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue.

    Science.gov (United States)

    Sharma, Brij B; Kalia, Pritam; Singh, Dinesh; Sharma, Tilak R

    2017-01-01

    Black rot caused by Xanthomonas campestris pv. campestris ( Xcc ) is a very important disease of cauliflower ( Brassica oleracea botrytis group) resulting into 10-50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B 1 ) were generated between cauliflower "Pusa Sharad" and Ethiopian mustard "NPC-9" employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F 1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2 n = 18, CC) × B. carinata (2 n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2 n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F 1 hybrid and BC 1 plants. The F 1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC 1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC 1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.

  3. Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue

    Science.gov (United States)

    Sharma, Brij B.; Kalia, Pritam; Singh, Dinesh; Sharma, Tilak R.

    2017-01-01

    Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a very important disease of cauliflower (Brassica oleracea botrytis group) resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1) were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2n = 18, CC) × B. carinata (2n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides. PMID:28769959

  4. Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group through Embryo Rescue

    Directory of Open Access Journals (Sweden)

    Brij B. Sharma

    2017-07-01

    Full Text Available Black rot caused by Xanthomonas campestris pv. campestris (Xcc is a very important disease of cauliflower (Brassica oleracea botrytis group resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome, therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1 were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC primers. Meiosis in the di-genomic (BCC interspecific hybrid of B. oleracea botrytis group (2n = 18, CC × B. carinata (2n = 4x = 34, BBCC was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.

  5. Mutation breeding against black pod (Phytophthora pod rot) disease of cacao (Theobroma cacao)

    International Nuclear Information System (INIS)

    Opeke, L.K.

    1977-01-01

    Black pod rot disease, caused by Phytophthora palmivora, is an important disease of cacao (Theobroma cacao L.) in Nigeria and other cacao producing countries of West Africa and Latin America. A naturally occurring source of genetic resistance to the disease has not been found. This paper completes the report, the first part of which was published in Induced Mutations in Vegetatively Propagated Plants, IAEA, Vienna (1973). The survivors of the irradiated seedlings reported on in this publication were transplanted to the field along with their controls. When the Phytophthora pod disease season began in 1973, all experimental plants along with the controls were sprayed with active and freshly prepared dense sporangial suspension of P. palmivora. Observations on Phytophthora infection were recorded at two-weekly intervals for three months. Results were pooled for each set of experimental plants, after having confirmed that no marked difference appeared among individual plants of each group. Contrary to the observations recorded at the nursery stage, all experimental plants that showed no infection indicated disease infection levels normally characteristic of the F 3 Amazon cultivar of Cacao in Nigeria. Although the nursery and the field data are difficult to reconcile and interpret, it is suggested that probably temporary disease tolerance/resistance, which some irradiated plants showed at the nursery (seedling) stage, was lost as the plants matured, thus suggesting different resistance factor systems for juvenile and mature cacao trees. (author)

  6. Antagonistic Effect of Native Bacillus Isolates against Black Root Rot ...

    African Journals Online (AJOL)

    Faba bean (Vicia faba L.) is one of the most important pulse crops grown in eastern Africa. Black root rot (Fusarium solani) is known to cause great yield losses in faba bean, especially in the highlands of Ethiopia. The objective of this study was to evaluate the biological control ability of native Bacillus species on the basis of ...

  7. Evaluation of rhizobacterial indicators of tobacco black root rot suppressiveness in farmers' fields

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Almario, J.; Kopecký, J.; Ságová-Marečková, M.; Haurat, J.; Muller, D.; Grundmann, G.L.; Moënne-Loccoz, Y.

    2014-01-01

    Roč. 6, č. 4 (2014), s. 346-353 ISSN 1758-2229 Institutional support: RVO:60077344 Keywords : rhizobacterial indicators * tobacco black root rot suppressiveness * farmers' fields Subject RIV: EH - Ecology, Behaviour Impact factor: 3.293, year: 2014

  8. Bacterial Infection Potato Tuber Soft Rot Disease Detection Based on Electronic Nose

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    Chang Zhiyong

    2017-11-01

    Full Text Available Soft rot is a severe bacterial disease of potatoes, and soft rot infection can cause significant economic losses during the storage period of potatoes. In this study, potato soft rot was selected as the research object, and a type of potato tuber soft rot disease early detection method based on the electronic nose technology was proposed. An optimized bionic electronic nose gas chamber and a scientific and reasonable sampling device were designed to detect a change in volatile substances of the infected soft rot disease of potato tuber. The infection of soft rot disease in potato tuber samples was detected and identified by using the RBF NN algorithm and SVM algorithm. The results revealed that the proposed bionic electronic nose system can be utilized for early detection of potato tuber soft rot disease. Through comparison and analysis, the recognition rate using the SVM algorithm reached up to 89.7%, and the results were superior to the RBF NN algorithm.

  9. Root rots

    Science.gov (United States)

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  10. Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn.

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    Asad-Uz-Zaman, Md; Bhuiyan, Mohammad Rejwan; Khan, Mohammad Ashik Iqbal; Alam Bhuiyan, Md Khurshed; Latif, Mohammad Abdul

    2015-02-01

    An investigation was made to manage strawberry black root rot caused by Rhizoctonia solani (R. solani) through the integration of Trichoderma harzianum (T. harzianum) isolate STA7, mustard oil cake and Provax 200. A series of preliminary experiments were conducted to select a virulent isolate of R. solani, an effective isolate of T. harzianum, a suitable organic amendment, and a suitable fungicide before setting the experiment for integration. The pathogenicity of the selected four isolates of R. solani was evaluated against strawberry and isolate SR1 was selected as the test pathogen due to its highest virulent (95.47% mortality) characteristics. Among the 20 isolates of T. harzianum, isolate STA7 showed maximum inhibition (71.97%) against the test pathogen (R. solani). Among the fungicides, Provax-200 was found to be more effective at lowest concentration (100 ppm) and highly compatible with Trichoderma isolates STA7. In the case of organic amendments, maximum inhibition (59.66%) of R. solani was obtained through mustard oil cake at the highest concentration (3%), which was significantly superior to other amendments. Minimum percentages of diseased roots were obtained with pathogen (R. solani)+Trichoderma+mustard oil cake+Provax-200 treatment, while the highest was observed with healthy seedlings with a pathogen-inoculated soil. In the case of leaf and fruit rot diseases, significantly lowest infected leaves as well as fruit rot were observed with a pathogen+Trichoderma+mustard oil cake+Provax-200 treatment in comparison with the control. A similar trend of high effectiveness was observed by the integration of Trichoderma, fungicide and organic amendments in controlling root rot and fruit diseases of strawberry. Single application of Trichoderma isolate STA7, Provax 200 or mustard oil cake did not show satisfactory performance in terms of disease-free plants, but when they were applied in combination, the number of healthy plants increased significantly. The

  11. Toward The identification Of candidate genes involved in black pod disease resistance in Theobroma cacao L.

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    Increasing yield, quality and disease resistance are important objectives for cacao breeding programs. Some of the diseases, such as black pod rot (Phytophtora spp), frosty pod (Moniliophthora roreri) and witches’ broom (M. perniciosa), produce significant losses in all or in some of the various pro...

  12. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

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    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  13. Fungi associated with base rot disease of aloe vera (Aloe ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... full base rot disease after 6 days of inoculation. Key words: Fungi, base rot, Aloe vera. INTRODUCTION. Aloe barbadensis Miller, popularly called Aloe vera is a phanerogame angiosperm which belongs to the family. Liliaceae. The plant is a perennial drought resistant succulent plant (Figure 1). Aloe vera is ...

  14. Survey of root rot diseases of sugar bett in Central Greece

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available An extensive survey was conducted during the summer and autumn of 2004 in sugar beet fields in the area of Larissa, Thessaly region, with plants showing symptoms of root rot diseases. The aim of the monitoring was to identify the causal agents of root rot diseases. In total, 76 sugar beet fields were surveyed and 5-10 diseased roots were examined from each field. Isolations, carried out on PDA, showed that two main fungal pathogens causing root rot were Rhizoctonia solani and Phytophthora cryptogea. The former was isolated in 46% of the fields and the latter in 38% of the fields. In addition, Rhizopus stolonifer, Fusarium spp., Scerotium rolfsii and Rhizoctonia violacea were isolated in 14%, 7%, 4% and 1% of the fields respectively. In most of the surveyed fields only one pathogen species was isolated and only in a few of them more than one fungal species was identified.

  15. Root rot diseases of sugar beet

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    Jacobsen Barry J.

    2006-01-01

    Full Text Available Root rot diseases of sugar beet caused by Rhizoctonia solani (AG 2-2 IIIB and AG 2-2 IV, R. crocorum, Aphanomyces cochlioides, Phoma betae, Macrophomina phaeseolina, Fusarium oxysporum f.sp. radicis-betae, Pythium aphanidermatum Phytophthora drechsleri, Rhizopus stolonifer, R. arrhizus and Sclerotium rolfsii cause significant losses wherever sugar beets are grown. However, not all these soil-borne pathogens have been reported in all sugar beet production areas. Losses include reduced harvestable tonnage and reduced white sugar recovery. Many of these pathogens also cause post harvest losses in storage piles. Control for diseases caused by these pathogens include disease resistant cultivars, avoidance of stresses, cultural practices such as water management and the use of fungicides.

  16. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

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    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  17. FOOT ROT DISEASE IDENTIFICATION FOR VELLAIKODI VARIETY OF BETELVINE PLANTS USING DIGITAL IMAGE PROCESSING

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    J. Vijayakumar

    2012-11-01

    Full Text Available Betelvine plants are infected variety of diseases in the complete plantation without any premature warning of the diseases. The aim of this paper is to detection of foot rot disease in the vellaikodi variety of betelvine plants using digital image processing techniques. The digital images of the uninfected or normal betelvine leaves and the digital images of the infected in foot rot diseased betelvine leaves at different stages are collected from different Betelvine plants using a high resolution digital camera and collected betelvine images are stored with JPEG format. The digital images of the betelvine leaves analyses are done using the image processing toolbox in MATLAB which gives the normal patterns of the digital images. Using RGB encoding process, the RGB components of the betelvine leaves are separated. The mean and median values for all sample leaves are computed and calculated values are stored in the system. The mean and median values of test leaves are computed and compared with the stored values. As the result of this comparison, it is identified whether test leaves are affected by foot rot disease or not. Finally this analysis helps to recognize the foot rot disease can be identified before it spreads to entire crop.

  18. Inflorescence rot disease of date palm caused by Fusarium ...

    African Journals Online (AJOL)

    Date palm is one of the important income sources for many farmers in different parts of several countries, including Iraq, Iran, Saudi Arabia, North Africa etc. Inflorescence rot is a serious disease of date palm which limits its yield. The identification of the causal organism is a key step to tackling this disease, and such studies ...

  19. Biological control of Black Pod Disease and Seedling Blight of cacao caused by Phytophthora Species using Trichoderma from Aceh Sumatra

    Science.gov (United States)

    The cocoa tree, Theobroma cacao L., suffers large yield losses in Aceh Indonesia to the disease black pod rot, caused by Phytophthora spp. Despite having the largest area under cacao production in Sumatra, farmers in the Aceh region have low overall production because of losses to insect pests and b...

  20. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

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    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

  1. Levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina Survey of the intensity of Alternaria black spot and black rot on brassica species under organic farming systems in Pernambuco and Santa Catarina states, Brazil

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    Luiz A M Peruch

    2006-12-01

    organic farming systems with different brassicas. High prevalence of the diseases was registered in both states, except on Chinese cabbage in Santa Catarina. Prevalence of Alternaria black spot was 100% on broccoli fields in Pernambuco, as well as on cauliflower in both states, while the black rot reached that level on broccoli and cauliflower fields in Santa Catarina. On the average of the different brassica species, the diseases were more prevalent in Pernambuco than in Santa Catarina. However, when the severity averages of each disease were considered, no significant differences were observed between the two states, although the climatic conditions were highly different. The Alternaria black spot severity varied among the brassica species in Pernambuco, being lower on kale. In Santa Catarina no significant differences were observed among the brassicas species. In relation to the black rot, only in Santa Catarina was there a difference in the disease severity, with the lowest level on Chinese cabbage. No significant correlations were observed either between severity levels of Alternaria black spot and black rot, neither between disease severity and total number of plants or plant age.

  2. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt. PMID:24808737

  3. Fungi associated with base rot disease of aloe vera ( Aloe ...

    African Journals Online (AJOL)

    Fungi associated with base rot disease of Aloe vera (syn. Aloe barbadensis) were investigated in Niger Delta Area of Nigeria. Fungi and their percentage frequency were Aspergillus verocosa 28.03%, Fusarium oxysporium 24.24%, Plectosphaerella cucumerina 16.67%, Mammeria ehinobotryoides 15.91% and Torula ...

  4. Diversity and activity of biosurfactant-producing Pseudomonas in the rhizosphere of black pepper in Vietnam.

    Science.gov (United States)

    Tran, H; Kruijt, M; Raaijmakers, J M

    2008-03-01

    Phytophthora capsici is a major pathogen of black pepper and zoospores play an important role in the infection process. Fluorescent pseudomonads that produce biosurfactants with zoosporicidal activities were isolated from the black pepper rhizosphere in Vietnam, and their genotypic diversity and potential to control Phy. capsici root rot was determined. Biosurfactant-producing pseudomonads were genotypically and biochemically characterized by BOX-polymerase chain reaction (PCR), 16S-rDNA sequencing, reverse-phase-high-performance liquid chromatography and liquid chromatography-mass spectrometry analyses. Biosurfactant-producing fluorescent pseudomonads make up c. 1.3% of the culturable Pseudomonas population in the rhizosphere of black pepper. Although BOX-PCR revealed substantial genotypic diversity, the isolates were shown to produce the same biosurfactants and were all identified as Pseudomonas putida. When applied to black pepper stem cuttings, several of the biosurfactant-producing strains provided significant disease control. In absence of the disease, several of the bacterial strains promoted shoot and root growth of black pepper stem cuttings. Biosurfactant-producing pseudomonads indigenous to the rhizosphere of black pepper plants are genotypically diverse and provide a novel resource for the control of Phy. capsici root rot and growth promotion of black pepper stem cuttings. The results of this study provide a strong basis for further development of supplementary strategies with antagonistic bacteria to control foot and root rot of black pepper and to promote plant growth.

  5. [Research progress in root rot diseases of Chinese herbal medicine and control strategy by antagonistic microorganisms].

    Science.gov (United States)

    Gao, Fen; Ren, Xiao-xia; Wang, Meng-liang; Qin, Xue-mei

    2015-11-01

    In recent years, root rot diseases of Chinese herbal medicine have been posing grave threat to the development of the traditional Chinese medicine industry. This article presents a review on the occurring situation of the root rot disease, including the occurrence of the disease, the diversity of the pathogens, the regional difference in dominant pathogens,and the complexity of symptoms and a survey of the progress in bio-control of the disease using antagonistic microorganisms. The paper also discusses the existing problems and future prospects in the research.

  6. Mucor rot - An emerging postharvest disease of mandarin fruit caused by Mucor piriformis and other Mucor spp. in California

    Science.gov (United States)

    In recent years, an emerging, undescribed postharvest fruit rot disease was observed on mandarin fruit after extended storage in California. We collected decayed mandarin fruit from three citrus packinghouses in the Central Valley of California in 2015 and identified this disease as Mucor rot caused...

  7. Assessment of the relationship between geologic origin of soil, rhizobacterial community composition and soil receptivity to tobacco black root rot in Savoie region (France)

    Czech Academy of Sciences Publication Activity Database

    Almario, J.; Kyselková, Martina; Kopecký, J.; Ságová-Marečková, M.; Muller, D.; Grundmann, G.L.; Moënne-Loccoz, Y.

    2013-01-01

    Roč. 371, 1/2 (2013), s. 397-408 ISSN 0032-079X Grant - others:MŚMT(CZ) ME09077 Institutional support: RVO:60077344 Keywords : suppressive soils * Thielaviopsis basicola * black root rot Subject RIV: EE - Microbiology, Virology Impact factor: 3.235, year: 2013

  8. Response of the Andean diversity panel to root rot in a root rot nursery in Puerto Rico

    Science.gov (United States)

    The Andean Diversity Panel (ADP) was evaluated under low-fertility and root rot conditions in two trials conducted in 2013 and 2015 in Isabela, Puerto Rico. About 246 ADP lines were evaluated in the root rot nursery with root rot and stem diseases caused predominantly by Fusarium solani, which cause...

  9. Root rot in sugar beet piles at harvest

    Science.gov (United States)

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  10. Molecular Characterization of Resistant Accessions of Cocoa (Theobroma cocoa L.) to Phytophthora Pod Rot Selected on-Farm in Côte-d’Ivoire.

    Science.gov (United States)

    Cocoa is (Theobroma cacao L.) is a significant agricultural commodity in Côted’Ivoire which ranks 1st in the world cocoa export. Phytophthora pod rot (Ppr)also call Black pod is the most widespread disease of cocoa. Lost due to this disease depends on the species of the pathogen and vary globally fr...

  11. PATHOLOGICAL AND MOLECULAR GENETIC STUDIES ON SOME SOYBEAN MUTANTS INDUCED BY GAMMA RAYS IN RELATION TO CHARCOAL ROT DISEASE

    International Nuclear Information System (INIS)

    ASHRY, N.A.; EL-DEMERDASH, H.M.; ABD EL-RAHMAN, S.S.

    2008-01-01

    The Egyptian soybean cultivar Giza-22 was used to induce resistant mutants for charcoal rot disease using gamma rays. Sixteen mutants and their parental cultivar were evaluated in M3 generation for their agronomic traits and for resistance to charcoal rot disease. Four mutants showed superiority in their agronomic traits as compared with their parental cultivar. Three mutants were significantly resistant to the disease than their parental cultivar (Giza-22). These three resistant mutants showed non-significant improvement in their agronomic traits as compared with Giza-22 cultivar. DNA extractions from the three resistant mutants and their parent were used to test the differences on the molecular level. Seven random amplified polymorphic DNA (RAPD) primers were used to detect RAPD markers related to charcoal rot resistance in soybean, and to differentiate these mutants. Six RAPD-primers showed molecular markers associated with resistance to charcoal rot in soybean, where five RAPD-primers could differentiate each of the three mutants from each other and from their parental cultivar

  12. Cacao diseases: A history of old enemies and new encounters

    Science.gov (United States)

    This book reviews the current knowledge of cacao pathogens and their management methods. Topics discussed include the history, biology, and genetic diversity of Moniliophthora (causing witches’ broom and frosty pod rot) and Phytophthora species (causing black pod rot) that cause diseases resulting i...

  13. Root Rot Disease of Five Fruit Tree Seedlings in the Nursery ...

    African Journals Online (AJOL)

    The incidence of root rot disease in the nursery of Chrysophyllum albidun Dacryodes edulis, persea Americana, Irvingia gabonensis and Annona muricala was assessed. Ten fungal pathogen were isolated using serial dilution and pathogenicity tests were carried out on the 5 fruit trees with the 10 isolated fungi. The 5 fruit ...

  14. root rot disease of five fruit tree seedlings in the nursery

    African Journals Online (AJOL)

    KAMALDEEN

    on them. Our experience in the nursery in Port Harcourt had been that many tree species of the tropical region are susceptible to root rot diseases of fungal origin. The fungal invasion of the succulent root tissues causes the young tree seedlings to dieback; their leaves becomes discoloured, wilted and eventually dead.

  15. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  16. Phytophthora megakarya and P. palmivora, closely related causal agents of cacao black pod rot, underwent increases in genome sizes and gene numbers by different mechanisms

    Science.gov (United States)

    Phytophthora megakarya (Pmeg) and P. palmivora (Ppal) are closely related species causing black pod rot of cacao. While Ppal is a cosmopolitan plant pathogen, cacao is the only known host of importance for Pmeg. Pmeg is more virulent on cacao than Ppal. Therefore, we have sequenced both the Pmeg and...

  17. The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2010-06-01

    Full Text Available Ten isolates of Fusarium spp were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. Anaheim-M. The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

  18. The preventive Control of White Root Rot Disease in Small Holder Rubber Plantation Using Botanical, Biological and Chemical Agents

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo

    2014-03-01

    Full Text Available The preventive control of white root rot disease in small holder plantation using botanical, biological, and chemical agents. A field and laboratory experiment were conducted from June 2008 to December 2009 in Panumangan, Tulang Bawang - Lampung. The  field experiment was intended to evaluate the effect of  botanical plants (Alpinia galanga, Sansiviera auranthii, and Marantha arundinacea, biological agents (organic matter and Trichoderma spp., and chemical agents (lime and natural sulphur on the incidence of white root rot disease and population of some soil microbes. The laboratory experiment was conducted  to observe the mechanism of botanical agents  in controlling white root rot disease. In the field experiment, the treatments were applied  in the experimental plot with cassava plant infection as the indicator. The variables  examined were the incidence of  white root rot and population of soil microbes. In the laboratory experiment, culture of R. microporus was grown in PDA containing root exudate of the antagonistic plant (botanical agent. The variable examined was colony diameter of R. microporus growing in the PDA plates. The results of the  field experiment  showed that planting of the botanical agents, and application of Trichoderma spp., as well as natural sulphur, decreased the incidence of white root rot disease. The effectiveness of M. arundinacea and Trichoderma spp. was comparable to natural  sulphur. The laboratory experiment showed only root exudate of  A. galanga and  S. auranthii that were significantly inhibit the growth of R. microporus.

  19. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

    Science.gov (United States)

    Macedo, Renan; Sales, Lilian Patrícia; Yoshida, Fernanda; Silva-Abud, Lidianne Lemes; Lobo, Murillo

    2017-01-01

    Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans.

  20. Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

    Directory of Open Access Journals (Sweden)

    Renan Macedo

    Full Text Available Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%. Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070 was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans.

  1. Effects of bunch rot (Botrytis cinerea) and powdery mildew (Erysiphe necator) fungal diseases on wine aroma

    Science.gov (United States)

    Lopez Pinar, Angela; Rauhut, Doris; Ruehl, Ernst; Buettner, Andrea

    2017-03-01

    This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quality parameter of wine, the aroma. The influence of these fungal diseases was studied by comparative Aroma Extract Dilution Analyses (AEDA) and sensory tests. The effect of bunch rot was investigated on three grape varieties, namely White Riesling, Red Riesling and Gewürztraminer and that of powdery mildew on the hybrid Gm 8622-3; thereby, samples were selected that showed pronounced cases of infection to elaborate potential currently unknown effects. Both infections revealed aromatic differences induced by these fungi. The sensory changes were not associated with one specific compound only, but were due to quantitative variations of diverse substances. Bunch rot predominantly induced an increase in the intensities of peach-like/fruity, floral and liquor-like/toasty aroma notes. These effects were found to be related to variations in aroma substance composition as monitored via AEDA, mainly an increase in the FD factors of lactones and a general moderate increase of esters and alcohols. On the other hand, powdery mildew decreased the vanilla-like character of the wine while the remaining sensory attributes were rather unaffected. Correspondingly, FD factors of the main aroma constituents were either the same or only slightly modified by this disease. Moreover, bunch rot influenced the aroma profiles of the three varieties studied to a different degree. In hedonic evaluation, bunch rot-affected samples were rated as being more pleasant in comparison to their healthy controls in all three varieties while the powdery mildew-affected sample was rated as being less pleasant than its healthy control.

  2. Foot Rot of Ulluco Caused by Pythium aphanidermatum

    OpenAIRE

    Keisuke, TOMIOKA; Toyozo, SATO; Tateo, NAKANISHI; National Agricultural Research Center for Western Region; National Institute of Agrobiological Sciences; National Agricultural Research Center for Western Region

    2002-01-01

    Severe rot of stem bases caused by Pythium aphanidermatum was found on ulluco (Ullucus tuberosus) grown in Kagawa Prefecture, Japan, in September 1999. The name "foot rot of ulluco" is proposed for this new disease.

  3. Sclerotinia Rot on Basil Caused by Sclerotinia sclerotiorum in Korea

    Directory of Open Access Journals (Sweden)

    Soo Sang Hahm

    2017-03-01

    Full Text Available During growing season of 2011 to 2013, Sclerotinia rot symptoms consistently have been observed on basil in Yesan-gun, Chungcheongnam-do in Korea. The typical symptom formed initially brownish spot on leaf and stem, and then advancing margins, wilting the whole plant and blighting, eventually died. On the surface of diseased lesions was observed cottony, white, dense mat of mycelial growth, and sclerotia (30–100 µm diameter formed on stem and leaf. Morphological and cultural characteristic on potato dextrose agar, color of colony was white and colorless chocolate, sclerotium of irregular shape of the oval was black and 5–50 µm diameter in size. In pathogenicity test, necrosis and wilt of the inoculated stem were observed in all plants and the pathogen was reisolated from stems. On the basis of mycological characteristics, pathogenicity, and internal transcribed spacer rDNA sequence analysis, this fungus was identified as Sclerotinia sclerotiorum. This is the first report of Sclerotinia rot on basil caused by S. sclerotiorum in Korea.

  4. Biological Control of White Rot in Garlic Using Burkholderia pyrrocinia CAB08106-4

    Directory of Open Access Journals (Sweden)

    Kwang Seop Han

    2013-03-01

    Full Text Available White rot caused by Sclerotium cepivorum was reported to be severe soil-born disease on garlic. Disease progress of white rot of garlic (Allium sativum L. was investigated during the growing season of 2009 to 2011 at Taean and Seosan areas. The white rot disease on bulb began to occur from late April and peaked in late May. The antifungal bacteria, Burkholderia pyrrocinia CAB08106-4 was tested in field bioassay for suppression of white rot disease. As a result of the nucleotide sequence of the gene 16S rRNA, CAB008106-4 strain used in this study has been identified as B. pyrrocinia. B. pyrrocinia CAB080106-4 isolate suppressed the white rot with 69.6% control efficacy in field test. These results suggested that B. pyrrocinia CAB08106-4 isolate could be an effective biological control agent against white rot of garlic.

  5. Selection individual on mutant genotype of soybean (Glycine maxl.merrill) in m5 generation based on resistance of stem rot disease Athelia rolfsii (curzi)

    Science.gov (United States)

    Rahmah, M.; Hanafiah, D. S.; Siregar, L. A. M.; Safni, I.

    2018-02-01

    This study was aimed to obtain selected individuals on soybean plant Glycine max L. (Merrill) in M5 generation based on high production character and tolerance of stem rot disease Athelia rolfsii (Curzi). This research was conducted in Plant Disease Laboratory and experimental field Faculty of Agriculture Universitas Sumatera Utara Medan, Indonesia. This research was conducted from December 2016 to June 2017. The treatments were 15 mutant lines genotypes and Anjasmoro variety. The results showed that some lines mutant genotypes can gave the good agronomic appearance character than Anjasmoro variety on inoculation treatment of stem rot disease. Selection performed on population M5 producesselected individuals with tolerance of stem rot disease from 100 and 200 Gy population.

  6. High-throughput sequencing of black pepper root transcriptome

    Science.gov (United States)

    2012-01-01

    Background Black pepper (Piper nigrum L.) is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms. PMID:22984782

  7. High-throughput sequencing of black pepper root transcriptome

    Directory of Open Access Journals (Sweden)

    Gordo Sheila MC

    2012-09-01

    Full Text Available Abstract Background Black pepper (Piper nigrum L. is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms.

  8. A survey of pre-harvest ear rot diseases of maize and associated mycotoxins in south and central Zambia.

    Science.gov (United States)

    Mukanga, Mweshi; Derera, John; Tongoona, Pangirayi; Laing, Mark D

    2010-07-15

    Maize ear rots reduce grain yield and quality with implication on food security and health. Some of the pathogenic fungi produce mycotoxins in maize grain posing a health risk to humans and livestock. Unfortunately, the levels of ear rot and mycotoxin infection in grain produced by subsistence farmers in sub-Saharan countries are not known. A survey was thus conducted to determine the prevalence of the ear rot problem and levels of mycotoxins in maize grain. A total of 114 farmsteads were randomly sampled from 11 districts in Lusaka and southern provinces in Zambia during 2006. Ten randomly picked cobs were examined per farmstead and the ear rot disease incidence and severity were estimated on site. This was followed by the standard seed health testing procedures for fungal isolation in the laboratory. Results indicated that the dominant ear rots were caused by Fusarium and Stenocarpella. Incidence of Fusarium verticillioides ranged from 2 to 21%, whereas that of Stenocarpella maydis reached 37% on ear rot diseased maize grain. In addition, 2-7% F. verticillioides, and 3-18% Aspergillus flavus, respectively, were recovered from seemingly healthy maize grain. The mean rank of fungal species, from highest to lowest, was F. verticillioides, S. maydis, A. flavus, Fusarium graminearum, Aspergillus niger, Penicillium spp., Botrydiplodia spp., and Cladosporium spp. The direct competitive ELISA-test indicated higher levels of fumonisins than aflatoxins in pre-harvest maize grain samples. The concentration of fumonisins from six districts, and aflatoxin from two districts, was 10-fold higher than 2 ppm and far higher than 2 ppb maximum daily intake recommended by the FAO/WHO. The study therefore suggested that subsistence farmers and consumers in this part of Zambia, and maybe also in similar environments in sub-Saharan Africa, might be exposed to dangerous levels of mycotoxins due to the high levels of ear rot infections in maize grain. 2010 Elsevier B.V. All rights

  9. Soft rot erwiniae: from genes to genomes.

    Science.gov (United States)

    Toth, Ian K; Bell, Kenneth S; Holeva, Maria C; Birch, Paul R J

    2003-01-01

    SUMMARY The soft rot erwiniae, Erwinia carotovora ssp. atroseptica (Eca), E. carotovora ssp. carotovora (Ecc) and E. chrysanthemi (Ech) are major bacterial pathogens of potato and other crops world-wide. We currently understand much about how these bacteria attack plants and protect themselves against plant defences. However, the processes underlying the establishment of infection, differences in host range and their ability to survive when not causing disease, largely remain a mystery. This review will focus on our current knowledge of pathogenesis in these organisms and discuss how modern genomic approaches, including complete genome sequencing of Eca and Ech, may open the door to a new understanding of the potential subtlety and complexity of soft rot erwiniae and their interactions with plants. The soft rot erwiniae are members of the Enterobacteriaceae, along with other plant pathogens such as Erwinia amylovora and human pathogens such as Escherichia coli, Salmonella spp. and Yersinia spp. Although the genus name Erwinia is most often used to describe the group, an alternative genus name Pectobacterium was recently proposed for the soft rot species. Ech mainly affects crops and other plants in tropical and subtropical regions and has a wide host range that includes potato and the important model host African violet (Saintpaulia ionantha). Ecc affects crops and other plants in subtropical and temperate regions and has probably the widest host range, which also includes potato. Eca, on the other hand, has a host range limited almost exclusively to potato in temperate regions only. Disease symptoms: Soft rot erwiniae cause general tissue maceration, termed soft rot disease, through the production of plant cell wall degrading enzymes. Environmental factors such as temperature, low oxygen concentration and free water play an essential role in disease development. On potato, and possibly other plants, disease symptoms may differ, e.g. blackleg disease is associated

  10. Antibacterial Effect of Potassium Tetraborate Tetrahydrate against Soft Rot Disease Agent Pectobacterium carotovorum in Tomato

    Directory of Open Access Journals (Sweden)

    Firas A. Ahmed

    2017-09-01

    Full Text Available Soft rot caused by Pectobacterium carotovorum is one of most common bacterial diseases occurring in fruits and vegetables worldwide, yet consumer-acceptable options for post-harvest disease management are still insufficient. We evaluated the effect of potassium tetraborate tetrahydrate (B4K2O7.4H2O (PTB on the growth of P. carotovorum using strain BA17 as a representative of high virulence. Complete inhibition of bacterial growth was achieved by treatment with PTB at 100 mM both at pH 9.2 and after adjustment to pH 7.0. Bactericidal activity was quantified and validated by counting fluorescently labeled live and dead bacterial cells using flow cytometry, and reconfirmed using qPCR with high-affinity photoreactive DNA binding dye propidium monoazide (PMA. The results of flow cytometry, qPCR, and culturing confirmed that bacterial cells were killed following exposure to PTB at 100 mM. Bacterial cell membranes were damaged following a 5-min treatment and extrusion of cytoplasmic material from bacterial cells was observed using electronic transmission microscopy. Soft rot incidence on inoculated tomato fruit was significantly reduced by dipping infected fruits in PTB at 100 mM for 5 min and no lesions developed following a 10-min treatment. PTB does not pose a hazard to human health and is an effective alternative to other bactericides and antibiotics for controlling soft rot disease of tomato caused by P. carotovorum.

  11. Integrated Management of Stem Rot Disease (Sclerotium rolfsii) of Groundnut (Arachis hypogaea L.) Using Rhizobium and Trichoderma harzianum (ITCC - 4572)

    OpenAIRE

    GANESAN, S.; KUPPUSAMY, R. GANESH; SEKAR, R.

    2014-01-01

    Soil-borne plant pathogenic fungi cause heavy crop losses all over the world. With variable climate from region to region, most crops grown in India are susceptible to diseases caused by soil-borne fungal pathogens. Among tropical and subtropical land crops, groundnut (Arachis hypogaea L.) is an important oil seed crop, providing vegetable oil as human food and oil cake meal as animal poultry feed. A large number of diseases attack groundnut plants in India; of these, stem rot (collar rot) ca...

  12. Improvement of resistance to Fusarium root rot through gene ...

    African Journals Online (AJOL)

    Fusarium root rot (FRR), caused by Fusarium solani f.sp. , is one of the most serious root rot diseases of common bean (Phaseolus vulgaris L.) throughout the world. Yield losses of up to 84% have been attributed to the disease. Development and deployment of resistant materials is the most feasible approach to managing ...

  13. Integrated management of foot rot of lentil using biocontrol agents under field condition.

    Science.gov (United States)

    Hannan, M A; Hasan, M M; Hossain, I; Rahman, S M E; Ismail, Alhazmi Mohammed; Oh, Deog-Hwan

    2012-07-01

    The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAUbiofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAUbiofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.

  14. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  15. Roland Weber first part

    DEFF Research Database (Denmark)

    2016-01-01

    The Sooty bloch complex - species identity, infection biology and control options. Rubbery rot and Black summer rot - two new diseases of apple......The Sooty bloch complex - species identity, infection biology and control options. Rubbery rot and Black summer rot - two new diseases of apple...

  16. Evaluation of some garlic (Allium Sativum L.) mutants resistant to white rot disease by RAPD analysis

    International Nuclear Information System (INIS)

    Nabulsi, I.; Al-Safadi, B.; Mir ali, N.; Arabi, M.I.E.

    2002-01-01

    Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic diversity among eight garlic mutants resistant to white rot disease (Sclerotium cepivorum) and two controls. Twelve of 13 synthetic random primers were found to identify polymorphism in amplification products. Mutants characterised with moderate resistance to white rot were closely related to the control using cluster and correlation analyses. On the other hand, highly resistant mutants were quite distant from the control with low correlation coefficients. The banding patterns produced by primer OPB-15 (GGAAGGGTGTT) with highly resistant mutants may be used as genetic markers for early selection of resistant plants. (author)

  17. Pseudomonas cichorii as the causal agent of midrib rot, an emerging disease of greenhouse-grown butterhead lettuce in Flanders.

    Science.gov (United States)

    Cottyn, Bart; Heylen, Kim; Heyrman, Jeroen; Vanhouteghem, Katrien; Pauwelyn, Ellen; Bleyaert, Peter; Van Vaerenbergh, Johan; Höfte, Monica; De Vos, Paul; Maes, Martine

    2009-05-01

    Bacterial midrib rot of greenhouse-grown butterhead lettuce (Lactuca sativa L. var. capitata) is an emerging disease in Flanders (Belgium) and fluorescent pseudomonads are suspected to play an important role in the disease. Isolations from infected lettuces, collected from 14 commercial greenhouses in Flanders, yielded 149 isolates that were characterized polyphasically, which included morphological characteristics, pigmentation, pathogenicity tests by both injection and spraying of lettuce, LOPAT characteristics, FAME analysis, BOX-PCR fingerprinting, 16S rRNA and rpoB gene sequencing, as well as DNA-DNA hybridization. Ninety-eight isolates (66%) exhibited a fluorescent pigmentation and were associated with the genus Pseudomonas. Fifty-five of them induced an HR+ (hypersensitive reaction in tobacco leaves) response. The other 43 fluorescent isolates were most probably saprophytic bacteria and about half of them were able to cause rot on potato tuber slices. BOX-PCR genomic fingerprinting was used to assess the genetic diversity of the Pseudomonas midrib rot isolates. The delineated BOX-PCR patterns matched quite well with Pseudomonas morphotypes defined on the basis of colony appearance and variation in fluorescent pigmentation. 16S rRNA and rpoB gene sequence analyses allowed most of the fluorescent isolates to be allocated to Pseudomonas, and they belonged to either the Pseudomonas fluorescens group, Pseudomonas putida group, or the Pseudomonas cichorii/syringae group. In particular, the isolates allocated to this latter group constituted the vast majority of HR+ isolates and were identified as P. cichorii by DNA-DNA hybridization. They were demonstrated by spray-inoculation tests on greenhouse-grown lettuce to induce the midrib rot disease and could be re-isolated from lesions of inoculated plants. Four HR+ non-fluorescent isolates associated with one sample that showed an atypical midrib rot were identified as Dickeya sp.

  18. Effects of glucose on the Reactive Black 5 (RB5 decolorization by two white rot basidiomycetes

    Directory of Open Access Journals (Sweden)

    Tony Hadibarata

    2011-11-01

    Full Text Available The capacities of glucose in the decolorization process of an azo dye, Reactive Black 5 (RB5, by two white rot basidiomycetes, Pleurotus sp. F019 and Trametes sp. F054 were investigated. The results indicated that the dye degradation by the two fungi was extremely correlated with the presence of glucose in the culture and the process of fungi growth. Decolorization of 200 mg dye/l was increased from 62% and 69% to 100% within 20–25 h with the increase of glucose from 5 to 15 g/l, and the activity of manganese dependent peroxidase (MnP increased by 2–9 fold in this case. Hydrogen peroxide of 0.55 mg/l and 0.43 mg/l were detected in 10 h in Pleurotus sp. F019 and Trametes sp. F054 cultures.

  19. Relevance of the main postharvest handling operations on the development of brown rot disease on stone fruits.

    Science.gov (United States)

    Bernat, Maria; Segarra, Joan; Casals, Carla; Teixidó, Neus; Torres, Rosario; Usall, Josep

    2017-12-01

    Brown rot caused by Monilinia spp. is one of the most important postharvest diseases of stone fruit. The aim of this study was to evaluate the relevance of the main postharvest operations of fruit - hydrocooling, cold room, water dump, sorting and cooling tunnel - in the development of M. laxa on peaches and nectarines artificially infected 48, 24 or 2 h before postharvest operations. Commercial hydrocooling operation reduced incidence to 10% in 'Pp 100' nectarine inoculated 2 and 24 h before this operation; however, in 'Fantasia' nectarine incidence was not reduced, although lesion diameter was decreased in all studied varieties. Hydrocooling operation for 10 min and 40 mg L -1 of sodium hypochlorite reduced brown rot incidence by 50-77% in nectarines inoculated 2 h before operation; however, in peach varieties it was not reduced. Water dump operation showed reduction of incidence on nectarine infected 2 h before immersion for 30 s in clean water at 4 °C and 40 mg L -1 sodium hypochlorite; however, in peach varieties it was not reduced. Cold room, sorting and cooling tunnel operation did not reduce brown rot incidence. From all studied handling operations on stone fruit packing houses, hydrocooling is the most relevant in the development of brown rot disease. Duration of the treatment seems to be more important than chlorine concentration. In addition, hydrocooling and water dump were less relevant in peaches than in nectarines. As a general trend, hydrocooling and water dump reduced incidence on fruit with recent infections (2 or 24 h before operation); however, when infections have been established (48 h before operation) diseases were not reduced. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  20. Basal Root Rot, a new Disease of Teak (Tectona grandis in Malaysia caused by Phellinus noxius

    Directory of Open Access Journals (Sweden)

    Mohd Farid, A.

    2005-01-01

    Full Text Available Basal root rot of teak was first reported from Sabak Bernam, Selangor making this the first report of the disease on teak in Peninsular Malaysia. The fungus found associated with the disease was Phellinus noxious. The disease aggressively killed its host irrespective of the host health status. Bark depression at the root collar which was visible from a distance was the characteristic symptom and the main indicator in identifying the disease in the plantation since above ground symptoms of the canopy could not be differentiated from crowns of healthy trees. However, although above ground symptoms were not easily discernible, the disease was already advanced and the trees mostly beyond treatment; 3.4 % of the trees in the plantation were affected and the disease occurred both on solitary trees and in patches. Below ground, infected trees had rotted root systems, mainly below and around the collar region with brown discolored wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the wood. Pathogenicity tests showed that the fungus produced symptoms similar to those observed in the plantation and killed two year-old teak plants. The disease killed all the inoculated hosts within three months, irrespective of wounded or unwounded treatments.

  1. Crop protection strategies for major diseases of cocoa, coffee and ...

    African Journals Online (AJOL)

    In Nigeria, crop protection measures that are cheap, simple, cost-effective and sustainable are desirable to combat Phytophthora pod rot (black pod) and cocoa swollen shoot virus diseases of cocoa, coffee leaf rust and coffee berry diseases, inflorescence blight disease of cashew in order to make farming profitable and ...

  2. Incidence of root rot diseases of soybean in Multan Pakistan and its management by the use of plant growth promoting rhizobacteria

    International Nuclear Information System (INIS)

    Haq, M.I.; Tahir, M.I.; Mahmood, S.

    2012-01-01

    Eight villages in Multan district were surveyed to record incidence of disease and losses of soybean (Glycine max L.) caused by root rot fungi. The root incidence ranged 10-17% and losses ranged 6.75-15.5%. The evaluation of four PGPR isolates was used in combination with organic amendment for the management of root-rot disease incidence and to reduce the population of root pathogenic fungi and to increase the yield in field. This study demonstrated effective biological control by the PGPR isolates tested, thereby indicating the possibility of application of rhizobacteria for control of soil bor ne diseases of soybean in Pakistan and other countries. (author)

  3. Black pod: diverse pathogens with a global impact on cocoa yield.

    Science.gov (United States)

    Guest, David

    2007-12-01

    ABSTRACT Pathogens of the Straminipile genus Phytophthora cause significant disease losses to global cocoa production. P. megakarya causes significant pod rot and losses due to canker in West Africa, whereas P. capsici and P. citrophthora cause pod rots in Central and South America. The global and highly damaging P. palmivora attacks all parts of the cocoa tree at all stages of the growing cycle. This pathogen causes 20 to 30% pod losses through black pod rot, and kills up to 10% of trees annually through stem cankers. P. palmivora has a complex disease cycle involving several sources of primary inoculum and several modes of dissemination of secondary inoculum. This results in explosive epidemics during favorable environmental conditions. The spread of regional pathogens must be prevented by effective quarantine barriers. Resistance to all these Phytophthora species is typically low in commercial cocoa genotypes. Disease losses can be reduced through integrated management practices that include pruning and shade management, leaf mulching, regular and complete harvesting, sanitation and pod case disposal, appropriate fertilizer application and targeted fungicide use. Packaging these options to improve uptake by smallholders presents a major challenge for the industry.

  4. Biocontrol of charcoal-rot of sorghum by actinomycetes isolated from ...

    African Journals Online (AJOL)

    use

    2011-12-12

    Dec 12, 2011 ... Streptomyces but with different species in BLAST analysis. This study indicates that the selected actinomycetes have the potential for PGP and control of charcoal-rot disease in sorghum. Key words: Antagonistic actinomycetes, biocontrol, charcoal-rot, Macrophomina phaseolina. INTRODUCTION.

  5. De novo transcriptome sequencing of black pepper (Piper nigrum L.) and an analysis of genes involved in phenylpropanoid metabolism in response to Phytophthora capsici.

    Science.gov (United States)

    Hao, Chaoyun; Xia, Zhiqiang; Fan, Rui; Tan, Lehe; Hu, Lisong; Wu, Baoduo; Wu, Huasong

    2016-10-21

    Piper nigrum L., or "black pepper", is an economically important spice crop in tropical regions. Black pepper production is markedly affected by foot rot disease caused by Phytophthora capsici, and genetic improvement of black pepper is essential for combating foot rot diseases. However, little is known about the mechanism of anti- P. capsici in black pepper. The molecular mechanisms underlying foot rot susceptibility were studied by comparing transcriptome analysis between resistant (Piper flaviflorum) and susceptible (Piper nigrum cv. Reyin-1) black pepper species. 116,432 unigenes were acquired from six libraries (three replicates of resistant and susceptible black pepper samples), which were integrated by applying BLAST similarity searches and noted by adopting Kyoto Encyclopaedia of Genes and Gene Ontology (GO) genome orthology identifiers. The reference transcriptome was mapped using two sets of digital gene expression data. Using GO enrichment analysis for the differentially expressed genes, the majority of the genes associated with the phenylpropanoid biosynthesis pathway were identified in P. flaviflorum. In addition, the expression of genes revealed that after susceptible and resistant species were inoculated with P. capsici, the majority of genes incorporated in the phenylpropanoid metabolism pathway were up-regulated in both species. Among various treatments and organs, all the genes were up-regulated to a relatively high degree in resistant species. Phenylalanine ammonia lyase and peroxidase enzyme activity increased in susceptible and resistant species after inoculation with P. capsici, and the resistant species increased faster. The resistant plants retain their vascular structure in lignin revealed by histochemical analysis. Our data provide critical information regarding target genes and a technological basis for future studies of black pepper genetic improvements, including transgenic breeding.

  6. Fengycin produced by Bacillus subtilis 9407 plays a major role in the biocontrol of apple ring rot disease.

    Science.gov (United States)

    Fan, Haiyan; Ru, Jinjiang; Zhang, Yuanyuan; Wang, Qi; Li, Yan

    2017-06-01

    Apple ring rot, caused by Botryosphaeria dothidea, is a serious apple disease in China. Bacillus subtilis 9407 was isolated from healthy apples and showed strong antifungal activity against B. dothidea. To identify the primary antifungal compound of B. subtilis 9407 and determine its role in controlling apple ring rot, a transposon mutant library was constructed using TnYLB-1, and a mutant completely defective in antifungal activity was obtained. The gene inactivated in the antifungal activity mutant had 98.5% similarity to ppsB in B. subtilis subsp. subtilis str. 168, which encodes one of the five synthetases responsible for synthesizing fengycin. A markerless ppsB deletion mutant was constructed. Compared with the wild-type strain, lipopeptide crude extracts from ΔppsB showed almost no inhibition of B. dothidea mycelial growth. Furthermore, fengycin-like lipopeptides (retention factor 0.1-0.2) that exhibited antifungal activity against B. dothidea were observed in the wild-type strain by thin-layer chromatography (TLC)-bioautography analysis, but not in ΔppsB. Semipreparative reverse-phase high performance liquid chromatography (RP-HPLC) detection revealed that ΔppsB lost the ability to synthesize fengycin. These results suggest that ppsB is responsible for synthesizing fengycin and that fengycin is the major antifungal compound produced by B. subtilis 9407 against B. dothidea. Moreover, a biocontrol assay showed that the control efficacy of ΔppsB was reduced by half compared with the wild-type strain, indicating that fengycin plays a major role in controlling apple ring rot disease. This is the first report on the use of a B. subtilis strain as a potential biological control agent to control apple ring rot disease by the production of fengycin. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Rhizoctonia crown and root rot disease nursery

    Science.gov (United States)

    The BSDF cooperative CRR Eastern Evaluation Nursery Rhizoctonia crown and root rot Evaluation Nursery in 2016 was a randomized complete-block design with five replications in 15 feet long, one-row plots (20 in row spacing), at the Saginaw Valley Research and Education Center near Frankenmuth, MI. F...

  8. Root rot diseases of sugarbeet (Beta vulgaris L as affected by defloliation intensity

    Directory of Open Access Journals (Sweden)

    Karadimos Dimitros A.

    2006-01-01

    Full Text Available The aim of this work was to study the effect of sugar beet re-growth after water stress defoliation on root rots of three cultivars (Europa, Rival Corsica, which were spring sown in Thessaly, central Greece, for two growing seasons (2003-04. At the beginning of July, sugar beets were subjected to water deficit with irrigation withholding. A month later, three defoliation levels (control - C, moderate - MD, severe - SD and irrigation were applied. Thus, sugar beets were forced to re-grow and three harvests (15, 30 and 40 days after defoliation - DAD were conducted. Rotted roots per hectare were counted and pathogens were identified. Data were analyzed as a four-factor randomized complete block design with years, defoliation levels, sampling times and cultivars as main factors. The number of rotted roots was increased with the defoliation level and was significantly higher for SD sugar beets (3748 roots ha–1. No significant differences were found between C and MD treatments (1543 and 2116 roots ha–1, respectively. Rival was the most susceptible cultivar to root rots. Sugar beets were more susceptible to rotting 15 and 40 DAD (2778 and 2998 roots ha–1. The causal agents of root rots were the fungi, Fusarium spp., Rhizopus stolonifer, Macrophomina phaseolina and Rhizoctonia solani.

  9. Integrated Management of Damping-off, Root and/or Stem Rot Diseases of Chickpea and Efficacy of the Suggested Formula

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2011-08-01

    Full Text Available Eleven fungal isolates were isolated from naturally infected chickpea roots collected from different locations in New Valley Governorate (Egypt. The isolated fungi were purified and identified as Rhizoctonia solani (5 isolates, Fusarium solani (4 isolates and Sclerotinia sclerotiorum (2 isolates. The isolated fungi proved their pathogenicity on cv. Giza 3. Response of chickpea cvs. Giza 1, Giza 2, Giza 3, Giza 4, Giza 88, Giza 195, Giza 531 to infection by the tested fungi was significantly varied. Giza 1 was the most resistant one followed by Giza 531, while the other tested cvs. were highly susceptible. Seven biocontrol agents, namely Bacillus subtilis, B. megaterium, B. cereus, Trichoderma viride, T. harzianum, Aspergillus sp., Penicillium sp. isolated from chickpea rhizosphere, were tested for their antagonistic action against the tested pathogens. B. subtilis isolate BSM1, B. megaterium isolate TVM5, T. viride isolate TVM2 and T. harzianum isolate THM4 were the most antagonistic ones to the tested fungi in vitro, while the other isolates were moderate or weak antagonists. The most antagonistic isolates as well as the commercial biocide Rhizo-N were applied as seed treatment for controlling damping-off, root and/or stem rot diseases caused by the tested fungi under greenhouse conditions. The obtained data showed that all tested antagonistic isolates were able to cause significant reduction of damping-off, root and/or stem rot diseases in chickpea plants. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 proved to be the most effective isolates for controlling the diseases. Under field condition, the obtained data indicated that all the tested antagonistic isolates significantly reduced damping-off, root and/or stem rot. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 recorded the highest reduction of damping-off, root and/or stem rot in all sowing dates. Sowing of treated seeds with bioagents in first of November gave the

  10. Distribution and prevalence of crown rot pathogens affecting wheat crops in southern Chile

    Directory of Open Access Journals (Sweden)

    Ernesto Moya-Elizondo

    2015-03-01

    Full Text Available Crown rot pathogens are associated with higher losses for wheat crop farmers, but information about the distribution and prevalence of these pathogens in Chile is inadequate. Distribution and prevalence of wheat (Triticum aestivum L. crown rot pathogens were examined in a survey of 48 commercial fields from December 2011 to February 2012 in southern Chile. These fields were located between Collipulli (37°56'00" S; 72°26'39" W and Purranque (40°50'30" S; 73°22'03" W. Severity of crown rot disease was determined through visual assessment of the first internode of 20 tillers obtained from each field. Incidence of crown rot pathogens per field was determined by plating the 20 tillers on Petri plates with 20% potato dextrose agar amended with lactic acid (aPDA medium. Resulting fungal colonies from monoxenic culture were identified by morphological or molecular-assisted identification. Severity of crown rot varied between 11.3% and 80% for individual fields. Culture plate analysis showed 72.2% of stems were infected with some fungus. Fusarium avenaceum, F. graminearum, and F. culmorum, pathogens associated with Fusarium crown rot disease were isolated from 13.5% of tillers. Gaeumannomyces graminis, causal agent of take-all disease in cereals, was isolated from 11.1% of culms. Phaeosphaeria sp., an endophyte and possibly a non-pathogenic fungus, was isolated from 13.9% of tillers. Pathogenic fungi such as Rhizoctonia spp. and Microdochium nivale, other saprophyte, and several unidentified non-sporulating fungi were isolated at frequencies lower than 3% of the total. Fusarium crown rot and take-all were the most prevalent and distributed crown rot diseases present in wheat crops in southern Chile.

  11. Rhizopus Soft Rot on Lily Caused by Rhizopus oryzae in Korea

    Directory of Open Access Journals (Sweden)

    Soo-Sang Hahm

    2014-03-01

    Full Text Available Rhizopus soft rot of lily (Lilium longiflorum caused by Rhizopus oryzae was observed in the experimental field in Taean Lily Experiment Station in Korea, 2012. The typical symptoms were water-soaked lesions on bottom stem and leaf rot. The lesion rapidly expanded and the plant was softened totally. The fungus grew vigorously at an optimum temperature (25oC and brownish colony and black sporangia were formed on potato dextrose agar medium. Sporangiophores formed on end of sporangia were sub-globose, brownish and 6-10 μm in size. Sporangia were globose, blackish and 87-116 μm in size. Sporangiospores were irregularly oval and sub-globose, brownish 4-8 μm in size. On the basis of mycological characteristics, analyzing sequences of internal transcribed spacer region of ribosomal DNA, and pathogenicity test on host plants, the causal fungus was identified as R. oryzae. This is the first report of Rhizopus soft rot on lily caused by R. oryzae in Korea.

  12. Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici.

    Science.gov (United States)

    Aravind, R; Kumar, A; Eapen, S J; Ramana, K V

    2009-01-01

    To isolate and identify black pepper (Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease. Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici. Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in greenhouse trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa (Pseudomonas EF568931), IISRBP 25 as P. putida (Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium (B. megaterium EU071712) based on 16S rDNA sequencing. Black pepper associated P. aeruginosa, P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper. This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.

  13. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt

    OpenAIRE

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated wit...

  14. MANAGEMENT OF ROOT ROT IN AVOCADO TREES

    Directory of Open Access Journals (Sweden)

    SIMONE RODRIGUES DA SILVA

    Full Text Available ABSTRACT Root rot (Phytophthora cinnamomi Rands is one of the most restrictive factors to avocado growing in main producing regions worldwide. In Brazil, scientific reports on the effectiveness of control methods are scarce. The objective of this study was to evaluate the efficiency of gypsum applications and dolomitic limestone to the soil and potassium phosphite sprays in controlling this disease in ‘Hass’ avocado, grown without irrigation. The application of dolomitic limestone or gypsum alone is not effective to recover plants affected by root rot. The application of potassium phosphite, combined or not with dolomitic lime or gypsum enables the partial recovery ‘Hass’ avocado plants affected by the disease.

  15. Resistance to post-harvest microbial rot in yam: Integration of ...

    African Journals Online (AJOL)

    Post-harvest microbial rot is an important disease that causes severe losses in yam (Dioscorea spp.) storage. Rot from microbial infection of healthy yam tubers reduces their table quality and renders them unappealing to consumers. A study was carried out at Bimbilla in the Nanumba North District of Ghana to evaluate ...

  16. Assessment of Sugarcane Germplasm ( Saccharum spp. complex Against Red Rot Pathogen Colletotrichum Falcatum

    Directory of Open Access Journals (Sweden)

    Atul Singh

    2017-08-01

    Full Text Available ABSTRACT Red rot, caused by Colletotrichum falcatum Went is the most important disease of sugarcane in India inflicting substantial loss to both cane industry and cane growers. To keep in view the importance of red rot disease of sugarcane, 117 accession of sugarcane germplasm including different Saccharum species and Indian and foreign commercial hybrids were tested against red rot with Cf 07, Cf 08 & Cf 09 (national pathotypes by plug method of inoculation. Out of 117, 6 were found resistant and 12 were moderately resistant against red rot and rest were moderately susceptible/susceptible/highly susceptible. Theses resistance and moderately resistant accession can be further utilize to produce resistance varieties against the most devastating pathogen of sugarcane.

  17. Spatial Heterogeneity of SOM Concentrations Associated with White-rot Versus Brown-rot Wood Decay.

    Science.gov (United States)

    Bai, Zhen; Ma, Qiang; Dai, Yucheng; Yuan, Haisheng; Ye, Ji; Yu, Wantai

    2017-10-23

    White- and brown-rot fungal decay via distinct pathways imparts characteristic molecular imprints on decomposing wood. However, the effect that a specific wood-rotting type of fungus has on proximal soil organic matter (SOM) accumulation remains unexplored. We investigated the potential influence of white- and brown-rot fungi-decayed Abies nephrolepis logs on forest SOM stocks (i.e., soil total carbon (C) and nitrogen (N)) and the concentrations of amino sugars (microbial necromass) at different depths and horizontal distances from decaying woody debris. The brown-rot fungal wood decay resulted in higher concentrations of soil C and N and a greater increase in microbial necromass (i.e., 1.3- to 1.7-fold greater) than the white-rot fungal wood decay. The white-rot sets were accompanied by significant differences in the proportions of the bacterial residue index (muramic acid%) with soil depth; however, the brown-rot-associated soils showed complementary shifts, primarily in fungal necromass, across horizontal distances. Soil C and N concentrations were significantly correlated with fungal rather than bacterial necromass in the brown-rot systems. Our findings confirmed that the brown-rot fungi-dominated degradation of lignocellulosic residues resulted in a greater SOM buildup than the white-rot fungi-dominated degradation.

  18. Stem rots of oil palm caused by Ganoderma boninense: pathogen biology and epidemiology.

    Science.gov (United States)

    Pilotti, C A

    2005-01-01

    Oil palm (Elaeis guineensis Jacq.) has been grown in Papua New Guinea since the early 1960s. The most important disease of oil palm in PNG is a stem rot of the palm base. This is the same disease that constitutes a major threat to sustainable oil palm production in SE Asia. Investigations into the causal pathogen have revealed that the stem rots in PNG are caused predominantly by the basidiomycete Ganoderma boninense, with a minor pathogen identified as G. tornatum G. tornatum was found to have a broad host range whereas G. boninense appears to be restricted to palms. The population structure of G. boninense was investigated using inter-fertility studies between isolates collected from basal stem rots on oil palm. Although the G. boninense field populations are predominantly comprised of distinct individuals, a number of isolates were found that share single mating alleles. This indicates that out-crossing had occurred over several generations in the resident or wild population of G. boninense prior to colonization of oil palm. No direct hereditary relationship between isolates on neighbouring diseased palms was found, although an indirect link between isolates causing upper stem rot and basal stem rot was detected.

  19. Avaliação da atividade de indutores de resistência abiótica, fungicida químico e extratos vegetais no controle da podridão-negra em Abacaxi 'Pérola' Activity evaluation of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple, cv. pérola

    Directory of Open Access Journals (Sweden)

    Mônica Danielly de Mello Oliveira

    2009-03-01

    probabilidade. O tratamento que apresentou melhor resultado foi o indutor de resistência Ecolife®, aumentando o período de vida útil dos frutos e diminuindo a severidade dos sintomas da doença.Black rot of pineapple, caused by Chalara paradoxa (De Seyn. Sacc., is a postharvest disease responsible by high losses on fruits destined to the fresh market and to the processing industry. Penetration of fungus inside cells occurs through wounds and stem cutting, causing infection. The objective of this work was to evaluate the effect of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple control. 32 fruits of pineapple cv pérola were used. They were disinfested with sodium hypochlorite (commercial product at 4% for 5 minutes. After drying at room temperature, fruits were treated, by spraying, with: 1 Distilled water (control, 2 Derosal 3 Bion® (Acibenzolar-S-methyl; 4 Ecolife®; 5 Agro-Mos®; 6 Allium sativum extract at 20%; 7 A. cepa at 20% and 8 Azadirachta indica at 20%. Treated fruits were incubated on humid chamber with polyethylene bags during 24 hours before inoculation procedure using a mycelia disk added to a wound at the epidermic area of the fruit. Evaluation of disease progress was done by a disease index: 1- no symptoms, 2- black rot on epidermis reaching 1-5 simple fruits, 3- black rot on epidermis reaching 6-10 simple fruits, 4- internal brown yellow rot, 5- black rot and disintegration of internal area in more than 50%. The experimental design was a completely randomized with eight treatments and five replicates, using general linear models with multinomial distribution and the averages were compared by Scott-Knott test at 5%. The best results were found in the Ecolife treatment with longer fruit life span and less severity in the symptoms of the disease.

  20. Pathological and rhizospherical studies on root-rot disease of ...

    African Journals Online (AJOL)

    AJB SERVER

    2007-02-05

    Feb 5, 2007 ... Rhizoctonia solani root-rot aggressive pathogens to squash on media containing culture of Trichoderma ..... The bacteriology of root region of cat ... (2004): Comparison of the behavior of a transformed hygromycin resistant ...

  1. Potential of bulb-associated bacteria for biocontrol of hyacinth soft rot caused by Dickeya zeae

    NARCIS (Netherlands)

    Jafra, S.; Przysowa, J.; Gwizdek-Wisniewska, A.; Wolf, van der J.M.

    2009-01-01

    Dickeya zeae is a pectinolytic bacterium responsible for soft rot disease in flower bulb crops. In this study, the possibility of controlling soft rot disease in hyacinth by using antagonistic bacteria isolated from hyacinth bulbs was explored. Bacterial isolates with potential for biocontrol were

  2. Grapevine bunch rots: impacts on wine composition, quality, and potential procedures for the removal of wine faults.

    Science.gov (United States)

    Steel, Christopher C; Blackman, John W; Schmidtke, Leigh M

    2013-06-05

    Bunch rot of grape berries causes economic loss to grape and wine production worldwide. The organisms responsible are largely filamentous fungi, the most common of these being Botrytis cinerea (gray mold); however, there are a range of other fungi responsible for the rotting of grapes such as Aspergillus spp., Penicillium spp., and fungi found in subtropical climates (e.g., Colletotrichum spp. (ripe rot) and Greeneria uvicola (bitter rot)). A further group more commonly associated with diseases of the vegetative tissues of the vine can also infect grape berries (e.g., Botryosphaeriaceae, Phomopsis viticola ). The impact these fungi have on wine quality is poorly understood as are remedial practices in the winery to minimize wine faults. Compounds found in bunch rot affected grapes and wine are typically described as having mushroom, earthy odors and include geosmin, 2-methylisoborneol, 1-octen-3-ol, 2-octen-1-ol, fenchol, and fenchone. This review examines the current state of knowledge about bunch rot of grapes and how this plant disease complex affects wine chemistry. Current wine industry practices to minimize wine faults and gaps in our understanding of how grape bunch rot diseases affect wine production and quality are also identified.

  3. Kwoseh et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    Black mould, blue mould, soft rot, neck rot and basal plate rot were the major storage rots iden- tified in a dry .... holes made in healthy bulbs. Observation for ... Aspergillus flavus. 9.0. Penicillium sp. 27.0. Rhizopus stolonifer. 14.5. Fusarium oxysporum. 14.5. Market. Post-harvest disease incidence (%). Black mould. Dry Wet.

  4. Black lung: the social production of disease.

    Science.gov (United States)

    Smith, B E

    1981-01-01

    The black lung movement that erupted in West Virginia in 1968 was not simply a struggle for recognition of an occupational disease; it grew into a bitter controversy over who would control the definition of that disease. This article examines the historical background and medical politics of that controversy, arguing that black lung was socially produced and defined on several different levels. As a medical construct, the changing definitions of this disease can be traced to major shifts in the political economy of the coal industry. As an occupational disease, the history of black lung is internally related to the history of the workplace in which it is produced. As the object of a mass movement, black lung acquired a political definition that grew out of the collective experience of miners and their families. The definition of disease with which black lung activists challenged the medical establishment has historical roots and justification; their experience suggests that other health advocates may need to redefine the diseases they hope to eradicate.

  5. First report of Fusarium proliferatum causing dry rot in Michigan commercial potato (Solanum tuberosum) production

    Science.gov (United States)

    Fusarium dry rot of potato is a postharvest disease caused by several Fusarium spp. and is of worldwide importance. Thirteen Fusarium spp. have been implicated in fungal dry rots of potatoes worldwide. Among them, 11 species have been reported causing potato dry rot of seed tubers in the northern Un...

  6. Soil Nutrient Condition of Coffee Cultivation with Industrial Woody-crops

    Directory of Open Access Journals (Sweden)

    Rudy Erwiyo

    2008-05-01

    Full Text Available Black pod rot disease (BPRD which is caused by Phytophthora palmivora is one of the main diseases of cocoa cultivations particularly in plantations with wet climate. Black pod rot can develop rapidly under high humidity environments, particularly during rainy seasons. This disease can cause loss of harvest of up to 46.63% in East Java. The various control efforts attempted so far have not resulted in significant improvements. Urea, in addition to functioning as fertilizer, can also produce the ammonia gas which is believed to be able to suppress black pod rot. This research aims to determine the effectiveness of black pod rot control using the combination of lime and urea. This research was conducted from June to September 2013. The materials used in test included sterile soil, black pod rot infected cocoa, urea, and agricultural lime. Observation results showed that ammonia could form from urea. Lime can increase the speed of the formation. The ammonia gas forming from 0.06% urea and 0.3% lime can control the P. palmivora fungus inside the soil. Key words: Pod rot, P. palmivora, urea, lime, ammonia

  7. Performance and suggested alternative strategies in developing Indonesian cocoa export business

    Directory of Open Access Journals (Sweden)

    Bambang Dradjat

    2010-12-01

    Full Text Available Black pod rot disease (BPRD which is caused by Phytophthora palmivora is one of the main diseases of cocoa cultivations particularly in plantations with wet climate. Black pod rot can develop rapidly under high humidity environments, particularly during rainy seasons. This disease can cause loss of harvest of up to 46.63% in East Java. The various control efforts attempted so far have not resulted in significant improvements. Urea, in addition to functioning as fertilizer, can also produce the ammonia gas which is believed to be able to suppress black pod rot. This research aims to determine the effectiveness of black pod rot control using the combination of lime and urea. This research was conducted from June to September 2013. The materials used in test included sterile soil, black pod rot infected cocoa, urea, and agricultural lime. Observation results showed that ammonia could form from urea. Lime can increase the speed of the formation. The ammonia gas forming from 0.06% urea and 0.3% lime can control the P. palmivora fungus inside the soil. Key words: Pod rot, P. palmivora, urea, lime, ammonia

  8. to Cocoa Pod Borer Infestation in Central Sulawesi

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Soesilo

    2009-12-01

    Full Text Available Black pod rot disease (BPRD which is caused by Phytophthora palmivora is one of the main diseases of cocoa cultivations particularly in plantations with wet climate. Black pod rot can develop rapidly under high humidity environments, particularly during rainy seasons. This disease can cause loss of harvest of up to 46.63% in East Java. The various control efforts attempted so far have not resulted in significant improvements. Urea, in addition to functioning as fertilizer, can also produce the ammonia gas which is believed to be able to suppress black pod rot. This research aims to determine the effectiveness of black pod rot control using the combination of lime and urea. This research was conducted from June to September 2013. The materials used in test included sterile soil, black pod rot infected cocoa, urea, and agricultural lime. Observation results showed that ammonia could form from urea. Lime can increase the speed of the formation. The ammonia gas forming from 0.06% urea and 0.3% lime can control the P. palmivora fungus inside the soil. Key words: Pod rot, P. palmivora, urea, lime, ammonia

  9. Application of lime and urea and its effect on development of Phythophthora palmivora.

    Directory of Open Access Journals (Sweden)

    Sakti Widyanta Pratama

    2015-03-01

    Full Text Available Black pod rot disease (BPRD which is caused by Phytophthora palmivora is one of the main diseases of cocoa cultivations particularly in plantations with wet climate. Black pod rot can develop rapidly under high humidity environments, particularly during rainy seasons. This disease can cause loss of harvest of up to 46.63% in East Java. The various control efforts attempted so far have not resulted in significant improvements. Urea, in addition to functioning as fertilizer, can also produce the ammonia gas which is believed to be able to suppress black pod rot. This research aims to determine the effectiveness of black pod rot control using the combination of lime and urea. This research was conducted from June to September 2013. The materials used in test included sterile soil, black pod rot infected cocoa, urea, and agricultural lime. Observation results showed that ammonia could form from urea. Lime can increase the speed of the formation. The ammonia gas forming from 0.06% urea and 0.3% lime can control the P. palmivora fungus inside the soil. Key words: Pod rot, P. palmivora, urea, lime, ammonia

  10. Rhizoctonia root rot (Rhizoctoni solani K ü h n of sugar beet in province Vojvodina

    Directory of Open Access Journals (Sweden)

    Stojšin Vera B.

    2006-01-01

    Full Text Available Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Bačka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die.

  11. Detecting cotton boll rot with an electronic nose

    Science.gov (United States)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  12. Studies on the epidemiology of spear rot in oil palm (Elaeis guineensis Jacq.) in Suriname

    NARCIS (Netherlands)

    Lande, van de H.L.

    1993-01-01

    The epidemiology of spear rot, an infectious disease of unknown etiology, was studied over 10 years at three government-owned oil palm plantations in Suriname. As with other and similar diseases, amarelecimento fatal in Brazil and pudrición del cogollo in Latin America, which too show rot

  13. Botanicals to Control Soft Rot Bacteria of Potato

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available Extracts from eleven different plant species such as jute (Corchorus capsularis L., cheerota (Swertia chiraita Ham., chatim (Alstonia scholaris L., mander (Erythrina variegata, bael (Aegle marmelos L., marigold (Tagetes erecta, onion (Allium cepa, garlic (Allium sativum L., neem (Azadiracta indica, lime (Citrus aurantifolia, and turmeric (Curcuma longa L. were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments.

  14. Management of Potato Soft Rot by Gamma Irradiation

    International Nuclear Information System (INIS)

    Abd El-Ghany, H.; Moussa, Z.; Abd El-Rahman, A.F.; Salem, E.A.

    2017-01-01

    This investigation aims to apply a safe practice to minimize potato losses due to soft rot disease of tubers kept under ambient temperature. In this regard, gamma irradiation was used to extend keeping quality through its effect on soft rot bacteria. Eight bacterial isolates were recovered on Logan’s medium from kitchen kept tubers with symptoms of soft rot disease. Five isolates were found pathogenic and tentatively identified as Pectobacterium atrosepticum and Pectobacterium carotovorum sub sp. brasiliense on the basis of the usual bacteriological methods. A molecular method using 16SrDNA sequence analysis for verification of the identity of two isolates was made. The two bacterial isolates, Pectobacterium atrosepticum and Pectobacterium carotovorum sub sp. brasiliense, were irradiated by different doses of gamma rays. Complete inhibition occurred at doses 2.5 and 2.0 KGy for high densities (Approximately 4.0x10"9 CFU/ml) of P. atrosepticum and P. carotovorum sub sp. brasiliense, respectively. The D10 value of gamma irradiation was 0.24 KGy for P. atrosepticum and 0.20 KGy for P. carotovorum subsp. brasiliense. Irradiation of artificially infected tubers with soft rot bacteria using the two mentioned D10 doses for the two bacterial species increased the shelf life of tubers kept under ambient temperature. The internal chemical quality of tubers was shown to be improved by keeping the tubers under ambient temperature after irradiation by the two D10 doses 0.24 and 0.20 KGy

  15. Cacao diseases-the trilogy revisited.

    Science.gov (United States)

    Evans, Harry C

    2007-12-01

    ABSTRACT This paper reviews the significant advances by the diseases themselves, as well as by the scientists, in the intervening period since the disease trilogy was first delimited in 1989. The impact of these diseases, black pod, witches' broom, and frosty pod rot, has increased dramatically. In addition, there have been radical changes in the taxonomic profiles of these pathogens, which have been based on both traditional (morphological, cytological) and modern (molecular) approaches. Black pod is caused by a complex of Phytophthora species, in which P. palmivora still is the most important worldwide. However, recent invasion of the principal cacao-growing countries of West Africa by the more virulent P. megakarya has been cause for concern. The latter evolved in the ancient forests straddling the Cameroon-Nigerian border as a primary coloniser of fallen fruit. Conversely, frosty pod rot, caused by Moniliophthora roreri, and witches' broom, caused by M. (Crinipellis) perniciosa, both neotropical diseases, are hemibiotrophic, coevolved pathogens. Respectively, M. roreri arose on Theobroma gileri in submontane forests on the north-western slopes of the Andes, whereas M. perniciosa developed as a complex of pathotypes with a considerably wider geographic and host range within South America; the cacao pathotype evolved on that host in the Amazon basin. The inter-relationships of these vicariant species and their recent spread are discussed, together with control strategies.

  16. First Report of Calonectria hongkongensis Causing Fruit Rot of Rambutan (Nephelium lappaceum)

    NARCIS (Netherlands)

    Serrato-Diaz, L.M.; Latoni-Brailowsky, E.I.; Rivera-Vargas, L.I.; Goenaga, R.J.; Crous, P.W.; French-Monar, R.D.

    2013-01-01

    Fruit rot of rambutan is a pre- and post-harvest disease problem of rambutan orchards. In 2011, fruit rot was observed at USDA-ARS orchards in Mayaguez, Puerto Rico. Infected fruit were collected and 1 mm2 tissue sections were surface disinfested with 70% ethanol followed by 0.5% sodium

  17. Fusarium spp. causing dry rot of seed potato tubers in Michigan and their sensitivity to fungicides

    Science.gov (United States)

    Fusarium dry rot of potato (Solanum tuberosum L.) is a postharvest disease that can be caused by several Fusarium spp. A survey was conducted to establish the composition of Fusarium species causing dry rot of seed tubers in Michigan. A total of 370 dry rot symptomatic tubers were collected in 2009 ...

  18. Improvement of garlic resistance to white rot disease and its productivity and storability using gamma radiation

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Mir Ali, N.; Arabi, M.I.D.

    1999-01-01

    A mutation program was conducted to improve garlic (Allium sativum) resistance to white rot (Sclerotium cepivorum) and to improve its storability under natural conditions. Cloves of two local garlic cultivars (Kisswany and Yabroudy) were irradiated with gamma ray doses 4, 5, 6 and 7 gray. The cloves were then planted in the the field and plants were advanced for 4 generations in order to isolate mutations in stable form. The results indicated that the cultivar Yabroudy was more sensitive to gamma irradiation than Kisswany. Rate of morphological mutants increased with increasing gamma ray dosage. Selection pressure against white rot disease was applied starting in the second generation by adding infected garlic leaves to the soil. In the third and fourth generations, however, full selection pressure was applied by inoculating the cloves with the fungus sclerotic and planting them in a soil previously planted with infected garlic plants. Healthy garlic bulbs were harvested and stored under natural conditions and then planted to obtain the next generation. By the end of the fourth generation, we have been able to improve garlic resistance to white rot disease and its storability. Twenty four mutant lines from each garlic cultivar have been selected. Out of the selected lines, twelve lines from cultivar Kisswany had only 3% infection percentage as compared to 29% in the control, and twelve lines from cultivar Yabroudy had less than 5% infection percentage as compared to 20% in the control. Also, we have been able to improve storability under natural conditions. Weight loss during storage decreased from 8.25% in the control to only 4% in some Kisswany lines and from 10% to 3% in some Yabroudy lines. However, we have not been able to increase the bulb weight over the control but the weights of the selected lines were comparable to those of the control. (authors)

  19. Improvement of garlic resistance to white rot disease and its productivity and storability using gamma radiation

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Mir Ali, N.; Arabi, M. I. D.

    1998-12-01

    A mutation program was conducted to improve garlic (Allium sativum) resistance to white rot (Sclerotium cepivorum) and to improve its storability under natural conditions. Cloves of two local garlic cultivars (Kisswany and Yabroudy) were irradiated with gamma ray doses 4, 5, 6, and 7 gray. The cloves were then planted in the field and plants were advanced for 4 generations in order to isolate mutations in stable form. The results indicated that the cultivar Yabroudy was more sensitive to gamma irradiation than Kisswany. Rate of morphological mutants increased with increasing gamma ray dosage. Selection pressure against white rot disease was applied starting in the second generation by adding infected garlic leaves to the soil. In the third and fourth generations, however, full selection pressure was applied by inoculating the cloves with the fungus sclerotia and planting them in a soil previously planted with infected garlic plants. healthy garlic bulbs were harvested and stored under natural conditions and then planted to obtain the next generation. By the end of the fourth generation, we have been able to improve garlic resistance to white rot disease and its storability. Twenty four mutant lines from each garlic cultivar have been selected. Out of the selected lines, twelve lines from cultivar Kisswany had only 3% infection percentage as compared to 29% in the control, and twelve lines from cultivar Yabroudy had less than 5% infection percentage as compared to 20% in the control. Also, we have been able to improve storability under natural conditions. Weight loss during storage decreased from 8.25% in the control to only 4% in some Kisswany lines and from 10% to 3% in some Yabroudy lines. However, we have not been able to increase the bulb weight over the control but the weights of the selected lines were comparable to those of the control. (author)

  20. Impact of management strategies in the basal rot, charcoal rots epidemiology and Phaseolus vulgaris L. yield.

    Directory of Open Access Journals (Sweden)

    Ulacio Osorio Dilcia

    2013-02-01

    Full Text Available The effect of chemical, physical, biologycal and cultural strategies individually or combinated were evaluated in the epidemiology of the basal rot (Sclerotium rolfsii, charcoal rot (Macrophomina phaseolina and the Phaseolus vulgaris cv Tacarigua yield at Barinas state from Venezuela. In the experiment, Tebuconazole (Teb was applicated at seed (1 L/Ton and at soil, a los 30 y 60 days after of the sow (1 L/ha; Trichoderma harzianum (Tri was applicated at seed (15 g for each 1.5 k and to 15, 30, 45 y 60 days after of the sow (30 g/10 L of water. On the other hand, soil was solarizated (Sol during 15 days and calcium nitrate (Ca (60 g/10 L of water was applicated each 15 days until 60 days of growth of cultivated plants. Basal rot was registered as far as 42 days after of the sow, showing less of 5.3% in Teb y the combination SolTeb. The hightest incidence of this disease was observed in the treatment Tri with 28.5%, being highter that control (14.5%. Last to 42 days predominated the charcoal rot in the rest of the plants for a total of 100% of incidente in everything the treatments. Nevertheless, Teb showed the hightest yield with 555 k/ha, being different estatistically at treatment TriCa, which showed the lowest yield with 31 k/ha, however, the roots not formed nodules nitrogen uptake in these replications with the fungicide and Ca. It is concluded that S. rolfsii was sensible at action of some of the treatments; but not M. phaseolina; nevertheless, the plants were capables to produce seeds health apparently in treatments in which observed less severity of charcoal rot.

  1. First report of in-vitro fludioxonil-resistant isolates of Fusarium spp. causing potato dry rot in Michigan

    Science.gov (United States)

    Fusarium dry rot of potato (Solanum tuberosum) is a postharvest disease caused by several Fusarium species and is of worldwide importance. Measures for controlling dry rot in storage are limited. Dry rot has been managed primarily by reducing tuber bruising, providing conditions for rapid wound heal...

  2. Effects of Fungicides, Essential Oils and Gamma Irradiated Bioagents on Chickpea Root Rot Caused by Sclerotium rolfsii

    International Nuclear Information System (INIS)

    El-Batal, A.I.; Fathy, R.M.; Ismail, A.A.; Mubark, H.M.; Mahmoud, Y.A.

    2011-01-01

    Sclerotium rolfsii (S. rolfsii) causes root rot disease in several crops including Cicer arietinum (chickpea) that results in low yield. In vitro experiments on fungicides, vitavax and monceren T, and essential oils, clove and mint oils, were conducted to control root rot disease of chickpea caused by S. rolfsii. The treatments resulted in 80 % suppression of root rot disease. Gliocladium virens (G. virens) and Gliocladium deliquescens (G. deliquescens) were effective as biocontrol agents against S. rolfsii. The results showed that these treatments greatly reduced the root rot disease in chickpea. In this study, the effect of gamma irradiation at doses 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy on the pathogenecity of G. virens and G. deliquescens against S. rolfsii were investigated. The results revealed that gamma irradiation increased the pathogenecity of G. virens and G. deliquescens against S. rolfsii

  3. Genetic analysis of partial resistance to basal stem rot (Sclerotinia sclerotiorum in sunflower

    Directory of Open Access Journals (Sweden)

    Amouzadeh Masoumeh

    2013-01-01

    Full Text Available Basal stem rot, caused by Sclerotinia sclerotiorum (Lib. de Bary, is one of the major diseases of sunflower (Helianthus annuus L. in the world. Quantitative trait loci (QTLs implicated in partial resistance to basal stem rot disease were identified using 99 recombinant inbred lines (RILs from the cross between sunflower parental lines PAC2 and RHA266. The study was undertaken in a completely randomized design with three replications under controlled conditions. The RILs and their parental lines were inoculated with a moderately aggressive isolate of S. sclerotiorum (SSKH41. Resistance to disease was evaluated by measuring the percentage of necrosis area three days after inoculation. QTLs were mapped using an updated high-density SSR and SNP linkage map. ANOVA showed significant differences among sunflower lines for resistance to basal stem rot (P≤0.05. The frequency distribution of lines for susceptibility to disease showed a continuous pattern. Composite interval mapping analysis revealed 5 QTLs for percentage of necrotic area, localized on linkage groups 1, 3, 8, 10 and 17. The sign of additive effect was positive in 5 QTLs, suggesting that the additive allele for partial resistance to basal stem rot came from the paternal line (RHA266. The phenotypic variance explained by QTLs (R2 ranged from 0.5 to 3.16%. Identified genes (HUCL02246_1, GST and POD, and SSR markers (ORS338, and SSL3 encompassing the QTLs for partial resistance to basal stem rot could be good candidates for marker assisted selection.

  4. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  5. Improving cost-effectiveness of brown rot control: the value of bio-economic modelling

    NARCIS (Netherlands)

    Breukers, A.; Werf, van der W.; Mourits, M.C.M.; Oude Lansink, A.G.J.M.

    2007-01-01

    Since 1995, the Dutch potato production chain has been hit by several outbreaks of brown rot, a quarantine disease caused by Ralstonia solanacearum race 3, biovar 2. To avoid establishment of brown rot in the potato production chain and avert the consequences on potato export, the Dutch government

  6. Pathogenicity and genetic diversity of Fusarium oxysporum causing soybean root rot in northeast China

    Science.gov (United States)

    Soybean is an important edible legume cultivated around the world. However, soybean production is seriously impacted by the widespread occurrence of root rot disease. In this study, genetic diversity and pathogenicity of Fusarium oxysporum associated with root rot of soybean in Heilongjiang province...

  7. First report of Colletotrichum fructicola and C. queenslandicum causing fruit rot of rambutan (Nephelium lappaceum L.)

    Science.gov (United States)

    In rambutan production, fruit rot is the main pre- and post-harvest disease of concern. In a 2008-2013 fruit disease survey, fruit rot was observed in eight orchards in Puerto Rico. Infected fruit were collected and 1 mm2 tissue sections were surface disinfested with 70% ethanol followed by 0.5% sod...

  8. Assessment of Injuries Caused by Anastrepha fraterculus (Wied.) (Diptera: Tephritidae) on the Incidence of Bunch Rot Diseases in Table Grape.

    Science.gov (United States)

    Machota, R; Bortoli, L C; Cavalcanti, F R; Botton, M; Grützmacher, A D

    2016-08-01

    Anastrepha fraterculus (Wied.) is the main insect pest of table grapes (Vitis vinifera) in the Southern Region of Brazil. In this study, we aimed to investigate the effect of fruit puncturing by adult females and larval infestation by A. fraterculus on the occurrence of bunch rot disease in the grape (cultivar "Itália") by evaluating grapes (a) punctured for oviposition by females of A. fraterculus, sterilized in laboratory with novaluron (40 mg L(-1)) and further spray-inoculated separately with Botrytis cinerea (1 × 10(6) conidia mL(-1)), Glomerella cingulata (1 × 10(6) conidia mL(-1)), and bacteria and yeast that cause sour rot (1 × 10(5) cells mL(-1)), (b) grapes punctured for oviposition by non-sterilized females with pathogen spraying, (c) grapes with mechanical wounds and pathogen spraying, (d) grapes with no wounds and with pathogen spraying, (e) grapes punctured for oviposition by A. fraterculus chemically sterilized in laboratory with novaluron, (f) grapes punctured for oviposition by A. fraterculus non-sterilized in laboratory with novaluron, (g) grapes with mechanical wounds, and (h) grapes with no sterilization or pathogen spraying. Our data indicated that the mechanical and oviposition wounds caused by A. fraterculus increased the percentage of grapes infected by B. cinerea, G. cingulata, and microorganisms of acid rot. The grape puncturing by A. fraterculus and the mechanical wound allows the penetration of B. cinerea and microorganisms leading to acid rot. We conclude that the fruit fly A. fraterculus may facilitate phytopathogens penetration leading to bunch rots in the table grape Itália.

  9. First report of Calonectria hongkongensis causing fruit rot of rambutan (Nephelium lappaceum L.)

    Science.gov (United States)

    Fruit rot is a major pre- and post-harvest disease problem in rambutan orchards. In 2011, fruit rot was observed at the USDA-TARS orchards in Mayaguez, Puerto Rico. Infected fruit were collected and tissue sections (1 mm2) were superficially sterilized with 70% ethanol and 0.5% sodium hypochlorite. ...

  10. Energy balance associated with the degradation of lignocellulosic material by white-rot and brown-rot fungi.

    Science.gov (United States)

    Derrien, Delphine; Bédu, Hélène; Buée, Marc; Kohler, Annegret; Goodell, Barry; Gelhaye, Eric

    2017-04-01

    Forest soils cover about 30% of terrestrial area and comprise between 50 and 80% of the global stock of soil organic carbon (SOC). The major precursor for this forest SOC is lignocellulosic material, which is made of polysaccharides and lignin. Lignin has traditionally been considered as a recalcitrant polymer that hinders access to the much more labile structural polysaccharides. This view appears to be partly incorrect from a microbiology perspective yet, as substrate alteration depends on the metabolic potential of decomposers. In forest ecosystems the wood-rotting Basidiomycota fungi have developed two different strategies to attack the structure of lignin and gain access to structural polysaccharides. White-rot fungi degrade all components of plant cell walls, including lignin, using enzymatic systems. Brown-rot fungi do not remove lignin. They generate oxygen-derived free radicals, such as the hydroxyl radical produced by the Fenton reaction, that disrupt the lignin polymer and depolymerize polysaccharides which then diffuse out to where the enzymes are located The objective of this study was to develop a model to investigate whether the lignin relative persistence could be related to the energetic advantage of brown-rot degradative pathway in comparison to white-rot degradative pathway. The model simulates the changes in substrate composition over time, and determines the energy gained from the conversion of the lost substrate into CO2. The energy cost for the production of enzymes involved in substrate alteration is assessed using information derived from genome and secretome analysis. For brown-rot fungus specifically, the energy cost related to the production of OH radicals is also included. The model was run, using data from the literature on populous wood degradation by Trametes versicolor, a white-rot fungus, and Gloeophyllum trabeum, a brown-rot fungus. It demonstrates that the brown-rot fungus (Gloeophyllum trabeum) was more efficient than the white-rot

  11. Bacterial Diseases of Bananas and Enset: Current State of Knowledge and Integrated Approaches Toward Sustainable Management

    Directory of Open Access Journals (Sweden)

    Guy Blomme

    2017-07-01

    Full Text Available Bacterial diseases of bananas and enset have not received, until recently, an equal amount of attention compared to other major threats to banana production such as the fungal diseases black leaf streak (Mycosphaerella fijiensis and Fusarium wilt (Fusarium oxysporum f. sp. cubense. However, bacteria cause significant impacts on bananas globally and management practices are not always well known or adopted by farmers. Bacterial diseases in bananas and enset can be divided into three groups: (1 Ralstonia-associated diseases (Moko/Bugtok disease caused by Ralstonia solanacearum and banana blood disease caused by R. syzygii subsp. celebesensis; (2 Xanthomonas wilt of banana and enset, caused by Xanthomonas campestris pv. musacearum and (3 Erwinia-associated diseases (bacterial head rot or tip-over disease Erwinia carotovora ssp. carotovora and E. chrysanthemi, bacterial rhizome and pseudostem wet rot (Dickeya paradisiaca formerly E. chrysanthemi pv. paradisiaca. Other bacterial diseases of less widespread importance include: bacterial wilt of abaca, Javanese vascular wilt and bacterial fingertip rot (probably caused by Ralstonia spp., unconfirmed. This review describes global distribution, symptoms, pathogenic diversity, epidemiology and the state of the art for sustainable disease management of the major bacterial wilts currently affecting banana and enset.

  12. New record of Phytophthora root and stem rot of Lavandula angustifolia

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  13. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/ brown rot paradigm for wood decay fungi

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Salamov, Asaf; Brown, Daren W.; Nagy, Laszlo G.; Floudas, Dimitris; Held, Benjamin; Levasseur, Anthony; Lombard, Vincent; Morin, Emmanuelle; Otillar, Robert; Lindquist, Erika; Sun, Hui; LaButti, Kurt; Schmutz, Jeremy; Jabbour, Dina; Luo, Hong; Baker, Scott E.; Pisabarro, Antonio; Walton, Jonathan D.; Blanchette, Robert; Henrissat, Bernard; Martin, Francis; Cullen, Dan; Hibbett, David; Grigoriev, Igor V.

    2014-03-14

    Basidiomycota (basidiomycetes) make up 32percent of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white rot/brown rot classification paradigm we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically-informed Principal Components Analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs, but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown rot fungi. Our results suggest a continuum rather than a dichotomy between the white rot and brown rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.

  14. A review of the Phytophthora pod rot disease situation in Ghana ...

    African Journals Online (AJOL)

    The presence of Phytophthora megakarya, which until 1985 was unknown in Ghana, has changed the status of black pod disease of cocoa in the country. Hitherto, only Phytophthora palmivora was known to be present. This paper reviews the Phytophthora pod disease situation, the origin, distribution, incidence and ...

  15. Black lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Ramani, R.V.; Frantz, R.L. [Pennsylvania State University, University Park, PA (United States)

    1995-12-31

    Coal workers` pneumoconiosis (CWP), often called Black Lung Disease is a occupational disease which results from inhalation of coal mine dust which usually contains small amounts of free crystalline silica. This chapter reviews the current knowledge of the epidemiology and clinical aspects of CWP and how it has been controlled in the USA through the 1969 Coal Mine Act and dust level standards. It describes the sampling methods used. Medical control methods and engineering control of the disease is discussed. Work of the Generic Mineral Technology Center for Respirable Dust is described. 28 refs., 6 figs.

  16. First report of Fusarium redolens causing crown rot of wheat (Triticum spp.) in Turkey

    Science.gov (United States)

    Fusarium crown rot, caused by a complex of Fusarium spp., is a yield-limiting disease of wheat world-wide, especially in dry Mediterranean climates. In order to identify Fusarium species associated with crown rot of wheat, a survey was conducted in summer 2013 in the major wheat growing regions of T...

  17. Bioremediation of the heavy metal complex dye Isolan Dark Blue 2SGL-01 by white rot fungus Irpex lacteus

    Energy Technology Data Exchange (ETDEWEB)

    Kalpana, Duraisamy [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of); Shim, Jae Hong; Oh, Byung-Taek [Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan (Korea, Republic of); Senthil, Kalaiselvi [Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam University for Women, Tamil Nadu (India); Lee, Yang Soo, E-mail: ysoolee@chonbuk.ac.kr [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Application of the White rot fungus Irpex lacteus. Black-Right-Pointing-Pointer Heavy metal (Cr) conjugated dye. Black-Right-Pointing-Pointer Economic, easy, and rapid. Black-Right-Pointing-Pointer Non toxic nature of the degraded products. Black-Right-Pointing-Pointer Decolorization and degradation at higher concentrations. - Abstract: The present study was conducted to evaluate the decolorization and degradation of the chromium metal complex dye Isolan Dark Blue 2SGL-01 by Irpex lacteus, a white rot lignolytic fungus. I. lacteus effectively decolorized the sulphonated reactive dye at a high concentration of 250 mg/l over a wide range of pH values of 5-9 and temperatures between 20 and 35 Degree-Sign C. Complete (100%) decolorization occurred within 96 h, and I. lacteus demonstrated resistance to the metallic dye. UV-vis spectroscopy, HPLC, GC-MS, and FT-IR analyses of the extracted metabolites confirmed that the decolorization process occurred due to degradation of the dye and not merely by adsorption. GC-MS analysis indicated the formation of 1(2H)-naphthalenone, 3,4-dihydro- and 2-naphthalenol as the main metabolite. ICP analysis demonstrated the removal of 13.49% chromium, and phytotoxicity studies using germinated seeds of Vigna radiata and Brassica juncea demonstrated the nontoxic nature of the metabolites formed during the degradation of Isolan Dark Blue 2SGL-01 dye.

  18. Differential induction of chitinase in Piper colubrinum in response to inoculation with Phytophthora capsici, the cause of foot rot in black pepper

    Science.gov (United States)

    Sandeep Varma, R.; Johnson George, K.; Balaji, S.; Parthasarathy, V.A.

    2009-01-01

    Plant chitinases have been of particular interest since they are known to be induced upon pathogen invasion. Inoculation of Piper colubrinum leaves with the foot rot fungus, Phytophthora capsici leads to increase in chitinase activity. A marked increase in chitinase activity in the inoculated leaves was observed, with the maximum activity after 60 h of inoculation and gradually decreased thereafter. Older leaves showed more chitinase activity than young leaves. The level of chitinase in black pepper (Piper nigrum L.) upon inoculation was found to be substantially high when compared to P. colubrinum. RT–PCR using chitinase specific primers revealed differential accumulation of mRNA in P. colubrinum leaves inoculated with P. capsici. However, hyphal extension assays revealed no obvious differences in the ability of the protein extracts to inhibit growth of P. capsici in vitro. PMID:23961037

  19. Status of maize stalk rot complex in western belts of Nepal and its integrated management

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2016-12-01

    Full Text Available Maize stalk rot complex is becoming a serious threat for maize growing areas of Nepal. A field monitoring for maize stalk rot complex was done during crop season (August, 2016 covering 10 farmers field each of Surkhet, Banke, Dang, Chitwan and Nawalparasi districts. Maize crop showed highly susceptible reaction to the disease at western belts of Dang and susceptible reaction was marked in Chitwan and Nawalparasi districts while the disease effect was mild at Banke and Surkhet district. Most of the plant diseases managed successfully through the application of bio-control agents, host resistance, chemicals and other different cultural control methods. The result of field experiment conducted at Dang showed that all the treatments had significant (P≤0.05 effect on percent disease index (PDI and crop yield over farmers practice to control maize stalk rot. The higher percent disease control (52.36% and yield increase (40.29% were recorded from the plot sprayed with streptocyclin @ 2 g L-1 and insecticide (cypermethrin + chloropyrifos @ 2.5 ml L-1 of water during knee height and subsequent spray after 15 days interval as compared to farmers practice. Out of 30 genotypes, Rampur composit, Arun 2, Rampur 34, RamS03F08, TLBRS07F16 and Rampur 24 were found resistant against stalk rot complex with higher yield at Rampur Chitwan.

  20. Laminated Root Rot of Western Conifers

    Science.gov (United States)

    E.E. Nelson; N.E. Martin; R.E. Williams

    1981-01-01

    Laminated root rot is caused by the native fungus Phellinus weirii (Murr.) Gilb. It occurs throughout the Northwestern United States and in southern British Columbia, Canada. The disease has also been reported in Japan and Manchuria. In the United States, the pathogen is most destructive in pure Douglas-fir stands west of the crest of the Cascade Range in Washington...

  1. Stand tending and root rot in Norway spruce stands - economical effects caused by root rot at different thinning regimes

    International Nuclear Information System (INIS)

    Johansson, Mats

    1997-01-01

    This report is divided into three parts: 1) a literature study describing the most common fungi causing rot in wood and descriptions of various strategies to reduce economic loss from root rot, 2) a check of a model describing the development of butt rot in pure Norway spruce plantations in southern Sweden, and 3) simulated economic effects of root rot in stands with various stand tending. The rot model was used to estimate future rot frequencies in the economic calculations. In order to avoid overestimations of rot frequencies, the calculations were also executed when assuming slower growth of rot than shown in the model. When analysing the economical effects of rot, the following three thinning programmes were used: Program 1: thinning at the ages of 30- and 45 years. Final felling at the ages 50-, 55-, 60-, 65-, and 70 years. Program 2: thinning at the ages of 40- and 60- years. Final felling at the ages 65 and 75 years. Program 3: thinning at the ages of 30-, 40-, 55-, and 70 years. Final felling at the ages 80 and 90 years. With an interest rate of 3%, programme 2 (final felling at the age of 65 years) had the highest value at present. This result was valid when presuming butt rot in the stand as well as when presuming no butt rot in the stand. There was a small difference between the value at present in programme 1 (final felling at the age of 60 years) and in programme 3 (final felling at the age of 80 years). When presuming butt rot in the stand, the value at present in programme 3 decreased somewhat more in comparison to the value at present in programme 1. Compared to no butt rot in the stand, the optimal final felling time appeared five to ten years earlier when assuming butt rot in the stand. Stand tending programme 1 and an interest rate of 3% were used. Interest rates 2 and 4% did not indicate shorter rotation. The calculated optimal time of final felling appeared at the same stand age whether assuming rot preset or not. The results in this study

  2. Discussion on Occurrence and Prevention and Control Technology of Rice Bacterial Foot-rot Disease%水稻细菌性基腐病的发生与防控技术探讨

    Institute of Scientific and Technical Information of China (English)

    危崇德

    2013-01-01

    Rice bacterial foot-rot disease is one of the most important diseases in rice, in recent years, has happened in southern rice areas and caused a severe yield loss of rice crop. In this paper, influencing factors and disease symptom of rice bacterial foot-rot disease were introduced, and puts forward the corresponding prevention and control technical measures, provide a reference for the effective control of rice bacterial foot- rot disease.%水稻细菌性基腐病是水稻上重要的细菌病害之一,近几年在南方稻区陆续发生,已给水稻生产带来较为严重威胁。介绍了水稻细菌性基腐病的为害症状、影响因素,并提出了相应的防控技术措施,为有效控制水稻细菌性基腐病提供参考。

  3. A single dominant Ganoderma species is responsible for root rot of ...

    African Journals Online (AJOL)

    Ganoderma root rot is the most serious disease affecting commercially planted Acacia mangium in plantations in Indonesia. Numerous Ganoderma spp. have been recorded from diseased trees of this species and to a lesser extent Eucalyptus, causing confusion regarding the primary cause of the disease. In this study, a ...

  4. Draft Genome Sequence of the Phytopathogenic Fungus Ganoderma boninense, the Causal Agent of Basal Stem Rot Disease on Oil Palm.

    Science.gov (United States)

    Utomo, Condro; Tanjung, Zulfikar Achmad; Aditama, Redi; Buana, Rika Fithri Nurani; Pratomo, Antonius Dony Madu; Tryono, Reno; Liwang, Tony

    2018-04-26

    Ganoderma boninense is the dominant fungal pathogen of basal stem rot (BSR) disease on Elaeis guineensis We sequenced the nuclear genome of mycelia using both Illumina and Pacific Biosciences platforms for assembly of scaffolds. The draft genome comprised 79.24 Mb, 495 scaffolds, and 26,226 predicted coding sequences. Copyright © 2018 Utomo et al.

  5. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens

    DEFF Research Database (Denmark)

    Nayaka, Siddaiah Chandra; Shankar, Akarere C. Udaya; Reddy, Munagala S.

    2009-01-01

    Abstract BACKGROUND: Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have...... disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars....... verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. CONCLUSION: The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize...

  6. Potential of UVC germicidal irradiation in suppressing crown rot disease, retaining postharvest quality and antioxidant capacity of Musa AAA "Berangan" during fruit ripening.

    Science.gov (United States)

    S Mohamed, Nuratika Tamimi; Ding, Phebe; Kadir, Jugah; M Ghazali, Hasanah

    2017-09-01

    Crown rot caused by fungal pathogen is the most prevalent postharvest disease in banana fruit that results significant economic losses during transportation, storage, and ripening period. Antifungal effects of ultraviolet C (UVC) irradiation at doses varied from 0.01 to 0.30 kJ m -2 were investigated in controlling postharvest crown rot disease, maintenance of fruit quality, and the effects on antioxidant capacity of Berangan banana fruit during ripening days at 25 ± 2°C and 85% RH. Fruits irradiated with 0.30 kJ m -2 exhibited the highest (i.e., 62.51%) reduction in disease severity. However, the application of UVC at all doses caused significant browning damages on fruit peel except the dose of 0.01 kJ m -2 . This dose synergistically reduced 46.25% development of postharvest crown and did not give adverse effects on respiration rate, ethylene production, weight loss, firmness, color changes, soluble solids concentration, titratable acidity, and pH in banana as compared to the other treatments and control. Meanwhile, the dose also enhanced a significant higher level of total phenolic content, FRAP, and DPPH values than in control fruits indicating the beneficial impact of UVC in fruit nutritional quality. The results of scanning electron micrographs confirmed that UVC irradiation retarded the losses of wall compartments, thereby maintained the cell wall integrity in the crown tissue of banana fruit. The results suggest that using 0.01 kJ m -2 UVC irradiation dose as postharvest physical treatment, the crown rot disease has potential to be controlled effectively together with maintaining quality and antioxidant of banana fruit.

  7. The association of Tarsonemus mites (Acari: Heterostigmata) with different apple developmental stages and apple core rot diseases

    OpenAIRE

    Ueckermann, Edward Albert; Van der Walt, Lené; Spotts, Robert A.; Smit, Francois J.; Jensen, Tamaryn; McLeod, Adéle

    2011-01-01

    Information on the role of mites in the genus Tarsonemus Canestrini and Fanzago, 1876 in the epidemiology of apple core rots (wet and dry) is limited. The aims of this study were to (1) assess the effect of different apple developmental stages (buds, blossoms, 4-cm diameter fruit, mature fruit and mummies) on the relative abundance of Tasonemus mites, (2) determine if there is a tendency of Tarsonemus mites to be associated with wet core rot (WCR) and dry core rot (DCR) apples, and (3) evalua...

  8. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  9. Evidence that the Ceratobasidium-like white-thread blight and black rot fungal pathogens from persimmon and tea crops in the Brazilian Atlantic Forest agroecosystem are two distinct phylospecies

    Directory of Open Access Journals (Sweden)

    Paulo C. Ceresini

    2012-01-01

    Full Text Available The white-thread blight and black rot (WTBR caused by basidiomycetous fungi of the genus Ceratobasidium is emerging as an important plant disease in Brazil, particularly for crop species in the Ericales such as persimmon (Diospyros kaki and tea (Camellia sinensis. However, the species identity of the fungal pathogen associated with either of these hosts is still unclear. In this work, we used sequence variation in the internal transcribed spacer regions, including the 5.8S coding region of rDNA (ITS-5.8S rDNA, to determine the phylogenetic placement of the local white-thread-blight-associated populations of Ceratobasidium sp. from persimmon and tea, in relation to Ceratobasidium species already described world-wide. The two sister populations of Ceratobasidium sp. from persimmon and tea in the Brazilian Atlantic Forest agroecosystem most likely represent distinct species within Ceratobasidium and are also distinct from C. noxium, the etiological agent of the first description of white-thread blight disease that was reported on coffee in India. The intraspecific variation for the two Ceratobasidium sp. populations was also analyzed using three mitochondrial genes (ATP6, nad1 and nad2. As reported for other fungi, variation in nuclear and mitochondrial DNA was incongruent. Despite distinct variability in the ITS-rDNA region these two populations shared similar mitochondrial DNA haplotypes.

  10. Evidence that the Ceratobasidium-like white-thread blight and black rot fungal pathogens from persimmon and tea crops in the Brazilian Atlantic Forest agroecosystem are two distinct phylospecies.

    Science.gov (United States)

    Ceresini, Paulo C; Costa-Souza, Elaine; Zala, Marcello; Furtado, Edson L; Souza, Nilton L

    2012-04-01

    The white-thread blight and black rot (WTBR) caused by basidiomycetous fungi of the genus Ceratobasidium is emerging as an important plant disease in Brazil, particularly for crop species in the Ericales such as persimmon (Diospyros kaki) and tea (Camellia sinensis). However, the species identity of the fungal pathogen associated with either of these hosts is still unclear. In this work, we used sequence variation in the internal transcribed spacer regions, including the 5.8S coding region of rDNA (ITS-5.8S rDNA), to determine the phylogenetic placement of the local white-thread-blight-associated populations of Ceratobasidium sp. from persimmon and tea, in relation to Ceratobasidium species already described world-wide. The two sister populations of Ceratobasidium sp. from persimmon and tea in the Brazilian Atlantic Forest agroecosystem most likely represent distinct species within Ceratobasidium and are also distinct from C. noxium, the etiological agent of the first description of white-thread blight disease that was reported on coffee in India. The intraspecific variation for the two Ceratobasidium sp. populations was also analyzed using three mitochondrial genes (ATP6, nad1 and nad2). As reported for other fungi, variation in nuclear and mitochondrial DNA was incongruent. Despite distinct variability in the ITS-rDNA region these two populations shared similar mitochondrial DNA haplotypes.

  11. Suppression of Rhizome Rot in Organically Cultivated Ginger Using Integrated Pest Management

    Directory of Open Access Journals (Sweden)

    Chang-Ki Shim

    2015-09-01

    Full Text Available This study was conducted to control ginger rhizome rot treated with the combined treatment, the hairy vetch, carbonized rice husk and eggshell calcium in organic ginger farm. Early symptoms of leaf yellowing and plant wilt began in the chemical fertilizer treatment on July 1. Ginger rhizome rot was more progressed on October 2, and stem browning and dead plant showed a high disease incidence with from 36.7% to 43.0%. On the other hand, the combined treatment did not occur at all until July 1 and delayed the disease incidence to October 2. It showed a low disease incidence of 1.3% to 1.7%. In the combined treatment, the content of soil Na, Fe, Cu was decreased and organic matter was increased twice with 31.6% than previous. Population density of Pythium sp. is lower in the combined treatment (0.3-2.0×103 cfu/g than the chemical fertilizer treatments (12.0-12.3×103 cfu/g. The combined treatment, hairy vetch, carbonized rice husk and the eggshell calcium is able to control the ginger rhizome rot in organically cultivated ginger field.

  12. The persistence of Gliocephalotrichum bulbilium and G. simplex causing fruit rot of rambutan in Puerto Rico

    Science.gov (United States)

    Fruit rot of rambutan (Nephelium lappaceum L.) is a pre and post-harvest disease problem that affects fruit quality. Significant post-harvest losses have occurred worldwide and several pathogens have been identified in Malaysia, Costa Rica, Hawaii, Thailand, and Puerto Rico. In 2011, fruit rot was o...

  13. Occurrence, characterization and management of fruit rot of immature cucumber fruits under arid greenhouse conditions

    Directory of Open Access Journals (Sweden)

    ABDULLAH M AL-SADI

    2012-01-01

    Full Text Available A study was undertaken to characterize and manage pathogens associated with fruit rot of immature cucumber fruits in greenhouses in Oman. A survey over 5 growing seasons from 2008 to 2010 in 99 different greenhouses in Oman showed that the disease is prevalent in 91 (92% greenhouses and results in losses of 10 to 60% (avg. 33% of immature fruits per plant. Incidence of the disease was not found to be affected by growing seasons, which could be attributed to the limited fluctuations in ambient temperatures in greenhouses. Isolations from diseased cucumber fruits yielded Alternaria alternata (isolation frequency = 52%, Fusarium equiseti (40%, Cladosporium tenuissium (27%, Botrytis cinerea (6%, Fusarium solani (6%, Corynespora cassiicola (3%, Aspergillus spp. (2%, Curvularia sp. (1% and Bipolaris sp. (1%. With the exception of Curvularia and Bipolaris species, all other fungi were pathogenic on cucumber fruits, with Fusarium equiseti being the most aggressive, followed by Corynespora cassiicola, Botrytis cinerea and Alternaria alternata. Cladosporium and Aspergillus spp. were found to be weakly pathogenic. Comparing the efficacy of foliar and soil applications of carbendazim fungicide on fruit rot of cucumber showed that foliar applications significantly reduced fruit rot and increased cucumber yield when compared to soil application or to control (P < 0.01. This appears to be the first report of the association of Corynespora cassiicola and Fusarium equiseti with fruit rot of immature greenhouse cucumbers. This is also the first report in Oman for the association of Cladosporium tenuissimum with fruit rot of immature cucumbers. Findings are discussed in terms of factors affecting disease control in greenhouses using carbendazim.

  14. Application of arbuscular mycorrhizal fungi with Pseudomonas aeruginosa UPMP3 reduces the development of Ganoderma basal stem rot disease in oil palm seedlings.

    Science.gov (United States)

    Sundram, Shamala; Meon, Sariah; Seman, Idris Abu; Othman, Radziah

    2015-07-01

    The effect of arbuscular mycorrhizal fungi (AMF) in combination with endophytic bacteria (EB) in reducing development of basal stem rot (BSR) disease in oil palm (Elaeis guineensis) was investigated. BSR caused by Ganoderma boninense leads to devastating economic loss and the oil palm industry is struggling to control the disease. The application of two AMF with two EB as biocontrol agents was assessed in the nursery and subsequently, repeated in the field using bait seedlings. Seedlings pre-inoculated with a combination of Glomus intraradices UT126, Glomus clarum BR152B and Pseudomonas aeruginosa UPMP3 significantly reduced disease development measured as the area under disease progression curve (AUDPC) and the epidemic rate (R L) of disease in the nursery. A 20-month field trial using similar treatments evaluated disease development in bait seedlings based on the rotting area/advancement assessed in cross-sections of the seedling base. Data show that application of Glomus intraradices UT126 singly reduced disease development of BSR, but that combination of the two AMF with P. aeruginosa UPMP3 significantly improved biocontrol efficacy in both nursery and fields reducing BSR disease to 57 and 80%, respectively. The successful use of bait seedlings in the natural environment to study BSR development represents a promising alternative to nursery trial testing in the field with shorter temporal assessment.

  15. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/brown rot paradigm for wood decay fungi

    Science.gov (United States)

    Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade ...

  16. Associations of planting date, drought stress, and insects with Fusarium ear rot and fumonisin B1 contamination in California maize.

    Science.gov (United States)

    Parsons, M W; Munkvold, G P

    2010-05-01

    Fusarium ear rot, caused by Fusarium verticillioides, is one of the most common diseases of maize, causing yield and quality reductions and contamination of grain by fumonisins and other mycotoxins. Drought stress and various insects have been implicated as factors affecting disease severity. Field studies were conducted to evaluate the interactions and relative influences of drought stress, insect infestation, and planting date upon Fusarium ear rot severity and fumonisin B1 contamination. Three hybrids varying in partial resistance to Fusarium ear rot were sown on three planting dates and subjected to four irrigation regimes to induce differing levels of drought stress. A foliar-spray insecticide treatment was imposed to induce differing levels of insect injury. Populations of thrips (Frankliniella spp.), damage by corn earworm (Helicoverpa zeae), Fusarium ear rot symptoms, and fumonisin B1 levels were assessed. There were significant effects of hybrid, planting date, insecticide treatment, and drought stress on Fusarium ear rot symptoms and fumonisin B1 contamination, and these factors also had significant interacting effects. The most influential factors were hybrid and insecticide treatment, but their effects were influenced by planting date and drought stress. The more resistant hybrids and the insecticide-treated plots consistently had lower Fusarium ear rot severity and fumonisin B1 contamination. Later planting dates typically had higher thrips populations, more Fusarium ear rot, and higher levels of fumonisin B1. Insect activity was significantly correlated with disease severity and fumonisin contamination, and the correlations were strongest for thrips. The results of this study confirm the influence of thrips on Fusarium ear rot severity in California, USA, and also establish a strong association between thrips and fumonisin B1 levels.

  17. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens.

    Science.gov (United States)

    Nayaka, Siddaiah Chandra; Shankar, Arakere C Udaya; Reddy, Munagala S; Niranjana, Siddapura R; Prakash, Harishchandra S; Shetty, Hunthrike S; Mortensen, Carmen N

    2009-07-01

    Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have elicited considerable attention over the past decade owing to their association with animal disease syndromes. Hence, the present study was conducted to evaluate ecofriendly approaches by using a maize rhizosphere isolate of Pseudomonas fluorescens (Trev.) Mig. and its formulation to control ear rot disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars. The field trials included both seed treatment and foliar spray. For all the experiments, P. fluorescens was formulated using corn starch, wheat bran and talc powder. In each case there were three different treatments of P. fluorescens, a non-treated control and chemical control. Pure culture and the formulations, in comparison with the control, increased plant growth and vigour as measured by seed germination, seedling vigour, plant height, 1000 seed weight and yield. P. fluorescens pure culture used as seed treatment and as spray treatment enhanced the growth parameters and reduced the incidence of F. verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize kernels intended for human and animal feed. (c) 2009 Society of Chemical Industry.

  18. Selection of sugarcane mutants with resistance to red-rot disease, water-logging and delayed/non-flowering

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, M A.Q.; Shamsuzzaman, K M; Majid, M A; Howlider, M A.R.; Islam, M M [Institute of Nuclear Agriculture, Mymensingh (Bangladesh)

    1997-07-01

    Three batches of sugarcane cuttings were irradiated with gamma-rays in three different years for isolating mutants for delayed flowering, resistance to red-rot disease and water-logged conditions. In the first batch cuttings of cvs. `Isd-2/54`, `Latarijaba` and `Nagarbari` were irradiated with 20-40 Gy gamma-rays. In M{sub 1} V{sub 4} generation, 2,114 canes selected from inoculated M{sub 1}V{sub 3} generation, were re-inoculated with red-hot pathogen. Of these, four canes were resistant and 64 canes were moderately resistant to the disease. The M{sub 1}V{sub 5} generation of the selected clones was grown at two locations for selection. In the second batch, cuttings of cvs. `Isd-16`, `Isd-2/54`, `Nagarbari` and `Latarijaba` were irradiated with 20-60 Gy gamma-rays. The irradiated material was divided into three lots and each lot was put under different selection pressure. For isolating mutants with resistance to red-rot disease, 15,104 canes were artificially inoculated in the M{sub 1}V{sub 3}. Among these, one clone was resistant and 16 were moderately resistant. Of the 10,000 M{sub 1}V{sub 3} canes, grown under water-logged condition and selected for greenness of leaf at harvest, 38 canes were reasonably tolerant. For selecting late flowering mutants, about 8,500 canes were left in a field for a month after normal harvest; of these five showed late flowering. These mutants were grown for further selection in the M{sub 1}V{sub 4}. To screen out non-flowering canes, cvs. `I-291/87`, an early flowering types, and `I525/85`, a late flowering type were irradiated with 20-40 Gy gamma rays. M{sub 1}V{sub 3} generation has been grown in the field. (author). 13 refs, 6 tabs.

  19. Control of Black Rot Disease in Tomato Fruits by Using Formulated Ginger Essential oil Treated by Gamma Radiation

    International Nuclear Information System (INIS)

    Helal, I.M.; Abdeldaiem, M.H.

    2008-01-01

    Ginger essential oil (Zingiber officinale) treated by gamma radiation at dose of 10 kGy was selected as an active ingredient for formulation of the biocide. Liquid formulations (emulsifiable concentrates) were prepared using different emulsifiers (Emulgator B.L.M. and tween 80 or tween 20) and additive oil (soybean oil). Physicochemical properties of the formulated oil (spontaneous emulsification, emulsion stability; cold stability and heat stability, viscosity, surface tension and ph) were measured. The formulated oil was tested in vivo to investigate its efficiency for controlling the growth of Alternaria alternata inoculated into tomato fruits. The results indicated that soaking inoculated tomato fruits in the formulated oil (ginger essential oil + soybean oil + emulgator B.L.M. + tween 80) treatment at concentration of 300 ppm for a period of 12 minute was the most effective for controlling the growth of the tested fungus. In addition, the formulated oil had efficiency for controlling the rot development on tomato fruits when applied as therapeutic and protective agents

  20. Report of postharvest rot of kiwifruit in Korea caused by Sclerotinia sclerotiorum.

    Science.gov (United States)

    Lee, Jung Han; Kwon, Young Ho; Kwack, Yong-Bum; Kwak, Youn-Sig

    2015-08-03

    In May 2014, sclerotinia rot symptoms caused by Sclerotinia sclerotiorum were observed on stored kiwifruit in Jinju, South Korea. The symptoms appeared as soft, water-soaked lesions on fruit covered with a white mycelium. The morphological characteristics and the internal transcribed spacer sequences of rRNA of the pathogen isolated from the sclerotinia rot showed it to be S. sclerotiorum. This was confirmed by performing a pathogenicity test with pure cultures of S. sclerotiorum and by reisolating S. sclerotiorum from artificially inoculated kiwifruits. Our results should help promote a better understanding of the diseases that affect kiwifruit and improve practices for postharvest disease control in the kiwifruit industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Phytophthora cinnamon causing stem canker and root rot of nursery-grown Platanus × acerifolia: first report in the Northern emisphere

    Directory of Open Access Journals (Sweden)

    Massimo PILOTTI

    2014-05-01

    Full Text Available Lethal stem and root cankers were observed in nursery-grown Platanus × acerifolia trees in Rome. Externally, canker lesions appeared as bluish or blackish areas starting from the stem base and extending upward. Inner bark was necrotised. In some cases an irregularly-shaped callus reaction attempted to heal the bark lesions. Black-stained necrosis affected the primary roots and the small branch roots to different degrees. The presence of Ceratocystis platani was excluded in the diseased trees. Phytophthora-like organisms were isolated from the altered tissue. Morphological and ITS-region-based analyses identified the isolates as Phytophthora cinnamomi. A pathogenicity test confirmed P. cinnamomi as the causal agent of the disease here defined as: stem canker and root rot of plane tree. This is the first report of P. cinnamomi in Platanus spp. in the Northern emisphere.

  2. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi

    Science.gov (United States)

    Robert Riley; Asaf A. Salamov; Daren W. Brown; Laszlo G. Nagy; Dimitrios Floudas; Benjamin W. Held; Anthony Levasseur; Vincent Lombard; Emmanuelle Morin; Robert Otillar; Erika A. Lindquist; Hui Sun; Kurt M. LaButti; Jeremy Schmutz; Dina Jabbour; Hong Luo; Scott E. Baker; Antonio G. Pisabarro; Jonathan D. Walton; Robert A. Blanchette; Bernard Henrissat; Francis Martin; Daniel Cullen; David S. Hibbett; Igor V. Grigoriev

    2014-01-01

    Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood-decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic...

  3. Detection, identification and differentiation of Pectobacterium and Dickeya species causing potato blackleg and tuber soft rot: a review

    NARCIS (Netherlands)

    Czajkowski, R.L.; Pérombelon, M.C.M.; Jafra, S.; Lojkowska, E.; Potrykus, M.; Wolf, van der J.M.; Sledz, W.

    2015-01-01

    The soft rot Enterobacteriaceae (SRE) Pectobacterium and Dickeya species (formerly classified as pectinolytic Erwinia spp.) cause important diseases on potato and other arable and horticultural crops. They may affect the growing potato plant causing blackleg and are responsible for tuber soft rot in

  4. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

    NARCIS (Netherlands)

    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia

  5. Higher cardiovascular disease prevalence and mortality among younger blacks compared to whites.

    Science.gov (United States)

    Jolly, Stacey; Vittinghoff, Eric; Chattopadhyay, Arpita; Bibbins-Domingo, Kirsten

    2010-09-01

    Blacks have higher rates of cardiovascular disease than whites. The age at which these differential rates emerge has not been fully examined. We examined cardiovascular disease prevalence and mortality among black and white adults across the adult age spectrum and explored potential mediators of these differential disease prevalence rates. We conducted a cross-sectional analysis of National Health and Nutrition Examination Survey data from 1999-2006. We estimated age-adjusted and age-specific prevalence ratios (PR) for cardiovascular disease (heart failure, stroke, or myocardial infarction) for blacks versus whites in adults aged 35 years and older and examined potential explanatory factors. From the National Compressed Mortality File 5-year aggregate file of 1999-2003, we determined age-specific cardiovascular disease mortality rates. In young adulthood, cardiovascular disease prevalence was higher in blacks than whites (35-44 years PR 1.9; 95% confidence interval [CI], 1.1-3.4). The black-white PR decreased with each decade of advancing age (P for trend=.04), leading to a narrowing of the racial gap at older ages (65-74 years PR 1.2; 95% CI, 0.8-1.6; > or =75 years PR 1.0; 95% CI, 0.7-1.4). Clinical and socioeconomic factors mediated some, but not all, of the excess cardiovascular disease prevalence among young to middle-aged blacks. Over a quarter (28%) of all cardiovascular disease deaths among blacks occurred in those aged <65 years, compared with 13% among whites. Reducing black/white disparities in cardiovascular disease will require a focus on young and middle-aged blacks.

  6. Huntington\\'s disease: Genetic heterogeneity in black African patients

    African Journals Online (AJOL)

    Objective. Huntington's disease (HD) has been reported to occur rarely in black patients. A new genetic variant– Huntington's disease-like 2 (HDL2) – occurring more frequently in blacks, has recently been described. The absence of an expanded trinucleotide repeat at the chromosome 4 HD locus was previously regarded ...

  7. Motor neuron disease in blacks | Cosnett | South African Medical ...

    African Journals Online (AJOL)

    A series of 86 black, Indian and white patients with motor neuron disease were analysed retrospectively. Although the material does not allow statistically valid conclusions, there are sufficient cases among blacks to allow two prima facie observations in this population group: (i) motor neuron disease has an earlier age of ...

  8. Performance of Ceriporiopsis sp. in the Treatment of Black Liquor Wastewater

    OpenAIRE

    Sari, Ajeng Arum

    2016-01-01

    High amounts of black liquor wastewater are generated from bioethanol production by using oil palm empty fruit bunches. It contains an alkaline solution (NaOH), so it is quite toxic for aquatic ecosystems if discharged directly into waters. Black liquor has been treated by coagulation method, and it still needs additional treatment. This study aimed to determine degradation of black liquor wastewater by selected white-rot fungi (WRF). Five different strains of WRF have been tested for their a...

  9. Huanglongbing increases Diplodia Stem End Rot in Citrus sinensis

    Science.gov (United States)

    Huanglongbing (HLB), one of the most devastating diseases of citrus is caused by the a-Proteobacteria Candidatus Liberibacter. Diplodia natalensis Pole-Evans is a fungal pathogen which has been known to cause a postharvest stem-end rot of citrus, the pathogen infects citrus fruit under the calyx, an...

  10. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2012-06-01

    Full Text Available Rot of cherry tomato (Lycopersicon esculentum fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pathogens albeit at different degrees. Their culture filtrate inhibited pathogen spore germination possibly due to the released extracellular diffusible metabolite(s. Besides, aberrant morphology of conidia was observed with deformation of hyphal tips. Furthermore, the resulting mycelia appeared desiccated with coagulated protoplasm leading to complete collapse of protoplasm in presence of T. harzianum culture filtrate. Application of T. harzianum spores to tomato fruits decreased disease severity significantly with the most profound effect at higher spore concentrations (108 cells per ml. Similarly, culture filtrate of T. harzianum prevented pathogen spore germination on the surface of tomato fruits leading to decreased incidence of rot symptoms at high culture filtrate concentrations. This work provides strong evidence that T. harzianum is a competent antagonist and its spore suspension and culture filtrate can be used efficiently to control postharvest tomato rot.

  11. Biological control of banana black Sigatoka disease with Trichoderma

    OpenAIRE

    Poholl Adan Sagratzki Cavero; Rogério Eiji Hanada; Luadir Gasparotto; Rosalee Albuquerque Coelho Neto; Jorge Teodoro de Souza

    2015-01-01

    Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both f...

  12. First report of root rot of cowpea caused by Fusarium equiseti in Georgia in the United States

    Science.gov (United States)

    Root rot was observed on cowpea in Tift County, Georgia, in May of 2015. The disease occurred on approximately 10% of cowpea plants in 2 fields (2 ha). Symptoms appeared as sunken reddish brown lesions on roots and stems under the soil line, secondary roots became dark brown and rotted, and infected...

  13. The expansion of brown rot disease throughout Bolivia: possible role of climate change.

    Science.gov (United States)

    Castillo, José Antonio; Plata, Giovanna

    2016-05-01

    Bacterial wilt is a devastating plant disease caused by the bacterial pathogen Ralstonia solanacearum species complex and affects different crops. Bacterial wilt infecting potato is also known as brown rot (BR) and is responsible for significant economic losses in potato production, especially in developing countries. In Bolivia, BR affects up to 75% of the potato crop in areas with high incidence and 100% of stored potatoes. The disease has disseminated since its introduction to the country in the mid-1980s mostly through contaminated seed tubers. To avoid this, local farmers multiply seed tubers in highlands because the strain infecting potatoes cannot survive near-freezing temperatures that are typical in the high mountains. Past disease surveys have shown an increase in seed tubers with latent infection in areas at altitudes lower than 3000 m a.s.l. Since global warming is increasing in the Andes Mountains, in this work, we explored the incidence of BR in areas at altitudes above 3000 m a.s.l. Results showed BR presence in the majority of these areas, suggesting a correlation between the increase in disease incidence and the increase in temperature and the number of irregular weather events resulting from climate change. However, it cannot be excluded that the increasing availability of latently infected seed tubers has boosted the spread of BR.

  14. Agronomic Performance of Flue-Cured Tobacco F1 Hybrids Obtained with Different Sources of Male Sterile Cytoplasm

    Directory of Open Access Journals (Sweden)

    Berbec A

    2014-12-01

    Full Text Available Four cytoplasmic male sterile (cms F1flue-cured hybrids cv. Wiaelica × cv. Virginia Golta (VG, the male fertile analogue and the parental varieties were tested at two locations in Poland in a replicated field trial. The cms sources in the hybrids wereN. suaveolens,N. amplexicaulis,N. bigeloviiand aN. tabacumcms mutant. Under the slight to moderate pressure from black root rot present at the trial sites the hybrids showed a moderate tolerance of the disease characteristic of VG as opposed to medium strong susceptibility of Wislica. Apart from the effect of black root rot tolerance the vegetative vigor of the hybrids (plant height, leaf size, earliness was affected by cytoplasm source. The F1hybrid withN. suaveolens cytoplasm flowered approximately three days later than the remaining hybrids. Of the cms hybrids tested cmsN. bigelovii produced the tallest plants with largest mid-position leaves. Yields of cured leaves were largely influenced by black root rot and were generally higher in VG and in the hybrids than in Wislica. Leaf yields and curability were generally little affected by cms source under low pressure from black root rot. At the site with a relatively high level of black root rot infestation the yields of cmsN. suaveolens were slightly lower but the percentage of light grades slightly higher compared to those of other cms hybrids. CmsN. suaveolens was the best hybrid in terms of money returns at the low black root rot field but it was the poorest hybrid performer under high pressure from the disease. Contents of nitrogen, sugars, nicotine and ash was little affected by source of cms. There was an increased incidence of potato virus Y (PVY and white spots in cmsN. suaveolens and, to a lesser extent, in cmsN. bigelovii as compared to the remaining disease-free entries.

  15. Molecular mapping of QTLs for resistance to Gibberella ear rot, in corn, caused by Fusarium graminearum.

    Science.gov (United States)

    Ali, M Liakat; Taylor, Jeff H; Jie, Liu; Sun, Genlou; William, Manilal; Kasha, Ken J; Reid, Lana M; Pauls, K Peter

    2005-06-01

    Gibberella ear rot, caused by the fungus Fusarium graminearum Schwabe, is a serious disease of corn (Zea mays) grown in northern climates. Infected corn is lower yielding and contains toxins that are dangerous to livestock and humans. Resistance to ear rot in corn is quantitative, specific to the mode of fungal entry (silk channels or kernel wounds), and highly influenced by the environment. Evaluations of ear rot resistance are complex and subjective; and they need to be repeated over several years. All of these factors have hampered attempts to develop F. graminearum resistant corn varieties. The aim of this study was to identify molecular markers linked to the genes for resistance to Gibberella ear rot. A recombinant inbred (RI) population, produced from a cross between a Gibberella ear rot resistant line (CO387) and a susceptible line (CG62), was field-inoculated and scored for Gibberella ear rot symptoms in the F4, F6, and F7 generations. The distributions of disease scores were continuous, indicating that resistance is probably conditioned by multiple loci. A molecular linkage map, based on segregation in the F5 RI population, contained 162 markers distributed over 10 linkage groups and had a total length of 2237 cM with an average distance between markers of 13.8 cM. Composite interval mapping identified 11 quantitative trait loci (QTLs) for Gibberella ear rot resistance following silk inoculation and 18 QTLs following kernel inoculation in 4 environments that accounted for 6.7%-35% of the total phenotypic variation. Only 2 QTLs (on linkage group 7) were detected in more than 1 test for silk resistance, and only 1 QTL (on linkage group 5) was detected in more than 1 test for kernel resistance, confirming the strong influence of the environment on these traits. The majority of the favorable alleles were derived from the resistant parent (CO387). The germplasm and markers for QTLs with significant phenotypic effects may be useful for marker-assisted selection

  16. Control of Ralstonia Solanacearum The Causal Agent of Brown Rot in Potato Using Essential Oils

    International Nuclear Information System (INIS)

    Salem, E.A.

    2011-01-01

    Five essential oils, namely peppermint (Mentha piperita L.), caraway (Carium carvum L.), fennel (Foeniculum vulgare Mill.), lemongrass (Cymbopogon citratus Staph.) and thyme (Thymus vulgaris), were used separately against Ralstonia solanacearum; the causal agent of brown rot in potato. The most two effective oils (peppermint and thyme) were used in vitro and in vivo after testing their effects on potato tubers buds germination. Peppermint inhibited buds germination but thyme have no effects on buds germination. In vivo, the control of brown rot using thyme oil in glass house experiment reduced the percentage of brown rot infection to 30.6% and reduced the severity of disease from 5 to 3.

  17. Moniliophthora roreri, causal agent of cacao frosty pod rot.

    Science.gov (United States)

    Bailey, Bryan A; Evans, Harry C; Phillips-Mora, Wilbert; Ali, Shahin S; Meinhardt, Lyndel W

    2017-12-01

    Taxonomy: Moniliophthora roreri (Cif.) H.C. Evans et al. ; Phylum Basidiomycota; Class Agaricomycetes; Order Agaricales; Family Marasmiaceae; Genus Moniliophthora. Biology: Moniliophthora roreri attacks Theobroma and Herrania species causing frosty pod rot. Theobroma cacao (cacao) is the host of major economic concern. Moniliophthora roreri is a hemibiotroph with a long biotrophic phase (45-90 days). Spore masses, of apparent asexual origin, are produced on the pod surface after initiation of the necrotrophic phase. Spores are spread by wind, rain and human activity. Symptoms of the biotrophic phase can include necrotic flecks and, in some cases, pod malformation, but pods otherwise remain asymptomatic. Relationship to Moniliophthora perniciosa: Moniliophthora roreri and Moniliophthora perniciosa, causal agent of witches' broom disease of cacao, are closely related. Their genomes are similar, including many of the genes they carry which are considered to be important in the disease process. Moniliophthora perniciosa, also a hemibiotroph, has a typical basidiomycete lifestyle and morphology, forming clamp connections and producing mushrooms. Basidiospores infect meristematic tissues including flower cushions, stem tips and pods. Moniliophthora roreri does not form clamp connections or mushrooms and infects pods only. Both pathogens are limited to the Western Hemisphere and are a threat to cacao production around the world. Agronomic importance: Disease losses caused by frosty pod rot can reach 90% and result in field abandonment. Moniliophthora roreri remains in the invasive phase in the Western Hemisphere, not having reached Brazil, some islands within the Caribbean and a few specific regions within otherwise invaded countries. The disease can be managed by a combination of cultural (for example, maintenance of tree height and removal of infected pods) and chemical methods. These methods benefit from regional application, but can be cost prohibitive. Breeding for

  18. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR.

    Science.gov (United States)

    D'Souza, T M; Boominathan, K; Reddy, C A

    1996-01-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. PMID:8837429

  19. Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

    Science.gov (United States)

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2011-09-28

    The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

  20. Apple ring rot-responsive putative microRNAs revealed by high-throughput sequencing in Malus × domestica Borkh.

    Science.gov (United States)

    Yu, Xin-Yi; Du, Bei-Bei; Gao, Zhi-Hong; Zhang, Shi-Jie; Tu, Xu-Tong; Chen, Xiao-Yun; Zhang, Zhen; Qu, Shen-Chun

    2014-08-01

    MicroRNAs (miRNAs) are small non-coding RNAs, which silence target mRNA via cleavage or translational inhibition to function in regulating gene expression. MiRNAs act as important regulators of plant development and stress response. For understanding the role of miRNAs responsive to apple ring rot stress, we identified disease-responsive miRNAs using high-throughput sequencing in Malus × domestica Borkh.. Four small RNA libraries were constructed from two control strains in M. domestica, crabapple (CKHu) and Fuji Naga-fu No. 6 (CKFu), and two disease stress strains, crabapple (DSHu) and Fuji Naga-fu No. 6 (DSFu). A total of 59 miRNA families were identified and five miRNAs might be responsive to apple ring rot infection and validated via qRT-PCR. Furthermore, we predicted 76 target genes which were regulated by conserved miRNAs potentially. Our study demonstrated that miRNAs was responsive to apple ring rot infection and may have important implications on apple disease resistance.

  1. Suppression of crown and root rot of wheat by the rhizobacterium Paenibacillus polymyxa

    Directory of Open Access Journals (Sweden)

    Lamia LOUNACI

    2017-01-01

    Full Text Available A seedling bioassay was developed for screening a wheat root-associated rhizobacterial strain of Paenibacillus polymyxa for ability to suppress crown and root rot pathogens of wheat. The primary aim was to evaluate the ability of P. polymyxa to suppress Fusarium graminearum, F. culmorum, F. verticillioides and Microdochium nivale, the fungal pathogens responsible for Fusarium crown and root rot and head blight of wheat in Algeria. Bioassays conducted under controlled conditions indicated that seed treatments with P. polymyxa strain SGK2 significantly reduced disease symptoms caused by all four fungal pathogens. Plant growth promotion (increased shoot and root dry weights, however, depended on the pathogen tested. Our results indicate that seed treatments with a biocontrol agent could be an additional strategy for management of wheat crown and root rot pathogens.

  2. Salmonella enterica suppresses Pectobacterium carotovorum subsp. carotovorum population and soft rot progression by acidifying the microaerophilic environment.

    Science.gov (United States)

    Kwan, Grace; Charkowski, Amy O; Barak, Jeri D

    2013-02-12

    Although enteric human pathogens are usually studied in the context of their animal hosts, a significant portion of their life cycle occurs on plants. Plant disease alters the phyllosphere, leading to enhanced growth of human pathogens; however, the impact of human pathogens on phytopathogen biology and plant health is largely unknown. To characterize the interaction between human pathogens and phytobacterial pathogens in the phyllosphere, we examined the interactions between Pectobacterium carotovorum subsp. carotovorum and Salmonella enterica or Escherichia coli O157:H7 with regard to bacterial populations, soft rot progression, and changes in local pH. The presence of P. carotovorum subsp. carotovorum enhanced the growth of both S. enterica and E. coli O157:H7 on leaves. However, in a microaerophilic environment, S. enterica reduced P. carotovorum subsp. carotovorum populations and soft rot progression by moderating local environmental pH. Reduced soft rot was not due to S. enterica proteolytic activity. Limitations on P. carotovorum subsp. carotovorum growth, disease progression, and pH elevation were not observed on leaves coinoculated with E. coli O157:H7 or when leaves were coinoculated with S. enterica in an aerobic environment. S. enterica also severely undermined the relationship between the phytobacterial population and disease progression of a P. carotovorum subsp. carotovorum budB mutant defective in the 2,3-butanediol pathway for acid neutralization. Our results show that S. enterica and E. coli O157:H7 interact differently with the enteric phytobacterial pathogen P. carotovorum subsp. carotovorum. S. enterica inhibition of soft rot progression may conceal a rapidly growing human pathogen population. Whereas soft rotted produce can alert consumers to the possibility of food-borne pathogens, healthy-looking produce may entice consumption of contaminated vegetables. Salmonella enterica and Escherichia coli O157:H7 may use plants to move between animal

  3. Efficacy of gaseous ozone to counteract postharvest table grape sour rot.

    Science.gov (United States)

    Pinto, L; Caputo, L; Quintieri, L; de Candia, S; Baruzzi, F

    2017-09-01

    This work aims at studying the efficacy of low doses of gaseous ozone in postharvest control of the table grape sour rot, a disease generally attributed to a consortium of non-Saccharomyces yeasts (NSY) and acetic acid bacteria (AAB). Sour rot incidence of wounded berries, inoculated with 8 NSYstrains, or 7 AAB, or 56 yeast-bacterium associations, was monitored at 25 °C up to six days. Sour rot incidence in wounded berries inoculated with yeast-bacterium associations resulted higher than in berries inoculated with one single NSY or AAB strain. Among all NSY-AAB associations, the yeast-bacterium association composed of Candida zemplinina CBS 9494 (Cz) and Acetobacter syzygii LMG 21419 (As) showed the highest prevalence of sour rot; thus, after preliminary in vitro assays, this simplified As-Cz microbial consortium was inoculated in wounded berries that were stored at 4 °C for ten days under ozone (2.14 mg m -3 ) or in air. At the end of cold storage, no berries showed sour-rot symptoms although ozonation mainly affected As viable cell count. After additional 12 days at 25 °C, the sour rot index of inoculated As-Cz berries previously cold-stored under ozone or in air accounted for 22.6 ± 3.7% and 66.7 ± 4.5%, respectively. Molecular analyses of dominant AAB and NSY populations of both sound and rotten berries during post-refrigeration period revealed the appearance of new strains mainly belonging to Gluconobacter albidus and Hanseniaspora uvarum species, respectively. Cold ozonation resulted an effective approach to extend the shelf-life of table grapes also after cold storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Using airborne imagery to monitor cotton root rot infection before and after fungicide treatment

    Science.gov (United States)

    Cotton root rot is a severe soilborne disease that has affected cotton production for over a century. Recent research has shown that a commercial fungicide, flutriafol, has potential for the control of this disease. To effectively and economically control this disease, it is necessary to identify in...

  5. Biological control of banana black Sigatoka disease with Trichoderma

    Directory of Open Access Journals (Sweden)

    Poholl Adan Sagratzki Cavero

    2015-06-01

    Full Text Available Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation

  6. Biochemical response and host-pathogen relation of stalk rot fungi ...

    African Journals Online (AJOL)

    Stalk rot is a destructive disease in maize caused by Fusarium and Macrophomina species. A study was carried out to understand the mode of infection, host biochemical response and comparison of inoculation techniques in Fusarium verticillioides and Macrophomina phaseolina in maize. In seed inoculation experiment, ...

  7. RESISTANCE TO POST-HARVEST MICROBIAL ROT IN YAM ...

    African Journals Online (AJOL)

    ACSS

    for resistance to internal rot, with Olordor and Kplondzo recording the lowest internal microbial rot, suggesting their potential in .... material. Dried maize stocks were then used to cover the pile of tubers. There were four .... effort in breeding for host plant resistance. Also, ... rot in Dioscorea species under all storage methods.

  8. Potential of bulb-associated bacteria for biocontrol of hyacinth soft rot caused by Dickeya zeae.

    Science.gov (United States)

    Jafra, S; Przysowa, J; Gwizdek-Wiśniewska, A; van der Wolf, J M

    2009-01-01

    Dickeya zeae is a pectinolytic bacterium responsible for soft rot disease in flower bulb crops. In this study, the possibility of controlling soft rot disease in hyacinth by using antagonistic bacteria isolated from hyacinth bulbs was explored. Bacterial isolates with potential for biocontrol were selected on the basis of antibiosis against D. zeae, siderophore production, and the N-acyl homoserine lactones (AHLs)-inactivation. In in vitro assays, 35 out of 565 hyacinth-associated bacterial isolates produced antimicrobial substances against D. zeae, whereas 20 degraded AHLs, and 35 produced siderophores. Isolates of interest were identified by 16S rDNA sequence analysis and reaction in BIOLOG tests. Twenty-six isolates that differed in characteristics were selected for pathogenicity testing on hyacinth cultivars, Pink Pearl and Carnegie. Two strains identified as Rahnella aquatilis and one as Erwinia persicinus significantly reduced tissue maceration caused by D. zeae 2019 on hyacinth bulbs, but not on leaves. Hyacinth bulbs harbour bacteria belonging to different taxonomic groups that are antagonistic to D. zeae, and some can attenuate decay of bulb tissue. Selected hyacinth-associated bacterial isolates have potential for control of soft rot disease caused by D. zeae in hyacinth bulb production.

  9. 7 CFR 29.6039 - Stem rot.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  10. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  11. Efficacy of four plant extracts in the control of root rot disease of ...

    African Journals Online (AJOL)

    Garcinia cola) and neem (Azadirachta indica) extracts in the control of root rot of cowpea caused by Pythium aphanidermatum was carried out in vitro and in the field (in vivo). They were evaluated for their antifungal activity over P.

  12. Studies on black stain root disease in ponderosa pine. pp. 236-240. M. Garbelotto & P. Gonthier (Editors). Proceedings 12th International Conference on Root and Butt Rots of Forest Trees.

    Science.gov (United States)

    W. J. Otrosina; J. T. Kliejunas; S. S. Sung; S. Smith; D. R. Cluck

    2008-01-01

    Black stain root disease of ponderosa pine, caused by Lepfographium wageneri var. ponderosum (Harrington & Cobb) Harrington & Cobb, is increasing on many eastside pine stands in northeastern California. The disease is spread from tree to tree via root contacts and grafts but new infections are likely vectored by root...

  13. Fusarium basal rot in the Netherlands

    NARCIS (Netherlands)

    Visser, de C.L.M.; Broek, van den R.C.F.M.; Brink, van den L.

    2006-01-01

    Fusarium basal rot of onion, caused by Fusarium oxysporum f.sp. cepae, is a steadily increasing problem in The Netherlands. Financial losses for Dutch farmers confronted with Fusarium basal rot is substantial, due to yield reduction and high storage costs. This paper describes the development and

  14. BIOMODIFICATION OF KENAF USING WHITE ROT FUNGI

    OpenAIRE

    Rasmina Halis,; Hui Rus Tan,; Zaidon Ashaari,; Rozi Mohamed

    2012-01-01

    White rot fungi can be used as a pretreatment of biomass to degrade lignin. It also alters the structure of the lignocellulosic matter, thus increasing its accessibility to enzymes able to convert polysaccharides into simple sugars. This study compares the ability of two species of white rot fungi, Pycnoporous sanguineus and Oxyporus latemarginatus FRIM 31, to degrade lignin in kenaf chips. The white rot fungi were originally isolated from the tropical forest in Malaysia. Kenaf chips were fir...

  15. Identification of sources of resistance to anthracnose stalk rot in maize

    Directory of Open Access Journals (Sweden)

    Alessandro Nicoli

    Full Text Available ABSTRACT: Adoption of resistant cultivars is the primary measure used to control anthracnose stalk rot. The goal of this study was to identify maize-resistant genotypes to anthracnose stalk rot, which are similar to the hybrid 2B710. Experiments were performed at Embrapa Maize and Sorghum experimental fields in Brazil. The first experimental trial evaluated 234 maize lines as well as two commercials hybrids, BRS1010 (susceptible and 2B710 (resistant. Artificial inoculations were performed with a strain at the blister (R2 phase, and evaluation of disease severity was performed after 30 days. The second experimental trial evaluated 48 maize lines and hybrids, inoculated with two Colletotrichum graminicola strains. In the first trial, eight resistance groups were formed, and the last lines were more resistant, as was the hybrid 2B710, with values between 11.50% and 23.0% of severity. In the second trial, there was an interaction between the two factors, lines and isolates, and the lines often showed the same reaction features as those obtained in the first trial. However, the disease severity was higher for most lines, even when using other isolates. These lines with effective levels of resistance could be used in future studies of inheritance, in programs to develop hybrids, and to identify molecular markers associated with resistance to anthracnose stalk rot in maize.

  16. Root rots of common and tepary beans in Puerto Rico

    Science.gov (United States)

    Root rots are a disease complex affecting common bean and can be severe in bean growing areas in the tropics and subtropics. The presence of several pathogens makes it difficult to breed for resistance because of the synergistic effect of the pathogens in the host and the interaction of soil factors...

  17. Speech characteristics of miners with black lung disease (pneumoconiosis).

    Science.gov (United States)

    Gilbert, H R

    1975-06-01

    Speech samples were obtained from 10 miners with diagnosed black lung disease and 10 nonminers who had never worked in a dusty environment and who had no history of respiratory diseases. Frequency, intensity and durational measures were used as a basis upon which to compare the two groups. Results indicated that four of the six pausal measures, vowel duration, vowel intensity variation and vowel perturbation differentiated the miners from the nonminers. The results indicate that black lung disease may affect not only respiratory physiology associated with speech production but also laryngeal physiology.

  18. Fungi associated with fruit crown rot in organic banana (Musa spp. L. in Piura, Peru

    Directory of Open Access Journals (Sweden)

    René Aguilar Anccota

    2013-05-01

    Full Text Available The department of Piura is the principal banana-producing zone in Peru, sharing 87% of exportations. In this zone, one of the most important postharvest diseases is crown rot. The economic loses attributed to this disease are estimated to be between 25 and 30% of organic bananas exported. The objective of this study was to identify the causal agents associated with this disease. Samples taken refrigerated fruit from the areas of Querecotillo, Salitral and Mallares were taken and selected after the fact. Thielaviopsis paradoxa, Lasiodiplodia theobromae, Colletotrichum musae and Fusarium verticilloides. In order to demonstrate the pathogenicity of the isolated species, inoculations were given in the area of the crown of the fruit on healthy bananas. These fungi caused symptoms of infection in different proportions, concluding that crown rot is a disease with a complex etiology.

  19. Creating prescription maps from historical imagery for site-specific management of cotton root rot

    Science.gov (United States)

    Cotton root rot, caused by the soilborne fungus Phymatotrichopsis omnivore, is a severe plant disease that has affected cotton production for over a century. Recent research found that a commercial fungicide, Topguard (flutriafol), was able to control this disease. As a result, Topguard Terra Fungic...

  20. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

    Energy Technology Data Exchange (ETDEWEB)

    D`Souza, T.M.; Boominathan, K.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States)

    1996-10-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.

  1. Black-white differences in infectious disease mortality in the United States

    NARCIS (Netherlands)

    J.H. Richardus (Jan Hendrik); A.E. Kunst (Anton)

    2001-01-01

    textabstractOBJECTIVES: This study determined the degree to which Black-White differences in infectious disease mortality are explained by income and education and the extent to which infectious diseases contribute to Black-White differences in all-cause mortality. METHODS: A

  2. Management of chili pepper root rot and wilt (caused by Phytophthora nicotianae by grafting onto resistant rootstock

    Directory of Open Access Journals (Sweden)

    Mourad SAADOUN

    2013-05-01

    Full Text Available Root rot and plant wilting caused by Phytophthora nicotianae is a severe disease of chili pepper (Capsicum annuum L. in open fields and under greenhouse production in Tunisia. Chili pepper grafting for disease manage- ment is attracting increased interest in recent years. Using the tube grafting technique, different compatible scion/rootstock combinations were obtained with the wild-type pepper SCM334 and the local chili pepper cultivars ‘Beldi’ and ‘Baker’. SCM334 was resistant to P. nicotianae, while the cultivars Beldi and Baker were susceptible. Plant inoculations were performed with P. nicotianae zoospores, and severity of root rot was rated 30 days post- inoculation using a 0 (healthy plant to 5 (dead plant severity score. On SCM334 rootstock and with ‘Beldi’ or ‘Baker’ scions, the intensity of root rot was very low (mean score 0.1–0.2 and plants were healthy. However, with Baker or Beldi rootstocks and SCM334 scions, root rot was severe (mean score 3.1–4.6, leading to high numbers of wilting and dead plants. This severe root rot was similar to that observed on non-grafted plants of ‘Baker’ and ‘Beldi’ inoculated with the pathogen. Under greenhouse conditions, measurements of agronomic characters indicated non-consistent improvement of these features on the scion cultivar when SCM334 was the rootstock. Since plant foliage is not attacked by this pathogen, these results show that susceptible chili pepper scions grafted onto SCM334 rootstocks could be used for root rot management and improvement of pepper yields in P. nicotianae infested soils.

  3. First report of anthracnose fruit rot of blueberry caused by Colletotrichum fioriniae in New Jersey

    Science.gov (United States)

    Anthracnose fruit rot is the most important disease of blueberry in New Jersey. Most fungicide applications in New Jersey and other blueberry growing regions is for the control of this disease. The causal agent of this disease has been reported to be Colletotrichum acutatum and other species in the ...

  4. Simultaneous Detection of Brown Rot- and Soft Rot-Causing Bacterial Pathogens from Potato Tubers Through Multiplex PCR.

    Science.gov (United States)

    Ranjan, R K; Singh, Dinesh; Baranwal, V K

    2016-11-01

    Ralstonia solanacearum (Smith) Yabuuchi et al. and Erwinia carotovora subsp. carotovora (Jones) Bergey et al. (Pectobacterium carotovorum subsp. carotovorum) are the two major bacterial pathogens of potato causing brown rot (wilt) and soft rot diseases, respectively, in the field and during storage. Reliable and early detection of these pathogens are keys to avoid occurrence of these diseases in potato crops and reduce yield loss. In the present study, multiplex polymerase chain reaction (PCR) protocol was developed for simultaneous detection of R. solanacearum and E. carotovora subsp. carotovora from potato tubers. A set of oligos targeting the pectatelyase (pel) gene of E. carotovora subsp. carotovora and the universal primers based on 16S r RNA gene of R. solanacearum were used. The standardized multiplex PCR protocol could detect R. solanacearum and E. carotovora subsp. carotovora up to 0.01 and 1.0 ng of genomic DNA, respectively. The protocol was further validated on 96 stored potato tuber samples, collected from different potato-growing states of India, viz. Uttarakhand, Odisha, Meghalaya and Delhi. 53.1 % tuber samples were positive for R. solanacearum, and 15.1 % of samples were positive for E. carotovora subsp. carotovora, and both the pathogens were positive in 26.0 % samples when BIO-PCR was used. This method offers sensitive, specific, reliable and fast detection of two major bacterial pathogens from potato tubers simultaneously, particularly pathogen-free seed certification in large scale.

  5. First report of frosty pod rot caused by Moniliophthora roreri on cacao in Bolivia

    Science.gov (United States)

    Frosty pod rot (FPR) is a devastating cacao disease caused by the basidiomycete Moniliophthora roreri (Aime and Phillips-Mora, 2005). The disease is confined to 13 countries in Central and South America and constitutes a permanent threat for cacao cultivation worldwide. In July 2012, FPR was detect...

  6. Gaucher's disease in a black child in South Africa. A case report.

    Science.gov (United States)

    Patel, R; MacDougall, L G

    1984-09-01

    A 7-year-old Black boy presented with massive splenomegaly and a tendency to haemorrhage due to type 1 Gaucher's disease. After splenectomy he became asymptomatic and the haematological parameters returned to normal. Although type 1 Gaucher's disease has been described in adult Blacks, it has not been reported previously in a Black child in southern Africa.

  7. Black-white differences in infectious disease mortality in the United States

    NARCIS (Netherlands)

    Richardus, J. H.; Kunst, A. E.

    2001-01-01

    OBJECTIVES: This study determined the degree to which Black-White differences in infectious disease mortality are explained by income and education and the extent to which infectious diseases contribute to Black-White differences in all-cause mortality. METHODS: A sample population of the National

  8. Genetic Architecture of Charcoal Rot (Macrophomina phaseolina) Resistance in Soybean Revealed Using a Diverse Panel

    Science.gov (United States)

    Charcoal rot disease caused by Macrophomina phaseolina is responsible for significant yield losses in soybean production. Among the methodologies available for controlling this disease, breeding for resistance is the most promising. Progress in breeding efforts has been slow due to the insufficient ...

  9. Shade tree spatial structure and pod production explain frosty pod rot intensity in cacao agroforests, Costa Rica.

    Science.gov (United States)

    Gidoin, Cynthia; Avelino, Jacques; Deheuvels, Olivier; Cilas, Christian; Bieng, Marie Ange Ngo

    2014-03-01

    Vegetation composition and plant spatial structure affect disease intensity through resource and microclimatic variation effects. The aim of this study was to evaluate the independent effect and relative importance of host composition and plant spatial structure variables in explaining disease intensity at the plot scale. For that purpose, frosty pod rot intensity, a disease caused by Moniliophthora roreri on cacao pods, was monitored in 36 cacao agroforests in Costa Rica in order to assess the vegetation composition and spatial structure variables conducive to the disease. Hierarchical partitioning was used to identify the most causal factors. Firstly, pod production, cacao tree density and shade tree spatial structure had significant independent effects on disease intensity. In our case study, the amount of susceptible tissue was the most relevant host composition variable for explaining disease intensity by resource dilution. Indeed, cacao tree density probably affected disease intensity more by the creation of self-shading rather than by host dilution. Lastly, only regularly distributed forest trees, and not aggregated or randomly distributed forest trees, reduced disease intensity in comparison to plots with a low forest tree density. A regular spatial structure is probably crucial to the creation of moderate and uniform shade as recommended for frosty pod rot management. As pod production is an important service expected from these agroforests, shade tree spatial structure may be a lever for integrated management of frosty pod rot in cacao agroforests.

  10. Root rot symptoms in sugar beet lines caused by Fusarium oxysporum f. sp. betae

    Science.gov (United States)

    The soil-borne fungus Fusarium oxysporum may cause both Fusarium yellows and Fusarium root rot diseases with severe yield losses in cultivated sugar beet worldwide. These two diseases cause similar foliar symptoms but different root response and have been proposed to be due to two distinct F. oxyspo...

  11. Diagnostic of dry rot in living trees

    International Nuclear Information System (INIS)

    Schaetzler, H.P.

    1978-01-01

    The γ-desorption method has been used in the early diagnosis of dry rot in trees. The attenuation of a 60 keV γ-beam ( 241 Am) has been measured on eleven healthy spruce disks. It is seen that early diagnostic of rotten trees is limited by natural density variation of the wood itself, but for a 95% confidence level that the wood is diseased, a tree must have an average of less than 0.59 g./cm 3 . (Auth/C.F.)

  12. Symptoms of main Callistephus chinensis L. Nees. diseases under Ukrainian urban ecosystem conditions of the forest-steppe zone

    Directory of Open Access Journals (Sweden)

    Marchenko Alla

    2017-12-01

    Full Text Available Phytopathological monitoring of C. chinensis (L. Nees. has proven withering and root rot to be the dominating diseases in agrobiocenoses under Ukrainian urban ecosystem conditions of the forest-steppe zone. Their spread was 5,1 and 4 times more than one of spotting. The complex of plant pathogenic overground and underground microflora consists of 24 causative agents. B. cinerea, F. oxysporum, V. albo-atrum have been found on all the vegetative and reproductive parts of Callistephus chinensis (L. Nees., , Ph. cactorum – on plant overground and underground parts, Rh. solani – on underground parts and seeds, A. zinniae – on overground parts and seeds. The main C. chinensis (L. Nees. disease symptoms have been diagnosed (leaf spots, powdery mildew, verticillium wilt, rust, ramularia spot, septoria spots, botrytis blight, grey mold rot, late blight, fusarium blight, black stem.

  13. Combining fuzzy set theory and nonlinear stretching enhancement for unsupervised classification of cotton root rot

    Science.gov (United States)

    Cotton root rot is a destructive disease affecting cotton production. Accurate identification of infected areas within fields is useful for cost-effective control of the disease. The uncertainties caused by various infection stages and newly infected plants make it difficult to achieve accurate clas...

  14. Seventeen years of research on genetics of resistance to Aphanomyces root rot of pea

    Science.gov (United States)

    Aphanomyces root rot, caused by the oomycete Aphanomyces euteiches, is a major soil borne disease of pea in many countries. Genetic resistance is considered to be a main way to control the disease. Since 2000, INRA has engaged a long-term research program to study genetic resistance to A. euteiches ...

  15. Creating prescription maps from satellite imagery for site-specific management of cotton root rot

    Science.gov (United States)

    Cotton root rot is a century-old cotton disease that can now be controlled with Topguard Terra Fungicide. However, as this disease tends to occur in the same general areas within fields year after year, site-specific treatment can be more effective and economical. The objective of this study was to ...

  16. Pathogen toxin-indiced electrolyte leakage and phytoalexin accumulation as indices of red-rot (Colletotrichum falcatum Went resistance in sugarcane

    Directory of Open Access Journals (Sweden)

    D. Mohanraj

    2003-08-01

    Full Text Available A phytotoxin produced by the sugarcane red-rot fungus Colletotrichum falcatum Went was partially purified. The phytotoxin caused increased electrolyte leakage in susceptible sugarcane varieties and higher levels of phytoalexins (3-deoxyanthocyanidins in resistant sugarcane varieties. This relationship between phytotoxin induced changes and disease reaction could possibly be used as an additional index to rapidly identify red-rot resistant varieties.

  17. Enhancing biological control of basal stem rot disease (Ganoderma boninense) in oil palm plantations.

    Science.gov (United States)

    Susanto, A; Sudharto, P S; Purba, R Y

    2005-01-01

    Basal Stem Rot (BSR) disease caused by Ganoderma boninense is the most destructive disease in oil palm, especially in Indonesia and Malaysia. The available control measures for BSR disease such as cultural practices and mechanical and chemical treatment have not proved satisfactory due to the fact that Ganoderma has various resting stages such as melanised mycelium, basidiospores and pseudosclerotia. Alternative control measures to overcome the Ganoderma problem are focused on the use of biological control agents and planting resistant material. Present studies conducted at Indonesian Oil Palm Research Institute (IOPRI) are focused on enhancing the use of biological control agents for Ganoderma. These activities include screening biological agents from the oil palm rhizosphere in order to evaluate their effectiveness as biological agents in glasshouse and field trials, testing their antagonistic activities in large scale experiments and eradicating potential disease inoculum with biological agents. Several promising biological agents have been isolated, mainly Trichoderma harzianum, T. viride, Gliocladium viride, Pseudomonas fluorescens, and Bacillus sp. A glasshouse and field trial for Ganoderma control indicated that treatment with T. harzianum and G. viride was superior to Bacillus sp. A large scale trial showed that the disease incidence was lower in a field treated with biological agents than in untreated fields. In a short term programme, research activities at IOPRI are currently focusing on selecting fungi that can completely degrade plant material in order to eradicate inoculum. Digging holes around the palm bole and adding empty fruit bunches have been investigated as ways to stimulate biological agents.

  18. Biocontrol with Trichoderma species for the management of postharvest crown rot of banana

    Directory of Open Access Journals (Sweden)

    G. Sangeetha

    2009-09-01

    Full Text Available Lasiodiplodia theobromae and Colletotrichum musae cause the postharvest crown rot disease complex of banana. In vitro experiments evaluated the effect of twelve isolates of Trichoderma spp. from the soil of organic banana orchards (‘native isolates’ and eight isolates of Trichoderma spp. from culture collections (‘introduced isolates’ on the two pathogens. The native and introduced Trichoderma spp. had varied antagonistic effects against the two pathogens. Eight Trichoderma spp. isolates effective in the in vitro assays were evaluated singly on fruits both at room temperature and in cold storage. Single antagonists did not satisfactorily control crown rot on the fruits as compared with the fungicide carbendazim. However, two isolates of T. viride, one of T. harzianum and one of T. koningii performed well when applied singly, and these were selected for evaluation in isolate mixtures. There was very little antagonism between these isolates. Of 11 two-way, three-way and four-way mixtures of these isolates, the four-way and a three-way mixtures reduced crown rot incidence, both at room temperature and in cold storage, giving better control than carbendazim. The study identified consortia of compatible Trichoderma antagonists with superior biocontrol potential for the management of the postharvest crown rot complex of banana.

  19. Quantifying the Severity of Phytophthora Root Rot Disease in Avocado Trees Using Image Analysis

    Directory of Open Access Journals (Sweden)

    Arachchige Surantha Ashan Salgadoe

    2018-02-01

    Full Text Available Phytophthora root rot (PRR infects the roots of avocado trees, resulting in reduced uptake of water and nutrients, canopy decline, defoliation, and, eventually, tree mortality. Typically, the severity of PRR disease (proportion of canopy decline is assessed by visually comparing the canopy health of infected trees to a standardised set of photographs and a corresponding disease rating. Although this visual method provides some indication of the spatial variability of PRR disease across orchards, the accuracy and repeatability of the ranking is influenced by the experience of the assessor, the visibility of tree canopies, and the timing of the assessment. This study evaluates two image analysis methods that may serve as surrogates to the visual assessment of canopy decline in large avocado orchards. A smartphone camera was used to collect red, green, and blue (RGB colour images of individual trees with varying degrees of canopy decline, with the digital photographs then analysed to derive a canopy porosity percentage using a combination of ‘Canny edge detection’ and ‘Otsu’s’ methods. Coinciding with the on-ground measure of canopy porosity, the canopy reflectance characteristics of the sampled trees measured by high resolution Worldview-3 (WV-3 satellite imagery was also correlated against the observed disease severity rankings. Canopy porosity values (ranging from 20–70% derived from RGB images were found to be significantly different for most disease rankings (p < 0.05 and correlated well (R2 = 0.89 with the differentiation of three disease severity levels identified to be optimal. From the WV-3 imagery, a multivariate stepwise regression of 18 structural and pigment-based vegetation indices found the simplified ratio vegetation index (SRVI to be strongly correlated (R2 = 0.96 with the disease rankings of PRR disease severity, with the differentiation of four levels of severity found to be optimal.

  20. Effect of bunch rot on the sensory characteristics of the Gewürztraminer wine

    Directory of Open Access Journals (Sweden)

    Julio Meneguzzo

    2008-06-01

    Significance and impact of the study: In viticultural regions characterized by rainy and hot summers many pathogens have appropriate conditions to develop. In this way, to make quality wines it is very important to control grape rot diseases in the vineyards and to avoid grapes infected with pathogens related to these diseases during vinification.

  1. Characterization of calla Lily sot rot caused by Pectobacterium Carotovorum subsp. Carotovorum ZT0505 bacterial growth and pectate lyase activity under different conditions.

    NARCIS (Netherlands)

    Ni, L.; Guo, L.; Custers, J.B.M.; Zhang, L.

    2010-01-01

    Soft rot is a major disease of calla lily (Zantedeschia spp.) and other important crops worldwide. In this report, the bacterial isolate ZT0505 proved to be a soft rot pathogen of calla lily growing around Kunming (subtropical China) and was identified as Pectobacterium carotovorum subsp.

  2. Rhizoctonia solani as a component in the bottom rot complex of glasshouse lettuce

    NARCIS (Netherlands)

    Kooistra, T.

    1983-01-01

    The basal parts of maturing glasshouse lettuce can be attacked by several soil fungi, which cause bottom rot. Until recently quintozene was generally applied against this disease complex. The study of the causal fungi - especially Rhizoctonia solani - and their control was

  3. Mechanisms of qualitative and quantitative resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot (ARR), caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa (Medicago sativa) in the United States. Two races of the pathogen are currently recognized. Most modern alfalfa cultivars have high levels of resistance to race 1 but few cultivars have resi...

  4. Isolation and identification of bacteria causing blackleg and soft rot of potato

    Science.gov (United States)

    Both Dickeya and Pectobacterium spp. are important causal agents of blackleg and soft rot of potato. To understand the outbreak of blackleg in the Northeastern U.S. in 2015, samples were collected from symptomatic plants, dormant tubers, and surface water in 2016 and 2017. Diseased plant samples wer...

  5. Pathogenesis and Treatment of Bovine Foot Rot.

    Science.gov (United States)

    Van Metre, David C

    2017-07-01

    Bovine foot rot (BFR) is an infectious disease of the interdigital skin and subcutaneous tissues of beef and dairy cattle that occurs under a variety of management and environmental settings. The anaerobic, gram-negative bacteria Fusobacterium necrophorum, Porphyromonas levii, and Prevotella intermedia are commonly isolated from lesions. A multitude of host, agent, and environmental factors contribute to the development of BFR. Initiation of systemic antimicrobial therapy early in the course of disease commonly leads to resolution. Delays in treatment may result in extension of infection into deeper bone, synovial structures, or ligamentous structures, and the prognosis for recovery is reduced. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Co-inoculation with rhizobia and AMF inhibited soybean red crown rot: from field study to plant defense-related gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases.We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for co-inoculation with rhizobia and AMF at low P. The root colony forming unit (CFU decreased over 50% when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF.Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined with optimal P fertilization, inoculation with rhizobia and AMF could be considered as an efficient method to control soybean red crown rot in acid soils.

  7. Biodegrading effects of some rot fungi on Pinus caribaea wood

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... species of white-rot fungi; Corioliopsis polyzona and Pleurotus squarrosulus, and two species of brown- rot fungi; Lentinus ... The results indicated that biodegradation by rot fungi differs in intensity according to the fungus ..... wood of coast red wood Sequoia Sempervirens (D. Don). For. Prod. J. 33(5): 15-20 ...

  8. Biological Control Of The Egyptian Brown Rot In Potato (Solanum Tuberosum L.)

    International Nuclear Information System (INIS)

    Salem, E.A.; Askora, A. M.

    2012-01-01

    Pseudomonas fluorescence, P. aeruginosa, Bacillus subtillus and streptomyces spp. Were used in control of Ralstonia solanacearum, the casual agent of brown rot in potato. In vitro, antagonistic activities showed that streptomyces spp. was the most antagonistic followed by P. fluorescence, Bacillus subtilus and P. aeruginosa respectively. Also, in vivo, biological control of R. solanacearum showed that Streptomyces spp. was found to reduce the percentage of brown rot infection to 5% followed by P. fluorescence, Bacillus subtilus and P. aeruginosa reducing the percentage of infection to 15 , 25 and 40%, respectively. Also, the disease severity when using Streptomyces spp. and P. fluorescence was reduced from 5 to 1 and reduced from 5 to 2 when using Bacillus subtilus and P. aeruginosa.

  9. Site-specific management of cotton root rot using historical remote sensing imagery

    Science.gov (United States)

    Cotton root rot can now be effectively controlled with Topguard Terra Fungicide, but site-specific application of the fungicide can greatly reduce treatment cost as only portions of the field are infested with the disease. The overall goal of this three-year project was to demonstrate how to use his...

  10. Control of Basal Stem Rot Disease in Oil Palm by Supplementation of Calcium, Copper, and Salicylic Acid

    Science.gov (United States)

    Bivi, M. Shahul Hamid Rahamah; Paiko, Adamu Saidu; Khairulmazmi, Ahmad; Akhtar, M. S.; Idris, Abu Seman

    2016-01-01

    Continuous supplementation of mineral nutrients and salicylic acid (SA) as foliar application could improve efficacy in controlling basal stem rot (BSR) disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3%) was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA]) (5.0%) followed by T1 (5.5%), T5 (5.8%), T3 (8.3%), T6 (8.3%), T4 (13.3%), and T2 (15.8%) treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease. PMID:27721689

  11. Control of Basal Stem Rot Disease in Oil Palm by Supplementation of Calcium, Copper, and Salicylic Acid.

    Science.gov (United States)

    Bivi, M Shahul Hamid Rahamah; Paiko, Adamu Saidu; Khairulmazmi, Ahmad; Akhtar, M S; Idris, Abu Seman

    2016-10-01

    Continuous supplementation of mineral nutrients and salicylic acid (SA) as foliar application could improve efficacy in controlling basal stem rot (BSR) disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3%) was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA]) (5.0%) followed by T1 (5.5%), T5 (5.8%), T3 (8.3%), T6 (8.3%), T4 (13.3%), and T2 (15.8%) treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease.

  12. Control of Basal Stem Rot Disease in Oil Palm by Supplementation of Calcium, Copper, and Salicylic Acid

    Directory of Open Access Journals (Sweden)

    M. Shahul Hamid Rahamah Bivi

    2016-10-01

    Full Text Available Continuous supplementation of mineral nutrients and salicylic acid (SA as foliar application could improve efficacy in controlling basal stem rot (BSR disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3% was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA] (5.0% followed by T1 (5.5%, T5 (5.8%, T3 (8.3%, T6 (8.3%, T4 (13.3%, and T2 (15.8% treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease.

  13. Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years - United States, 1968-2015.

    Science.gov (United States)

    Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele

    2018-03-30

    Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. 1968-2015. The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968-2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968-2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases occurring during the 1970s and 1980s followed by small but steady

  14. Variable intertidal temperature explains why disease endangers black abalone

    Science.gov (United States)

    Ben-Horin, Tal; Lenihan, Hunter S.; Lafferty, Kevin D.

    2013-01-01

    Epidemiological theory suggests that pathogens will not cause host extinctions because agents of disease should fade out when the host population is driven below a threshold density. Nevertheless, infectious diseases have threatened species with extinction on local scales by maintaining high incidence and the ability to spread efficiently even as host populations decline. Intertidal black abalone (Haliotis cracherodii), but not other abalone species, went extinct locally throughout much of southern California following the emergence of a Rickettsiales-like pathogen in the mid-1980s. The rickettsial disease, a condition known as withering syndrome (WS), and associated mortality occur at elevated water temperatures. We measured abalone body temperatures in the field and experimentally manipulated intertidal environmental conditions in the laboratory, testing the influence of mean temperature and daily temperature variability on key epizootiological processes of WS. Daily temperature variability increased the susceptibility of black abalone to infection, but disease expression occurred only at warm water temperatures and was independent of temperature variability. These results imply that high thermal variation of the marine intertidal zone allows the pathogen to readily infect black abalone, but infected individuals remain asymptomatic until water temperatures periodically exceed thresholds modulating WS. Mass mortalities can therefore occur before pathogen transmission is limited by density-dependent factors.

  15. Biodiversity of Fusarium species in Mexico associated with ear rot in maize, and their identification using a phylogenetic approach.

    Science.gov (United States)

    Morales-Rodríguez, Irma; Yañez-Morales, María de J; Silva-Rojas, Hilda V; García-de-Los-Santos, Gabino; Guzmán-de-Peña, Doralinda A

    2007-01-01

    Fusarium proliferatum, F. subglutinans, and F. verticillioides are known causes of ear and kernel rot in maize worldwide. In Mexico, only F. verticillioides and F. subglutinans, have been reported previously as causal agents of this disease. However, Fusarium isolates with different morphological characteristics to the species that are known to cause this disease were obtained in the Highland-Valley region of this country from symptomatic and symptomless ears of native and commercial maize genotypes. Moreover, while the morphological studies were not sufficient to identify the correct taxonomic position at the species level, analyses based in the Internal Transcribed Spacer region and the Nuclear Large Subunit Ribosomal partial sequences allowed for the identification of F. subglutinans, F. solani, and F. verticillioides, as well as four species (F. chlamydosporum, F. napiforme, F. poae, and F. pseudonygamai) that had not previously been reported to be associated with ear rot. In addition, F. napiforme and F. solani were absent from symptomless kernels. Phylogenetic analysis showed genetic changes in F. napiforme, and F. pseudonygamai isolates because they were not true clones, and probably constitute separate sibling species. The results of this study suggest that the biodiversity of Fusarium species involved in ear rot in Mexico is greater than that reported previously in other places in the world. This new knowledge will permit a better understanding of the relationship between all the species involved in ear rot disease and their relationship with maize.

  16. Detection, Occurrence, and Survey of Rice Stripe and Black-Streaked Dwarf Diseases in Zhejiang Province, China

    OpenAIRE

    Heng-mu ZHANG; Hua-di WANG; Jian YANG; Michael J ADAMS; Jian-ping CHEN

    2013-01-01

    The major viral diseases that occur on rice plants in Zhejiang Province, eastern China, are stripe and rice black-streaked dwarf diseases. Rice stripe disease is only caused by rice stripe tenuivirus (RSV), while rice black-streaked dwarf disease can be caused by rice black-streaked dwarf fijivirus (RBSDV) and/or southern rice black-streaked dwarf fijivirus (SRBSDV). Here we review the characterization of these viruses, methods for their detection, and extensive surveys showing their occurren...

  17. Lettuce genotype resistance to "soft rot" caused by Pectobacterium carotovorum subsp. carotovorum

    Directory of Open Access Journals (Sweden)

    Kátia Cilene da Silva Felix

    2014-08-01

    Full Text Available Soft rot, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc, is the main bacterial disease affecting lettuce (Lactuca sativa L. crops in Brazil and leads to significant yield losses. This study aimed to assess the reaction of lettuce genotypes to soft rot induced by a virulent isolate and the stability of the resistance to three isolates varying in virulence. Using a descriptive ordinal scale ranging from 1 to 9 a classification system was defined: class 1 = resistant (R: severity (Sev 3.5. Of the 41 tested genotypes, 14 were classified as MR and 27 as S when inoculated with a Pcc isolate of intermediate virulence. Eleven of these genotypes (four S and seven MR were selected to test their resistance stability against three other isolates with an increasing degree of virulence (Pcc36 < Pcc-A1.1 < Pcc-23. Out of the 11 genotypes eight retained the original classification and three moved from S to MR resistant class when challenged with the least virulent isolate. Vitória de Santo Antão was the only genotype classified as MR for all tested isolates and is a promising candidate for durable soft rot resistance breeding.

  18. Wilt, crown, and root rot of common rose mallow (Hibiscus moscheutos) caused by a novel Fusarium sp

    Science.gov (United States)

    A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to complete Koch's postulates, document the disease sypmtoms photographically, and iden...

  19. Nitric oxide production by necrotrophic pathogen Macrophomina phaseolina and the host plant in charcoal rot disease of jute: complexity of the interplay between necrotroph-host plant interactions.

    Directory of Open Access Journals (Sweden)

    Tuhin Subhra Sarkar

    Full Text Available M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2',7'-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction.

  20. Mutant of Japanese pear resistant to Black Spot Disease

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1987-01-01

    Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

  1. REACTION OF INTRODUCED BEAN (PHASEOLUS ACCESSIONS TO THE INFESTATION BY THIELAVIOPSIS BASICOLA (BERKELEY & BROOME UNDER NATURAL EPIPHYTOTIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    O. Georgieva

    2015-01-01

    Full Text Available A periodic phytopathology field monitoring was conducted on 35 introduced common bean (Phaseolus accessions at Maritsa Vegetable Crops Research Institute in 2014. The epiphytotic disease black root rot on the bean crops (over 75 % reduction of the stand was recorded for the first time for the area of Bulgaria. The causal agent isolated from the plant tissue was identified as the fungus Thielaviopsis basicola (Berkeley Ferraris. A strong relationship between disease severity variation and environmental and soil conditions was established. Black root rot was most severe when cool and wet weather occurred from seedling time to about three weeks after planting, combined with increased soil compaction. Field resistance was recorded in Bulgarian var. “Plovdivski zult”, var. “Starozagorski tzer” and line № 564 (3,66%, 5.33% and 6,50 % dumping-off of bean seedlings, respectively. Bean accession introduced from dry climate areas were highly susceptible to black root rot pathogen (over 76.0 % dumping-off of bean seedlings. Indirect relationship was found between bean tolerance to Th. basicola and presence of the anthocyanin in the hypocotyl and seed coat color. Install the average negative correlation between seed color signs (and hypocotyl and the resistance of plants to Th. basicola. Samples with resistance to black root rot belong to the group with beige, red, brown or black color of seeds. The presence of phenolic compounds (anthocyanins in the seed coat and hypocotyls beans can serve as an indirect indication of the selection of resistant to black rot breeding materials.

  2. Trichoderma spp. decrease Fusarium root rot in common bean

    Directory of Open Access Journals (Sweden)

    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.

  3. Role of Rot in bacterial autolysis regulation of Staphylococcus aureus NCTC8325.

    Science.gov (United States)

    Chu, Xinmin; Xia, Rui; He, Nianan; Fang, Yuting

    2013-09-01

    Autolysis is an important process in cell wall turnover in Staphylococcus aureus, performed by several peptidoglycan hydrolases or so-called autolysins and controlled by many regulators. Rot is a global regulator that regulates numerous virulence genes, including genes encoding lipase, hemolysins, proteases and genes related to cell surface adhesion. The aim of our study was to determine whether Rot has the ability to regulate autolysis. We compared Triton-X-100-induced autolysis of S. aureus NCTC8325 and its rot knock-out mutant. We found that the rot mutant showed increased autolysis rates. By examining the transcript level of several autolysins and some known regulators responsible for regulating autolysis using real-time RT-PCR assays, we found that transcription of two autolysins (lytM, lytN) and one regulatory operon (lrgAB) was changed in the rot mutant. An in vitro approach was undertaken to determine which of these genes are directly controlled by Rot. Rot proteins were overproduced in Escherichia coli and purified. Gel mobility shift DNA binding assays were used and showed that in-vitro-purified Rot can directly bind to the promoter region of lytM, lytN, lrgA and lytS. We also tested biofilm formation of the rot mutant, and it showed enhancement in biofilm formation. Taken together, our results reveal that Rot affects autolysis by directly regulating autolysins LytM and LytN, and, via a regulatory system, LrgAB. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  4. Candidate gene association mapping of Sclerotinia stalk rot resistance in sunflower (Helianthus annuus L.) uncovers the importance of COI1 homologs.

    Science.gov (United States)

    Talukder, Zahirul I; Hulke, Brent S; Qi, Lili; Scheffler, Brian E; Pegadaraju, Venkatramana; McPhee, Kevin; Gulya, Thomas J

    2014-01-01

    Functional markers for Sclerotinia basal stalk rot resistance in sunflower were obtained using gene-level information from the model species Arabidopsis thaliana. Sclerotinia stalk rot, caused by Sclerotinia sclerotiorum, is one of the most destructive diseases of sunflower (Helianthus annuus L.) worldwide. Markers for genes controlling resistance to S. sclerotiorum will enable efficient marker-assisted selection (MAS). We sequenced eight candidate genes homologous to Arabidopsis thaliana defense genes known to be associated with Sclerotinia disease resistance in a sunflower association mapping population evaluated for Sclerotinia stalk rot resistance. The total candidate gene sequence regions covered a concatenated length of 3,791 bp per individual. A total of 187 polymorphic sites were detected for all candidate gene sequences, 149 of which were single nucleotide polymorphisms (SNPs) and 38 were insertions/deletions. Eight SNPs in the coding regions led to changes in amino acid codons. Linkage disequilibrium decay throughout the candidate gene regions declined on average to an r (2) = 0.2 for genetic intervals of 120 bp, but extended up to 350 bp with r (2) = 0.1. A general linear model with modification to account for population structure was found the best fitting model for this population and was used for association mapping. Both HaCOI1-1 and HaCOI1-2 were found to be strongly associated with Sclerotinia stalk rot resistance and explained 7.4 % of phenotypic variation in this population. These SNP markers associated with Sclerotinia stalk rot resistance can potentially be applied to the selection of favorable genotypes, which will significantly improve the efficiency of MAS during the development of stalk rot resistant cultivars.

  5. Characterisation of Alternaria species-groups associated with core rot of apples in South Africa

    DEFF Research Database (Denmark)

    Serdani, M.; Kang, J.C.; Andersen, Birgitte

    2002-01-01

    Alternaria core rot of red apple cultivars is a serious post-harvest disease in South Africa. Thirty isolates of Alternaria spp. previously isolated from apple, together with reference isolates of A. alternata and A. infectoria, were characterised and grouped according to their sporulation patter...

  6. Evaluation of environmentally friendly products for control of fungal diseases of grapes

    OpenAIRE

    Schilder, A.M.C.; Gillett, J.M.; Sysak, R.W.; Wise, J.C.

    2002-01-01

    Various environmentally friendly products were tested for efficacy in controlling powdery mildew, downy mildew, black rot, Phomopsis, and Botrytis bunch rot in grapes over several years. The products tested were: JMS stylet oil (paraffinic oil), Serenade (Bacillus subtilis), Croplife (citrus and coconut extract) + Plant food (foliar fertilizer), Armicarb (potassium bicarbonate), Elexa (chitosan), Milsana (giant knotweed extract), and AQ10 (Ampelomyces quisqua/is). JMS Stylet Oil, Armicarb, Se...

  7. NODC Standard Format Pathology Data Sets (1973-1975): Fin Rot (F006) Data (NODC Accession 0014147)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fin Rot (F006) dataset contains data from examinations of the biological condition of diseased fishes. For tow samples collected, data include: total number of...

  8. Association of Verde plant bug, Creontiades signatus (Hemiptera: Miridae), with cotton boll rot

    Science.gov (United States)

    Cotton along the Gulf Coast of south Texas has experienced loss from cotton boll rot especially during the last 10 to 15 years, and stink bugs and plant bugs (Hemiptera: Pentatomidae and Miridae) that feed on cotton bolls have been suspected in introducing the disease. A replicated grower field surv...

  9. Maize Cob Rot in Kenya and Its Association with Stalk Borer Damage

    International Nuclear Information System (INIS)

    Ajanga, S.I.

    2002-01-01

    Cob rots are a major cause of crop loss in areas such as western Kenya that experience prolonged rainfall during the period of crop maturation. Cob rot fungi cause spoilage of the grain and some of them produce mycotoxins which can pose a health risk to humans and animals consuming foods prepared from contaminate grain. survey conducted in western Kenya in 1998 showed that cob rot incidence exceeded 20%. In the following year when rainfall was greater around the harvest period, cob rot fungi affected 68% of cobs. in 1998 stalk borer larvae (mainly Busseola fusca) damaged 20% of the cobs and there was a strong correlation (R= 0.87) between cob rot incidence and borer damage. In 1999 almost half of the cobs sampled showed evidence of borer damage. The result indicate that the high cob rot incidence in this pert of Kenya is due to stalk bore damage, which predisposes the cobs to fungal infection, and that management of the borer would greatly decrease cob rot incidence

  10. Black Americans' Perspectives of Barriers and Facilitators of Community Screening for Kidney Disease.

    Science.gov (United States)

    Umeukeje, Ebele M; Wild, Marcus G; Maripuri, Saugar; Davidson, Teresa; Rutherford, Margaret; Abdel-Kader, Khaled; Lewis, Julia; Wilkins, Consuelo H; Cavanaugh, Kerri

    2018-04-06

    Incidence of ESKD is three times higher in black Americans than in whites, and CKD prevalence continues to rise among black Americans. Community-based kidney disease screening may increase early identification and awareness of black Americans at risk, but it is challenging to implement. This study aimed to identify participants' perspectives of community kidney disease screening. The Health Belief Model provides a theoretic framework for conceptualization of these perspectives and optimization of community kidney disease screening activities. Researchers in collaboration with the Tennessee Kidney Foundation conducted three focus groups of adults in black American churches in Nashville, Tennessee. Questions examined views on CKD information, access to care, and priorities of kidney disease health. Content analysis was used. Guided by the Health Belief Model, a priori themes were generated, and additional themes were derived from the data using an inductive approach. Thirty-two black Americans completed the study in 2014. Participants were mostly women (79%) with a mean age of 56 years old (range, 24-78). Two major categories of barriers to kidney disease screening were identified: ( 1 ) participant factors, including limited kidney disease knowledge, spiritual/religious beliefs, emotions, and culture of the individual; and ( 2 ) logistic factors, including lack of convenience and incentives and poor advertisement. Potential facilitators of CKD screening included provision of CKD education, convenience of screening activities, and use of culturally sensitive and enhanced communication strategies. Program recommendations included partnering with trusted community members, selecting convenient locations, tailored advertising, and provision of compensation. Findings of this study suggest that provider-delivered culturally sensitive education and stakeholder engagement are critical to increase trust, decrease fear, and maximize participation and early identification of

  11. QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

    Science.gov (United States)

    Naegele, R P; Ashrafi, H; Hill, T A; Chin-Wo, S Reyes; Van Deynze, A E; Hausbeck, M K

    2014-05-01

    Phytophthora capsici is an important pepper (Capsicum annuum) pathogen causing fruit and root rot, and foliar blight in field and greenhouse production. Previously, an F6 recombinant inbred line population was evaluated for fruit rot susceptibility. Continuous variation among lines and partial and isolate-specific resistance were found. In this study, Phytophthora fruit rot resistance was mapped in the same F6 population between Criollo del Morelos 334 (CM334), a landrace from Mexico, and 'Early Jalapeno' using a high-density genetic map. Isolate-specific resistance was mapped independently in 63 of the lines evaluated and the two parents. Heritability of the resistance for each isolate at 3 and 5 days postinoculation (dpi) was high (h(2) = 0.63 to 0.68 and 0.74 to 0.83, respectively). Significant additive and epistatic quantitative trait loci (QTL) were identified for resistance to isolates OP97 and 13709 (3 and 5 dpi) and 12889 (3 dpi only). Mapping of fruit traits showed potential linkage with few disease resistance QTL. The partial fruit rot resistance from CM334 suggests that this may not be an ideal source for fruit rot resistance in pepper.

  12. BIOMODIFICATION OF KENAF USING WHITE ROT FUNGI

    Directory of Open Access Journals (Sweden)

    Rasmina Halis,

    2012-01-01

    Full Text Available White rot fungi can be used as a pretreatment of biomass to degrade lignin. It also alters the structure of the lignocellulosic matter, thus increasing its accessibility to enzymes able to convert polysaccharides into simple sugars. This study compares the ability of two species of white rot fungi, Pycnoporous sanguineus and Oxyporus latemarginatus FRIM 31, to degrade lignin in kenaf chips. The white rot fungi were originally isolated from the tropical forest in Malaysia. Kenaf chips were first inoculated with each fungus separately using corn steep liquor as a fungal growth promoter. The kenaf chips were inoculated with white rot fungus for a period of 1, 2, 4, 8 and 16 weeks, after which they were observed under the scanning electron microscope (SEM. Chemical analyses were conducted following TAPPI Standard Methods and Fourier Transmission Infra Red (FTIR. SEM observations showed evidence of fungal colonization. When calculating weight loss, both P. sanguineus and O. latemarginatus FRIM 31 showed the greatest reduction. Amounts by mass of cellulose, hemicelluloses, extractives, and lignin in the treated kenaf chips all were lowered. The results show that O. latemarginatus FRIM 31 had a greater ability to degrade lignin when compared to P. sanguineus.

  13. Resistance to Fusarium dry root rot disease in cassava accessions

    Directory of Open Access Journals (Sweden)

    Saulo Alves Santos de Oliveira

    2013-10-01

    Full Text Available The objective of this work was to identify sources of resistance to dry root rot induced by Fusarium sp. in cassava accessions. A macroconidial suspension (20 µL of 11 Fusarium sp. isolates was inoculated in cassava roots, from 353 acessions plus seven commercial varieties. Ten days after inoculation, the total area colonized by the pathogen on the root pulp was evaluated by digital image analysis. Cluster analysis revealed the presence of five groups regarding resistance. The root lesion areas ranged from 18.28 to 1,096.07 mm² for the accessions BGM 1518 and BGM 556, respectively. The genotypes BGM 1042, BGM 1552, BGM 1586, BGM 1598, and BGM 1692 present the best agronomical traits.

  14. Evaluation of host resistance to Botrytis bunch rot in Vitis spp. and its correlation with Botrytis leaf spot

    Science.gov (United States)

    Botrytis cinerea, the causal agent of Botrytis bunch rot and gray mold, is the number one postharvest disease of fresh grapes in the United States. Fungicide applications are used to manage the disease, but fungicide-resistant isolates are common and postharvest losses occur annually. Host resistanc...

  15. Study the Reaction of Some Barley Cultivars to Rhizoctonia solani AG-8, the Causal Agent of Root Rot Disease

    Directory of Open Access Journals (Sweden)

    M. Yazdani Kohanstani

    2016-03-01

    Full Text Available Introduction: Barley is one of the important agricultural products, mostly as livestock feed, and secondly for its important role in human nutrition as bread, soups, baby food and etc. It has the second-largest rank of cultivation area and yield of the national grain production and the Isfahan province, with production 5% of total barley yield, has been ranked eighth in 2010. Because its consumption exceed over the production, barley is one of the major imports to the country. In addition to, agronomy operations, plant diseases are important factors in yield loss. Rhizoctonia root rot (caused by soil-inhabiting fungus Rhizoctonia solani is one of the important diseases of cereals include barley over the worldwide cultivation area. Apropriate soil fertility, delaying planting dates, crop rotation with insensitive crops such as legumes, planting resistant varieties and fungicide seed dressing are recommended methods to reduce disease damage. Chemical control of this disease is difficult because of its soil-born the pathogen. Therefore, reducing disease level requires application of other methods especially resistance cultivars. Materials and Methods In this research, the reaction of 8 barley cultivars were examined against root rot disease in greenhouse conditions, in the winter of 2009. Fifteen isolates of the fungus were isolated from infected barley fields in the Isfahan province and their pathogenicity was examined on barley. One isolate with the highest pathogenicity potential was selected and special tests showed that the isolate was Rhizoctonia solani AG-8. The experiment was conducted in a completely randomized design with 4 replications. The test plants were harvested at two times of 4 & 8 weeks after planting. Following parameters were measured: 1- dry weight of plant root and aerial part, 2- disease severity as an index of subcrown internodes infection. Results and discussion Statistical analysis of recorded data showed that there were

  16. Effects of postharvest salicylic acid dipping on Alternaria rot and disease resistance of jujube fruit during storage.

    Science.gov (United States)

    Cao, Jiankang; Yan, Jiaqi; Zhao, Yumei; Jiang, Weibo

    2013-10-01

    Considerable postharvest losses caused by Alternaria alternata often occur in Chinese jujube fruit, and synthetic fungicides have been widely used to protect the fruit from Alternaria rot. However, the potential harmfulness of fungicide residues to human health and the environment cannot be ignored. This study was conducted to develop an alternative approach for controlling postharvest disease by inducing fruit resistance with salicylic acid (SA) dipping. Disease incidence and lesion area in the jujube fruit inoculated with A. alternata were significantly inhibited by 2 and 2.5 mmol L(-1) SA dipping. Naturally infected decay rate and index in jujubes were also significantly reduced by SA dipping during long-term storage at 0°C. SA enhanced activities of the main defense-related enzymes including phenylalanine ammonia-lyase, peroxidase, chitinase and β-1,3-glucanase in the fruit during storage. SA strongly decreased catalase activity but increased superoxide dismutase activity and ascorbic acid content in jujubes. The beneficial effects of SA on fruit protection may be due to its ability to activate several highly coordinated defence-related systems in jujubes, instead of its fungicidal activity. The findings indicated that application of SA would offer an alternative approach that helps to control postharvest disease and maintain storage quality in fruits. © 2013 Society of Chemical Industry.

  17. Development of Phytophthora fruit rot caused by Phytophthora capsici on resistant and susceptible watermelon fruit of different ages

    Science.gov (United States)

    Watermelon is an important crop grown in 44 states in the United States. Phytophthora fruit rot caused by Phytophthora capsici is a serious disease in the southeastern U.S., where over 50% of the watermelons are produced. The disease has resulted in severe losses to watermelon growers, especially in...

  18. Structure of Rot, a global regulator of virulence genes in Staphylococcus aureus.

    Science.gov (United States)

    Zhu, Yuwei; Fan, Xiaojiao; Zhang, Xu; Jiang, Xuguang; Niu, Liwen; Teng, Maikun; Li, Xu

    2014-09-01

    Staphylococcus aureus is a highly versatile pathogen that can infect human tissue by producing a large arsenal of virulence factors that are tightly regulated by a complex regulatory network. Rot, which shares sequence similarity with SarA homologues, is a global regulator that regulates numerous virulence genes. However, the recognition model of Rot for the promoter region of target genes and the putative regulation mechanism remain elusive. In this study, the 1.77 Å resolution X-ray crystal structure of Rot is reported. The structure reveals that two Rot molecules form a compact homodimer, each of which contains a typical helix-turn-helix module and a β-hairpin motif connected by a flexible loop. Fluorescence polarization results indicate that Rot preferentially recognizes AT-rich dsDNA with ~30-base-pair nucleotides and that the conserved positively charged residues on the winged-helix motif are vital for binding to the AT-rich dsDNA. It is proposed that the DNA-recognition model of Rot may be similar to that of SarA, SarR and SarS, in which the helix-turn-helix motifs of each monomer interact with the major grooves of target dsDNA and the winged motifs contact the minor grooves. Interestingly, the structure shows that Rot adopts a novel dimerization model that differs from that of other SarA homologues. As expected, perturbation of the dimer interface abolishes the dsDNA-binding ability of Rot, suggesting that Rot functions as a dimer. In addition, the results have been further confirmed in vivo by measuring the transcriptional regulation of α-toxin, a major virulence factor produced by most S. aureus strains.

  19. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  20. Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years — United States, 1968–2015

    Science.gov (United States)

    Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele

    2018-01-01

    Problem/Condition Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. Period Covered 1968–2015. Description of System The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968–2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968–2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. Results From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases

  1. Armillaria root rot of tea in Kenya : characterization of the pathogen and approaches to disease management

    NARCIS (Netherlands)

    Otieno, W.

    2002-01-01

    The rare occurrence of basidiomata and rhizomorphs constrains diagnosis of Armillaria root rot and identification of Armillaria species in Africa. This has had a negative impact on taxonomic research on the genus Armillaria in the continent, where the

  2. efficient screening procedure for black sigatoka disease of banana

    African Journals Online (AJOL)

    ACSS

    3 University of Copenhagen, Faculty of Science, Department of Plant and Environmental Sciences, ... procedure for black sigatoka disease in order to provide a reliable controlled environment ..... Inoculation of emerging leaves, on average.

  3. Weevil - red rot associations in eastern white pine

    Science.gov (United States)

    Myron D. Ostrander; Clifford H. Foster

    1957-01-01

    The presence of red rot (Fomes pini) in pruned white pine stands has often been attributed to the act of pruning. This assumption may well be true for heavily stocked stands where thinning has been neglected and pruning scars are slow to heal. The question then arises: How do we account for the red rot often found in vigorous unpruned white pine stands? Evidence...

  4. Attempts to control Fusarium root rot of bean by seed dressing.

    Science.gov (United States)

    Gilardi, G; Baudino, M; Gullino, M L; Garibaldi, A

    2008-01-01

    In summer 2006, a root rot caused by Fusarium oxysporum was observed in commercial farms on common bean (Phaseolus vulgaris) on the cv Billò and Borlotto. A study was undertaken in order to evaluate the efficacy of different biological control agents applied as seed dressing. In the presence of a medium-high disease incidence, among the biocontrol agents tested, Trichoderma harzianum T 22, Bacillus subtilis QST 713, followed by Pseudomonas chlororaphis, provided generally the best control. Their efficacy was also consistent in the different trials. Also the mixture of T. harzianum + T. viride provide a good disease control. Streptomyces griseoviridis and the 3 strains of Fusarim oxysporum, although less effective, provided a partial control of the disease. The fungicide mancozeb provided only a partial disease control.

  5. Extraction and Study of Bacteriophages, Used against Agents of Potato Soft Rot

    Directory of Open Access Journals (Sweden)

    Magda D. Davitashvili

    2012-12-01

    Full Text Available The use of specific bacteriophages and their complex mixtures against bacterial diseases is very effective. As for causative agent of potato soft rot Erwinia carotovora, specific phages (25 phages in total were extracted from diseased potato, soil and sewage. The study of their biological properties showed the diversity of phages in terms of lytic action, virion plaque and morphology, as well as in relation to different environmental factors. Phages showed explicit antibacterial activity in vitro in liquid and solid media, as well as during model tests of potato tubers artificial inoculation.

  6. Black leaf streak disease affects starch metabolism in banana fruit.

    Science.gov (United States)

    Saraiva, Lorenzo de Amorim; Castelan, Florence Polegato; Shitakubo, Renata; Hassimotto, Neuza Mariko Aymoto; Purgatto, Eduardo; Chillet, Marc; Cordenunsi, Beatriz Rosana

    2013-06-12

    Black leaf streak disease (BLSD), also known as black sigatoka, represents the main foliar disease in Brazilian banana plantations. In addition to photosynthetic leaf area losses and yield losses, this disease causes an alteration in the pre- and postharvest behavior of the fruit. The aim of this work was to investigate the starch metabolism of fruits during fruit ripening from plants infected with BLSD by evaluating carbohydrate content (i.e., starch, soluble sugars, oligosaccharides, amylose), phenolic compound content, phytohormones, enzymatic activities (i.e., starch phosphorylases, α- and β-amylase), and starch granules. The results indicated that the starch metabolism in banana fruit ripening is affected by BLSD infection. Fruit from infested plots contained unusual amounts of soluble sugars in the green stage and smaller starch granules and showed a different pattern of superficial degradation. Enzymatic activities linked to starch degradation were also altered by the disease. Moreover, the levels of indole-acetic acid and phenolic compounds indicated an advanced fruit physiological age for fruits from infested plots.

  7. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  8. Detection, identification and differentiation of Pectobacterium and Dickeya species causing potato blackleg and tuber soft rot: a review.

    Science.gov (United States)

    Czajkowski, R; Pérombelon, McM; Jafra, S; Lojkowska, E; Potrykus, M; van der Wolf, Jm; Sledz, W

    2015-01-01

    The soft rot Enterobacteriaceae (SRE) Pectobacterium and Dickeya species (formerly classified as pectinolytic Erwinia spp.) cause important diseases on potato and other arable and horticultural crops. They may affect the growing potato plant causing blackleg and are responsible for tuber soft rot in storage thereby reducing yield and quality. Efficient and cost-effective detection and identification methods are essential to investigate the ecology and pathogenesis of the SRE as well as in seed certification programmes. The aim of this review was to collect all existing information on methods available for SRE detection. The review reports on the sampling and preparation of plant material for testing and on over thirty methods to detect, identify and differentiate the soft rot and blackleg causing bacteria to species and subspecies level. These include methods based on biochemical characters, serology, molecular techniques which rely on DNA sequence amplification as well as several less-investigated ones.

  9. Automatic Image-Based Plant Disease Severity Estimation Using Deep Learning.

    Science.gov (United States)

    Wang, Guan; Sun, Yu; Wang, Jianxin

    2017-01-01

    Automatic and accurate estimation of disease severity is essential for food security, disease management, and yield loss prediction. Deep learning, the latest breakthrough in computer vision, is promising for fine-grained disease severity classification, as the method avoids the labor-intensive feature engineering and threshold-based segmentation. Using the apple black rot images in the PlantVillage dataset, which are further annotated by botanists with four severity stages as ground truth, a series of deep convolutional neural networks are trained to diagnose the severity of the disease. The performances of shallow networks trained from scratch and deep models fine-tuned by transfer learning are evaluated systemically in this paper. The best model is the deep VGG16 model trained with transfer learning, which yields an overall accuracy of 90.4% on the hold-out test set. The proposed deep learning model may have great potential in disease control for modern agriculture.

  10. Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot

    Science.gov (United States)

    Tomato crown and root rot or tomato foot and root rot (TFRR) is caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici (Forl). The disease occurs in both greenhouse and outdoor tomato cultivations and cannot be treated efficiently with the existing fungicides. We conducte...

  11. Evaluation of the biocontrol efficacy of a Serratia marcescens strain indigenous to tea rhizosphere for the management of root rot disease in tea.

    Directory of Open Access Journals (Sweden)

    Gargee Dhar Purkayastha

    Full Text Available The aim of the present study is to evaluate plant growth promoting and biocontrol efficacy of a Serratia marcescens strain ETR17 isolated from tea rhizosphere for the effective management of root rot disease in tea. Isolated bacterial culture ETR17 showed significant level of in vitro antagonism against nine different foliar and root pathogens of tea. The phenotypic and molecular characterization of ETR17 revealed the identity of the bacterium as Serratia marcescens. The bacterium was found to produce several hydrolytic enzymes like chitinase, protease, lipase, cellulase and plant growth promoting metabolites like IAA and siderophore. Scanning electron microscopic studies on the interaction zone between pathogen and antagonistic bacterial isolate revealed severe deformities in the fungal mycelia. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometry and HPLC and TLC indicated the presence of the antibiotics pyrrolnitrin and prodigiosin in the extracellular bacterial culture extracts. Biofilm formation by ETR17 on polystyrene surface was also observed. In vivo application of talc-based formulations prepared with the isolate ETR17 in tea plantlets under green house conditions revealed effective reduction of root-rot disease as well as plant growth promotion to a considerable extent. Viability studies with the ETR17 talc formulation showed the survivability of the isolate up to six months at room temperature. The sustenance of ETR17 (concentration of 8-9x108 cfu g-1 in the soil after the application of talc formulation was recorded by ELISA. Safety studies revealed that ETR17 did not produce hemolysin as observed in pathogenic Serratia strains. The biocontrol strain reported in this study can be used for field application in order to minimize the use of chemical fungicides for disease control in tea gardens.

  12. Evaluation of the biocontrol efficacy of a Serratia marcescens strain indigenous to tea rhizosphere for the management of root rot disease in tea.

    Science.gov (United States)

    Dhar Purkayastha, Gargee; Mangar, Preeti; Saha, Aniruddha; Saha, Dipanwita

    2018-01-01

    The aim of the present study is to evaluate plant growth promoting and biocontrol efficacy of a Serratia marcescens strain ETR17 isolated from tea rhizosphere for the effective management of root rot disease in tea. Isolated bacterial culture ETR17 showed significant level of in vitro antagonism against nine different foliar and root pathogens of tea. The phenotypic and molecular characterization of ETR17 revealed the identity of the bacterium as Serratia marcescens. The bacterium was found to produce several hydrolytic enzymes like chitinase, protease, lipase, cellulase and plant growth promoting metabolites like IAA and siderophore. Scanning electron microscopic studies on the interaction zone between pathogen and antagonistic bacterial isolate revealed severe deformities in the fungal mycelia. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometry and HPLC) and TLC indicated the presence of the antibiotics pyrrolnitrin and prodigiosin in the extracellular bacterial culture extracts. Biofilm formation by ETR17 on polystyrene surface was also observed. In vivo application of talc-based formulations prepared with the isolate ETR17 in tea plantlets under green house conditions revealed effective reduction of root-rot disease as well as plant growth promotion to a considerable extent. Viability studies with the ETR17 talc formulation showed the survivability of the isolate up to six months at room temperature. The sustenance of ETR17 (concentration of 8-9x108 cfu g-1) in the soil after the application of talc formulation was recorded by ELISA. Safety studies revealed that ETR17 did not produce hemolysin as observed in pathogenic Serratia strains. The biocontrol strain reported in this study can be used for field application in order to minimize the use of chemical fungicides for disease control in tea gardens.

  13. Identification of two new races of Diplocarpon rosae Wolf, the causal agent of rose black spot disease

    Science.gov (United States)

    The fungal pathogen, Diplocarpon rosae Wolf, infects only roses (Rosa spp.) and leads to rose black spot disease. Rose black spot is the most problematic disease of outdoor grown roses worldwide, due to the potential for rapid leaf yellowing and defoliation. Plants repeatedly defoliated from black ...

  14. Red rot resistant transgenic sugarcane developed through expression of β-1,3-glucanase gene.

    Directory of Open Access Journals (Sweden)

    Shivani Nayyar

    Full Text Available Sugarcane (Saccharum spp. is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum Went. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery. We report development of red rot resistant transgenic sugarcane through expression of β-1,3-glucanase gene from Trichoderma spp. The transgene integration and its expression were confirmed by quantitative reverse transcription-PCR in first clonal generation raised from T0 plants revealing up to 4.4-fold higher expression, in comparison to non-transgenic sugarcane. Bioassay of transgenic plants with two virulent C. falcatum pathotypes, Cf 08 and Cf 09 causing red rot disease demonstrated that some plants were resistant to Cf 08 and moderately resistant to Cf 09. The electron micrographs of sucrose storing stalk parenchyma cells from these plants displayed characteristic sucrose-filled cells inhibiting Cf 08 hyphae and lysis of Cf 09 hyphae; in contrast, the cells of susceptible plants were sucrose depleted and prone to both the pathotypes. The transgene expression was up-regulated (up to 2.0-fold in leaves and 5.0-fold in roots after infection, as compared to before infection in resistant plants. The transgene was successfully transmitted to second clonal generation raised from resistant transgenic plants. β-1,3-glucanase protein structural model revealed that active sites Glutamate 628 and Aspartate 569 of the catalytic domain acted as proton donor and nucleophile having role in cleaving β-1,3-glycosidic bonds and pathogen hyphal lysis.

  15. DEGRADATION OF TEXTILE DYES BY WHITE ROT BASIDIOMYCETES

    OpenAIRE

    B.P. PARMAR, P.N. MERVANA B.R.M. VYAS*

    2014-01-01

    ABSTRACT: Dyes released by the textile industries pose a threat to environmental quality. Ligninolytic white-rot basidiomycetes can effectively degrade colored effluents and conventional dyes. White-rot fungi produce various isoforms of extracellular oxidases including laccase, Mn peroxidase and lignin peroxidase (LiP), which are involved in the degradation of lignin in their natural lignocellulosic substrates.  The textile industry, by far the most avid user of synthetic dyes, is in need...

  16. Applications of volatile compounds acquired from Muscodor heveae against white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.) and relevant allelopathy effects.

    Science.gov (United States)

    Siri-Udom, Sakuntala; Suwannarach, Nakarin; Lumyong, Saisamorn

    The bioactive compounds of the volatile metabolite-producing endophytic fungus, Muscodor heveae, were examined by the process of biofumigation for the purposes of controlling white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.). Volatile organic compounds (VOCs) of M. heveae possess antimicrobial activity against Rigidoporus microporus in vitro with 100 % growth inhibition. The synthetic volatile compounds test confirmed that the major component, 3-methylbutan-1-ol, and the minor compounds, 3-methylbutyl acetate and 2-methylpropanoic acid, inhibited root and shoot growth in the tested plants 3-methylbutan-1-ol showed ED 50 value and MIQ value on seed germination of ruzi grass, Arabidopsis thaliana Col-0 and tomato at 10, 5 and 5 μL -1 airspace, respectively. In vivo tests were carried out under greenhouse conditions using M. heveae inoculum fumigated soil that had been inoculated with R. microporus inoculum. After which, all seven treatments were compared. Significant differences were observed with a disease score at 150 d after treatment. Biofumigation by M. heveae showed great suppression of the disease. Biocontrol treatments; RMH40 (40 g kg -1 M. heveae inoculum) and RMH80 (80 g kg -1 M. heveae inoculum) were not found to be significantly different when compared with fungicide treatment (RT) and the non-infected control, but results were found to be significantly different from R. microporus infested (R) treatment. RMH40 and RMH80 revealed a low disease scores with a high survival rate of rubber tree seedling at 100 %, while R treatment showed the highest disease score of 4.8 ± 0.5 with a survival rate of rubber tree seedling at 25 %. The infected roots, appearing as a white colour. We have concluded that the bioactive VOCs of M. heveae would be an alternative method for the control of white root rot disease in rubber trees. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  17. First report of Gliocephalotrichum bulbilium and G. simplex causing fruit rot of rambutan in Puerto Rico

    Science.gov (United States)

    Worldwide, significant post-harvest disease losses of rambutan (Nephelium lappaceum L.) have been reported and several pathogens have been associated with fruit rot. Even though rambutan was introduced to Puerto Rico in 1927, it was not until 1998 that commercial farms were established in the wester...

  18. DYNAMICS AND INTENSITY OF APLE DISEASE DEVELOPMENT DURING ITS STORAGE

    Directory of Open Access Journals (Sweden)

    D. Ivić

    2006-12-01

    Full Text Available Post-harvest apple fruit diseases are primarily caused by fungi. The object of this research was to quantify yield loss caused by post-harvest diseases and to determine fungal species responsible for storage rots on the cv. Idared during three months of storage, as well as to compare the development of fungi inoculated on apple fruits in the laboratory conditions. Only fruits with the visible rot symptoms were regarded as "diseased". Total yield loss during all three months of storage was 1.9%. The percentage of diseased fruits increased from the harvest moment to the end of storage. The most frequent cause of post-harvest rot in all assessments was Monilia fructigena. Penicillium species and Botrytis cinerea were present in relatively high percentage. All fungal isolates from diseased fruits caused fruit rot when inoculated on apples and incubated for 28 days at 22°C. On fruits inoculated with the same isolates and incubated at 4°C rot development was slower. Isolates of M. fructigena developed most rapidly on inoculated fruits at 22°C, while the isolates of B. cinerea developed most rapidly at 4°C.

  19. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control

    OpenAIRE

    Blaya, Josefa; Marhuenda, Frutos C.; Pascual, Jose A.; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-indus...

  20. ( Azadirachta Indica ) Leaf Extracts on the Rot Fungus ( Fusarium ...

    African Journals Online (AJOL)

    The storage lifespan of kola nuts is challenged by the problem of decay of nuts in storage as a result of the attack by the rot fungus (Fusarium spp). The effect of the neem leaf (Azadirachta indica) extracts on the rot fungus was investigated in order to aid extended kola nuts storage. The aqueous and ethanolic leaf extracts of ...

  1. The influence of formulation on Trichoderma biological activity and frosty pod rot disease management in Theobroma cacao

    Science.gov (United States)

    Frosty pod rot (FPR), caused by Moniliophthora roreri is responsible for significant losses in Theobroma cacao. Due to the limited options for FPR management, biological control methods using Trichoderma are being studied. Combinations of three formulations and two Trichoderma isolates were studied ...

  2. Etiology and Population Genetics of Colletotrichum spp. Causing Crown and Fruit Rot of Strawberry.

    Science.gov (United States)

    Ureña-Padilla, A R; Mackenzie, S J; Bowen, B W; Legard, D E

    2002-11-01

    ABSTRACT Isolates of Colletotrichum spp. from diseased strawberry fruit and crowns were evaluated to determine their genetic diversity and the etiology of the diseases. Isolates were identified to species using polymerase chain reaction primers for a ribosomal internal transcribed spacer region and their pathogenicity was evaluated in bioassays. Isolates were scored for variation at 40 putative genetic loci with random amplified polymorphic DNA and microsatellite markers. Only C. acutatum was recovered from diseased fruit. Nearly all isolates from crowns were C. gloeosporioides. In crown bioassays, only isolates of C. gloeosporioides from strawberry caused collapse and death of plants. A dendrogram generated from the genetic analysis identified several primary lineages. One lineage included isolates of C. acutatum from fruit and was characterized by low diversity. Another lineage included isolates of C. gloeosporioides from crowns and was highly polymorphic. The isolates from strawberry formed distinctive clusters separate from citrus isolates. Evaluation of linkage disequilibrium among polymorphic loci in isolates of C. gloeosporioides from crowns revealed a low level of disequilibrium as would be expected in sexually recombining populations. These results suggest that epidemics of crown rot are caused by Glomerella cingulata (anamorph C. gloeosporioides) and that epidemics of fruit rot are caused by C. acutatum.

  3. Control of bull’s-eye rot of apple caused by Neofabraea perennans and Neofabraea kienholzii using pre- and postharvest fungicides

    Science.gov (United States)

    Bull’s-eye rot is a major postharvest disease of apple caused by several fungi belonging to the Neofabraea and Phlyctema genera. Chemical control of these fungi is a crucial component of disease management for apples that are conventionally grown. The efficacy of several pre-harvest and postharvest ...

  4. Thyme and Savory Essential Oil Vapor Treatments Control Brown Rot and Improve the Storage Quality of Peaches and Nectarines, but Could Favor Gray Mold.

    Science.gov (United States)

    Santoro, Karin; Maghenzani, Marco; Chiabrando, Valentina; Bosio, Pietro; Gullino, Maria Lodovica; Spadaro, Davide; Giacalone, Giovanna

    2018-01-05

    The effect of biofumigation, through slow-release diffusors, of thyme and savory essential oils (EO), was evaluated on the control of postharvest diseases and quality of peaches and nectarines. EO fumigation was effective in controlling postharvest rots. Naturally contaminated peaches and nectarines were exposed to EO vapors for 28 days at 0 °C in sealed storage cabinets and then exposed at 20 °C for five days during shelf-life in normal atmosphere, simulating retail conditions. Under low disease pressure, most treatments significantly reduced fruit rot incidence during shelf-life, while, under high disease pressure, only vapors of thyme essential oil at the highest concentration tested (10% v / v in the diffusor) significantly reduced the rots. The application of thyme or savory EO favored a reduction of brown rot incidence, caused by Monilinia fructicola , but increased gray mold, caused by Botrytis cinerea . In vitro tests confirmed that M. fructicola was more sensitive to EO vapors than B. cinerea . Essential oil volatile components were characterized in storage cabinets during postharvest. The antifungal components of the essential oils increased during storage, but they were a low fraction of the volatile organic compounds in storage chambers. EO vapors did not influence the overall quality of the fruit, but showed a positive effect in reducing weight loss and in maintaining ascorbic acid and carotenoid content. The application of thyme and savory essential oil vapors represents a promising tool for reducing postharvest losses and preserving the quality of peaches and nectarines.

  5. Conductimetric detection of Pseudomonas syringae pathover pisi in pea seeds and soft rot Erwinia spp. on potato tubers

    NARCIS (Netherlands)

    Fraaije, B.

    1996-01-01


    Pea bacterial blight and potato blackleg are diseases caused by Pseudomonas syringae pv. pisi ( Psp ) and soft rot Erwinia spp., respectively. The primary source of inoculum for these bacteria is

  6. Effect of corn steep liquor on lettuce root rot (Fusarium oxysporum f.sp. lactucae) in hydroponic cultures.

    Science.gov (United States)

    Chinta, Yufita D; Kano, Kazuki; Widiastuti, Ani; Fukahori, Masaru; Kawasaki, Shizuka; Eguchi, Yumi; Misu, Hideyuki; Odani, Hiromitsu; Zhou, Songying; Narisawa, Kazuhiko; Fujiwara, Kazuki; Shinohara, Makoto; Sato, Tatsuo

    2014-08-01

    Recent reports indicate that organic fertilisers have a suppressive effect on the pathogens of plants grown under hydroponic systems. Furthermore, microorganisms exhibiting antagonistic activity to diseases have been observed in organic hydroponic systems. This study evaluated the effect of corn steep liquor (CSL) on controlling lettuce root rot disease [Fusarium oxysporum f.sp. lactucae (FOL)] in a hydroponic system. The effect of CSL and Otsuka A (a chemical fertiliser) on the inhibition of FOL in terms of mycelial growth inhibition was tested in vivo. Addition of CSL suppressed FOL infection rates. CSL inhibited FOL infection by 26.3-42.5% from 2 days after starting incubation. In comparison, Otsuka A inhibited FOL growth by 5.5-19.4%. In addition, four of 10 bacteria isolated from the nutrient media containing CSL exhibited inhibition zones preventing FOL mycelial growth. We found that CSL suppressed FOL in lettuce via its antifungal and biostimulatory effects. We suggest that activation of beneficial microorganisms present in CSL may be used to decrease lettuce root rot disease and contribute to lettuce root growth. © 2014 Society of Chemical Industry.

  7. Effect of (/sup 60/cobalt) gamma rays on growth and root rot diseases in mungbean (vigna radiata L.)

    International Nuclear Information System (INIS)

    Ikram, N.; Dawar, S.; Zaki, M.J.; Abass, Z.

    2010-01-01

    Present investigation showed that gamma rays influences suppressive effect on root rot fungi such as Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kuhn and Fusarium spp., and inducive effect on growth parameters of mung bean (Vigna radiata L.). Seeds of mung bean were treated with gamma rays (/sup 60/Cobalt) at time periods of 0 and 4 minutes and stored for 90 days at room temperature to determine its effect on growth parameters and infection of root infecting fungi. All treatments of gamma rays enhanced the growth parameters as compared to untreated plants. Infection of M. phaseolina, R. solani and Fusarium spp., were significantly decreased on mung bean seeds treated with gamma rays. Gamma rays significantly increased the growth parameters and controlled the root rot fungi up to 90 days of storage of seeds. (author)

  8. Site-specific management of cotton root rot using airborne and satellite imagery and variable rate technology

    Science.gov (United States)

    Cotton root rot is a serious cotton disease that can now be effectively controlled with Topguard Terra Fungicide. However, its recurrence in the same areas year after year makes fungicide application only to infested areas more effective and economical than uniform application. Base on 17 years of r...

  9. Internal Rot Detection with the Use of Low-Frequency Flaw Detector

    Science.gov (United States)

    Proskórnicki, Marek; Ligus, Grzegorz

    2014-12-01

    The issue of rot detection in standing timber or stocked wood is very important in forest management. Rot flaw detection used for that purpose is represented by invasive and non-invasive devices. Non-invasive devices are very accurate, but due to the cost and complicated operation they have not been applied on a large scale in forest management. Taking into account the practical needs of foresters a prototype of low-frequency flaw was developed. The principle of its operation is based on the difference in acoustic wave propagation in sound wood and wood with rot.

  10. Automatic Image-Based Plant Disease Severity Estimation Using Deep Learning

    Directory of Open Access Journals (Sweden)

    Guan Wang

    2017-01-01

    Full Text Available Automatic and accurate estimation of disease severity is essential for food security, disease management, and yield loss prediction. Deep learning, the latest breakthrough in computer vision, is promising for fine-grained disease severity classification, as the method avoids the labor-intensive feature engineering and threshold-based segmentation. Using the apple black rot images in the PlantVillage dataset, which are further annotated by botanists with four severity stages as ground truth, a series of deep convolutional neural networks are trained to diagnose the severity of the disease. The performances of shallow networks trained from scratch and deep models fine-tuned by transfer learning are evaluated systemically in this paper. The best model is the deep VGG16 model trained with transfer learning, which yields an overall accuracy of 90.4% on the hold-out test set. The proposed deep learning model may have great potential in disease control for modern agriculture.

  11. Potential of popcorn germplasm as a source of resistance to ear rot

    Directory of Open Access Journals (Sweden)

    Railan do Nascimento Ferreira Kurosawa

    Full Text Available ABSTRACT Because of its multi-purpose nature, popcorn has sparked the interest of the World Trade Organization as regards fungal contamination by mycotoxins. However, no investigations have been conducted on popcorn for resistance of genotypes to ear rot. The aim of this study was to evaluate the potential of popcorn genotypes as to resistance to ear rot and rotten kernels, as an initial step for the implementation of a breeding program with the popcorn crop in Northern Rio de Janeiro State, Brazil. Thirty-seven accessions from different ecogeographic regions of Latin America were evaluated in 2 cultivation periods, in a randomized block design with 4 replications. We evaluated the incidence of rotten ears, incidence of rotten ears caused by Fusarium spp., severity of ears with Fusarium spp. rot, and incidence of rotten kernels. The results were subjected to analysis of variance, and means were compared by the Scott-Knott clustering test (p < 0.05. A significant effect was observed for all evaluated variables, characterizing them as efficient in the discrimination of genotypic variability for reaction to fungal injuries in popcorn. The gene pool of the tropical and temperate Germplasm Collection evaluated here has the potential to generate superior segregants and provide hybrid combinations with alleles of resistance to diseases affecting ears and stored kernels. Based on the different variables and times, the experiment was conducted, and genotypes L65, L80, and IAC 125 showed the highest levels of resistance.

  12. The resistance response of sunflower genotypes to black stem disease under controlled conditions

    Directory of Open Access Journals (Sweden)

    Reza DARVISHZADEH

    2010-09-01

    Full Text Available Phoma black stem, caused by Phoma macdonaldii, is one of the most important diseases of sunflower in the world. The sources of resistance to Phoma black stem were investigated. A total of 184 genotypes, including some recombinant inbred lines (RILs, several M6 mutant lines obtained by gamma irradiation of seed of the genotype AS 613, and other genotypes from different countries, were evaluated against an aggressive French isolate (MP6 in controlled conditions. The study was carried out in a randomized complete block design with three replicates. Each replicate consisted of 10–12 seedlings. Twenty μL of spore suspension (106 pycnidiospores mL-1 were deposited on the intersection of the cotyledon petiole and the hypocotyl of sunflower plantlets at the two-leaf stage. The percentage of the area exhibiting disease symptoms was scored on the two cotyledon petioles of each of the plantlets three, five and seven days after inoculation. The disease progress rate (rd, as the slope of the regression line for disease severity against time, was also calculated. Analysis of variance detected significant differences among sunflower genotypes for disease severity 7 days after inoculation,as well as for the disease progress rate. A strong correlation (r=0.96, P<0.01 was found between disease severity 7 days after inoculation and the disease progress rate. The inbred lines F1250/03 (origin: Hungary, M5-54-1, M6-862-1 (mutant lines, SDR 18 (origin: USA and two wild Helianthus accessions, 1012 Nebraska and 211 Illinois, (wild type were highly resistant to Phoma black stem. These findings will assist breeders in choosing parent plants for breeding durable resistance to Phoma black stem.

  13. The influence of root rot incidence on cassava genotype on ...

    African Journals Online (AJOL)

    In Nigeria cassava root rot causes serious yield losses in cassava tuber production every year. However, the influence of root rot incidence on cassava genotype at harvest on consumers' acceptability of the gari produced from it has not been studied. A sensory evaluation was conducted on gari processed from the tuberous ...

  14. Removal of phenanthrene in contaminated soil by combination of alfalfa, white-rot fungus, and earthworms.

    Science.gov (United States)

    Deng, Shuguang; Zeng, Defang

    2017-03-01

    The aim of this study was to investigate the removal of phenanthrene by combination of alfalfa, white-rot fungus, and earthworms in soil. A 60-day experiment was conducted. Inoculation with earthworms and/or white-rot fungus increased alfalfa biomass and phenanthrene accumulation in alfalfa. However, inoculations of alfalfa and white-rot fungus can significantly decrease the accumulation of phenanthrene in earthworms. The removal rates for phenanthrene in soil were 33, 48, 66, 74, 85, and 93% under treatments control, only earthworms, only alfalfa, earthworms + alfalfa, alfalfa + white-rot fungus, and alfalfa + earthworms + white-rot fungus, respectively. The present study demonstrated that the combination of alfalfa, earthworms, and white-rot fungus is an effective way to remove phenanthrene in the soil. The removal is mainly via stimulating both microbial development and soil enzyme activity.

  15. Rhamnolipid Biosurfactant against Fusarium verticillioides to Control Stalk and Ear Rot Disease of Maize

    Directory of Open Access Journals (Sweden)

    Siddhartha Narayan Borah

    2016-09-01

    Full Text Available Antifungal activity of rhamnolipids (RLs has been widely studied against many plant pathogenic fungi, but not against Fusarium verticillioides, a major pathogen of maize (Zea mays L.. F. verticillioides causes stalk and ear rot of maize or asymptomatically colonizes the plant and ears resulting in moderate to heavy crop loss throughout the world. F. verticillioides produces fumonisin mycotoxins, reported carcinogens, which makes the contaminated ears unsuitable for consumption. In this study, the RL produced using glucose as sole carbon source was characterized by FTIR and LCMS analyses and its antifungal activity against F. verticillioides was evaluated in vitro on maize stalks and seeds. Further, the effect of RL on the mycelia of F. verticillioides was investigated by scanning electron microscopy which revealed visible damage to the mycelial structure as compared to control samples. In planta, treatment of maize seeds with a RL concentration of 50 mg l-1 resulted in improved biomass and fruiting compared to those of healthy control plants and complete suppression of characteristic disease symptoms and colonization of maize by F. verticillioides. The study highlights the potential of RLs to be used for an effective biocontrol strategy against colonization of maize plant by F. verticillioides.

  16. Registration of an oilseed sunflower germplasm line HA-BSR1 highly tolerant to Sclerotinia basal stalk rot

    Science.gov (United States)

    Basal stalk rot (BSR) caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease that causes a significant damage to worldwide sunflower (Helianthus annuus L.) production by reducing seed yield and quality. The objective of this research was to develop highly BSR tolerant sunflower g...

  17. QTL analysis of Fusarium root rot resistance in an Andean x Middle American common bean RIL population

    Science.gov (United States)

    Aims Fusarium root rot (FRR) is a soil-borne disease that constrains common bean (Phaseolus vulgaris L.) production. FRR causal pathogens include clade 2 members of the Fusarium solani species complex. Here we characterize common bean reaction to four Fusarium species and identify genomic regions as...

  18. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    Science.gov (United States)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  19. First Report of Cadophora luteo-olivacea Causing Side Rot on ‘Conference’ Pears in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Lemmers, M.E.C.; Boer, de Astrid; Leeuwen, van Paul; Hollinger, T.C.; Haas, de B.H.; Köhl, J.

    2016-01-01

    Pear (Pyrus communis) is an important fruit crop in the Netherlands. Symptoms of side rot disease of pear fruits were first observed in 2008 on cv. Conference in storage in the Netherlands. Typical round to oval, dark-brown, and slightly sunken spots (size 0.5 to 1.0 cm in diameter) appeared after

  20. Detection and identification of six Monilinia spp. causing brown rot using TaqMan real-time PCR from pure cultures and infected apple fruit

    Science.gov (United States)

    Brown rot is a severe disease affecting stone and pome fruits. This disease was recently confirmed to be caused by the following six closely related species: Monilinia fructicola, Monilinia laxa, Monilinia fructigena, Monilia polystroma, Monilia mumecola and Monilia yunnanensis. Because of differenc...

  1. Thyme and Savory Essential Oil Vapor Treatments Control Brown Rot and Improve the Storage Quality of Peaches and Nectarines, but Could Favor Gray Mold

    Science.gov (United States)

    Santoro, Karin; Maghenzani, Marco; Chiabrando, Valentina; Gullino, Maria Lodovica; Giacalone, Giovanna

    2018-01-01

    The effect of biofumigation, through slow-release diffusors, of thyme and savory essential oils (EO), was evaluated on the control of postharvest diseases and quality of peaches and nectarines. EO fumigation was effective in controlling postharvest rots. Naturally contaminated peaches and nectarines were exposed to EO vapors for 28 days at 0 °C in sealed storage cabinets and then exposed at 20 °C for five days during shelf-life in normal atmosphere, simulating retail conditions. Under low disease pressure, most treatments significantly reduced fruit rot incidence during shelf-life, while, under high disease pressure, only vapors of thyme essential oil at the highest concentration tested (10% v/v in the diffusor) significantly reduced the rots. The application of thyme or savory EO favored a reduction of brown rot incidence, caused by Monilinia fructicola, but increased gray mold, caused by Botrytis cinerea. In vitro tests confirmed that M. fructicola was more sensitive to EO vapors than B. cinerea. Essential oil volatile components were characterized in storage cabinets during postharvest. The antifungal components of the essential oils increased during storage, but they were a low fraction of the volatile organic compounds in storage chambers. EO vapors did not influence the overall quality of the fruit, but showed a positive effect in reducing weight loss and in maintaining ascorbic acid and carotenoid content. The application of thyme and savory essential oil vapors represents a promising tool for reducing postharvest losses and preserving the quality of peaches and nectarines. PMID:29303966

  2. Thyme and Savory Essential Oil Vapor Treatments Control Brown Rot and Improve the Storage Quality of Peaches and Nectarines, but Could Favor Gray Mold

    Directory of Open Access Journals (Sweden)

    Karin Santoro

    2018-01-01

    Full Text Available The effect of biofumigation, through slow-release diffusors, of thyme and savory essential oils (EO, was evaluated on the control of postharvest diseases and quality of peaches and nectarines. EO fumigation was effective in controlling postharvest rots. Naturally contaminated peaches and nectarines were exposed to EO vapors for 28 days at 0 °C in sealed storage cabinets and then exposed at 20 °C for five days during shelf-life in normal atmosphere, simulating retail conditions. Under low disease pressure, most treatments significantly reduced fruit rot incidence during shelf-life, while, under high disease pressure, only vapors of thyme essential oil at the highest concentration tested (10% v/v in the diffusor significantly reduced the rots. The application of thyme or savory EO favored a reduction of brown rot incidence, caused by Monilinia fructicola, but increased gray mold, caused by Botrytis cinerea. In vitro tests confirmed that M. fructicola was more sensitive to EO vapors than B. cinerea. Essential oil volatile components were characterized in storage cabinets during postharvest. The antifungal components of the essential oils increased during storage, but they were a low fraction of the volatile organic compounds in storage chambers. EO vapors did not influence the overall quality of the fruit, but showed a positive effect in reducing weight loss and in maintaining ascorbic acid and carotenoid content. The application of thyme and savory essential oil vapors represents a promising tool for reducing postharvest losses and preserving the quality of peaches and nectarines.

  3. Disease limits populations: plague and black-tailed prairie dogs

    Science.gov (United States)

    Cully, Jack F.; Johnson, T.; Collinge, S.K.; Ray, C.

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  4. Creation of initial breeding material of potato with complex resistance to Fusarium dry rot and tuber late blight

    Directory of Open Access Journals (Sweden)

    В. В. Гордієнко

    2017-09-01

    Full Text Available Purpose. To select the initial breeding material with complex resistance to Fusarium dry rot and tuber late blight among the created potato of secondary interspecific hyb­rids. Methods. Interspecific hybridization, laboratory test, analytical approach. Results. Based on the interspecific hybridization, the initial breeding material was created and the degree of its resistance to the above pathogens was determined by way of artificial infection of tubers with the inoculum of such fungi as Fusarium sambucinum Fuck and Phytophthora infestans (Mont. De Bary. During interspecific hybridization based on schemes of saturating and enriching crosses, using forms of various species with a high phenotypic expression of resistance to Fusarium dry rot, the result of the cumulative effect of genes that control resistance to the pathogen was observed. Crossing combinations differed significantly for the degree of population average manifestation of resistance to the diseases. Conclusions. Combinations В54, В53, В61 with a mean resistance (above 7 grades to Fusarium dry rot have been selected. Such combinations as B52, B50 and B54 had increased resistance to tuber late blight. It was found that the combination В54 is characterized by complex resistance to both diseases. For further work, the following samples with complex resistance to Fusarium dry rot and tuber late blight (7 grades or more were selected: В59с42, В59с43, В50с16, В50с19, В50с44, В51с1, В51с26, В51с28, В52с11, В52с23, В52с24, В52с29, В53с1, В53с11, В53с17 , В53с23, В54с13, В54с14.

  5. Antifungal Effects Of Botanical Leaf Extracts On Tuber Rots Of Yam ...

    African Journals Online (AJOL)

    The fungicidal effects of dry and fresh leaf extracts of Axardirachta indica (L) and Ocimum grattissimum on the rot of yam tubers were investigated. Fusaruim oxysporium, Rhjzopus stolonifer, Botryodiplodia theobromae and Aspergillus Niger (root pathogens) were isolated from the rotted yam. Both dry and fresh leaf extracts ...

  6. A Simple Method for Assessing Severity of Common Root Rot on Barley

    Directory of Open Access Journals (Sweden)

    Mohammad Imad Eddin Arabi

    2013-12-01

    Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

  7. Postharvest application of organic and inorganic salts to control potato (Solanum tuberosum L.) storage soft rot: plant tissue-salt physicochemical interactions.

    Science.gov (United States)

    Yaganza, E S; Tweddell, R J; Arul, J

    2014-09-24

    Soft rot caused by Pectobacterium sp. is a devastating disease affecting stored potato tubers, and there is a lack of effective means of controlling this disease. In this study, 21 organic and inorganic salts were tested for their ability to control soft rot in potato tubers. In the preventive treatment, significant control of soft rot was observed with AlCl3 (≥66%) and Na2S2O3 (≥57%) and to a lesser extent with Al lactate and Na benzoate (≥34%) and K sorbate and Na propionate (≥27%). However, only a moderate control was achieved by curative treatment with AlCl3 and Na2S2O3 (42%) and sodium benzoate (≥33%). Overall, the in vitro inhibitory activity of salts was attenuated in the presence of plant tissue (in vivo) to different degrees. The inhibitory action of the salts in the preventive treatment, whether effective or otherwise, showed an inverse linear relationship with water ionization capacity (pK') of the salt ions, whereas in the curative treatment, only the effective salts showed this inverse linear relationship. Salt-plant tissue interactions appear to play a central role in the attenuated inhibitory activity of salts in potato tuber through reduction in the availability of the inhibitory ions for salt-bacteria interactions. This study demonstrates that AlCl3, Na2S2O3, and Na benzoate have potential in controlling potato tuber soft rot and provides a general basis for understanding of specific salt-tissue interactions.

  8. Interactions of predominant insects and diseases with climate change in Douglas-fir forests of western Oregon and Washington, U.S.A.

    Science.gov (United States)

    Agne, Michelle C; Beedlow, Peter A; Shaw, David C; Woodruff, David R; Lee, E Henry; Cline, Steven P; Comeleo, Randy L

    2018-02-01

    Forest disturbance regimes are beginning to show evidence of climate-mediated changes, such as increasing severity of droughts and insect outbreaks. We review the major insects and pathogens affecting the disturbance regime for coastal Douglas-fir forests in western Oregon and Washington State, USA, and ask how future climate changes may influence their role in disturbance ecology. Although the physiological constraints of light, temperature, and moisture largely control tree growth, episodic and chronic disturbances interacting with biological factors have substantial impacts on the structure and functioning of forest ecosystems in this region. Understanding insect and disease interactions is critical to predicting forest response to climate change and the consequences for ecosystem services, such as timber, clean water, fish and wildlife. We focused on future predictions for warmer wetter winters, hotter drier summers, and elevated atmospheric CO 2 to hypothesize the response of Douglas-fir forests to the major insects and diseases influencing this forest type: Douglas-fir beetle, Swiss needle cast, black stain root disease, and laminated root rot. We hypothesize that 1) Douglas-fir beetle and black stain root disease could become more prevalent with increasing, fire, temperature stress, and moisture stress, 2) future impacts of Swiss needle cast are difficult to predict due to uncertainties in May-July leaf wetness, but warmer winters could contribute to intensification at higher elevations, and 3) laminated root rot will be influenced primarily by forest management, rather than climatic change. Furthermore, these biotic disturbance agents interact in complex ways that are poorly understood. Consequently, to inform management decisions, insect and disease influences on disturbance regimes must be characterized specifically by forest type and region in order to accurately capture these interactions in light of future climate-mediated changes.

  9. Persistence of Gliocephalotrichum spp. causing fruit rot of rambutan (Nephelium lappaceum L.) in Puerto Rico

    Science.gov (United States)

    Worldwide, fruit rot of rambutan is an important problem that limits the storage, marketing and long-distance transportation of the fruit. A complex of pathogens has been reported to cause fruit rot of rambutan and significant post-harvest economic losses. During 2009 and 2011 rambutan fruit rot was...

  10. Effect of irradiation and insect pest control on rots and sensory ...

    African Journals Online (AJOL)

    The coffee bean weevil, Araecerus fasciculatus Degeer (Coleoptera: Curculionidae) is associated with rots in stored yam tubers. The current study was designed to assess the effect of irradiation and other insect pest control strategies on rots and sensory quality of stored yams. 450 tubers each of two varieties of white yam ...

  11. Gene-for-gene relationships between strawberry and the causal agent of red stele root rot, Phytophthora fragariae var. fragariae

    NARCIS (Netherlands)

    Weg, van de W.E.

    1997-01-01

    Red stele (red core) root rot is the major soil-borne disease of strawberries (Fragaria spp.) in many areas with cool, moist soil conditions. It is caused by the soil-borne fungus Phytophthora fragariae var. fragariae. Red stele

  12. CHARACTERIZATION OF WOOD DECAY BY ROT FUNGI USING COLORIMETRY AND INFRARED SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Mírian de Almeida Costa

    2011-09-01

    Full Text Available Wood samples of marupá (Simarouba amara and andiroba (Carapa guianenis were submitted to Trametes versicolor (white rot and Gloeophylum trabeum (brown rot fungi attack. Colorimetry was used to determine the color of the wood before and after wood decaying fungi. To evaluate the changes in chemical compounds levels in the wood samples, the diffuse reflectance medium infrared spectroscopy was used. Both wood were non resistant against white rot fungus, while with brown rot attack andiroba was resistant and marupá was not. After Gloeophyllum trabeum attack both woods changed to a darken color, and after Trametes versicolor attack andiroba changed to a lighter color and marupá darkened slightly, The analysis showed a reduction in the peak intensity of cellulose, hemicellulose and lignin, for both species, after Trametes versicolor attack and a reduction in the peak intensity of cellulose after Gloeophyllum trabeum attack.

  13. Serpula lacrymans, The Dry Rot Fungus and Tolerance Towards Copper-Based Wood Preservatives

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol

    2005-01-01

    -rot fungi is thought to be due in part to oxalic acid production and accumulation. Oxalic acid has been implicated in copper tolerance by the formation of copper oxalate crystals. Twelve isolates of the dry rot fungus, S. lacrymans and four other brown rot species were evaluated for weight loss on wood...

  14. Association mapping for #Phytophthora# pod rot resistance in a cacao (#Theobroma cacao# L.) population grown in farmers' field

    OpenAIRE

    Efombagn, Mousseni Ives Bruno; Sounigo, Olivier; Courtois, Brigitte; Fouet, Olivier; Jeanneau, Mélanie; Lemainque, Arnaud; Pavek, Sylvana; Lanaud, Claire

    2016-01-01

    Phytophthora pod rot (PPR) caused by the specie Phytophthora megakarya is an important disease of cacao tree. Association mapping identified markers linked to PPR resistance in a cacao population of 260 trees planted under high disease pressure in a single plantation in a farmer's field. These cacao trees were derived from both selfing and full-sib progenies. The resistance traits were assessed through field observations of the natural pod attacks of the disease on the trunk (PRTnk) or the ca...

  15. Pink Mold Rot on Unishiu Orange (Citrus unshiu Mac. Caused by Trichothecium roseum (Pers. Link ex Gray in Korea

    Directory of Open Access Journals (Sweden)

    Jin-Hyeuk Kwon

    2013-09-01

    Full Text Available In 2012, a pink mold rot was observed on unishiu orange (Citrus unshiu Mac. fruits at the Wholesale Market for Agricultural Products, Jinju, Korea. The symptom on unishiu orange was a water-soaked lesion on the surface of fruit, which later on enlarged to form softened brown rot lesions. The diseased fruits were covered with pink-colored mold, consisting of conidia and conidiophores of the pathogen. Optimum temperature for mycelial growth was 25oC. Conidia were hyaline, smooth, 2-celled, and thick-walled conidia with truncate bases, ellipsoidal to pyriform, characteristically held together zig-zag chains and 12−26 × 8−12 μm in size. Conidiophore was erect, colorless, unbranched, and 4−5 μm wide. On the basis of mycological characteristics, pathogenicity test, and molecular analysis with complete ITS rDNA region, the causal fungus was identified as Trichothecium roseum (Pers. Link ex Gray. This is the first report of pink mold rot caused by T. roseum on unishiu orange in Korea.

  16. Screening strawberry plants for anthracnose disease resistance using traditional and molecular techniques

    Science.gov (United States)

    Anthracnose is one of the most destructive diseases of strawberry which may cause fruit rot, leaf and petiole lesions, crown rot, wilt, and death. Crop loss due to anthracnose diseases can reach into the millions of dollars. Three species of Colletotrichum are considered causative agents of anthr...

  17. Development of sugarcane mutants with resistance to red rot, water-logging and delayed or non-flowering through induced mutations

    International Nuclear Information System (INIS)

    Majid, M.A.; Shamsuzzaman, K.M.; Howlider, M.A.R.; Islam, M.M.

    2001-01-01

    Three varieties of sugarcane, 'Isd-2/54', 'Nagarbari' and 'Latarijaba', were irradiated with 20, 30 and 40 Gy gamma rays to induce variation for resistance to red rot disease. The MV 2 population was screened for disease resistance by planting infected canes in between the treated material, and selected plants were further propagated. Among the 2,954 MV 3 hills, inoculated with red rot spore suspension, 37 resistant and 151 moderately resistant plants were isolated. Selection was carried out in the MV 4 to MV 7 propagation. Seven MV 7 selected variants were tested for yield at two locations. Of these, four promising variants were selected on the basis of cane yield, Brix index and disease resistance. In another experiment, four varieties of sugarcane, 'Isd-2/54', 'Isd-16', 'Nagarbari' and 'Latarijaba' were irradiated with 20,40 and 60 Gy gamma rays. Approximately, 10,000 MV 3 canes were planted in a low-lying field, and subjected to water-logging stress. MV 5 and MV 6 populations were inoculated with red rot spore- suspension under waterlogged conditions. Five MV 5 variants were selected on the basis of greenness of the leaves, growth of the canes, number of nodes bearing adventitious roots, Brix index, cane yield and disease reactions, and grown as MV 6 propagation. Three selected variants, SCM-12, SCM-14 and SCM-15, were tolerant to waterlogged conditions in MV 6 . Two additional varieties, 'I-291/87' and 'I-525/85' were treated with 20, 30 and 40 Gy gamma rays to select for delayed/non-flowering types. Four variants were selected in MV 3 for delayed flowering; one mutant, SCM-28 flowered three months later than the parent 'I-291/87'. (author)

  18. Verde plant bug associatioin with boll damage including cotton boll rot and potential in-season indicators of damage

    Science.gov (United States)

    Cotton along the Gulf Coast of south Texas has experienced loss from cotton boll rot especially during the last 10 to 15 years, and stink bugs and plant bugs (Hemiptera: Pentatomidae and Miridae) that feed on cotton bolls have been suspected in introducing the disease. A replicated grower field surv...

  19. Pythium root rot of common bean: biology and control methods. A review

    Directory of Open Access Journals (Sweden)

    Baudoin, JP.

    2012-01-01

    Full Text Available Pythium root rot constitutes a highly damaging constraint on the common bean, Phaseolus vulgaris L., grown in several areas of Eastern and Central Africa. Here, this food legume is cultivated intensively under poor conditions of crop rotation due to the exiguity of the land in the region. Yield losses of up to 70% in traditional local bean cultivars have been reported in Kenya and Rwanda. In this study, a detailed analysis of the biology and diversity of the Pythium genus was carried out in order to understand the mechanisms leading to the development of the disease. Various control methods for reducing the damage provoked by this disease were analyzed.

  20. Soft rot decay capabilities and interactions of fungi and bacteria from fumigated utility poles

    International Nuclear Information System (INIS)

    Wang, C.J.K.; Worrall, J.J.

    1992-11-01

    The objectives were to (1) identify microfungi and bacterial associates isolated from fumigated southern pine poles from EPRI project RP 1471-72, (2) study the soft-rot capabilities of predominant fungi, and (3) study interactions among microorganisms in relation to wood decay. Methods for identification followed standard techniques using morphological and physiological criteria. Soft-rot by microfungi alone and with bacteria was determined as weight loss and anatomical examination of wood blocks using light microscopy and limited electron microscopy. Acinetobacter calcoaceticus was the predominant bacterium. Twenty-one species of microfungi were identified including four new species. A book entitled IDENTIFICATION MANUAL FOR FUNGI FROM UTILITY POLES IN THE EASTERN UNITED STATES was published. An improved soft-rot test was devised. Fifty-one of 84 species (60%) of microfungi from poles tested were soft-rot positive; that is much greater than previously reported. Three types of anatomical damage of wood of pine or birch caused by soft-rot fungi were described. Interaction tests showed that, in some cases, there was a strong synergism between bacteria and fungi in causing weight loss, but results were inconsistent. Although soft rot is often most apparent under conditions of very high moisture, intermediate moisture levels appear to be optimal, as with basidiomycete decayers

  1. Erwinia carotovora extracellular proteases : characterization and role in soft rot

    OpenAIRE

    Kyöstiö, Sirkka R. M.

    1990-01-01

    Erwinia carotovora subsp. carotovora (Ecc) strain EC14, a Gram-negative bacterium, causes soft rot on several crops, including potato. Maceration of potato tuber tissue is caused by secreted pectolytic enzymes. Other cell-degrading enzymes may also have roles in pathogenesis, including cellulases, phospholipases, and protease(s). The objectives of this research were to (1) characterize Ecc extracellular protease (Prt) and (2) elucidate its role in potato soft rot. A gene enc...

  2. Biological Control of Fusarium Stalk Rot of Maize Using Bacillus spp

    Directory of Open Access Journals (Sweden)

    Joon-Hee Han

    2015-12-01

    Full Text Available Maize (Zea mays L. is an economically important crop in worldwide. While the consumption of the maize is steadily increasing, the yield is decreasing due to continuous mono-cultivation and infection of soil-borne fungal pathogens such as Fusarium species. Recently, stalk rot disease in maize, caused by F. subglutinans and F. temperatum has been reported in Korea. In this study, we isolated bacterial isolates in rhizosphere soil of maize and subsequently tested for antagonistic activities against F. subglutinans and F. temperatum. A total of 1,357 bacterial strains were isolated from rhizosphere. Among them three bacterial isolates (GC02, GC07, GC08 were selected, based on antagonistic effects against Fusarium species. The isolates GC02 and GC07 were most efficient in inhibiting the mycelium growth of the pathogens. The three isolates GC02, GC07 and GC08 were identified as Bacillus methylotrophicus, B. amyloliquefaciens and B. thuringiensis using 16S rRNA sequence analysis, respectively. GC02 and GC07 bacterial suspensions were able to suppress over 80% conidial germination of the pathogens. GC02, GC07 and GC08 were capable of producing large quantities of protease enzymes, whereas the isolates GC07 and GC08 produced cellulase enzymes. The isolates GC02 and GC07 were more efficient in phosphate solubilization and siderophore production than GC08. Analysis of disease suppression revealed that GC07 was most effective in suppressing the disease development of stalk rot. It was also found that B. methylotrophicus GC02 and B. amyloliquefaciens GC07 have an ability to inhibit the growth of other plant pathogenic fungi. This study indicated B. methylotrophicus GC02 and B. amyloliquefaciens GC07 has potential for being used for the development of a biological control agent.

  3. Differences in crystalline cellulose modification due to degradation by brown and white rot fungi.

    Science.gov (United States)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Larsen, Flemming Hofmann; Sathitsuksanoh, Noppadon; Goodell, Barry; Jellison, Jody

    2012-10-01

    Wood-decaying basidiomycetes are some of the most effective bioconverters of lignocellulose in nature, however the way they alter wood crystalline cellulose on a molecular level is still not well understood. To address this, we examined and compared changes in wood undergoing decay by two species of brown rot fungi, Gloeophyllum trabeum and Meruliporia incrassata, and two species of white rot fungi, Irpex lacteus and Pycnoporus sanguineus, using X-ray diffraction (XRD) and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy. The overall percent crystallinity in wood undergoing decay by M. incrassata, G. trabeum, and I. lacteus appeared to decrease according to the stage of decay, while in wood decayed by P. sanguineus the crystallinity was found to increase during some stages of degradation. This result is suggested to be potentially due to the different decay strategies employed by these fungi. The average spacing between the 200 cellulose crystal planes was significantly decreased in wood degraded by brown rot, whereas changes observed in wood degraded by the two white rot fungi examined varied according to the selectivity for lignin. The conclusions were supported by a quantitative analysis of the structural components in the wood before and during decay confirming the distinct differences observed for brown and white rot fungi. The results from this study were consistent with differences in degradation methods previously reported among fungal species, specifically more non-enzymatic degradation in brown rot versus more enzymatic degradation in white rot. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Risk factors for coronary heart disease in the black population of the ...

    African Journals Online (AJOL)

    A cross-sectional study of risk factors for ischaemic heart disease (IHO) in a random sample of 986 black people aged 15 - 64 years living in the Cape ... In addition, schools should promote a healthy lifestyle and the prevention of chronic degenerative diseases should be incorporated into the evolving primary health care ...

  5. Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

    Science.gov (United States)

    Shrestha, Prachand

    This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

  6. Nonchemical, cultural management strategies to suppress phytophthora root rot in northern highbush blueberry

    Science.gov (United States)

    Phytophthora cinnamomi causes root rot of highbush blueberry and decreases plant growth, yield, and profitability for growers. Fungicides can suppress root rot, but cannot be used in certified organic production systems and fungicide resistance may develop. Alternative, non-chemical, cultural manag...

  7. Quantification of the changes in potent wine odorants as induced by bunch rot (Botrytis cinerea) and powdery mildew (Erysiphe necator)

    Science.gov (United States)

    Lopez Pinar, Angela; Rauhut, Doris; Ruehl, Ernst; Buettner, Andrea

    2017-08-01

    Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine quality. This study aimed to characterize the effects of bunch rot and powdery mildew on wine aroma by quantification of representative aroma compounds using Stable Isotope Dilution Analysis (SIDA). For this purpose, samples affected to a high degree by each fungus were compared with a healthy sample in each case; to this aim, the respective samples were collected and processed applying identical conditions. Thereby, the effects of bunch rot were studied in three different grape varieties: White Riesling, Red Riesling and Gewürztraminer whereas the influence of powdery mildew was studied on the hybrid Gm 8622-3. Analyses revealed that both fungal diseases caused significant changes in the concentration of most target compounds. Thereby, the greatest effects were increases in the concentration of phenylacetic acid, acetic acid and γ-decalactone for both fungi and all grape varieties. Regarding other compounds, however, inconsistent effects of bunch rot were observed for the three varieties studied.

  8. Quantification of the Changes in Potent Wine Odorants as Induced by Bunch Rot (Botrytis cinerea and Powdery Mildew (Erysiphe necator

    Directory of Open Access Journals (Sweden)

    Angela Lopez Pinar

    2017-08-01

    Full Text Available Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine quality. This study aimed to characterize the effects of bunch rot and powdery mildew on wine aroma by quantification of representative aroma compounds using Stable Isotope Dilution Analysis (SIDA. For this purpose, samples affected to a high degree by each fungus were compared with a healthy sample in each case; to this aim, the respective samples were collected and processed applying identical conditions. Thereby, the effects of bunch rot were studied in three different grape varieties: White Riesling, Red Riesling and Gewürztraminer whereas the influence of powdery mildew was studied on the hybrid Gm 8622-3. Analyses revealed that both fungal diseases caused significant changes in the concentration of most target compounds. Thereby, the greatest effects were increases in the concentration of phenylacetic acid, acetic acid and γ-decalactone for both fungi and all grape varieties. Regarding other compounds, however, inconsistent effects of bunch rot were observed for the three varieties studied.

  9. The Oil of Matico (Piper aduncum L.) an Alternative for the Control of Cacao Frosty Pod Rot (Moniliophthora roreri) in Peru

    Science.gov (United States)

    The cacao production in many Latin American countries is significantly reduced by frosty pod rot disease (Moniliophthora roreri) and yield reductions are to the extent of over 90% in many cases. The strategies of control includes: phytosanitation, genetic resistance, chemical and biological control....

  10. Expression of the β-1,3-glucanase gene bgn13.1 from Trichoderma harzianum in strawberry increases tolerance to crown rot diseases but interferes with plant growth.

    Science.gov (United States)

    Mercado, José A; Barceló, Marta; Pliego, Clara; Rey, Manuel; Caballero, José L; Muñoz-Blanco, Juan; Ruano-Rosa, David; López-Herrera, Carlos; de Los Santos, Berta; Romero-Muñoz, Fernando; Pliego-Alfaro, Fernando

    2015-12-01

    The expression of antifungal genes from Trichoderma harzianum, mainly chitinases, has been used to confer plant resistance to fungal diseases. However, the biotechnological potential of glucanase genes from Trichoderma has been scarcely assessed. In this research, transgenic strawberry plants expressing the β-1,3-glucanase gene bgn13.1 from T. harzianum, under the control of the CaMV35S promoter, have been generated. After acclimatization, five out of 12 independent lines analysed showed a stunted phenotype when growing in the greenhouse. Moreover, most of the lines displayed a reduced yield due to both a reduction in the number of fruit per plant and a lower fruit size. Several transgenic lines showing higher glucanase activity in leaves than control plants were selected for pathogenicity tests. When inoculated with Colletotrichum acutatum, one of the most important strawberry pathogens, transgenic lines showed lower anthracnose symptoms in leaf and crown than control. In the three lines selected, the percentage of plants showing anthracnose symptoms in crown decreased from 61 % to a mean value of 16.5 %, in control and transgenic lines, respectively. Some transgenic lines also showed an enhanced resistance to Rosellinia necatrix, a soil-borne pathogen causing root and crown rot in strawberry. These results indicate that bgn13.1 from T. harzianum can be used to increase strawberry tolerance to crown rot diseases, although its constitutive expression affects plant growth and fruit yield. Alternative strategies such as the use of tissue specific promoters might avoid the negative effects of bgn13.1 expression in plant performance.

  11. Copper tolerance of brown-rot fungi : time course of oxalic acid production

    Science.gov (United States)

    Frederick Green; Carol A. Clausen

    2003-01-01

    The increase in the use of non-arsenical copper-based wood preservatives in response to environmental concerns has been accompanied by interest in copper-tolerant decay fungi. Oxalic acid production by brown-rot fungi has been proposed as one mechanism of copper tolerance. Fifteen brown-rot fungi representing the genera Postia, Wolfiporia, Meruliporia, Gloeophyllum,...

  12. Developmental and Metabolic Plasticity of White-Skinned Grape Berries in Response to Botrytis cinerea during Noble Rot1[OPEN

    Science.gov (United States)

    Collins, Thomas S.; Vicente, Ariel R.; Doyle, Carolyn L.; Ye, Zirou; Allen, Greg; Heymann, Hildegarde

    2015-01-01

    Noble rot results from exceptional infections of ripe grape (Vitis vinifera) berries by Botrytis cinerea. Unlike bunch rot, noble rot promotes favorable changes in grape berries and the accumulation of secondary metabolites that enhance wine grape composition. Noble rot-infected berries of cv Sémillon, a white-skinned variety, were collected over 3 years from a commercial vineyard at the same time that fruit were harvested for botrytized wine production. Using an integrated transcriptomics and metabolomics approach, we demonstrate that noble rot alters the metabolism of cv Sémillon berries by inducing biotic and abiotic stress responses as well as ripening processes. During noble rot, B. cinerea induced the expression of key regulators of ripening-associated pathways, some of which are distinctive to the normal ripening of red-skinned cultivars. Enhancement of phenylpropanoid metabolism, characterized by a restricted flux in white-skinned berries, was a common outcome of noble rot and red-skinned berry ripening. Transcript and metabolite analyses together with enzymatic assays determined that the biosynthesis of anthocyanins is a consistent hallmark of noble rot in cv Sémillon berries. The biosynthesis of terpenes and fatty acid aroma precursors also increased during noble rot. We finally characterized the impact of noble rot in botrytized wines. Altogether, the results of this work demonstrated that noble rot causes a major reprogramming of berry development and metabolism. This desirable interaction between a fruit and a fungus stimulates pathways otherwise inactive in white-skinned berries, leading to a greater accumulation of compounds involved in the unique flavor and aroma of botrytized wines. PMID:26450706

  13. Filamentous fungi associated with natural infection of noble rot on withered grapes.

    Science.gov (United States)

    Lorenzini, M; Simonato, B; Favati, F; Bernardi, P; Sbarbati, A; Zapparoli, G

    2018-05-02

    The effects of noble rot infection of grapes on the characteristics of different types of wine, including Italian passito wine, are well known. Nevertheless, there is still little information on filamentous fungi associated with noble-rotten grapes. In this study, withered Garganega grapes for passito wine production, naturally infected by noble rot, were analyzed and compared to sound grapes. Skin morphology and fungal population on berry surfaces were analyzed. Scanning electron microscopy analysis revealed microcracks, germination conidia and branched hyphae on noble-rotten berries. Penicillium, Aureobasidium and Cladosporium were the most frequent genera present. Analysis of single berries displayed higher heterogeneity of epiphytic fungi in those infected by noble-rot than in sound berries. Penicillium adametzoides, Cladosporium cladospoirioides and Coniochaeta polymorpha were recovered. These, to the best of our knowledge, had never been previously isolated from withered grapes and, for C. polymorpha, from grapevine. This study provided novel data on noble rot mycobiota and suggests that fungi that co-habit with B. cinerea could have an important role on grape and wine quality. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Phytophthora megakarya and P. palmivora, closely related causal agents of cacao black pod induce similar reactions when infecting pods of a susceptible cacao genotype

    Science.gov (United States)

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao. Of these two clade 4 species; Pmeg is more virulent and is displacing Ppal on cacao in many cacao production areas in Africa. To understand the advantages Pmeg has over Ppal, we compared symptom...

  15. Control of Cocoa Pod Borer and Phytophthora Pod Rot Using Degradable Plastic Pod Sleeves and a Nematode, Steinernema Carpocapsae

    OpenAIRE

    Rosmana, Ade; Shepard, Merle; Hebbar, Prakash; Mustari, Anita

    2010-01-01

    Cocoa pod borer (CPB; Conopomorpha cramerella) and Phytophthora pod rot (PPR; Phytophthora palmivora) are serious pest and disease on cocoa plantations in Indonesia. Both pest and disease have been controlled with limited success using cultural practices such as pruning, frequent harvesting, sanitation, plastic sleeving, and chemical pesticides. An experiment was conducted on cocoa plantings in Pinrang Regency, South Sulawesi during the wet season of 2008/09 to test the effect of pod sleeving...

  16. Characterizing butt-rot fungi on USA-affiliated islands in the western Pacific

    Science.gov (United States)

    Phil Cannon; Ned B. Klopfenstein; Robert L. Schlub; Mee-Sook Kim; Yuko Ota; Norio Sahashi; Roland J. Quitugua; John W. Hanna; Amy L. Ross-Davis; J. D. Sweeney

    2014-01-01

    Ganoderma and Phellinus are genera that commonly cause tree butt-rot on USA-affiliated islands of the western Pacific. These fungal genera can be quite prevalent, especially in older mangrove stands. Although the majority of infections caused by these fungi lead to severe rotting of the heartwood, they typically do not directly kill the living tissues of the sapwood,...

  17. Field Efficiency Trial of 72% Streptomycin against Konjac Bacterial Soft Rot

    Institute of Scientific and Technical Information of China (English)

    Huang; Yongsheng; Li; Xiaojun; Zhu; Shijin; Ma; Yongsheng; Wang; Li

    2014-01-01

    72% Streptomycin soluble powder was used to control konjac bacterial soft rot in the study. The control efficiency and yield of different treatments were investigated,and the benefit was analyzed. The control scheme against konjac bacterial soft rot was as follows: spraying 72% atreptomycinon twice on rotation fields after all the seedlings were strong and uniform,or irrigating roots with 72% atreptomycinon once and spraying twice on continuous cropping fields.

  18. First report of Lasmenia sp. causing rachis necrosis, flower abortion, fruit rot and leaf spots on rambutan in Puerto Rico

    Science.gov (United States)

    Rambutan is an exotic tropical fruit that has increased in commercial importance for growers in Puerto Rico. In 2008 and 2009, fruit rot and lesions on both leaves and inflorescences were observed. A total of 276 diseased samples from these plant parts were collected at commercial orchards, Agricult...

  19. SOIL MYCOFLORA OF BLACK PEPPER RHIZOSPHERE IN THE PHILIPPINES AND THEIR IN VITRO ANTAGONISM AGAINST Phytophthora capsici L.

    Directory of Open Access Journals (Sweden)

    Rita Noveriza

    2016-10-01

    Full Text Available Foot rot disease of black pepper caused by Phytophthora capsici had been reported in Batangas and Laguna, Philippines. The plant was recovered following the application of crop residue (organic substrate and intercropping with other crops. This study was aimed to isolate, identify, and determine the soil mycoflora from the rhizosphere of black pepper grown on various cropping patterns in Batangas and Laguna. Antagonistic activity of mycoflora isolates was tested against P. capsici using dual culture technique. The result showed that 149 colonies of soil mycoflora isolated were belonging to 14 genera; three of them, i.e. Penicillium, Paecilomyces and Aspergillus, were the most dominant. All of the mycoflora isolates were able to inhibit the growth of the pathogen. Eighteen of them were the most promising antagonists, based on their inhibition growth of more than 60%. It is suggested that antagonistic mechanism of Mucor isolate (1001, Trichoderma (125, 170, 171, 179, 180, 181, Gliocladium (109, Cunninghamella (165, 168, Mortierella (177, and Aspergillus (106 was space competitor (competition for nutrient since they rapidly overgrew the pathogen. Aspergillus (67, 79, 81, 83, 108, and 202 isolates inhibited the pathogen apparently by producing antibiotic, whereas Trichoderma (125, 170, 171, 179, 180, and 181 isolates were able to penetrate the hyphae of the pathogen. The organic matter percentage in the soil was significantly correlated with the number of antagonistic mycoflora in rhizosphere (R2 = 0.1094, but the cropping pattern was negatively correlated. This study suggests that organic matter increased antagonistic mycoflora in black pepper rhizosphere, which will reduce severity of the disease.

  20. Reduced disease in black abalone following mass mortality: Phage therapy and natural selection

    Science.gov (United States)

    VanBlaricom, Glenn R.

    2014-01-01

    Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS). Natural recovery on San Nicolas Island (SNI) of Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO) had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv) reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus) coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host–parasite relationships will better enable us to manage declining populations.

  1. Reduced disease in black abalone following mass mortality: Phage therapy and natural selection

    Directory of Open Access Journals (Sweden)

    Carolyn S Friedman

    2014-03-01

    Full Text Available Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS. Natural recovery on San Nicolas Island (SNI off Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point (CP in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host-parasite relationships will better enable us to manage declining populations.

  2. Reduced disease in black abalone following mass mortality: phage therapy and natural selection.

    Science.gov (United States)

    Friedman, Carolyn S; Wight, Nathan; Crosson, Lisa M; Vanblaricom, Glenn R; Lafferty, Kevin D

    2014-01-01

    Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS). Natural recovery on San Nicolas Island (SNI) of Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO) had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv) reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus) coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host-parasite relationships will better enable us to manage declining populations.

  3. Development and application of qPCR and RPA genus and species-specific detection of Phytophthora sojae and Phytophthora sansomeana root rot pathogens of soybean

    Science.gov (United States)

    Phytophthora root rot of soybean, caused by Phytophthora sojae is one of the most important diseases in the Midwest US, causing losses of up to 44 million bushels per year. Disease may also be caused by P. sansomeana, however the prevalence and damage caused by this species is not well known, partl...

  4. Phytophthora megakarya and Phytophthora palmivora, Closely Related Causal Agents of Cacao Black Pod Rot, Underwent Increases in Genome Sizes and Gene Numbers by Different Mechanisms

    Science.gov (United States)

    Ali, Shahin S.; Shao, Jonathan; Lary, David J.; Kronmiller, Brent A.; Shen, Danyu; Strem, Mary D.; Amoako-Attah, Ishmael; Akrofi, Andrew Yaw; Begoude, B.A. Didier; ten Hoopen, G. Martijn; Coulibaly, Klotioloma; Kebe, Boubacar Ismaël; Melnick, Rachel L.; Guiltinan, Mark J.; Tyler, Brett M.; Meinhardt, Lyndel W.

    2017-01-01

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) are closely related species causing cacao black pod rot. Although Ppal is a cosmopolitan pathogen, cacao is the only known host of economic importance for Pmeg. Pmeg is more virulent on cacao than Ppal. We sequenced and compared the Pmeg and Ppal genomes and identified virulence-related putative gene models (PGeneM) that may be responsible for their differences in host specificities and virulence. Pmeg and Ppal have estimated genome sizes of 126.88 and 151.23 Mb and PGeneM numbers of 42,036 and 44,327, respectively. The evolutionary histories of Pmeg and Ppal appear quite different. Postspeciation, Ppal underwent whole-genome duplication whereas Pmeg has undergone selective increases in PGeneM numbers, likely through accelerated transposable element-driven duplications. Many PGeneMs in both species failed to match transcripts and may represent pseudogenes or cryptic genetic reservoirs. Pmeg appears to have amplified specific gene families, some of which are virulence-related. Analysis of mycelium, zoospore, and in planta transcriptome expression profiles using neural network self-organizing map analysis generated 24 multivariate and nonlinear self-organizing map classes. Many members of the RxLR, necrosis-inducing phytophthora protein, and pectinase genes families were specifically induced in planta. Pmeg displays a diverse virulence-related gene complement similar in size to and potentially of greater diversity than Ppal but it remains likely that the specific functions of the genes determine each species’ unique characteristics as pathogens. PMID:28186564

  5. Morphological and Molecular Identification of the Causal Agent of Anthracnose Disease of Avocado in Kenya.

    Science.gov (United States)

    Kimaru, S K; Monda, E; Cheruiyot, R C; Mbaka, J; Alakonya, A

    2018-01-01

    Anthracnose disease of avocado contributes to a huge loss of avocado fruits due to postharvest rot in Kenya. The causal agent of this disease has not been clear but presumed to be Colletotrichum gloeosporioides as reported in other regions where avocado is grown. The fungus mainly infects fruits causing symptoms such as small blackish spots, "pepper spots," and black spots with raised margin which coalesce as infection progresses. Due to economic losses associated with the disease and emerging information of other species of fungi as causal agents of the disease, this study was aimed at identifying causal agent(s) of the disease. A total of 80 fungal isolates were collected from diseased avocado fruits in Murang'a County, the main avocado growing region in Kenya. Forty-six isolates were morphologically identified as Colletotrichum spp. based on their cultural characteristics, mainly whitish, greyish, and creamish colour and cottony/velvety mycelia on the top side of the culture and greyish cream with concentric zonation on the reverse side. Their spores were straight with rounded end and nonseptate. Thirty-four isolates were identified as Pestalotiopsis spp. based on their cultural characteristics: whitish grey mycelium with black fruiting structure on the upper side and greyish black one on the lower side and septate spores with 3-4 septa and 2 or 3 appendages at one end. Further molecular studies using ITS indicated Colletotrichum gloeosporioides , Colletotrichum boninense , and Pestalotiopsis microspora as the causal agents of anthracnose disease in avocado. However, with this being the first report, there is a need to conduct further studies to establish whether there is coinfection or any interaction thereof.

  6. Morphological and Molecular Identification of the Causal Agent of Anthracnose Disease of Avocado in Kenya

    Directory of Open Access Journals (Sweden)

    S. K. Kimaru

    2018-01-01

    Full Text Available Anthracnose disease of avocado contributes to a huge loss of avocado fruits due to postharvest rot in Kenya. The causal agent of this disease has not been clear but presumed to be Colletotrichum gloeosporioides as reported in other regions where avocado is grown. The fungus mainly infects fruits causing symptoms such as small blackish spots, “pepper spots,” and black spots with raised margin which coalesce as infection progresses. Due to economic losses associated with the disease and emerging information of other species of fungi as causal agents of the disease, this study was aimed at identifying causal agent(s of the disease. A total of 80 fungal isolates were collected from diseased avocado fruits in Murang’a County, the main avocado growing region in Kenya. Forty-six isolates were morphologically identified as Colletotrichum spp. based on their cultural characteristics, mainly whitish, greyish, and creamish colour and cottony/velvety mycelia on the top side of the culture and greyish cream with concentric zonation on the reverse side. Their spores were straight with rounded end and nonseptate. Thirty-four isolates were identified as Pestalotiopsis spp. based on their cultural characteristics: whitish grey mycelium with black fruiting structure on the upper side and greyish black one on the lower side and septate spores with 3-4 septa and 2 or 3 appendages at one end. Further molecular studies using ITS indicated Colletotrichum gloeosporioides, Colletotrichum boninense, and Pestalotiopsis microspora as the causal agents of anthracnose disease in avocado. However, with this being the first report, there is a need to conduct further studies to establish whether there is coinfection or any interaction thereof.

  7. Diseases of chaetognaths from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    Three different diseases, provisionally assigned as spot disease, swell disease and tail rot disease, were observed in chaetognaths Sagitta enflata Grassi and S. bedoti Bernaneck. The first two diseases showed high percentage of occurrence. The spot...

  8. Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.

    Science.gov (United States)

    Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

    2015-03-16

    Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Symptoms and fungi associated with esca in South African vineyards

    Directory of Open Access Journals (Sweden)

    Chana-LEE WHITE

    2011-12-01

    Full Text Available In the past, only a few incidences of esca diseased grapevines were reported from the Slanghoekand Rawsonville areas of South Africa, with the damage believed to be of little importance so that the diseasehas not been studied in South Africa. In the present study, vines with internal or external symptoms of the esca disease complex were sampled from table, raisin and wine grape cultivars from 37 production areas inthe Western Cape, Northern Cape and Limpopo provinces of that country. Most vines were greater than 10years old, but younger vines (3 and 5 years old were also found to be infected. External symptoms, includingdieback, tiger striped leaves, berry symptoms (shrivelling, insufficient colouring and apoplexy, resembledthose found on grapevines in Europe and the USA, although the typical tiger stripe symptom was observedless frequently. The internal stem and trunk symptoms were similar to European symptoms, and includedwhite rot, black and brown wood streaking, brown necrosis within white rot, sectorial brown necrosis andbrown/red/margins next to decay, which often included back lines delimiting white decay. The fungi isolatedmostly from the white rot were basidiomycetes species (30.4%. Black and brown wood streaking was primarily caused by Phaeomoniella chlamydospora (45.4%. Brown necrosis within the white rot was linked to colonization by basidiomycetes (20.4%, Phaeoacremonium aleophilum (15.9% and Pa. chlamydospora (13.6%. Phaeomoniella chlamydospora (20.8% and Botryosphaeriaceae species (10.7% were isolated the most fromthe sectorial brown necrosis and Pa. chlamydospora (29.1% from the brown/red margins and black lines next to decay. Given the wide distribution of esca complex wood and foliar symptoms in the grape growing regions investigated, this disease should be considered as an important limiting factor in the productive lifespan of vineyards and the quality of produce from grapevine in South Africa.

  10. Foot-and-mouth disease in Asiatic black bears (Ursus thibetanus).

    Science.gov (United States)

    Officer, Kirsty; Lan, Nguyen Thi; Wicker, Leanne; Hoa, Nguyen Thi; Weegenaar, Annemarie; Robinson, Jill; Ryoji, Yamaguchi; Loukopoulos, Panayiotis

    2014-09-01

    Foot-and-mouth disease (FMD) is a highly contagious, debilitating, and globally significant viral disease typically affecting cloven-hoofed hosts. The diagnosis of FMD in bears in Vietnam is described. The current study describes a confirmed case of FMD in a bear species, and the clinical signs compatible with FMD in a Malayan sun bear. Thirteen Asiatic black bears (Ursus thibetanus) and 1 Malayan sun bear (Helarctos malayanus) were apparently affected. In August 2011, an adult bear became lethargic, and developed footpad vesicles. Over 15 days, 14 out of 17 bears developed similar signs; the remaining 3 co-housed bears and another 57 resident bears did not. All affected bears developed vesicles on all footpads, and most were lethargic for 24-48 hr. Nasal and oral lesions were noted in 6 and 3 cases, respectively. Within 1 month, all looked normal. Foot-and-mouth disease virus (FMDV) was detected by reverse transcription polymerase chain reaction, classified as serotype O, and isolated by virus isolation techniques. Phylogenetic analysis demonstrated clustering of 3 bear isolates, in a branch distinct from other FMDV type O isolates. The outbreak likely occurred due to indirect contact with livestock, and was facilitated by the high density of captive bears. It showed that Asiatic black bears are capable of contracting FMDV and developing clinical disease, and that the virus spreads easily between bears in close contact. © 2014 The Author(s).

  11. Incidence, progression and intensity of Bud Rot in Elaeis guineensis Jacq. in San Lorenzo, Ecuador

    Directory of Open Access Journals (Sweden)

    Fernando Rivas Figueroa

    2017-01-01

    Full Text Available BUD rot (BR is the most serious disease of oil palm in Latin America; in Equator has caused more than 150 million USD of losses. The aim of this work was to determine the incidence, progression and disease intensity of BR in E. guineensis. Incidence and disease progression was determined from data of oil palm enterprises: Palesema, PDA, Palpailón, Energy & Palma y Alespalma during 2006-2013. Disease intensity was determined at 2013. Incidence was 66.75 % and disease intensity was 46 %. Based on projections of accumulative incidence a polynomial equation was built that predicted 78.30 % of cumulative incidence for 2014, indicating exponential growth of BR from 2009 to 2013. Magnitude of damages based on incidence, disease progression and infection index indicated the occurrence of a lethal form of BR in San Lorenzo, province of Esmeraldas, Equator.

  12. Pectobacterium carotovorum subsp. carotovorum – the Causal Agent of Calla Soft Rot in Serbia and Montenegro

    Directory of Open Access Journals (Sweden)

    Milan Ivanović

    2009-01-01

    Full Text Available Bacterial strains were isolated from above- and underground parts of diseased calla plants originating from different localities in Serbia and one locality in Montenegro. They were characterized by studying their pathogenic, cultural, biochemical and physiologicalcharacteristics. All investigated strains caused soft rot of calla leaf stalks, potato slices and aloe leaves, and induced hypersensitive reaction on tobacco. Bacteriological properties of the strains indicated that symptoms on calla plants were caused by Gram-negative, nonfluorescent, oxidase negative, catalase positive and facultatively anaerobic bacterium belonging to the genus Pectobacterium. The investigated strains grew at 37ºC and in 5% NaCl, utilised lactose and trechalose, and produced neither indol nor lecitinase. These results, as well as the characteristic growth on Logan’s differential medium indicated that soft rot of tuber and stem base of calla plants was caused by Pectobacterium carotovorum subsp. carotovorum. This is the first report of this pathogen affecting calla plants in Serbia.

  13. Management of chili pepper root rot and wilt (caused by Phytophthora nicotianae) by grafting onto resistant rootstock

    OpenAIRE

    Mourad SAADOUN; Mohamed Bechir ALLAGUI

    2013-01-01

    Root rot and plant wilting caused by Phytophthora nicotianae is a severe disease of chili pepper (Capsicum annuum L.) in open fields and under greenhouse production in Tunisia. Chili pepper grafting for disease manage- ment is attracting increased interest in recent years. Using the tube grafting technique, different compatible scion/rootstock combinations were obtained with the wild-type pepper SCM334 and the local chili pepper cultivars ‘Beldi’ and ‘Baker’. SCM334 was resistant to P. nicoti...

  14. Population structure of Cylindrocladium parasiticum infecting peanuts (Arachis hypogaea) in Georgia, USA

    NARCIS (Netherlands)

    Wright, L.P.; Davis, A.J.; Wingfield, B.D.; Crous, P.W.; Brenneman, T.; Wingfield, M.J.

    2010-01-01

    Cylindrocladium parasiticum is an important pathogen of peanut (Arachis hypogaea) causing the disease Cylindrocladium black rot. The genetic structure of this haploid pathogen was determined for populations associated with peanut in Georgia, USA. Ten polymorphic microsatellite markers were used to

  15. Fungicide rotation schemes for managing Phytophthora fruit rot of watermelon across southeastern United States

    Science.gov (United States)

    Southeastern states produce about 50% of the watermelons in the United States (U.S.) where conditions are optimal for development of Phytophthora fruit rot prevail. Phytophthora fruit rot significantly limits watermelon production by causing serious yield losses to growers before and after harvest. ...

  16. Study on the effect of rhamnoIipid-enhanced white rot fungi on the treatment of puIping bIack Iiquor%鼠李糖脂强化白腐菌处理制浆黑液效果研究

    Institute of Scientific and Technical Information of China (English)

    张祥胜; 邹学东; 顾光辉

    2016-01-01

    The enhancement effects of different additives,including tween,rhamnolipids,CuSO4,ethanol,etc. on the treatment of white-rot fungi treated black liquid have been studied. It is found that rhamnolipids can enhance reme-diation effect better. When its mass concentration is in the range of 50-60 mg/L ,the treatment effect is the best. Cul-turing after the rhamnolipid-producing Pseudomonas aeruginosa strain and white rot fungi inoculate black liquor ,the COD can be reduced by 44%. This research provides a new idea for the microbial treatment of pulping black liquid.%研究了吐温、鼠李糖脂、硫酸铜和乙醇等不同添加物对白腐菌处理黑液效果的强化作用,发现鼠李糖脂能够较好地强化修复效果,当其质量浓度在50~60 mg/L时处理效果最佳。将产生鼠李糖脂的铜绿假单胞菌与白腐菌共同接种黑液后培养,可将COD降低44%。本研究为黑液的微生物处理提供了新的思路。

  17. Physiological attributes of fungi associated with stem end rot of mango (mangifera indica l.) cultivars in postharvest fruit losses

    International Nuclear Information System (INIS)

    Maqsood, A.; Nafees, M.; Ashraf, I.; Qureshi, R.

    2014-01-01

    Stem end rot majorly contribute in post-harvest losses of mango during storage. Maximum disease incidence (70%) was recorded in Sindhari cultivar followed by Chaunsa (64%), Fajri (62.5%) and 50% in both Langra and Anwar ratol. In vitro studies were carried out to identifyfungal pathogens responsible for rotting and decaying mango fruits during storage along with isolation and testing their pathogencity on healthy fruits. Results revealed that all selected commercial mango varieties infected by stem end rot. Colletotrichum gloeosporioides, Lasidodiplodia theobromae, Alternaria alternate, Aspergillus niger, Dothiorella domonicana were identified from Sindhri mango fruits, in which of C. gloeosporioides was found the most prevalent. Phomopsis mangiferae, Botryodiplodia theobromae, Altrnaria spp. Aspergillus niger, A. flavis were found in Chaunsa and Phomopsis mangiferae was most prevalent, while Botryodiplodia theobromae caused infection to locally cosumed Fajri variety. Effect of abiotic factors like pH, temperature, light intensity and carbon sources were tested against these isolates. The most efficient carbon source was glucose, which supported the maximum growth of the P. mangiferae and L. Theobromae, while C. gloeosporioides had maximum growth on lactose. All fungi had maximum growth at pH range of 6-6.5 and temperature range of 25-30 degree C on PDA medium. Alternate cycles of 12hr light and 12 hr darkness resulted maximum mycelial growth as compared to the 24 hour continuous exposure to either dark or light. Susceptibility of fungi with cultivars and intensity of spread under specific abiotic conditions provides basic information in this paper to minimize stem end rot of mango in field and storage conditions. (author)

  18. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    International Nuclear Information System (INIS)

    Luey, J.; Brouns, T.M.; Elliott, M.L.

    1990-11-01

    The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT ampersand E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs

  19. Paraphoma crown rot of pyrethrum (Tanacetum cinerariifolium)

    NARCIS (Netherlands)

    Moslemi, Azin; Ades, Peter Kevin; Groom, Tim; Crous, Pedro; Nicolas, Marc Edward; Taylor, Paul William James

    2016-01-01

    Pyrethrum (Tanacetum cinerariifolium) is commercially cultivated for the extraction of natural pyrethrin insecticides from the oil glands inside seeds. Yield-decline has caused significant yield losses in Tasmania during the last decade. A new pathogen of pyrethrum causing crown rot and reduced

  20. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin

      Oxalic acid (C2O4H2), the strongest of the organic acids is produced by both brown and white rot decay fungi and has been connected to various aspects of brown- and white rot decay including the Fenton reaction (Green and Highley, 1997; Munir et al.,2001). Oxalic acid is secreted into the wood...... cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary...... of formic acid and CO2 (Makela et al., 2002). So far only a few species of brown rot fungi have been shown to accumulate this enzyme (Micales, 1995, Howell and Jellison, 2006).   The purpose of this study was to investigate the variation in the levels of soluble oxalate and total oxalate, in correlation...

  1. Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

    Directory of Open Access Journals (Sweden)

    You-Kun Zheng

    2017-07-01

    Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

  2. Effectiveness of Neutral Electrolyzed Water on Incidence of Fungal Rot on Tomato Fruits ( Solanum lycopersicum L.).

    Science.gov (United States)

    Vásquez-López, Alfonso; Villarreal-Barajas, Tania; Rodríguez-Ortiz, Gerardo

    2016-10-01

    We assessed the effect of neutral electrolyzed water (NEW) on the incidence of rot on tomato ( Solanum lycopersicum L.) fruits inoculated with Fusarium oxysporum , Galactomyces geotrichum , and Alternaria sp. at sites with lesions. The inoculated fruits were treated with NEW at 10, 30, and 60 mg liter -1 active chlorine, with copper oxychloride fungicide, and with sterile distilled water (control) for 3, 5, and 10 min. In the experiment with F. oxysporum , 50 to 80% of the control fruits and 50 to 60% of the fruits treated with the fungicide exhibited symptoms of rot at the inoculated sites. The lowest incidence recorded was 30% for fruits treated with NEW at 60 mg liter -1 active chlorine with an immersion time of 5 min. In the experiment with G. geotrichum , incidence of rot on control fruits was 70 to 90%, and for treatment with fungicide rot incidence was 50 to 90%. NEW at 60 mg liter -1 active chlorine significantly reduced incidence of symptomatic fruit: only 30% of the inoculated fruits washed for 5 min had damage from rot. In the experiment with Alternaria sp., 60 to 90% of the fruits in the control group and 60 to 70% of the fruits in the fungicide group were symptomatic. The lowest incidence was recorded for the treatment in which the fruits were submerged in NEW with 60 mg liter -1 active chlorine for 3 min. In this group, 40 to 50% of the fruits exhibited symptoms of rot. These results were obtained 8 days after inoculation. NEW, with 60 mg liter -1 active chlorine, significantly reduced incidence of rot symptoms on fruits inoculated with one of the experimental fungi relative to the control (P ≤ 0.05). NEW at 60 mg liter -1 is effective in the control of fungal rot in tomatoes.

  3. Studies on storage rot of cocoyam

    African Journals Online (AJOL)

    uc network

    42(3): 2059-2068. Eze, C.S (1984). Studies on storage rot of cocoyam (Colocasia esculenta (L.) Schott) at Nsukka. MSc. Dissertation, Dept of Botany, Univ of Nigeria, Nsukka. 73pp. Loyonga, S. N and Nzietchueng S. (1987). Cocoyam and African food crisi. In: Tropical Root Crops: Root crops and the African food crisis Terry ...

  4. Somaclonal variation and irradiation in sugarcane calli for selection against red rot, water-logged conditions and delayed or non-flowering characters

    International Nuclear Information System (INIS)

    Samad, M.A.; Begum, S.; Majid, M.A.

    2001-01-01

    A protocol for callus induction and plant regeneration from primordial leaf culture was established in sugarcane cv. 'Isd-16'. The regenerated (R 1 ) plants were grown in field, and the subsequent propagations (R 2 -R 4 ) were screened for resistance to red rot disease and waterlogged conditions. Three clones showed moderate resistance (MR) to red rot and 3 clones were tolerant to water-logging in R 4 . In another experiment, callus cultures were irradiated with 2 to 10 Gy gamma rays. The maximum regeneration was obtained from 3 Gy treatment. Of the 768 R 1 plants, 50 survived to maturity. R 2 and R 3 populations were selected for delayed or non-flowering types. Five R 3 canes showed delayed flowering. (author)

  5. Comparative Methods of Application of Wild Plant Parts on Growth and in the Control of Root Rot Fungi of Leguminous Crops

    International Nuclear Information System (INIS)

    Ikram, N.; Dawae, S.

    2016-01-01

    Present research work was carried out for the management of root rot fungi with wild plant part capsules and pellets formulation in soil. When application of pellets and capsules was carried out with Prosopis juliflora stem, leaves and flowers showed significant reduction in disease incidence and enhancement in growth and physiological parameters. Colonization of Fusarium spp., Macrophomina phaseolina and Rhizoctonia solani was completely suppressed when P. juliflora leaves pellets incorporated in soil. Physiological parameters such as chlorophyll a and b and protein were significantly increased when leaves pellets incorporated in soil at the rate of 1 percent w/w so P. juliflora leaves pellets were most effective in the control of root rot fungi and enhanced the growth of crop plants. (author)

  6. Improvement of garlic (Allium Sativum L.) resistance to white rot and storability using gamma irradiation induced mutations

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Mirali, N.; Arabi, M. I. E.

    2001-01-01

    A mutation program was conducted to improve garlic (Allium sativum) resistance to white rot (Sclerotium cepivorum) and to improve its storability under natural conditions. Cloves of two local garlic cultivars (Kisswany and Yabroudy) were irradiated with gamma ray doses 4, 5, 6, and 7 gray. The cloves were then planted in the field and plants were advanced for 4 generations in order to isolate mutations in stable form. The results indicated that the cultivar Yabroudy was more sensitive to gamma irradiation than Kisswany. Rate of morphological mutants increased with increasing gamma ray dosage. Selection pressure against white rot disease was applied starting in the second generation by adding infected garlic leaves to the soil. In the third and fourth generations, however, full selection pressure was applied by inoculating the cloves with the fungus sclerotia and planting them in a soil previously planted with infected garlic plants. healthy garlic bulbs were harvested and stored under natural conditions and then planted to obtain the next generation. By the end of the fourth generation, we have been able to improve garlic resistance to white rot disease and its storability. Twenty four mutant lines from each garlic cultivar have been selected. Out of the selected lines, twelve lines from cultivar Kisswany had only 3% infection percentage as compared to 29% in the control, and twelve lines from cultivar Yabroudy had less than 5% infection percentage as compared to 20% in the control. Also, we have been able to improve storability under natural conditions. Weight loss during storage decreased from 8.25% in the control to only 4% in some Kisswany lines and from 10% to 3% in some Yabroudy lines. However, we have not been able to increase the bulb weight over the control but the weights of the selected lines were comparable to those of the control. (author)

  7. Interactions of Salmonella enterica Serovar Typhimurium and Pectobacterium carotovorum within a Tomato Soft Rot.

    Science.gov (United States)

    George, Andrée S; Cox, Clayton E; Desai, Prerak; Porwollik, Steffen; Chu, Weiping; de Moraes, Marcos H; McClelland, Michael; Brandl, Maria T; Teplitski, Max

    2018-03-01

    Salmonella spp. are remarkably adaptable pathogens, and this adaptability allows these bacteria to thrive in a variety of environments and hosts. The mechanisms with which these pathogens establish within a niche amid the native microbiota remain poorly understood. Here, we aimed to uncover the mechanisms that enable Salmonella enterica serovar Typhimurium strain ATCC 14028 to benefit from the degradation of plant tissue by a soft rot plant pathogen, Pectobacterium carotovorum The hypothesis that in the soft rot, the liberation of starch (not utilized by P. carotovorum ) makes this polymer available to Salmonella spp., thus allowing it to colonize soft rots, was tested first and proven null. To identify the functions involved in Salmonella soft rot colonization, we carried out transposon insertion sequencing coupled with the phenotypic characterization of the mutants. The data indicate that Salmonella spp. experience a metabolic shift in response to the changes in the environment brought on by Pectobacterium spp. and likely coordinated by the csrBC small regulatory RNA. While csrBC and flhD appear to be of importance in the soft rot, the global two-component system encoded by barA sirA (which controls csrBC and flhDC under laboratory conditions) does not appear to be necessary for the observed phenotype. Motility and the synthesis of nucleotides and amino acids play critical roles in the growth of Salmonella spp. in the soft rot. IMPORTANCE Outbreaks of produce-associated illness continue to be a food safety concern. Earlier studies demonstrated that the presence of phytopathogens on produce was a significant risk factor associated with increased Salmonella carriage on fruits and vegetables. Here, we genetically characterize some of the requirements for interactions between Salmonella and phytobacteria that allow Salmonella spp. to establish a niche within an alternate host (tomato). Pathways necessary for nucleotide synthesis, amino acid synthesis, and motility

  8. Altered cultivar resistance of kimchi cabbage seedlings mediated by salicylic Acid, jasmonic Acid and ethylene.

    Science.gov (United States)

    Lee, Young Hee; Kim, Sang Hee; Yun, Byung-Wook; Hong, Jeum Kyu

    2014-09-01

    Two cultivars Buram-3-ho (susceptible) and CR-Hagwang (moderate resistant) of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum), black spot (Alternaria brassicicola) and black rot (Xanthomonas campestris pv. campestris, Xcc) diseases in our previous study. Defense-related hormones salicylic acid (SA), jasmonic acid (JA) and ethylene led to different transcriptional regulation of pathogenesis-related (PR) gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ) treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

  9. Altered Cultivar Resistance of Kimchi Cabbage Seedlings Mediated by Salicylic Acid, Jasmonic Acid and Ethylene

    Directory of Open Access Journals (Sweden)

    Young Hee Lee

    2014-09-01

    Full Text Available Two cultivars Buram-3-ho (susceptible and CR-Hagwang (moderate resistant of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum, black spot (Alternaria brassicicola and black rot (Xanthomonas campestris pv. campestris, Xcc diseases in our previous study. Defense-related hormones salicylic acid (SA, jasmonic acid (JA and ethylene led to different transcriptional regulation of pathogenesis-related (PR gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

  10. Cytomegalovirus infection and risk of Alzheimer disease in older black and white individuals.

    Science.gov (United States)

    Barnes, Lisa L; Capuano, Ana W; Aiello, Alison E; Turner, Arlener D; Yolken, Robert H; Torrey, E Fuller; Bennett, David A

    2015-01-15

    Human cytomegalovirus (CMV) is prevalent in older adults and has been implicated in many chronic diseases of aging. This study investigated the relation between CMV and the risk of Alzheimer disease (AD). Data come from 3 cohort studies that included 849 participants (mean age [±SD], 78.6 ± 7.2 years; mean education duration [±SD], 15.4 ± 3.3 years; 25% black). A solid-phase enzyme-linked immunosorbent assay was used for detecting type-specific immunoglobulin G antibody responses to CMV and herpes simplex virus type 1 (HSV-1) measured in archived serum samples. Of 849 participants, 73.4% had serologic evidence of exposure to CMV (89.0% black and 68.2% white; P risk of AD (relative risk, 2.15; 95% confidence interval, 1.42-3.27) and a faster rate of decline in global cognition (estimate [±standard error], -0.02 ± 0.01; P = .03) in models that controlled for age, sex, education duration, race, vascular risk factors, vascular diseases, and apolipoprotein ε4 level. Results were similar in black and white individuals for both incident AD and change in cognitive function and were independent of HSV-1 status. These results suggest that CMV infection is associated with an increased risk of AD and a faster rate of cognitive decline in older diverse populations. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Development of biocontrol agents from food microbial isolates for controlling post-harvest peach brown rot caused by Monilinia fructicola.

    Science.gov (United States)

    Zhou, Ting; Schneider, Karin E; Li, Xiu-Zhen

    2008-08-15

    An unconventional strategy of screening food microbes for biocontrol activity was used to develop biocontrol agents for controlling post-harvest peach brown rot caused by Monilinia fructicola. Forty-four microbial isolates were first screened for their biocontrol activity on apple fruit. Compared with the pathogen-only check, seven of the 44 isolates reduced brown rot incidence by >50%, including four bacteria: Bacillus sp. C06, Lactobacillus sp. C03-b and Bacillus sp. T03-c, Lactobacillus sp. P02 and three yeasts: Saccharomyces delbrueckii A50, S. cerevisiae YE-5 and S. cerevisiae A41. Eight microbial isolates were selected for testing on peaches by wound co-inoculation with mixtures of individual microbial cultures and conidial suspension of M. fructicola. Only two of them showed significant biocontrol activity after five days of incubation at 22 degrees C. Bacillus sp. C06 suppressed brown rot incidence by 92% and reduced lesion diameter by 88% compared to the pathogen-only check. Bacillus sp.T03-c reduced incidence and lesion diameter by 40% and 62%, respectively. The two isolates were compared with Pseudomonas syringae MA-4, a biocontrol agent for post-harvest peach diseases, by immersing peaches in an aliquot containing individual microbial isolates and the pathogen conidia. Treatments with isolates MA-4, C06 and T03-c significantly controlled brown rot by 91, 100, and 100% respectively. However, only isolates MA-4 and C06 significantly reduced brown rot by 80% and 15%, respectively when bacterial cells alone were applied. On naturally infected peaches, both the bacterial culture and its cell-free filtrate of the isolate C06 significantly controlled peach decay resulting in 77 and 90% reduction, respectively, whereas the treatment using only the bacterial cells generally had no effect. Isolate C06 is a single colony isolate obtained from a mesophilic cheese starter, and has been identified belonging to Bacillus amyloliquefaciens. The results have clearly

  12. Two different PCR approaches for universal diagnosis of brown rot and identification of Monilinia spp. in stone fruit trees.

    Science.gov (United States)

    Gell, I; Cubero, J; Melgarejo, P

    2007-12-01

    To design a protocol for the universal diagnosis of brown rot by polymerase chain reaction (PCR) in plant material and subsequently Monilinia spp. identification. Primers for discrimination of Monilinia spp. from other fungal genera by PCR were designed following a ribosomal DNA analysis. Discrimination among species of Monilinia was subsequently achieved by developing primers using SCAR (Sequence Characterised Amplified Region) markers obtained after a random amplified polymorphic DNA study. In addition, an internal control (IC) based on the utilization of a mimic plasmid was designed to be used in the diagnostic protocol of brown rot to recognize false negatives due to the inhibition of PCR. The four sets of primers designed allowed detection and discrimination of all Monilinia spp. causing brown rot in fruit trees. Addition of an IC in each PCR reaction performed increased the reliability of the diagnostic protocol. The detection protocol presented here, that combined a set of universal primers and the inclusion of the plasmid pGMON as an IC for diagnosis of all Monilinia spp., and three sets of primers to discriminate the most important species of Monilinia, could be an useful and valuable tool for epidemiological studies. The method developed could be used in programmes to avoid the spread and introduction of this serious disease in new areas.

  13. Application of Trichoderma harzianum in the control of basal stem rot of oil palms

    Institute of Scientific and Technical Information of China (English)

    Abdullah F; Ilias G N M

    2004-01-01

    @@ The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3,769,000 ha, followed by Malaysia at 3,376,000 ha; however, the world' s leading producer of palm oil is still Malaysia, since the 1970's. Both countries are predicted to produce 82.4%of the world's palm oil production by the year 2005. However, the palm is susceptible to basal stem rot, a devastating disease which results in direct loss of field stands and to which no effective chemical control is yet available. Caused by Ganoderma boninense, infected palms appear symptomless, at the first sign of disease, at least 50 % of the internal trunk tissue stem would have actually rotted. This study investigated the efficacy of Trichoderma harzianum (isolate FA 1132) as a biological control agent, using 6-month old oil palm seedlings as models and the experiment performed in a greenhouse at 29-30 ℃ ambient conditions. The plants were artificially infected with G. boninense and a conidial suspension of 1 × 109-9 × 109 spores/mL was applied as a soil drench at 1L/plant every 2 weeks for 20weeks. The parameters examined were efficacy of the biocontrol agent and the effect of Trichodermaincorporated mulch in addition to the soil drench. Efficacy was assessed in terms disease severity index (DSI) where a higher percentage indicates a higher severity. Results showed that infection first sets in on untreated plants at week 12 and got worse progressively. The completely untreated plants were all infected and the DSI at 20 weeks after infection (wa. i.) was 92. 5%. Plants given only a Trichoderma -infused food base supplement without conidial suspension gave a DSI of 70% whereas those given a conidial soil drench without supplemental food base gave a DSI of 85% at 20 w.a.i.Infected plants given a conidial treatment together with a food base supplement gave a DSI

  14. Chemical and biological control of Sclerotinia stem rot in the soybean crop

    Directory of Open Access Journals (Sweden)

    Ciro Hideki Sumida

    2015-05-01

    Full Text Available It was evaluated the effect of fungicides and the microbial control agent Trichoderma harzianum on the inhibition of the carpogenic and ascospore germination of Sclerotinia sclerotiorum. This study also evaluated the chemical, fungicidal and microbial control of white mold or Sclerotinia stem rot of soybean in the field. Three experiments were conducted, as follows: 1 inhibition of carpogenic germination of sclerotia, 2 inhibition of ascospore germination, and 3 control of Sclerotinia stem rot in a soybean crop under field conditions. The treatments evaluated were fluazinam, procymidone, iprodione, thiophanate-methyl, carbendazim, benzalkonium chloride + fluazinam, and T. harzianum. Procymidone resulted in an inhibition of 13.5% and benzalkonium chloride in an inhibition of 13.9% in an ascospore germination test. Fluazinam and procymidone were the most effective in reducing the production of ascospores/apothecium, representing 65.6% and 82.4% of inhibition. Procymidone and fluazinam if combined or not with benzalkonium chloride were the most effective in controlling sclerotinia stem rot under field conditions when applied at the onset of flowering and 15 days later. In the 2009-10 harvest, these two fungicides reduced the incidence of Sclerotinia stem rot by 73.1 and 71.6% and in the 2010-11 harvest by 75.7 and 77.6%, respectively.

  15. Antifungal Compound Isolated from Catharanthus roseus L. (Pink for Biological Control of Root Rot Rubber Diseases

    Directory of Open Access Journals (Sweden)

    R. Zahari

    2018-01-01

    Full Text Available Rigidoporus microporus, Ganoderma philippii, and Phellinus noxius are root rot rubber diseases and these fungi should be kept under control with environmentally safe compounds from the plant sources. Thus, an antifungal compound isolated from Catharanthus roseus was screened for its effectiveness in controlling the growth of these fungi. The antifungal compound isolated from C. roseus extract was determined through thin layer chromatography (TLC and nuclear magnetic resonance (NMR analysis. Each C. roseus of the DCM extracts was marked as CRD1, CRD2, CRD3, CRD4, CRD5, CRD6, and CRD7, respectively. TLC results showed that all of the C. roseus extracts peaked with red colour at Rf = 0.61 at 366 nm wavelength, except for CRD7. The CRD4 extract was found to be the most effective against R. microporus and G. philippii with inhibition zones of 3.5 and 1.9 mm, respectively, compared to that of other extracts. These extracts, however, were not effective against P. noxius. The CRD4 extract contained ursolic acid that was detected by NMR analysis and the compound could be developed as a biocontrol agent for controlling R. microporus and G. philippii. Moreover, little or no research has been done to study the effectiveness of C. roseus in controlling these fungi.

  16. Identification and Differentiation of Monilinia Species Causing Brown Rot of Pome and Stone Fruit using High-Resolution Melting (HRM) Analysis.

    Science.gov (United States)

    Papavasileiou, Antonios; Madesis, Panagiotis B; Karaoglanidis, George S

    2016-09-01

    Brown rot is a devastating disease of stone fruit caused by Monilinia spp. Among these species, Monilinia fructicola is a quarantine pathogen in Europe but has recently been detected in several European countries. Identification of brown rot agents relies on morphological differences or use of molecular methods requiring fungal isolation. The current study was initiated to develop and validate a high-resolution melting (HRM) method for the identification of the Monilinia spp. and for the detection of M. fructicola among other brown rot pathogens. Based on the sequence of the cytb intron from M. laxa, M. fructicola, M. fructigena, M. mumecola, M. linhartiana, and M. yunnanensis isolates originating from several countries, a pair of universal primers for species identification and a pair of primers specific to M. fructicola were designed. The specificity of the primers was verified to ensure against cross-reaction with other fungal species. The melting curve analysis using the universal primers generated six different HRM curve profiles, each one specific for each species. Τhe HRM analysis primers specific to M. fructicola amplified a 120-bp region with a distinct melt profile corresponding to the presence of M. fructicola, regardless of the presence of other species. HRM analysis can be a useful tool for rapid identification and differentiation of the six Monilinia spp. using a single primer pair. This novel assay has the potential for simultaneous identification and differentiation of the closely related Monilinia spp. as well as for the differentiation of M. fructicola from other common pathogens or saprophytes that may occur on the diseased fruit.

  17. Studies on in vitro induction mutation for wheat mutant of resistance to root rot and its resistance mechanism

    International Nuclear Information System (INIS)

    Sun Guangzu

    1992-06-01

    The screening wheat mutant which has the resistance to root rot was completed in 37 varieties by in vitro induction mutation method. The effect of irradiation on in vitro culture of different wheat explants and the effectiveness of screening rude toxin were studied. Two wheat mutants, RB500 and RB501, which have the resistance to root rot, were obtained. Changes of the ultrastructure and defensive enzymes (SOD, ROD and PAL) were investigated by using mutants and parent under the action of rude toxin. The results showed that the rude toxin could induce changes of enzyme activity, isoenzyme pattern and ultrastructure of the mitochondria and chloroplast. These change correspond to their ability of resistance to disease. The mutant under the action of toxin has the ability to increase the defensive enzyme activity and to reduce the damage of cell membrane system that would result in resistance increasing

  18. The fungus that came in from the cold: dry rot's pre-adapted ability to invade buildings.

    Science.gov (United States)

    Balasundaram, S V; Hess, J; Durling, M B; Moody, S C; Thorbek, L; Progida, C; LaButti, K; Aerts, A; Barry, K; Grigoriev, I V; Boddy, L; Högberg, N; Kauserud, H; Eastwood, D C; Skrede, I

    2018-03-01

    Many organisms benefit from being pre-adapted to niches shaped by human activity, and have successfully invaded man-made habitats. One such species is the dry rot fungus Serpula lacrymans, which has a wide distribution in buildings in temperate and boreal regions, where it decomposes coniferous construction wood. Comparative genomic analyses and growth experiments using this species and its wild relatives revealed that S. lacrymans evolved a very effective brown rot decay compared to its wild relatives, enabling an extremely rapid decay in buildings under suitable conditions. Adaptations in intracellular transport machineries promoting hyphal growth, and nutrient and water transport may explain why it is has become a successful invader of timber in houses. Further, we demonstrate that S. lacrymans has poor combative ability in our experimental setup, compared to other brown rot fungi. In sheltered indoor conditions, the dry rot fungus may have limited encounters with other wood decay fungi compared to its wild relatives. Overall, our analyses indicate that the dry rot fungus is an ecological specialist with poor combative ability against other fungi.

  19. Enzymatic oxalic acid regulation correlated with wood degradation in four brown-rot fungi

    Science.gov (United States)

    Anne Christine Steenkjær Hastrup; Frederick Green III; Patricia K. Lebow; Bo Jensen

    2012-01-01

    Oxalic acid is a key component in the initiation of brown-rot decay and it has been suggested that it plays multiple roles during the degradation process. Oxalic acid is accumulated to varying degrees among brown-rot fungi; however, details on active regulation are scarce. The accumulation of oxalic acid was measured in this study from wood degraded by the four brown-...

  20. Analysis of Fusarium avenaceum Metabolites Produced during Wet Apple Core Rot

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Phipps, Richard Kerry; Nielsen, Kristian Fog

    2009-01-01

    Wet apple core rot (wACR) is a well-known disease of susceptible apple cultivars such as Gloster, Jona Gold, and Fuji. Investigations in apple orchards in Slovenia identified Fusarium avenaceum, a known producer of several mycotoxins, as the predominant causal agent of this disease. A LC...... and naturally infected apples. Levels of moniliformin, antibiotic Y, aurofusarin, and enniatins A, A1, B, and B1 were quantitatively examined in artificially inoculated and naturally infected apples, whereas the remaining metabolites were qualitatively detected. Metabolite production was examined...... in artificially inoculated apples after 3, 7, 14, and 21 days of incubation. Most metabolites were detected after 3 or 7 days and reached significantly high levels within 14 or 21 days. The highest levels of moniliformin, antibiotic Y, aurofusarin, and the combined sum of enniatins A, A1, B, and B1 were 7.3, 5...

  1. Rice-Infecting Pseudomonas Genomes Are Highly Accessorized and Harbor Multiple Putative Virulence Mechanisms to Cause Sheath Brown Rot

    Science.gov (United States)

    Quibod, Ian Lorenzo; Grande, Genelou; Oreiro, Eula Gems; Borja, Frances Nikki; Dossa, Gerbert Sylvestre; Mauleon, Ramil; Cruz, Casiana Vera; Oliva, Ricardo

    2015-01-01

    Sheath rot complex and seed discoloration in rice involve a number of pathogenic bacteria that cannot be associated with distinctive symptoms. These pathogens can easily travel on asymptomatic seeds and therefore represent a threat to rice cropping systems. Among the rice-infecting Pseudomonas, P. fuscovaginae has been associated with sheath brown rot disease in several rice growing areas around the world. The appearance of a similar Pseudomonas population, which here we named P. fuscovaginae-like, represents a perfect opportunity to understand common genomic features that can explain the infection mechanism in rice. We showed that the novel population is indeed closely related to P. fuscovaginae. A comparative genomics approach on eight rice-infecting Pseudomonas revealed heterogeneous genomes and a high number of strain-specific genes. The genomes of P. fuscovaginae-like harbor four secretion systems (Type I, II, III, and VI) and other important pathogenicity machinery that could probably facilitate rice colonization. We identified 123 core secreted proteins, most of which have strong signatures of positive selection suggesting functional adaptation. Transcript accumulation of putative pathogenicity-related genes during rice colonization revealed a concerted virulence mechanism. The study suggests that rice-infecting Pseudomonas causing sheath brown rot are intrinsically diverse and maintain a variable set of metabolic capabilities as a potential strategy to occupy a range of environments. PMID:26422147

  2. Combination of antagonistic yeasts with two food additives for control of brown rot caused by Monilinia fructicola on sweet cherry fruit.

    Science.gov (United States)

    Qin, G Z; Tian, S P; Xu, Y; Chan, Z L; Li, B Q

    2006-03-01

    To evaluate beneficial effect of two food additives, ammonium molybdate (NH4-Mo) and sodium bicarbonate (NaBi), on antagonistic yeasts for control of brown rot caused by Monilinia fructicola in sweet cherry fruit under various storage conditions. The mechanisms of action by which food additives enhance the efficacy of antagonistic yeasts were also evaluated. Biocontrol activity of Pichia membranefaciens and Cryptococcus laurentii against brown rot in sweet cherry fruit was improved by addition of 5 mmol l(-1) NH4-Mo or 2% NaBi when stored in air at 20 and 0 degrees C, and in controlled atmosphere (CA) storage with 10% O2 + 10% CO2 at 0 degrees C. Population dynamics of P. membranefaciens in the wounds of fruit were inhibited by NH4-Mo at 20 degrees C after 1 day of incubation and growth of C. laurentii was inhibited by NH4-Mo at 0 degrees C in CA storage after 60 days. In contrast, NaBi did not significantly influence growth of the two yeasts in fruit wounds under various storage conditions except that the growth of P. membranefaciens was stimulated after storage for 45 days at 0 degrees C in CA storage. When used alone, the two additives showed effective control of brown rot in sweet cherry fruit and the efficacy was closely correlated with the concentrations used. The result of in vitro indicated that growth of M. fructicola was significantly inhibited by NH4-Mo and NaBi. Application of additives improved biocontrol of brown rot on sweet cherry fruit under various storage conditions. It is postulated that the enhancement of disease control is directly because of the inhibitory effects of additives on pathogen growth, and indirectly because of the relatively little influence of additives on the growth of antagonistic yeasts. The results obtained in this study suggest that an integration of NH4-Mo or NaBi with biocontrol agents has great potential in commercial management of postharvest diseases of fruit.

  3. Gnomoniopsis castanea is the main agent of chestnut nut rot in Switzerland

    Directory of Open Access Journals (Sweden)

    Francesca G. DENNERT

    2015-09-01

    Full Text Available Nuts of sweet chestnut have been an important food source for the alpine population in Switzerland since the Middle Ages and are still valued today for the preparation of traditional food commodities. Nut quality is reduced by insect damage and by various pathogenic fungi. In the last few years, producers and consumers perceived an increase of brown nut rot; while the nut rot agent Gnomoniopsis castanea was reported locally in southern Switzerland, its presence has not been investigated over large areas until now. This study assessed the incidence of brown nut rot and identified the causal agent present in Switzerland. Fully ripened nuts were collected from the main sweet chestnut growing areas of Switzerland. A filamentous fungus morphologically identified as G. castanea was isolated from 10 to 91% of the sampled nuts, despite only 3 to 21% of the sampled nuts showing brown rot symptoms. This fungus was isolated from symptomatic chestnuts as well as from apparently healthy chestnuts. Our results suggest a possible endophytic lifestyle in ripened nuts as well as in branches, leaves and unripe nuts as previously found. Species identity of 45 isolates was confirmed by EF-1alpha, beta-tubulin and ITS sequencing. Concatenation of β-tubulin and calmodulin sequences showed that several haplotypes were present at each sampling locality. No other nut rot pathogens could be isolated in this study, suggesting that G. castanea is the main causal agent of nut rot in Switzerland. The presence of this species is reported for the first time in a site in northern Switzerland. Further studies are needed to assess the influence of meteorological conditions and chestnut varieties on the incidence of G. castanea in order to provide prevention strategies for chestnut growers. Normal 0 21 false false false FR-CH X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso

  4. Construction of 2 intraspecific linkage maps and identification of resistance QTLs for Phytophthora capsici root-rot and foliar-blight diseases of pepper (Capsicum annuum L.).

    Science.gov (United States)

    Ogundiwin, Ebenezer A; Berke, Terry F; Massoudi, Mark; Black, Lowell L; Huestis, Gordon; Choi, Doil; Lee, Sanghyeob; Prince, James P

    2005-08-01

    Two linkage maps of pepper were constructed and used to identify quantitative trait loci (QTLs) conferring resistance to Phytophthora capsici. Inoculations were done with 7 isolates: 3 from Taiwan, 3 from California, and 1 from New Mexico. The first map was constructed from a set of recombinant inbred lines (RILs) of the PSP-11 (susceptible) x PI201234 (resistant) cross; and the second map was from a set of F(2) lines of the Joe E. Parker' (susceptible) x 'Criollo de Morelos 334' (resistant) cross. The RIL map covered 1466.1 cM of the pepper genome, and it consisted of 144 markers -- 91 amplified fragment length polymorphisms (AFLPs), 34 random amplified polymorphic DNA (RAPDs), 15 simple sequence repeats (SSRs), 1 sequence characterized amplified region (SCAR), and 3 morphological markers -- distributed over 17 linkage groups. The morphological markers mapped on this population were erect fruit habit (up), elongated fruit shape (fs(e)), and fasciculate fruit clusters (fa). The F(2) map consisted of 113 markers (51 AFLPs, 45 RAPDs, 14 SSRs, and 3 SCARs) distributed in 16 linkage groups, covering a total of 1089.2 cM of the pepper genome. Resistance to both root rot and foliar blight were evaluated in the RIL population using the 3 Taiwan isolates; the remaining isolates were used for the root-rot test only. Sixteen chromosomal regions of the RIL map contained single QTLs or clusters of resistance QTLs that had an effect on root rot and (or) foliar blight, revealing a complex set of genetics involved in resistance to P. capsici. Five QTLs were detected in the F(2) map that had an effect on resistance to root rot.

  5. Trichoderma rot on ‘Fallglo’ Tangerine Fruit

    Science.gov (United States)

    In September 2009, brown rot symptoms were observed on ‘Fallglo’ fruit after 7 weeks of storage. Fourteen days prior to harvest, fruit were treated by dipping into one of four different fungicide solutions. Control fruit were dipped in tap water. After harvest, the fruit were degreened with 5 ppm et...

  6. Combating a Global Threat to a Clonal Crop : Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    NARCIS (Netherlands)

    Arango Isaza, Rafael E.; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F.; de Jong, Tristan V.; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fereira, Claudia Fortes; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza, Manoel; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Francoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the Dothideomycete fungus Pseudocercospora fijiensis (previously: Mycosphaerella fijiensis), is the most significant foliar disease of banana worldwide. Due to the lack of effective host resistance, management of this disease requires frequent

  7. Genotyping-by-sequencing uncovers the introgression alien segments associated with Sclerotinia basal stalk rot resistance from wild species—I. Helianthus argophyllus and H. petiolaris

    Science.gov (United States)

    Basal stalk rot (BSR), caused by Sclerotinia Sclerotiorum, is a devastating disease in sunflower worldwide. The progress of breeding for Sclerotinia BSR resistance has been hampered due to the lack of effective sources of resistance for cultivated sunflower. Our objective was to transfer BSR resista...

  8. Scholarly context not found: one in five articles suffers from reference rot.

    Directory of Open Access Journals (Sweden)

    Martin Klein

    Full Text Available The emergence of the web has fundamentally affected most aspects of information communication, including scholarly communication. The immediacy that characterizes publishing information to the web, as well as accessing it, allows for a dramatic increase in the speed of dissemination of scholarly knowledge. But, the transition from a paper-based to a web-based scholarly communication system also poses challenges. In this paper, we focus on reference rot, the combination of link rot and content drift to which references to web resources included in Science, Technology, and Medicine (STM articles are subject. We investigate the extent to which reference rot impacts the ability to revisit the web context that surrounds STM articles some time after their publication. We do so on the basis of a vast collection of articles from three corpora that span publication years 1997 to 2012. For over one million references to web resources extracted from over 3.5 million articles, we determine whether the HTTP URI is still responsive on the live web and whether web archives contain an archived snapshot representative of the state the referenced resource had at the time it was referenced. We observe that the fraction of articles containing references to web resources is growing steadily over time. We find one out of five STM articles suffering from reference rot, meaning it is impossible to revisit the web context that surrounds them some time after their publication. When only considering STM articles that contain references to web resources, this fraction increases to seven out of ten. We suggest that, in order to safeguard the long-term integrity of the web-based scholarly record, robust solutions to combat the reference rot problem are required. In conclusion, we provide a brief insight into the directions that are explored with this regard in the context of the Hiberlink project.

  9. Neofusicoccum luteum associated with leaf necrosis and fruit rot of olives in New South Wales, Australia

    Directory of Open Access Journals (Sweden)

    V. Sergeeva

    2009-09-01

    Full Text Available Neofusicoccum luteum is reported for the first time from olives (Olea europaea, causing fruit rot and leaf necrosis. Affected fruits initially became brown with pycnidia developing on the surface, later drying out and becoming mummified. The fungus was shown to be pathogenic on both fruits and leaves. The association of Botryosphaeriaceae with rotting olive fruits in Mediterranean regions and in New South Wales, Australia indicates that these fungi play a significant role in fruit rots of olives and deserve greater attention.

  10. An investigation of diverticular disease among black patients undergoing colonoscopy at Dr George Mukhari Academic Hospital, Pretoria, South Africa.

    Science.gov (United States)

    Vally, M; Koto, M Z; Govender, M

    2017-01-30

    Diverticular disease was previously thought to be non-existent in the black African population. Studies over the past four decades, however, have shown a steady increase in the prevalence of the disease. To report on the profile and current prevalence of diverticular disease in the black South African (SA) population at Dr George Mukhari Academic Hospital, Pretoria, SA. A retrospective descriptive study was performed in black SA patients who were diagnosed with diverticular disease by colonoscopy between 1 January and 31 December 2015. Of 348 patients who had undergone colonoscopies and who were eligible for inclusion in this study, 47 were diagnosed with diverticular disease - a prevalence of 13.50% (95% confidence interval 10.30 - 17.50). The greatest number of patients diagnosed were in their 7th and 8th decades, with an age range of 46 - 86 (mean 67) years. There was a female predominance of 57.45%. Lower gastrointestinal bleeding was the most common (65.96%) indication for colonoscopy. The left colon was most commonly involved (72.34%), followed by the right colon (55.31%). A substantial number of patients had pancolonic involvement (27.65%). This retrospective study suggests that there has been a considerable increase in the prevalence of diverticular disease among black South Africans, possibly owing to changes in dietary habits and socioeconomic status.

  11. An investigation of diverticular disease among black patients undergoing colonoscopy at Dr George Mukhari Academic Hospital, Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    M Vally

    2017-02-01

    Full Text Available Background. Diverticular disease was previously thought to be non-existent in the black African population. Studies over the past four decades, however, have shown a steady increase in the prevalence of the disease. Objective. To report on the profile and current prevalence of diverticular disease in the black South African (SA population at Dr George Mukhari Academic Hospital, Pretoria, SA. Methods. A retrospective descriptive study was performed in black SA patients who were diagnosed with diverticular disease by colonoscopy between 1 January and 31 December 2015. Results. Of 348 patients who had undergone colonoscopies and who were eligible for inclusion in this study, 47 were diagnosed with diverticular disease – a prevalence of 13.50% (95% confidence interval 10.30 - 17.50. The greatest number of patients diagnosed were in their 7th and 8th decades, with an age range of 46 - 86 (mean 67 years. There was a female predominance of 57.45%. Lower gastrointestinal bleeding was the most common (65.96% indication for colonoscopy. The left colon was most commonly involved (72.34%, followed by the right colon (55.31%. A substantial number of patients had pancolonic involvement (27.65%. Conclusion. This retrospective study suggests that there has been a considerable increase in the prevalence of diverticular disease among black South Africans, possibly owing to changes in dietary habits and socioeconomic status.

  12. The Burden of Cardiovascular Disease in Sub-Saharan Africa and the Black Diaspora.

    Science.gov (United States)

    Gillum, Richard F

    2018-03-19

    For over four decades the National Medical Association (NMA) and the Association of Black Cardiologists (ABC) have sought to bring to national attention the disparate burden of cardiovascular disease (CVD) among African Americans. However, systematic inquiry has been inadequate into the burden of CVD in the poor countries of Sub-Saharan Africa (SSA) and the African diaspora in the Americas outside the USA. However, recently, the Global Burden of Disease Study (GBD) has offered new tools for such inquiry. Several initial efforts in that direction using 2010 data have been published. This article highlights some new findings for SSA for 2016. It also suggests that NMA and ABC further this effort by direct advocacy and collaboration with the GBD to make estimates of CVD burden in African Americans and South American Blacks explicitly available in future iterations.

  13. A Genome-Wide Association Study Reveals Genes Associated with Fusarium Ear Rot Resistance in a Maize Core Diversity Panel

    Science.gov (United States)

    Zila, Charles T.; Samayoa, L. Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B.

    2013-01-01

    Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0–100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

  14. Distribution of cranberry fruit-rotting fungi in new jersey and evidence for nonspecific host resistance.

    Science.gov (United States)

    Stiles, C M; Oudemans, P V

    1999-03-01

    ABSTRACT A survey was conducted over a 3-year period to determine the frequencies and distributions of fruit-rotting fungi in New Jersey cranberry beds. In the first 2 years of the study, Physalospora vaccinii and Glomerella cingulata were the most prevalent and widespread field-rotting fungi. In the third year, the frequency of G. cingulata declined markedly. Other species such as Coleophoma empetri, Phyllosticta vaccinii, and Phomopsis vaccinii were isolated at high frequencies from a limited number of locations. Storage-rotting fungi including Allantophomopsis cytisporea and A. lycopodina were isolated at low frequencies, but were widely distributed within the growing region. On sound fruit, a somewhat different profile emerged. Fungi such as Phyllosticta elongata, Alternaria spp., and Physalospora vaccinii were commonly isolated. In comparisons among different cranberry cultivars, no differences in the fungal profiles were seen. This was interpreted to indicate that if differences in fruit-rot resistance exist, they are likely to be general forms of resistance rather than fungal species-specific mechanisms.

  15. Agro-ecological variations of sheath rot disease of rice caused by Sarocladium oryzae and DNA fingerprinting of the pathogen's population structure.

    Science.gov (United States)

    Tajul Islam Chowdhury, M; Salim Mian, M; Taher Mia, M A; Rafii, M Y; Latif, M A

    2015-12-28

    To examine the impact of regional and seasonal variations on the incidence and severity of sheath rot, a major seed-borne disease of rice caused by Sarocladium oryzae, data on incidence and severity were collected from 27 selected fields in the Gazipur, Rangpur, Bogra, Chittagong, Comilla, Gopalgonj, Jessore, Manikgonj, and Bhola districts of Bangladesh in rain-fed and irrigated conditions. Cultural variability of 29 pathogen isolates obtained from 8 different locations was studied on potato dextrose agar (PDA) and genetic variability was determined by DNA fingerprinting using variable number tandem repeat-polymerase chain reaction markers. Overall, disease incidence and severity were higher in irrigated rice. Disease incidence and severity were highest in the Bhola district in rain-fed rice and lowest in irrigated rice. Mycelial growth of 29 representative isolates was found to vary on PDA and the isolates were divided into 6 groups. The range of the overall size of conidia of the selected isolates was 2.40-7.20 x 1.20-2.40 μm. Analysis of the DNA fingerprint types of the 29 isolates of S. oryzae, obtained from the amplification reactions, revealed 10 fingerprinting types (FPTs) that were 80% similar. FPT-1 was the largest group and included 13 isolates (44.8%), while FPT-2 was the third largest group and included 3 isolates. Each of FPT-3, 4, 5, and 6 included only 1 isolate. We observed no relationship between cultural and genetic groupings.

  16. Production and optimization of ligninolytic enzymes by white rot ...

    African Journals Online (AJOL)

    Production and optimization of ligninolytic enzymes by white rot fungus Schizophyllum ... size and nutritional factors (carbon and nitrogen ratio, mediators and metal ions). ... scale production of these enzymes for diverse industrial applications.

  17. Rapid polyether cleavage via extracellular one-electron oxidation by a brown-rot basidiomycete

    OpenAIRE

    Kerem, Zohar; Bao, Wuli; Hammel, Kenneth E.

    1998-01-01

    Fungi that cause brown rot of wood are essential biomass recyclers and also the principal agents of decay in wooden structures, but the extracellular mechanisms by which they degrade lignocellulose remain unknown. To test the hypothesis that brown-rot fungi use extracellular free radical oxidants as biodegradative tools, Gloeophyllum trabeum was examined for its ability to depolymerize an environmentally recalcitrant polyether, poly(ethylene oxide) (PEO), that cannot penetrate cell membranes....

  18. Rapid polyether cleavage via extracellular one-electron oxidation by a brown-rot basidiomycete.

    Science.gov (United States)

    Kerem, Z; Bao, W; Hammel, K E

    1998-09-01

    Fungi that cause brown rot of wood are essential biomass recyclers and also the principal agents of decay in wooden structures, but the extracellular mechanisms by which they degrade lignocellulose remain unknown. To test the hypothesis that brown-rot fungi use extracellular free radical oxidants as biodegradative tools, Gloeophyllum trabeum was examined for its ability to depolymerize an environmentally recalcitrant polyether, poly(ethylene oxide) (PEO), that cannot penetrate cell membranes. Analyses of degraded PEOs by gel permeation chromatography showed that the fungus cleaved PEO rapidly by an endo route. 13C NMR analyses of unlabeled and perdeuterated PEOs recovered from G. trabeum cultures showed that a major route for depolymerization was oxidative C---C bond cleavage, a reaction diagnostic for hydrogen abstraction from a PEO methylene group by a radical oxidant. Fenton reagent (Fe(II)/H2O2) oxidized PEO by the same route in vitro and therefore might account for PEO biodegradation if it is produced by the fungus, but the data do not rule out involvement of less reactive radicals. The reactivity and extrahyphal location of this PEO-degrading system suggest that its natural function is to participate in the brown rot of wood and that it may enable brown-rot fungi to degrade recalcitrant organopollutants.

  19. Study on the Occurrence and Epidemic Model of Rape Sclerotinia Stem Rot of ‘Zheyou 50’

    OpenAIRE

    Xu Sen-fu; Wang Hui-fu; Yu Shanhong; Wang En-guo

    2013-01-01

    In order to investigate invading and epidemic rules of rape sclerotinia stem rot of ‘Zheyou 50’ and promote the development of brassica campestris industry, this paper studied the outbreak regularity and epidemic model of rape sclerotinia stem rot according to field investigation and infection. The result showed that machinery direct seeding rape was good for the occurrence of sclerotinia stem rot for the reason of late seeding and high density. The period from water damage appeared to wiltin...

  20. Black thread disease, control measures and yield stimulation in Hevea brasiliensis in Liberia

    NARCIS (Netherlands)

    Schreurs, J.

    1972-01-01

    Described are investigations, carried out in 1963 to 1971 in Hevea brasiliensis at the Firestone Plantation at Harbel in Liberia. Studied was the tapping panel disease, black thread, caused by the fungus Phytophthora palmivora. The emphasis of the

  1. A transposon-directed epigenetic change in ZmCCT underlies quantitative resistance to Gibberella stalk rot in maize.

    Science.gov (United States)

    Wang, Chao; Yang, Qin; Wang, Weixiang; Li, Yipu; Guo, Yanling; Zhang, Dongfeng; Ma, Xuena; Song, Wei; Zhao, Jiuran; Xu, Mingliang

    2017-09-01

    A major resistance quantitative trait locus, qRfg1, significantly enhances maize resistance to Gibberella stalk rot, a devastating disease caused by Fusarium graminearum. However, the underlying molecular mechanism remains unknown. We adopted a map-based cloning approach to identify the resistance gene at qRfg1 and examined the dynamic epigenetic changes during qRfg1-mediated maize resistance to the disease. A CCT domain-containing gene, ZmCCT, is the causal gene at the qRfg1 locus and a polymorphic CACTA-like transposable element (TE1) c. 2.4 kb upstream of ZmCCT is the genetic determinant of allelic variation. The non-TE1 ZmCCT allele is in a poised state, with predictive bivalent chromatin enriched for both repressive (H3K27me3/H3K9me3) and active (H3K4me3) histone marks. Upon pathogen challenge, this non-TE1 ZmCCT allele was promptly induced by a rapid yet transient reduction in H3K27me3/H3K9me3 and a progressive decrease in H3K4me3, leading to disease resistance. However, TE1 insertion in ZmCCT caused selective depletion of H3K4me3 and enrichment of methylated GC to suppress the pathogen-induced ZmCCT expression, resulting in disease susceptibility. Moreover, ZmCCT-mediated resistance to Gibberella stalk rot is not affected by photoperiod sensitivity. This chromatin-based regulatory mechanism enables ZmCCT to be more precise and timely in defense against F. graminearum infection. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  2. Two regimes of HIV/AIDS: The MMWR and the socio-political construction of HIV/AIDS as a 'black disease'.

    Science.gov (United States)

    Moseby, Kevin M

    2017-09-01

    Over the course of the HIV/AIDS epidemic, black Americans have become a central target of US public health prevention efforts. And today, HIV/AIDS is understood to disproportionately affect black Americans. This markedly contrasts with knowledge about the disease and efforts to prevent it in the first decade of the epidemic in the US, when expert and lay understandings and responses centred on white gay males. This article demonstrates that explaining these historical reversals as purely reflective of epidemiological data - or best knowledge available - is insufficient. Drawing on the concept disease regimes and utilising a discursive analysis of epidemiological results and editorial commentary published from 1981 to 1994 in the Morbidity and Mortality Weekly Reports (MMWR), this article argues for a socio-political explanation for the changing colour of HIV/AIDS. That is, it scrutinises institutional and discursive practices that within the HIV/AIDS prevention field and disease discourse constituted a 'regime of black American exclusion' (1981-1992) and a 'regime of black American inclusion (1993-present day). © 2017 Foundation for the Sociology of Health & Illness.

  3. Fungicides reduce Rhododendron root rot and mortality caused by Phytophthora cinnamomi, but not by P. plurivora

    Science.gov (United States)

    Rhododendron root rot, caused by several Phytophthora species, can cause devastating losses in nursery-grown plants. Most research on chemical control of root rot has focused on Phytophthora cinnamomi. However, it is unknown whether treatments recommended for P. cinnamomi are also effective for othe...

  4. Irradiation seed treatment reduces scald, common root rot and increases phosphorus absorption of barley

    International Nuclear Information System (INIS)

    Arabi, M.I.E.; Jawhar, M.

    2003-01-01

    The effect of low doses of gamma irradiation on severity of barley to scald and common root rot diseases, and phosphorus absorption was studied seeds were exposed to doses of 0, 10, 15, 20, 30, 40 and 50 Gy. A stimulatory effect was observed at irradiation doses of 30 and 40 Gy, which decreased the severity of barley to scald by 34% and 31% respectively. On the other hand, doses 20 and 30 Gy decreased the severity to CRR by 54% and 49% respectively, whereas, phosphorus absorption was significantly increased at doses of 15 and 20 Gy

  5. Behavior of hybrid corn crop as second rot incidence in West Region Paraná

    Directory of Open Access Journals (Sweden)

    Jean Sérgio Rosset

    2013-09-01

    Full Text Available The objective of this study was to evaluate the incidence and influence of stalk rot and ear in cultivation of hybrid corn second crop in west region Paraná. The experiment was conducted in randomized block design with six transgenic corn hybrids (DKB 330PRO, P4285HX, P3646HX, 30F53HX, P3340HX and P3161HX with four replications at spacing of 0.90 m between rows and 0.20 m between plants. The characteristics evaluated were: number of healthy and symptomatic plants, number of ears healthy and symptomatic and total number of spikes. After harvest, we assessed the length of ears healthy and symptomatic, bulk grain ears healthy and symptomatic, thousand grain weight of ears healthy and symptomatic, and grain mass per spike weighted, thousand grain weight and weighted productivity. The hybrid P3646HX showed 100% of plants with stem base rot (Colletotrichum graminicola and soft rot cob (Erwinia chrysanthemi pv. Zeae and 100% of ears with symptoms of soft rot, followed by hybrid 30F53HX, DKB 330PRO with 34.9 and 29.1% of ears with symptoms of soft rot respectively. The hybrid DKB330PRO showed healthy spikes and patients with superior size, resulting in less interference in the grain yield. The hybrid P3340 productivity was higher, with 7952 kg ha-1 , followed by hybrid 30F53HX and DKB330PRO. A positive correlation between agronomic characteristics and grain yield.

  6. Effect of gamma radiation on the growth of botryodiplodia theobromae and on rot development in banana fruits

    International Nuclear Information System (INIS)

    Mostafa, I.Y.; El-Ashmawi, A.M.; Fahim, M.M.; Kararah, M.A.

    1984-01-01

    Radiosensitivity of Botryodiplodia theobromae Pat. increased with the increase in doses of gamma radiation. Young cultures (7 days old) were less sensitive to radiation than old ones (48 days); lethal doses being 800 and 600 Krad respectively. Rot development was greatly reduced when inoculated banana fruits were exposed to 300 Krad. Disease development was checked for 10 days in inoculated fruits exposed to 400 Krad. The combined treatment of 200 p.p.m. T B Z and 100 or 200 Krad gamma radiation was more effective in reducing disease incidence than either treatments alone. No deleterious effects occurred in banana fruits that were irradiated with the low doses of gamma radiation

  7. Hendersonia Creberrima, the cause of soft brown rot of mango in South Africa

    International Nuclear Information System (INIS)

    Brodrick, H.T.; Van der westhuizen, G.C.A.

    1976-01-01

    A soft brown rot of mangoes in South Africa, is especially severe in export fruit kept in cold storage for prolonged periods. At present mangoes can be exported most economically by sea. This involves storage at 11 0 C for approximately 21 days. Unfortunately, these appear to be ideal conditions for the development of soft brown rot. Losses as high as 80% were recorded. The South African fungus agrees in morphology and cultural characters with Hendersonia Creberrima

  8. Aroma compounds and characteristics of noble-rot wines of Chardonnay grapes artificially botrytized in the vineyard.

    Science.gov (United States)

    Wang, Xing-Jie; Tao, Yong-Sheng; Wu, Yun; An, Rong-Yan; Yue, Zhuo-Ya

    2017-07-01

    Aroma characteristics and their impact volatile components of noble-rot wines elaborated from artificial botrytized Chardonnay grapes, obtained by spraying Botrytis cinerea suspension in Yuquan vineyard, Ningxia, China, were explored in this work. Dry white wine made from normal-harvested grapes and sweet wine produced from delay-harvested grapes were compared. Wine aromas were analysed by trained sensory panelists, and aroma compounds were determined by SPME-GC-MS. Results indicated that esters, fatty acids, thiols, lactones, volatile phenols and 2-nonanone increased markedly in noble-rot wines. In addition to typical aromas of noble-rot wines, artificial noble-rot wines were found to contain significant cream and dry apricot attributes. Partial Least-Squares Regression models of aroma characteristics against aroma components revealed that non-fermentative odorants were the primary contributor to dry apricot attribute, especially, thiols, C13-norisoprenoids, lactones, terpenols and phenolic acid derivatives, while cream attribute was dependent on both fermentative and non-fermentative volatile components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Black stain root disease studies on ponderosa pine parameters and disturbance treatments affecting infection and mortality

    Science.gov (United States)

    W.J. Otrosina; J.T. Kliejunas; S. Smith; D.R. Cluck; S.S. Sung; C.D. Cook

    2007-01-01

    Black stain root disease of ponderosa pine (Pinus ponderosa Doug. Ex Laws.), caused by Leptographium wageneri var. ponderosum (Harrington & Cobb) Harrington & Cobb, is increasing on many eastside Sierra Nevada pine stands in northeastern California. The disease is spread from tree to tree via root...

  10. Multi-gene analysis and morphology reveal novel Ilyonectria species associated with black foot disease of grapevines

    NARCIS (Netherlands)

    Cabral, A.; Rego, C.; Nascimento, T.; Oliveira, H.; Groenewald, J.Z.; Crous, P.W.

    2012-01-01

    Black foot is an important disease of grapevines, which has in recent years been recorded with increased incidence and severity throughout the world, affecting grapevines both in nurseries and young vineyards. In the past the disease has been associated with infections by Ilyonectria macrodidyma,

  11. Association of Pectolytic Fluorescent PSeudomonas with Postharvest Rots of Onion

    Directory of Open Access Journals (Sweden)

    H.H. El-Hendawy

    2004-12-01

    Full Text Available Five isolates of pectolytic fluorescent pseudomonads were obtained from a rotted onion bulb and identified as Pseudomonas marginalis. At both 4 and 25oC, all isolates caused soft rot to detached plant parts of onion and to carrot, celery, cucumber, pepper, spinach, tomato and turnip (but not garlic. They did not however cause any symptoms in living plants of these same species. These results suggest that the onion isolates are a postharvest pathogen which is not destructive in the field but becomes a threat to fresh vegetables stored at low-temperature. Analysis of cellulosolytic and pectic enzymes revealed that pectic lyases, but not polygalacturonases, pectin methyl esterases and cellulases were produced in culture by each isolate.

  12. Draft whole genome sequence of groundnut stem rot fungus Athelia rolfsii revealing genetic architect of its pathogenicity and virulence.

    Science.gov (United States)

    Iquebal, M A; Tomar, Rukam S; Parakhia, M V; Singla, Deepak; Jaiswal, Sarika; Rathod, V M; Padhiyar, S M; Kumar, Neeraj; Rai, Anil; Kumar, Dinesh

    2017-07-13

    Groundnut (Arachis hypogaea L.) is an important oil seed crop having major biotic constraint in production due to stem rot disease caused by fungus, Athelia rolfsii causing 25-80% loss in productivity. As chemical and biological combating strategies of this fungus are not very effective, thus genome sequencing can reveal virulence and pathogenicity related genes for better understanding of the host-parasite interaction. We report draft assembly of Athelia rolfsii genome of ~73 Mb having 8919 contigs. Annotation analysis revealed 16830 genes which are involved in fungicide resistance, virulence and pathogenicity along with putative effector and lethal genes. Secretome analysis revealed CAZY genes representing 1085 enzymatic genes, glycoside hydrolases, carbohydrate esterases, carbohydrate-binding modules, auxillary activities, glycosyl transferases and polysaccharide lyases. Repeat analysis revealed 11171 SSRs, LTR, GYPSY and COPIA elements. Comparative analysis with other existing ascomycotina genome predicted conserved domain family of WD40, CYP450, Pkinase and ABC transporter revealing insight of evolution of pathogenicity and virulence. This study would help in understanding pathogenicity and virulence at molecular level and development of new combating strategies. Such approach is imperative in endeavour of genome based solution in stem rot disease management leading to better productivity of groundnut crop in tropical region of world.

  13. Comparing self-reported disease outcomes, diet, and lifestyles in a national cohort of black and white Seventh-day Adventists.

    Science.gov (United States)

    Montgomery, Susanne; Herring, Patti; Yancey, Antronette; Beeson, Larry; Butler, Terry; Knutsen, Synnove; Sabate, Joan; Chan, Jacqueline; Preston-Martin, Susan; Fraser, Gary

    2007-07-01

    Few epidemiologic cohort studies on the etiology of chronic disease are powerful enough to distinguish racial and ethnic determinants from socioeconomic determinants of health behaviors and observed disease patterns. The Adventist Health Study-2 (AHS-2), with its large number of respondents and the variation in lifestyles of its target populations, promises to shed light on these issues. This paper focuses on some preliminary baseline analyses of responses from the first group of participants recruited for AHS-2. We administered a validated and pilot-tested questionnaire on various lifestyle practices and health outcomes to 56,754 respondents to AHS-2, comprising 14,376 non-Hispanic blacks and 42,378 non-Hispanic whites. We analyzed cross-sectional baseline data adjusted for age and sex and performed logistic regressions to test differences between responses from the two racial groups. In this Seventh-day Adventist (Adventist) cohort, blacks were less likely than whites to be lifelong vegetarians and more likely to be overweight or obese. Exercise levels were lower for blacks than for whites, but blacks were as likely as whites not to currently smoke or drink. Blacks reported higher rates of hypertension and diabetes than did whites but lower rates of high serum cholesterol, myocardial infarction, emphysema, and all cancers. After we eliminated skin cancer from the analysis, the age-adjusted prevalence of cancer remained significantly lower for black than for white women. The prevalence of prostate cancer was 47% higher for black men than for white men. The profile of health habits for black Adventists is better than that for blacks nationally. Given the intractable nature of many other contributors to health disparities, including racism, housing segregation, employment discrimination, limited educational opportunity, and poorer health care, the relative advantage for blacks of the Adventist lifestyle may hold promise for helping to close the gap in health status

  14. Bioconversion of dieldrin by wood-rotting fungi and metabolite detection.

    Science.gov (United States)

    Kamei, Ichiro; Takagi, Kazuhiro; Kondo, Ryuichiro

    2010-08-01

    Dieldrin is one of the most persistent organochlorine pesticides, listed as one of the 12 persistent organic pollutants in the Stockholm Convention. Although microbial degradation is an effective way to remediate environmental pollutants, reports on aerobic microbial degradation of dieldrin are limited. Wood-rotting fungi can degrade a wide spectrum of recalcitrant organopollutants, and an attempt has been made to select wood-rotting fungi that can degrade dieldrin, and to identify the metabolite. Thirty-four isolates of wood-rotting fungi were investigated for their ability to degrade dieldrin. Strain YK543 degraded 39.1 +/- 8.8% of dieldrin during 30 days of incubation. Phylogenetic analysis demonstrated that strain YK543 was closely related to the fungus Phlebia brevispora Nakasone TMIC33929, which has been reported as a fungus that can degrade chlorinated dioxins and polychlorinated biphenyls. 9-Hydroxydieldrin was detected as a metabolite in the cultures of strain YK543. It is important to select the microorganisms that degrade organic pollutants, and to identify the metabolic pathway for the development of bioremediation methods. Strain YK543 was selected as a fungus capable of degrading dieldrin. The metabolic pathway includes 9-hydroxylation reported in rat's metabolism catalysed by liver microsomal monooxygenase. This is the first report of transformation of dieldrin to 9-hydroxydieldrin by a microorganism. Copyright (c) 2010 Society of Chemical Industry.

  15. Signum, a new fungicide with interesting properties in resistance management of fungal diseases in strawberries.

    Science.gov (United States)

    Hauke, K; Creemers, P; Brugmans, W; Van Laer, S

    2004-01-01

    Signum, a new fungicide developed by BASF, was applied during 6 successive years against fungal diseases in strawberries. The product is formulated as a water dispersible granule, containing 6.7 % pyraclostrobin and 26.7 % boscalid. Pyraclostrobin is similar in chemistry to other strobilurin fungicides like kresoxim-methyl and trifloxystrobin, registered for fruit disease control. Boscalid belongs to the class of carboxyanilides. Both components in the premix formulation combine two different biochemical modes of action in the fungal cell respiration. Therefore, this co-formulation gives a broad-spectrum activity and also a reduced resistance risk for different target pathogens. Botrytis cinerea is the most important disease on strawberry-fruits and thus the control of fruit rot is mainly focused on this fungus. In average over 6 years, Signum has not only given a very good control against Botrytis fruit rot, but it has also shown a high performance in the control of Colletotrichum. Besides, Signum provides good control of powdery mildew (Podosphaera aphanis) and limits the shift to other fruit rots like leather rot (Phytophthora cactorum and leak (Rhizopus, Mucor). The availability of several categories of fungicide families with a different mode of action gives opportunities in alternating different fungicides and is the best guarantee for a sustainable control of fruit rot in all kinds of strawberry production methods. Signum should be integrated in an overall disease management program. Trials, in which the applications of Signum were timed on disease forecasting, based on environmental factors favorable for Botrytis development, were very promising. This tool can also help in establishing the IPM-concept in the production of strawberries.

  16. Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    NARCIS (Netherlands)

    Arango Isaza, Rafael E.; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F.; V. de Jong, Tristan; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fortes Fereira, Claudia; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza Manoel, Jr.; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Françoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the ascomycete fungus Pseudocercospora fijiensis, inflicts huge costs on banana producers, due to crop losses and expenses for disease control. The global banana export trade relies on Cavendish clones that are highly susceptible to P.

  17. Following basal stem rot in young oil palm plantings.

    Science.gov (United States)

    Panchal, G; Bridge, P D

    2005-01-01

    The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected.

  18. Fusarium rot of onion and possible use of bioproduct

    Directory of Open Access Journals (Sweden)

    Klokočar-Šmit Zlata

    2008-01-01

    Full Text Available Several species of Fusarium are causal agents of onion rot in field and storage. Most prevalent are F. oxysporum f. sp. cepae and F. solani, and recently F. proliferatum, a toxigenic species. Most frequently isolated fungi in our field experiments were F. solani and F. proliferatum with different pathogenicity. Certain differences in antagonistic activity of Trichoderma asperellum on different isolates of F. proliferatum and F. solani have been found in in vitro study in dual culture, expressed as a slower inhibition of growth of the former, and faster of the latter pathogen. Antagonistic abilities of species from genus Trichoderma (T. asperellum are important, and have already been exploited in formulated biocontrol products in organic and conventional production, in order to prevent soil borne pathogens inducing fusarium wilt and rot. The importance of preventing onion infection by Fusarium spp., possible mycotoxin producers, has been underlined.

  19. Evaluation of Muscodor suthepensis strain CMU-Cib462 as a postharvest biofumigant for tangerine fruit rot caused by Penicillium digitatum.

    Science.gov (United States)

    Suwannarach, Nakarin; Bussaban, Boonsom; Nuangmek, Wipornpan; Pithakpol, Wasna; Jirawattanakul, Bantoon; Matsui, Kenji; Lumyong, Saisamorn

    2016-01-15

    This study investigated both the in vitro and in vivo biofumigant ability of the endophytic fungus Muscodor suthepensis CMU-Cib462 to control Penicillium digitatum, the main cause of tangerine fruit rot. Volatile compounds from M. suthepensis inhibited mycelial growth of the pathogen. The most abundant compound was 2-methylpropanoic acid, followed by 3-methylbutan-1-ol. They showed median effective doses (ED50) on P. digitatum growth of 74.91 ± 0.73 and 250.29 ± 0.29 µL L(-1) airspace respectively. Rye grain was found to be a suitable solid medium for M. suthepensis inoculum production. The results indicated that mycofumigation with a 30 g rye grain culture of M. suthepensis for 12 h controlled tangerine fruit rot. The percentage weight loss and soluble solids concentration of fumigated tangerines were similar to those of non-infected and non-fumigated fruits. Muscodor suthepensis has potential as a biofumigant for controlling postharvest disease of tangerine fruit. © 2015 Society of Chemical Industry.

  20. Molecular characterization of a novel thermostable laccase PPLCC2 from the brown rot fungus Postia placenta MAD-698-R

    Directory of Open Access Journals (Sweden)

    Hongde An

    2015-11-01

    Conclusions: This is the first identified thermo activated and thermostable laccase in brown rot fungi. This investigation will contribute to understanding the roles played by laccases in brown rot fungi.

  1. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  2. A system for predicting the amount of Phellinus (Fomes) igniarius rot in trembling aspen stands

    Science.gov (United States)

    Robert L. Anderson; Arthur L. Jr. Schipper

    1978-01-01

    The occurrence of Phellinus (Fomes) igniarius white trunk rot in 45- to 50-year-old trembling aspen stands can be predicted by applying a constant to the stand basal area with P. igniarius conks to estimate the total basal area with P. igniarius rot. Future decay projections can be made by reapplying the basal area of hidden decay for each 6 years projected. This paper...

  3. Interaction between N-fertilizer and water availability on borer-rot complex in sugarcane

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo da Rocha Pannuti

    2015-03-01

    Full Text Available This study aimed to evaluate the effects of nitrogen availability in fertigation and rainfed management, as well as their interactions with the incidence of and damage caused by D. saccharalis and red rot in sugarcane. The experiment consisted of four treatments (0 and 150 kg ha–1 of N-fertilizer with irrigation; 0 and 150 kg ha–1 of N-fertilizer in rainfed management in a randomized complete block design with four replications. The evaluated parameters were the number of holes and internodes with red rot per meter of cultivation, stalk yield and sugar content. In the laboratory (T = 25 ± 2 °C; R.H. = 70 ± 10%: 12:12-L:D, we evaluated the attractiveness and consumption of fragments of stalks from the different treatments for fourth instar larvae through choice and no-choice tests in a randomized complete block design with ten replications. Nitrogen fertilization via irrigation has favorable effects on borer-rot complex and leads to higher gains in stalk and sugar yields when compared to rainfed management. The increments of stalk and sugar yields due to nitrogen fertilization compensates for the increase in borer-rot complex infestation. In laboratory tests, D. saccharalis larvae were similarly attracted to all treatments regardless of the doses of N-fertilizer or the water regimes evaluated. However, fragments of sugarcane stalks produced with nitrogen fertilization were consumed more by D. saccharalis in both water regimes.

  4. The influence of root rot incidence on cassava genotype on ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... model statistical procedures with the SAS system for windows. Comparisons ... significantly different at probability 0.05%. The results of this ... Due to inefficient harvesting, packaging ... from rot for gari processing. Where there ...

  5. Biodegrading effects of some rot fungi on Pinus caribaea wood ...

    African Journals Online (AJOL)

    morelet) in Ijaiye Forest Reserve, 38 km northwest of Ibadan, Nigeria. The wood samples were inoculated separately with two species of white-rot fungi; Corioliopsis polyzona and Pleurotus squarrosulus, and two species of brownrot fungi; ...

  6. Possible sources of genetic resistance in oil palm (Elaeis guineensis Jacq.) to basal stem rot caused by Ganoderma boninense--prospects for future breeding.

    Science.gov (United States)

    Durand-Gasselin, T; Asmady, H; Flori, A; Jacquemard, J C; Hayun, Z; Breton, F; de Franqueville, H

    2005-01-01

    Oil palm estates in southeast Asia suffer from substantial losses due to basal stem rot caused by Ganoderma boninense. Field observations have been carried out in North Sumatra, Indonesia, on a series of planting materials of known origin. Differences in susceptibility to the disease have been detected within the two Elaeis species, guineensis and oleifera. Within Elaeis guineensis, material of Deli origin is highly susceptible compared to material of African origin. It is also possible to detect differences in reaction between parents and between crosses within a given origin. The variability of resistance to basal stem rot within the same cross is also illustrated by the diverse responses of clones derived from palms of the same origin. The prospects opened up by these results are discussed, and the importance of performing an early selection test is highlighted.

  7. Diversity of black Aspergilli and mycotoxin risks in grape, wine and dried vine fruits

    Directory of Open Access Journals (Sweden)

    Stefania SOMMA

    2012-05-01

    Full Text Available Mycotoxin risk in the grape product chain is primarily due to ochratoxin A (OTA occurrence in wine and dried vine fruits. Aspergillus carbonarius and the A. niger group are the main agents of Aspergillus bunch rot of grape, and they, especially A. carbonarius, are responsible for OTA contamination worldwide. Fumonisin B2 (FB2 represents an additional potential mycotoxin risk in the grape-wine product chain and A. niger/A. awamori were recently reported as the FB2 producers in grapes. A deeper understanding of the species diversity of black Aspergilli, together with specific knowledge of their ecology and epidemiology, can help to predict their occurrence. From this perspective several studies have been done regarding prevention and control of black Aspergilli and reduction of mycotoxin risk at all stages, from vineyard management to wine-making procedures. In this review a comprehensive overview of all these aspects is presented.

  8. High-Q Fabry–Pérot Micro-Cavities for High-Sensitivity Volume Refractometry

    Directory of Open Access Journals (Sweden)

    Noha Gaber

    2018-01-01

    Full Text Available This work reports a novel structure for a Fabry–Pérot micro cavity that combines the highest reported quality factor for an on-chip Fabry–Pérot resonator that exceeds 9800, and a very high sensitivity for an on-chip volume refractometer based on a Fabry–Pérot cavity that is about 1000 nm/refractive index unit (RIU. The structure consists of two cylindrical Bragg micromirrors that achieve confinement of the Gaussian beam in the plan parallel to the chip substrate, while for the perpendicular plan, external fiber rod lenses (FRLs are placed in the optical path of the input and the output of the cavity. This novel structure overcomes number of the drawbacks presented in previous designs. The analyte is passed between the mirrors, enabling its detection from the resonance peak wavelengths of the transmission spectra. Mixtures of ethanol and deionized (DI-water with different ratios are used as analytes with different refractive indices to exploit the device as a micro-opto-fluidic refractometer. The design criteria are detailed and the modeling is based on Gaussian-optics equations, which depicts a scenario closer to reality than the usually used ray-optics modeling.

  9. Maize kernel antioxidants and their potential involvement in Fusarium ear rot resistance.

    Science.gov (United States)

    Picot, Adeline; Atanasova-Pénichon, Vessela; Pons, Sebastien; Marchegay, Gisèle; Barreau, Christian; Pinson-Gadais, Laëtitia; Roucolle, Joël; Daveau, Florie; Caron, Daniel; Richard-Forget, Florence

    2013-04-10

    The potential involvement of antioxidants (α-tocopherol, lutein, zeaxanthin, β-carotene, and ferulic acid) in the resistance of maize varieties to Fusarium ear rot was the focus of this study. These antioxidants were present in all maize kernel stages, indicating that the fumonisin-producing fungi (mainly Fusarium verticillioides and Fusarium proliferatum ) are likely to face them during ear colonization. The effect of these compounds on fumonisin biosynthesis was studied in F. verticillioides liquid cultures. In carotenoid-treated cultures, no inhibitory effect of fumonisin accumulation was observed while a potent inhibitory activity was obtained for sublethal doses of α-tocopherol (0.1 mM) and ferulic acid (1 mM). Using a set of genotypes with moderate to high susceptibility to Fusarium ear rot, ferulic acid was significantly lower in immature kernels of the very susceptible group. Such a relation was nonexistent for tocopherols and carotenoids. Also, ferulic acid in immature kernels ranged from 3 to 8.5 mg/g, i.e., at levels consistent with the in vitro inhibitory concentration. Overall, our data support the fact that ferulic acid may contribute to resistance to Fusarium ear rot and/or fumonisin accumulation.

  10. Atypical features of hyperthyroidism in Blacks

    International Nuclear Information System (INIS)

    Kalk, W.J.

    1980-01-01

    Hyperthyroidism is reportedly uncommon in the indigenous populations of Africa. The presenting symptoms volunteered, the symptoms elicited by direct questioning, and the results of physical examination were therefore prospectively compared in 60 Black and 56 White patients with thyrotoxicosis attending a single thyroid clinic. Fewer Blacks than Whites volunteered information about weight loss, while more Blacks complained only of the presence of a goitre. A 'chance' diagnosis of hyperthyroidism was made more frequently in Blacks. Symptomatology elicited by direct questioning and findings on physical examination were generally similar in each group, except that Blacks presented more frequently with complicated disease (cardiac failure and overt myopathy) and infiltrative ophthalmopathy. The frequency with which hyperthyroidism presents 'atypically' in Black compared with White patients may reflect educational, socio-economic and cultural differences in the Black and White populations, and may partly explain the infrequency with which this disease is diagnosed in Blacks

  11. The Black Aspergillus Species of Maize and Peanuts and Their Potential for Mycotoxin Production

    Science.gov (United States)

    Palencia, Edwin R.; Hinton, Dorothy M.; Bacon, Charles W.

    2010-01-01

    The black spored fungi of the subgenera Circumdata, the section Nigri (=Aspergillus niger group) is reviewed relative to their production of mycotoxins and their effects on plants as pathogens. Molecular methods have revealed more than 18 cryptic species, of which several have been characterized as potential mycotoxin producers. Others are defined as benign relative to their ability to produce mycotoxins. However, these characterizations are based on in vitro culture and toxins production. Several can produce the ochratoxins that are toxic to livestock, poultry, and humans. The black aspergilli produce rots of grapes, maize, and numerous other fruits and grain and they are generally viewed as post-harvest pathogens. Data are review to suggest that black aspergilli, as so many others, are symptomless endophytes. These fungi and their mycotoxins contaminate several major grains, foodstuffs, and products made from them such as wine, and coffee. Evidence is presented that the black aspergilli are producers of other classes of mycotoxins such as the fumonisins, which are known carcinogenic and known prior investigations as being produced by the Fusarium species. Three species are identified in U.S. maize and peanuts as symptomless endophytes, which suggests the potential for concern as pathogens and as food safety hazards. PMID:22069592

  12. Microbial detoxification of waste rubber material by wood-rotting fungi.

    Science.gov (United States)

    Bredberg, Katarina; Andersson, B Erik; Landfors, Eva; Holst, Olle

    2002-07-01

    The extensive use of rubber products, mainly tires, and the difficulties to recycle those products, has resulted in world wide environmental problems. Microbial devulcanisation is a promising way to increase the recycling of rubber materials. One obstacle is that several microorganisms tested for devulcanisation are sensitive to rubber additives. A way to overcome this might be to detoxify the rubber material with fungi prior to the devulcanisation. In this study, 15 species of white-rot and brown-rot fungi have been screened with regard to their capacity to degrade an aromatic model compound in the presence of ground waste tire rubber. The most effective fungus, Resinicium bicolor, was used for detoxification of rubber material. Increase in growth of the desulfurising bacterium Thiobacillus ferrooxidans in presence of the rubber treated with Resinicium bicolor compared to untreated rubber demonstrated that detoxification with fungi is possible.

  13. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage

    Science.gov (United States)

    The ability of chitosan and oligochitosan to enhance the resistance of ginger (Zingiber officinale) to rhizome rot, caused by Fusarium oxysporum, in storage was investigated. Both chitosan and oligochitosan at 1 and 5 g/L significantly inhibited rhizome rot, relative to the untreated control, with...

  14. Efficacies of quorum sensing inhibitors, piericidin A and glucopiericidin A, produced by Streptomyces xanthocidicus KPP01532 for the control of potato soft rot caused by Erwinia carotovora subsp. atroseptica.

    Science.gov (United States)

    Kang, Ji Eun; Han, Jae Woo; Jeon, Byeong Jun; Kim, Beom Seok

    2016-03-01

    To discover potential inhibitors of the quorum sensing (QS) system, a library of microbial culture extracts was screened with Chromobacterium violaceumCV026 strain. The culture extract of Streptomyces xanthocidicus KPP01532 contained quorum-sensing inhibitors (QSIs) of the CV026 strain. The active constituents of the culture extract of strain KPP01532 were purified using a series of chromatographic procedures, and based on data from NMR and mass spectroscopy, piericidin A and glucopiericidin A were identified. Erwinia carotovora subsp. atroseptica (Eca) is a plant pathogen that causes blackleg and soft rot diseases on potato stems and tubers. The virulence factors of Eca are regulated by QS. The expression of virulence genes (pelC, pehA, celV and nip) under the control of QS was monitored using quantitative real-time PCR (qRT-PCR). The transcription levels of the four genes were significantly lower when Eca was exposed to piericidin A or glucopiericidin A. These two compounds displayed similar control efficacies against soft rot caused by Eca in potato slices as furanone C-30. Therefore, piericidin A and glucopiericidin A are potential QSIs that suppress the expression of the virulence genes of Eca, suggesting that they could have potential use as control agents of soft rot disease on potato tubers. Copyright © 2015 Elsevier GmbH. All rights reserved.

  15. Effect of gamma radiation treatment on some fungi causing storage diseases of banana fruits

    International Nuclear Information System (INIS)

    EL-Ashmawi, A.M.M.

    1982-01-01

    Banana is one of the most popular fruits in many tropical and sub-tropical countries. in recent years, the quality of egyptian banana markedly declined. A major factor contributing to this decline is the development of fruit rot, which is the most widely occurring disease either in the field or in storage. Different fungi attack banana fruits causing considerable losses. Most of the fungi responsible for post harvest rots of banana are usually carried from the field, on the surface of the fruit itself or in injured and rotting fruits causing severe rats during storage. These rots make the fruits difficult to handle and undesirable to the consumers. Botryodiplodia theobromae is known to be the most important pathogen responsible for the infection in storage

  16. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  17. Lignin as a facilitator, not a barrier, during saccharification by brown rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, Jonathan S. [Univ. of Minnesota, Minneapolis, MN (United States); Tschirner, Ulrike [Univ. of Minnesota, Minneapolis, MN (United States); Blanchette, Robert A [Univ. of Minnesota, Minneapolis, MN (United States); Filley, Timothy [Purdue Univ., West Lafayette, IN (United States)

    2012-11-28

    This research focused on the biology of a group of wood-degrading fungi that cause brown rot in wood, with particular attention to the potential to mimic this biological approach ex situ for bioprocessing lignocellulosic biomass. Supported by the long-standing theory that these fungi use a two-step oxidative/enzymatic approach during brown rot, our team’s objectives were as follows: 1) to determine the discrete timing of lignin modifications, 2) to correlate these alterations with biocatalyst efficiency and ingress into plant cell walls, and 3) to reproduce modifications prior to saccharification for efficient bioprocessing. The core findings of our research were that 1) lignin modifications occur nearly coincident with enzyme secretion during brown rot and 2) there is no specificity to the benefit that a brown rot pretreatment has on the efficacy of cellulases – it is a general enhancement best predicted by chemical changes to lignin and side-chain hemicellulose sugars. In our work, this meant we could attain and predict broad improvements in saccharification using commercial cellulase cocktails, in some cases more than three-fold of that in untreated biomass. This project was completed with minimal variance from the original project management plan (PMP), resulting in fourteen presentations and posters, four peer-reviewed publications, and one additional publication now in review. The publications have been valuable to other scientists working toward similar goals and have been cited in thirteen peer-reviewed publications written by others since 2010. We are working with ADM to advance application options for industry, building on the lessons learned during this DOE award period.

  18. Evaluation of biocontrol potential of epiphytic fluorescent pseudomonas as associated with healthy fruits and vegetables against root rot and root knot pathogens of mungbean

    International Nuclear Information System (INIS)

    Habiba, A.; Noreen, R.; Ali, S. A.; Sultana, V.; Ara, J.

    2016-01-01

    Endophytic and rhizospheric fluorescent Pseudomonas have widely been used as biological control agents against soilborne plant pathogens. In this study, fifteen epiphytic fluorescent Pseudomonas isolated from the surfaces of citrus (grapefruit, orange and lemon) melon and tomato fruits were characterized for their in vitro activity against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani and nematicidal activity against the second stage juveniles of Meloidogyne javanica. Out of fifteen Pseudomonas isolates HAB-16, HAB-1 and HAB-25 inhibited the growth of all the test fungi and showed maximum nematicidal activity against second stage juvenile of M. javanica. Based on their effective in vitro activity nine epiphytic fluorescent Pseudomonas were evaluated for their growth promoting ability and biocontrol activity in screen house on mungbean. Pseudomonas isolates (HAB-13, HAB-2, HAB-4, HAB-1, HAB-14, HAB-9, HAB-7 and HAB-25) used as soil drench greatly reduced the root rot-root knot infection and thereby enhanced plant growth, root nodulation and yield in mungbean. Besides, rhizospheric and endophytic, epiphytic fluorescent Pseudomonas associated with healthy fruits may be used as biocontrol agent against root rotting fungi, besides, using for the mangemnet of postharvest diseases. (author)

  19. Gene cloning and heterologous expression of pyranose 2-oxidase from the brown-rot fungus, Gloeophyllum trabeum

    Science.gov (United States)

    Diane Dietrich; Casey Crooks

    2009-01-01

    A pyranose 2-oxidase gene from the brown-rot basidiomycete Gloeophyllum trabeum was isolated using homology-based degenerate PCR. The gene structure was determined and compared to that of several pyranose 2-oxidases cloned from white-rot fungi. The G. trabeum pyranose 2-oxidase gene consists of 16 coding exons with canonical promoter CAAT and TATA elements in the 5’UTR...

  20. A genomics-informed, SNP association study reveals FBLN1 and FABP4 as contributing to resistance to fleece rot in Australian Merino sheep

    Directory of Open Access Journals (Sweden)

    Norris Belinda J

    2010-05-01

    Full Text Available Abstract Background Fleece rot (FR and body-strike of Merino sheep by the sheep blowfly Lucilia cuprina are major problems for the Australian wool industry, causing significant losses as a result of increased management costs coupled with reduced wool productivity and quality. In addition to direct effects on fleece quality, fleece rot is a major predisposing factor to blowfly strike on the body of sheep. In order to investigate the genetic drivers of resistance to fleece rot, we constructed a combined ovine-bovine cDNA microarray of almost 12,000 probes including 6,125 skin expressed sequence tags and 5,760 anonymous clones obtained from skin subtracted libraries derived from fleece rot resistant and susceptible animals. This microarray platform was used to profile the gene expression changes between skin samples of six resistant and six susceptible animals taken immediately before, during and after FR induction. Mixed-model equations were employed to normalize the data and 155 genes were found to be differentially expressed (DE. Ten DE genes were selected for validation using real-time PCR on independent skin samples. The genomic regions of a further 5 DE genes were surveyed to identify single nucleotide polymorphisms (SNP that were genotyped across three populations for their associations with fleece rot resistance. Results The majority of the DE genes originated from the fleece rot subtracted libraries and over-representing gene ontology terms included defense response to bacterium and epidermis development, indicating a role of these processes in modulating the sheep's response to fleece rot. We focused on genes that contribute to the physical barrier function of skin, including keratins, collagens, fibulin and lipid proteins, to identify SNPs that were associated to fleece rot scores. Conclusions We identified FBLN1 (fibulin and FABP4 (fatty acid binding protein 4 as key factors in sheep's resistance to fleece rot. Validation of these

  1. Characterizing forest root‐ and butt‐rot fungi in Yap, Palau, Pohnpei, Kosrae, Guam and Saipan [Chapter III

    Science.gov (United States)

    Phil Cannon; Ned B. Klopfenstein; Mee-Sook Kim; Yuko Ota; Norio Sahashi; Robert L. Schlub; Roger Brown; Sara M. Ashiglar; Amy L. Ross-Davis; John W. Hanna

    2014-01-01

    Ganoderma and Phellinus are two common fungal genera causing butt-rot on trees growing on USA-affiliated islands of the western Pacific. Although these fungi can be quite prevalent, especially in some older mangrove stands, it appears that the majority of infections caused by these fungi leads to severe rotting of the heartwood but do not kill the living...

  2. Physico-chemical characterization of banana varieties resistant to black leaf streak disease for industrial purposes

    Directory of Open Access Journals (Sweden)

    Rossana Catie Bueno de Godoy

    2016-01-01

    Full Text Available ABSTRACT: Cultivated bananas have very low genetic diversity making them vulnerable to diseases such as black-Sigatoka leaf spot. However, the decision to adopt a new banana variety needs to be based on a robust evaluation of agronomical and physical-chemical characteristics. Here, we characterize new banana varieties resistant to black-Sigatoka leaf spot and compare them to the most widely used traditional variety (Grand Naine. Each variety was evaluated for a range of physic-chemical attributes associated with industrial processing and flavor: pH, TTA, TSS/TTA, total sugars, reducing sugars and non-reducing sugars, humidity, total solids and yield. The Thap Maeo variety had the highest potential as a substitute for the Grand Naine variety, having higher levels of total soluble solids, reducing sugars, total sugars and humidity. The Caipira and FHIA 2 varieties also performed well in comparison with the Grand Naine variety. Cluster analysis indicated that the Grand Naine variety was closely associated with varieties from the Gross Michel subgroup (Bucaneiro, Ambrosia and Calipso and the Caipira variety, all of which come from the same AAA genomic group. It was concluded that several of the new resistant varieties could potentially substitute the traditional variety in areas affected by black-Sigatoka leaf spot disease.

  3. Cacao diseases: a global perspective from an industry point of view.

    Science.gov (United States)

    Hebbar, Prakash K

    2007-12-01

    ABSTRACT Diseases of cacao, Theobroma cacao, account for losses of more than 30% of the potential crop. These losses have caused a steady decline in production and a reduction in bean quality in almost all the cacao-producing areas in the world, especially in small-holder farms in Latin America and West Africa. The most significant diseases are witches' broom, caused by Moniliophthora perniciosa, which occurs mainly in South America; frosty pod rot, caused by M. roreri, which occurs mainly in Central and northern South America; and black pod disease, caused by several species of Phytophthora, which are distributed throughout the tropics. In view of the threat that these diseases pose to the sustainability of the cacao crop, Mars Inc. and their industry partners have funded collaborative research involving cacao research institutes and governmental and nongovernmental agencies. The objective of this global initiative is to develop short- to medium-term, low-cost, environmentally friendly disease-management strategies until disease tolerant varieties are widely available. These include good farming practices, biological control and the rational or minimal use of chemicals that could be used for integrated pest management (IPM). Farmer field schools are used to get these technologies to growers. This paper describes some of the key collaborative partners and projects that are underway in South America and West Africa.

  4. Temporal changes in wood crystalline cellulose during degradation by brown rot fungi

    DEFF Research Database (Denmark)

    Howell, Caitlin; Hastrup, Anne Christine Steenkjær; Goodell, Barry

    2009-01-01

    The degradation of wood by brown rot fungi has been studied intensely for many years in order to facilitate the preservation of in-service wood. In this work we used X-ray diffraction to examine changes in wood cellulose crystallinity caused by the brown rot fungi Gloeophyllum trabeum, Coniophora...... planes in all degraded samples after roughly 20% weight loss, as well as a decrease in the average observed relative peak width at 2¿ = 22.2°. These results may indicate a disruption of the outer most semi-crystalline cellulose chains comprising the wood microfibril. X-ray diffraction analysis of wood...... subjected to biological attack by fungi may provide insight into degradative processes and wood cellulose structure....

  5. Management of high blood pressure in Blacks: an update of the International Society on Hypertension in Blacks consensus statement.

    Science.gov (United States)

    Flack, John M; Sica, Domenic A; Bakris, George; Brown, Angela L; Ferdinand, Keith C; Grimm, Richard H; Hall, W Dallas; Jones, Wendell E; Kountz, David S; Lea, Janice P; Nasser, Samar; Nesbitt, Shawna D; Saunders, Elijah; Scisney-Matlock, Margaret; Jamerson, Kenneth A

    2010-11-01

    Since the first International Society on Hypertension in Blacks consensus statement on the "Management of High Blood Pressure in African American" in 2003, data from additional clinical trials have become available. We reviewed hypertension and cardiovascular disease prevention and treatment guidelines, pharmacological hypertension clinical end point trials, and blood pressure-lowering trials in blacks. Selected trials without significant black representation were considered. In this update, blacks with hypertension are divided into 2 risk strata, primary prevention, where elevated blood pressure without target organ damage, preclinical cardiovascular disease, or overt cardiovascular disease for whom blood pressure consistently secondary prevention, where elevated blood pressure with target organ damage, preclinical cardiovascular disease, and/or a history of cardiovascular disease, for whom blood pressure consistently blood pressure is ≤10 mm Hg above target levels, monotherapy with a diuretic or calcium channel blocker is preferred. When blood pressure is >15/10 mm Hg above target, 2-drug therapy is recommended, with either a calcium channel blocker plus a renin-angiotensin system blocker or, alternatively, in edematous and/or volume-overload states, with a thiazide diuretic plus a renin-angiotensin system blocker. Effective multidrug therapeutic combinations through 4 drugs are described. Comprehensive lifestyle modifications should be initiated in blacks when blood pressure is ≥115/75 mm Hg. The updated International Society on Hypertension in Blacks consensus statement on hypertension management in blacks lowers the minimum target blood pressure level for the lowest-risk blacks, emphasizes effective multidrug regimens, and de-emphasizes monotherapy.

  6. Fungal hydroquinones contribute to brown rot of wood

    Science.gov (United States)

    Melissa R. Suzuki; Christopher G. Hunt; Carl J. Houtman; Zachary D. Dalebroux; Kenneth E. Hammel

    2006-01-01

    The fungi that cause brown rot of wood initiate lignocellulose breakdown with an extracellular Fenton system in which Fe2+ and H2O2 react to produce hydroxyl radicals (•OH), which then oxidize and cleave the wood holocellulose. One such fungus, Gloeophyllum trabeum, drives Fenton chemistry on defined media by reducing Fe3+ and O2 with two extracellular hydroquinones,...

  7. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Potential Mycotoxin Production in China.

    Science.gov (United States)

    Duan, Canxing; Qin, Zihui; Yang, Zhihuan; Li, Weixi; Sun, Suli; Zhu, Zhendong; Wang, Xiaoming

    2016-06-21

    Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B₁, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China.

  8. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Potential Mycotoxin Production in China

    Science.gov (United States)

    Duan, Canxing; Qin, Zihui; Yang, Zhihuan; Li, Weixi; Sun, Suli; Zhu, Zhendong; Wang, Xiaoming

    2016-01-01

    Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B1, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China. PMID:27338476

  9. Induction of somaclonal variation and mutations in sugarcane calli for selecting mutants with resistance to red-rot and tolerance to water-logged conditions

    International Nuclear Information System (INIS)

    Shaikh, M.A.Q.; Begum, S.; Samad, M.A.; Shmsuzzaman, K.M.

    1997-01-01

    Immature leaves of cv. 'Isd-16' of sugarcane were cultured on modified MS medium supplemented with 3.0 mg/l 2,4-D for callus induction. The calli were transferred to MS medium supplemented with 5.0 mg/l IAA and 2.0 mg/l KIN for shoot regeneration. The shoots were rooted on MS medium supplemented with 5.0 mg/1NAA and 70 g/l sucrose. The regenerated plants were screened against red-rot disease and water-logged condition in a field. Of the 368 plants inoculated with red-rot pathogen, only one was moderately resistant and two were moderately susceptible. In another set of 500 R 1 plants, six clones were tolerant to water-logged condition. Four week-old callus cultures were irradiated with doses of 2, 3, 4, 5, 6, 7, 8 and 10 Gy gamma-rays. Survival of calli decreased with increase in radiation dose and ranged from 58 to 91%. Regenerated shoots were obtained from all irradiated calli except those treated with 8 and 10 Gy. Shoot regeneration from the irradiated calli ranged from 8 to 50%, and gave 768 R 1 plants. The highest regeneration of plants was obtained from calli treated with 3 Gy. These plants are being grown in a field for screening against red-rot and water-logged conditions. (author). 10 refs, 2 tabs

  10. Induction of somaclonal variation and mutations in sugarcane calli for selecting mutants with resistance to red-rot and tolerance to water-logged conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, M A.Q.; Begum, S; Samad, M A; Shmsuzzaman, K M [Bangladesh Inst. of Nuclear Agriculture, Mymensingh (Bangladesh)

    1997-07-01

    Immature leaves of cv. `Isd-16` of sugarcane were cultured on modified MS medium supplemented with 3.0 mg/l 2,4-D for callus induction. The calli were transferred to MS medium supplemented with 5.0 mg/l IAA and 2.0 mg/l KIN for shoot regeneration. The shoots were rooted on MS medium supplemented with 5.0 mg/1NAA and 70 g/l sucrose. The regenerated plants were screened against red-rot disease and water-logged condition in a field. Of the 368 plants inoculated with red-rot pathogen, only one was moderately resistant and two were moderately susceptible. In another set of 500 R{sub 1} plants, six clones were tolerant to water-logged condition. Four week-old callus cultures were irradiated with doses of 2, 3, 4, 5, 6, 7, 8 and 10 Gy gamma-rays. Survival of calli decreased with increase in radiation dose and ranged from 58 to 91%. Regenerated shoots were obtained from all irradiated calli except those treated with 8 and 10 Gy. Shoot regeneration from the irradiated calli ranged from 8 to 50%, and gave 768 R{sub 1} plants. The highest regeneration of plants was obtained from calli treated with 3 Gy. These plants are being grown in a field for screening against red-rot and water-logged conditions. (author). 10 refs, 2 tabs.

  11. Inheritance of black sigatoka disease resistance in plantain-banana (Musa spp.) hybrids.

    Science.gov (United States)

    Ortiz, R; Vuylsteke, D

    1994-10-01

    Black sigatoka (Mycosphaerella fijiensis Morelet), an airborne fungal leaf-spot disease, is a major constraint to plantain and banana (Musa spp.) production world-wide. Gaining further knowledge of the genetics of host-plant resistance will enhance the development of resistant cultivars, which is considered to be the most appropriate means to achieve stable production. Genetic analysis was conducted on 101 euploid (2x, 3x and 4x) progenies, obtained from crossing two susceptible triploid plantain cultivars with the resistant wild diploid banana 'Calcutta 4'. Segregating progenies, and a susceptible reference plantain cultivar, were evaluated over 2 consecutive years. Three distinct levels of host response to black sigatoka were defined as follows: susceptible ( 10). Segregation ratios for resistance at the 2x level fitted a genetic model having one major recessive resistance allele (bs 1) and two independent alleles with additive effects (bsr 2 and bsr 3). A similar model explains the results at the 4x level assuming that the favourable resistance alleles have a dosage effect when four copies of them are present in their respective loci (bs i (4) ). The proposed model was further validated by segregation data of S 1 progenies. Mechanisms of black sigatoka resistance are discussed in relation to the genetic model.

  12. Brown Rot Strikes Prunus Fruit: An Ancient Fight Almost Always Lost.

    Science.gov (United States)

    Oliveira Lino, Leandro; Pacheco, Igor; Mercier, Vincent; Faoro, Franco; Bassi, Daniele; Bornard, Isabelle; Quilot-Turion, Bénédicte

    2016-05-25

    Brown rot (BR) caused by Monilinia spp., has been an economic problem for the stone fruit market due to dramatic losses, mainly during the postharvest period. There is much literature about basic aspects of Monilinia spp. infection, which indicates that environment significantly influences its occurrence in the orchard. However, progress is needed to sustainably limit this disease: the pathogen is able to develop resistance to pesticides, and most of BR resistance research programs in plant models perish. Solving this problem becomes important due to the need to decrease chemical treatments and reduce residues on fruit. Thus, research has recently increased, exploring a wide range of disease control strategies (e.g., genetic, chemical, physical). Summarizing this information is difficult, as studies evaluate different Monilinia and Prunus model species, with diverse strategies and protocols. Thus, the purpose of this review is to present the diversity and distribution of agents causing BR, focusing on the biochemical mechanisms of Monilinia spp. infection both of the fungi and of the fruit, and report on the resistance sources in Prunus germplasm. This review comprehensively compiles the information currently available to better understand mechanisms related to BR resistance.

  13. [Mixed connective tissue disease: prevalence and clinical characteristics in African black, study of 7 cases in Gabon and review of the literature].

    Science.gov (United States)

    Missounga, Landry; Ba, Josaphat Iba; Nseng Nseng Ondo, Ingrid Rosalie; Nziengui Madjinou, Maria Ines Carine; Malekou, Doris; Mouendou Mouloungui, Emeline Gracia; Nzengue, Emmanuel Ecke; Boguikouma, Jean Bruno; Kombila, Moussavou

    2017-01-01

    The literature reports that mixed connective tissue disease seems more frequent in the black population and among Asians. This study aims to determine the prevalence of mixed connective tissue disease (MCTD) among connective tissue disorders and all rheumatologic pathologies in a hospital population in Gabon as well as to describe the clinical features of this disease. We conducted a retrospective study by reviewing the medical records of patients treated for mixed connective tissue disease (Kasukawa criteria) and other entities of connective tissue disorders (ACR criteria) in the Division of Rheumatology at the University Hospital in Libreville between January 2010 and December 2015. For each case of MCTD the parameters studied were articular and extra-articular manifestations, anti-U1RNP antibodies levels, patient's evolution. Over a period of 6 years, data were collected by medical records of 7 patients out of 6050 patients and 67 cases of connective tissue disorders, reflecting a prevalence of 0.11% and 10.44% respectively. the 7 patients were women (100%), with an average age of 39.5 years. Articular manifestations included: polyarthritis, myalgias, chubby fingers and Raynaud's phenomenon in 87.5%, 87.5%, 28.6% and 14% respectively. The 7 patients had high anti-U1RNP antibodies levels, ranging between 5 and 35N (N≤ 7 IU). A case of death due to pulmonary arterial hypertension (PAH) was certified. This is the largest case series of MCTD reported in Black Africa. The disease seems to be rare among the black Africans; the reason could be genetic. The demographic and clinical aspects appear similar to those in Caucasians, Asians and Blacks except for a low frequency of Raynaud?s phenomenon among Blacks.

  14. Brown rot fungal early stage decay mechanism as a biological pretreatment for softwood biomass in biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Michael J.; Leak, David J.; Spanu, Pietro D.; Murphy, Richard J. [Division of Biology, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ (United Kingdom); Porter Alliance, Imperial College London, London SW7 2AZ (United Kingdom)

    2010-08-15

    A current barrier to the large-scale production of lignocellulosic biofuels is the cost associated with the energy and chemical inputs required for feedstock pretreatment and hydrolysis. The use of controlled partial biological degradation to replace elements of the current pretreatment technologies would offer tangible energy and cost benefits to the whole biofuel process. It has been known for some time from studies of wood decay that, in the early stages of growth in wood, brown rot fungi utilise a mechanism that causes rapid and extensive depolymerisation of the carbohydrate polymers of the wood cell wall. The brown rot hyphae act as delivery vectors to the plant cell wall for what is thought to be a combination of a localised acid pretreatment and a hydroxyl radical based depolymerisation of the cell wall carbohydrate polymers. It is this quality that we have exploited in the present work to enhance the saccharification potential of softwood forest residues for biofuel production. Here we show that after restricted exposure of pine sapwood to brown rot fungi, glucose yields following enzymatic saccharification are significantly increased. Our results demonstrate the potential of using brown rot fungi as a biological pretreatment for biofuel production. (author)

  15. Effect of essential oil of Satureja hortensis against Bacillus pumilus, which cause of soft rot on some plants

    Science.gov (United States)

    Dadaşoǧlu, Fatih

    2017-04-01

    In this study, it is aimmed to be determined the antimicrobial effects of the essential oil in vitro conditions, extracted from wild forms of plant which is known as Satureja hortensis around the world and grows naturally at Erzurum province of Turkey against Bacillus pumilus isolates, which are the agent of Soft Rot for some fruits and vegetables. For this purpose, 18 isolates of B. pumilus which have been determined as the agent of Soft Rot in previous studies performed in plants such as potatos, onions, strawberries, melons and watermelons. As the positive control, Streptomycin antibiotics sold as ready produce were used. According to the obtained results, the essential oil have the antibactericidal effect of 19-29 mm against 18 isolates of B. pumilus. It has been observed that the antibiotics used as the positive control has the antibacterial effect of 16-22 mm. In conclusion, the essential oil has the lethal effect against 18 B. pumilus isolates which are agents of Soft Rot. It is assesed that these essential oil extracted from Satureja hortensis can be used against these Soft Rot pathogens.

  16. Effect of combinations of gamma irradiation, hot water, Sodium chloride, and Acetic acid treatments on potato-dry rot

    International Nuclear Information System (INIS)

    El-Zayat, M.M.; Farahat, A.A.; Saad, N.H.; Shaarawy, N.S.M.

    1992-01-01

    Gamma irradiation increased the severity of dry rot in potato tubers when they were inoculated with any of 4 species of Fusarium, previously isolated either from irradiated or unirradiated tubers. Treating either irradiated or unirradiated tubers with warm water or sodium chloride solutions following inoculation with F. roseum also increased the severity of dry rot to some extent

  17. Biology, diagnosis and management of Heterobasidion Root Disease of southern pines

    Science.gov (United States)

    Tyler J. Dreaden; Jason A.  Smith; Michelle M. Cram; David R   Coyle

    2016-01-01

    Heterobasidion root disease (previously called annosum, annosus, or Fomes root disease / root rot) is one of the most economically damaging forest diseases in the Northern Hemisphere. Heterobasidion root disease (HRD) in the southeastern U.S. is caused by the pathogen Heterobasidion irregulare, which infects loblolly, longleaf, pitch, shortleaf, slash, Virginia, and...

  18. The Induction of Noble Rot (Botrytis cinerea Infection during Postharvest Withering Changes the Metabolome of Grapevine Berries (Vitis vinifera L., cv. Garganega

    Directory of Open Access Journals (Sweden)

    Stefano Negri

    2017-06-01

    Full Text Available The natural or induced development of noble rot caused by the fungus Botrytis cinerea during the late stages of grapevine (Vitis vinifera L. berry ripening is used in some traditional viticulture areas to produce high-quality wines such as Sauternes and Tokaji. In this research, we wanted to verify if by changing the environmental conditions during post-harvest withering we could induce the noble rot development on harvested berries in order to positively change the wine produced from withered Garganega berries. Therefore, we exposed the berries to postharvest withering under normal or artificially humid conditions, the latter to induce noble rot. The presence of noble rot symptoms was associated with the development of B. cinerea in the berries maintained under humid conditions. The composition of infected and non-infected berries was investigated by untargeted metabolomics using liquid chromatography/mass spectrometry. We also explored the effects of the two withering methods on the abundance of volatile organic compounds in wine by yeast-inoculated micro-fermentation followed by targeted gas chromatography/mass spectrometry. These experiments revealed significant metabolic differences between berries withered under normal and humid conditions, indicating that noble rot affects berry metabolism and composition. As well as well-known botrytization markers, we detected two novel lipids that have not been observed before in berries infected with noble rot. Unraveling the specific metabolic profile of berries infected with noble rot may help to determine the compounds responsible for the organoleptic quality traits of botrytized Garganega wines.

  19. Lignin-modifying enzymes of the white rot basidiomycete Ganoderma lucidum

    Energy Technology Data Exchange (ETDEWEB)

    D/Souza, T.M.; Merritt, C.S.; Reddy, C.A.

    1999-12-01

    Ganoderma lucidum, a white rot basidiomycete widely distributed worldwide, was studied for the production of the lignin-modifying enzymes laccase, manganese-dependent peroxidase (MnP), and lignin peroxidase (LiP). Laccase levels observed in high-nitrogen shaken cultures were much greater than those seen in low-nitrogen, malt extract, or wool-grown cultures and those reported for most other white rot fungi to date. Laccase production was readily seen in cultures grown with pine or poplar as the sole carbon and energy source. Cultures containing both pine and poplar showed 5- to 10-fold-higher levels of laccase than cultures containing pine or poplar alone. Since syringyl units are structural components important in poplar lignin and other hardwoods but much less so in pine lignin and other softwoods, pine cultures were supplemented with syringic acid, and this resulted in laccase levels comparable to those seen in pine-plus-poplar cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of concentrated extracellular culture fluid from HM cultures showed two laccase activity bands, where as isoelectric focusing revealed five major laccase activity bands with estimated pIs of 3.0, 4.25, 4.5, and 5.1. Low levels of MnP activity were detected in poplar-grown cultures but not in cultures grown with pine, with pine plus syringic acid, or in HN medium. No LiP activity was seen in any of the media tested; however, probing the genomic DNA with the LiP cDNA (CLG4) from the white rot fungus Phanerochaete chrysosporium showed distinct hybridization bands suggesting the presence of lip-like sequences in G. lucidum.

  20. Resistência genética à podridão amarga em maçãs, determinada pela taxa de desenvolvimento da doença em frutos com e sem ferimentos Genetic resistance to bitter rot on apples determined by the development rate of the disease on fruits with and without wounds

    Directory of Open Access Journals (Sweden)

    Frederico Denardi

    2003-12-01

    Full Text Available A maçã é um dos mais importantes produtos agrícolas de Santa Catarina e a segunda mais importante fruteira de clima temperado do Brasil. No entanto, a produção brasileira está alicerçada em cultivares importadas suscetíveis a diversas doenças. A podridão amarga causada pelo fungo Glomerella cingulata (Stoneman Spaulding & Schrenk, (forma imperfeita Colletotrichum gloeosporioides (Penz. Sacc. é uma das mais importantes doenças de verão, podendo causar perdas muito elevadas. No presente trabalho, a inoculação artificial de C. gloesporioides em frutos com e sem ferimentos objetivou verificar a diferença de evolução da podridão amarga e identificar possíveis fontes de resistência nas seleções e novas cultivares de macieira desenvolvidas pela Epagri. Verificou-se ampla variação na reação de resistência entre as cultivares e seleções estudadas. O estabelecimento e o desenvolvimento da podridão amarga mostrou-se muito mais rápido através de ferimentos. As seleções M-6/00 e M-13/00 manifestaram resistência superior à das atuais cultivares Gala, Fuji e Golden Delicious. Essas seleções também apresentaram resistência superior à cv. Melrose, indicada como resistente em outros estudos.Apple is one of the most important agricultural product of Santa Catarina State and represents the second most important temperate-zone fruit in Brazil. However the production is based on imported cultivars susceptible to many fungal diseases. Bitter rot caused by the fungus Glomerella cingulata (Stoneman Spaulding & Schrenk, (amorphous = Colletotrichum gloeosporioides (Penz. Sacc., is one of the most important summer diseases of apple in southern Brazil. Severe damages may occur every year. In the present study, artificial inoculation of C. gloeosporioides on fruits with and without wounding was carried out to verify differences in the evolution of bitter rot and to identify sources of resistance to the disease among the new apple

  1. Phytophthora megakarya and P. palmivora, Causal Agents of Black Pod Rot, Induce Similar Plant Defense Responses Late during Infection of Susceptible Cacao Pods

    Science.gov (United States)

    Ali, Shahin S.; Shao, Jonathan; Lary, David J.; Strem, Mary D.; Meinhardt, Lyndel W.; Bailey, Bryan A.

    2017-01-01

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao L. (cacao). Of these two clade 4 species, Pmeg is more virulent and is displacing Ppal in many cacao production areas in Africa. Symptoms and species specific sporangia production were compared when the two species were co-inoculated onto pod pieces in staggered 24 h time intervals. Pmeg sporangia were predominantly recovered from pod pieces with unwounded surfaces even when inoculated 24 h after Ppal. On wounded surfaces, sporangia of Ppal were predominantly recovered if the two species were simultaneously applied or Ppal was applied first but not if Pmeg was applied first. Pmeg demonstrated an advantage over Ppal when infecting un-wounded surfaces while Ppal had the advantage when infecting wounded surfaces. RNA-Seq was carried out on RNA isolated from control and Pmeg and Ppal infected pod pieces 3 days post inoculation to assess their abilities to alter/suppress cacao defense. Expression of 4,482 and 5,264 cacao genes was altered after Pmeg and Ppal infection, respectively, with most genes responding to both species. Neural network self-organizing map analyses separated the cacao RNA-Seq gene expression profiles into 24 classes, 6 of which were largely induced in response to infection. Using KEGG analysis, subsets of genes composing interrelated pathways leading to phenylpropanoid biosynthesis, ethylene and jasmonic acid biosynthesis and action, plant defense signal transduction, and endocytosis showed induction in response to infection. A large subset of genes encoding putative Pr-proteins also showed differential expression in response to infection. A subset of 36 cacao genes was used to validate the RNA-Seq expression data and compare infection induced gene expression patterns in leaves and wounded and unwounded pod husks. Expression patterns between RNA-Seq and RT-qPCR were generally reproducible. The level and timing of altered gene expression was

  2. Organics and mineral fertilizers and biological control on the incidence of stalk rot and corn yield

    Directory of Open Access Journals (Sweden)

    Elena Blume

    2014-06-01

    Full Text Available The expansion of area under maize (Zea mays L. and the use of no tillage have favored the incidence of stalk rot on this crop. The study aimed to evaluate the organic fertilizers and the treatment of corn seeds with Trichoderma spp. on the production of dry matter (DM of shoot, incidence of stalk rot and corn yield. The experiment consisted in a factorial with split-plot in strips, on the randomized block design with four replicates, and the fertilization treatments (pig slurry; swine deep bedding; cattle slurry; mineral fertilizer; control treatment were applied to the plots and the seeds treatment (with and without Trichoderma spp. in the subplots. At the flowering stage, three corn plants per subplot were collected for the assessment of DM production. At physiological maturity stage, the incidence of stalk rot was assessed, and the ears of corn harvested for productivity assessment. The organic and mineral fertilizers increased the production of DM and productivity of corn. Trichoderma spp. increased the production of DM of corn, but had no reflection on productivity. The incidence of stalk rot in corn was higher in treatments with organic and mineral fertilization. Organic fertilizers increase dry matter production of shoot and corn yield, and Trichoderma spp. provides an increase in dry matter production of shoot.

  3. Preliminary study on antifungal effect of commercial essential oils against white rot fungi

    Science.gov (United States)

    Khalid, Nurul Izzaty; Baharum, Azizah; Daud, Fauzi

    2015-09-01

    Protecting and preserving wood plastic composite from deterioration caused by fungal attack is a high challenge issue to cater nowadays. The objective of this study was to carry out a screening test towards antifungal effect of essential oil and to investigate the potential of raw materials that will be used as basic material for manufacturing wood plastic composite against white rot fungi. Essential oils from four types of natural products comprising cinnamon, lemongrass, lavender and geranium have been screened for their ability to inhibit five types of white rot fungi species which are Lentinus squarrosulus, Pleuorotus pulmonarius, Lentinus sp., Pleuorotus sajor-caju and Lignosus rhinocerus. The antifungal evaluation showed that no inhibitory effect against tested white rot fungi since the mycelia completely filled the plates. From the observation, mycelia of L. squarrosulus, P. pulmonarius and Lentinus sp. were found to filled the surface of falcon tubes with rubber sawdust after 15 days. Mycelia of L. squarrosulus and P. pulmonarius also were found to completely covered the surface of media that contain polypropylene and maleic anhydride grafted polypropylene on it. Therefore, this report proved that the main materials that will be applicable in manufacturing of wood plastic composite had potential to be degraded by this type of fungal attack.

  4. Watery rot of pseudo-stem (Dickeya sp. management in banana (Musa sp. under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Joaquín Guillermo Ramírez

    2014-12-01

    Full Text Available This crop has serious constraints with diseases, including those caused by bacteria, such as Dickeya sp. This research aimed to evaluate the effect of 4 resistance inductors and 3 doses in Chlorine Dioxide in handling watery rot of pseudo-stem (Dickeya sp. in banana. Resistance inducers and their doses were Potassium Phosphite: 1.5 cm 3 .l -1 ; 3-Aminobutanoic Acid: 1.0 g.l -1 ; Methyl Jasmonate: 0.2 g.l -1 ; S-Methyl-Acibenzolar: 0.3 ml.l -1 , all by foliar application, while Chlorine Dioxide was injected into the pseudo-stem, in doses of 10, 20 and 30 mg.l -1 . The evaluated variables were: development of the disease, total biomass and quantification of the bacterium in the inoculated pseudo-stems. Applications of Chlorine Dioxide achieved a reduction of disease by 65.4, 91.99 and 61.5%, in addition to an inhibition of 100% of the pathogen, using 30 and 50 mg.l -1 doses. Meanwhile, the use of resistance inductors reduced up to 60.6% of the disease, but this effect failed to improve plant growth.

  5. Effect of the planting material on the incidence of dry rot in Colocasia esculenta (L. Schott and Xanthosoma spp.

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa

    2012-10-01

    Full Text Available The cocoyam (Xanthosoma spp. and Colocasia esculenta is a monocot plant with vegetative propagation. This work was developed with the aim of determining the effect of the planting material type on the incidence of dry rot in two cultivars of Colocasia and Xanthosoma genera. Primary and secondary rhizomes, crowns of primary rhizomes and in vitro plants were used. The plantation was maintained for twelve months and the plants were characterized morphologically in the growing stage. Besides, it was determined the incidence of dry rot per treatment at growing and harvest stage. Finally, the yield was determined. When in vitro plants were used the percentage of incidence and intensity of the damage of dry rot was less in both cultivars. The yield in primary rhizomes and overall was significantly higher. The results indicated the superiority of in vitro plants as initial plantation material over the traditional seed used in taro culture. Furthermore, it allows the designing a seed production program by biotechnological methods. Key words: clone, cocoyam, dry rot, in vitro plants.

  6. EFIKASI TRICHODERMA HARZIANUM DENGAN BERBAGAI BAHAN ORGANIK DALAM PENGENDALIAN PENYAKIT BUSUK PANGKAL BATANG PADA LADA

    Directory of Open Access Journals (Sweden)

    Cipta Ginting

    2011-11-01

    Full Text Available The objective of this research was to determine the influence of the kinds of organic matter on the efficacy of Trichoderma harzianum Rifai to control foot rot of black pepper caused by Phytophthora capsici Leonian.  Trichoderma spp. were isolated from suppressive and non-suppressive soils taken from black pepper fields with high disease incidence.  Screening of Trichoderma spp. isolates was conducted through antagonistic test with dual culture technique.  Treatments were arranged in a completely randomized design with six replications.  Treatments were rice husk, rice straw, wood dust, Arachis pintoi, mixture of the four organic matters, the mixture without T. harzianum, and without organic matter.  The test was conducted in greenhouse with media consisted of soil, organic matter, and sand (2 : 2 : 1, v/v.  After being otoclaved, the medium was infested with T. harzianum and P. capsici each with five mycelium plugs of 1-cm diameter.  Black pepper seedlings were planted 5 days after fungal infestation.  After planting the seedlings, five leaf cuts were partly inserted into the soil on each pot.  The variables observed were disease incidence on the leaf cuts inserted into the soil and disease severity on the stems and roots.  The results show that all 16 Trichoderma isolates inhibited P. capsici colonies and some isolates showed stronger inhibition than the others.  T. harzianum reduced disease severity, but there was no effect of the kinds of organic matter on the ability of T. harzianum to control foot rot.

  7. New line selected from irradiated cuttings of sweet potato

    International Nuclear Information System (INIS)

    Lu Shuyun; Wu Chongguang; Li Weiji; Feng Qihuan

    1992-01-01

    Some clonal lines of resistance to black rot were obtained from M 1 V 3 of Xu-18 variety. Through some regional tests, provincial yield trial and production test, the mutant line Nong-Da 601 (12-11-8) as spring sweet potato showed a better yield than the control, the dry matter content of Nong-Da 601 was also better than that of control, further more, the resistance to black rot of mutant selected in M 1 V 3 could be passed onto their progeny. The analysis of esterase isozyme showed zymogram variation between Nong-Da 601 and Xu-18. From the observation of the root tip cells, the chromosome bridge appeared obviously after irradiation, but the frequency of chromosome aberration in M 1 V 6 was decreased almost to the level of control (Xu-18). It seems that the changes of disease resistance from susceptible to resistant by irradiation was not due to chromosome aberration but due to gene mutation

  8. White-rot fungi in phenols, dyes and other xenobiotics treatment – a brief review

    Directory of Open Access Journals (Sweden)

    B. Zelić

    2010-01-01

    Full Text Available Bioremediation is an attractive technology that utilizes the metabolic potential of microorganisms in order to clean up the environmental pollutants to the less hazardous or non-hazardous forms with less input of chemicals, energy and time. White-rot fungi are unique organisms that show the capacities of degrading and mineralizing lignin as well as organic, highly toxic and recalcitrant compounds. The key enzymes of their metabolism are extracellular lignolytic enzymes that enable fungi to tolerate a relatively high concentration of toxic substrates. This paper gives a brief review of many aspects concerning the application of white-rot fungi with the purpose of the industrial contaminants removal.

  9. Pineapple Fruit Collapse: Newly Emerging Disease of Pineapple Fruit in Lampung, Indonesia

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo

    2014-03-01

    Full Text Available ABSTRACT Pineapple fruit collapse: newly emerging disease of pineapple fruit in Lampung, Indonesia Recently, a new disease on pineapple fruit has occurred in Lampung. Symptoms of the disease are complex. Fruits rotted and exuded copious liquid from the inter- fruitlet tissues accompanied by gas bubbles. Open spaces were formed inside the rotten fruit. Dissection of diseased fruit showed many cavities within its sceletal fibres and bad odour was exerted from the rotten tissues. A bacterial entity was isolated  from the diseased materials. In a pathogenicity test, the isolated bacteria caused the same symptom as mentioned. In the growing-on test the crown of the heavily infected fruit  showed  heart rot symptom.  Those  indicated that the disease was pineapple fruit collapse. Both symptoms were known related to the same causal agent, Erwinia chrysanthemi (pineapple strain Dickeya sp.. In our opinion, this is the first report of pineapple fruit collapse in Indonesia.

  10. Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

    Directory of Open Access Journals (Sweden)

    John Clifford Sutton

    2006-09-01

    Full Text Available The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances, the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature and human interferences (cropping practices and control measures are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of

  11. Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

    Directory of Open Access Journals (Sweden)

    José Cristóbal Román-Reyes

    2014-11-01

    Full Text Available La producción de microalgas vivas para cultivar rotíferos constituye uno de los mayores costos de operación en la larvicultura de peces, por lo que se están desarrollando sustitutos comerciales de microalgas para la alimentación y producción de rotíferos. Se desconoce el efecto que tienen las formulaciones comerciales sobre la dinámica poblacional de rotíferos nativos del noroeste de México y en este estudio se evaluó el efecto de cuatro dietas comerciales (Espirulina, RotiMac®, Nanno 3600®, RotiGrow-Plus® y la microalga viva Nannochloropsis sp., sobre el crecimiento poblacional y fecundidad del rotífero Brachionus ibericus (GenBank KJ949043, aislado de una granja de camarón blanco (Litopenaeus vannamei. Se realizaron cinco réplicas por tratamiento alimenticio utilizando recipientes con volumen de 12 L de agua, con temperatura de 29 ± 1°C y salinidad de 35 ± 1, respectivamente. Los resultados mostraron que durante los periodos experimentales, las dietas probadas resultaron adecuadas para alimentar a B. ibericus, con tasas de crecimiento, tiempos de duplicación, densidades máximas y fecundidades que fluctuaron entre 0.20 a 0.27 rotíferos día-1, 2.60 a 3.42 días, 215 a 344 rotíferos mL-1 y de 0.16 a 0.39 huevos hembra-1, respectivamente. Las diferencias entre tratamientos fueron significativas (P 0.05 a las obtenidas con Nanno 3600®.

  12. Investigations on Fusarium spp. and their mycotoxins causing Fusarium ear rot of maize in Kosovo.

    Science.gov (United States)

    Shala-Mayrhofer, Vitore; Varga, Elisabeth; Marjakaj, Robert; Berthiller, Franz; Musolli, Agim; Berisha, Defrime; Kelmendi, Bakir; Lemmens, Marc

    2013-01-01

    After wheat, maize (Zea mays L.) is the second most important cereal crop in Kosovo and a major component of animal feed. The purpose of this study was to analyse the incidence and identity of the Fusarium species isolated from naturally infected maize kernels in Kosovo in 2009 and 2010, as well as the mycotoxin contamination. The disease incidence of Fusarium ear rot (from 0.7% to 40% diseased ears) on maize in Kosovo is high. The most frequently Fusarium spp. identified on maize kernels were Fusarium subglutinans, F. verticillioides/F. proliferatum and F. graminearum. Maize kernel samples were analysed by LC-MS/MS and found to be contaminated with deoxynivalenol (DON), DON-3-glucoside, 3-acetyl-DON, 15-acetyl-DON, zearalenone, zearalenone-14-sulphate, moniliformin, fumonisin B1 and fumonisin B2. This is the first report on the incidence and identification of Fusarium species isolated from naturally infected maize as well as the mycotoxin contamination in Kosovo.

  13. Black and White Differentials in Mortality.

    Science.gov (United States)

    Rene, Antonio A.; Clifford, Patrick R.

    1986-01-01

    Overviews vital statistics data, emphasizing differences in health status between the Black and White populations with respect to specific diseases and mortality. Discusses major causes of death among US Blacks. (GC)

  14. Probing genetic diversity to characterize red rot resistance in sugarcane

    Energy Technology Data Exchange (ETDEWEB)

    Mumtaz, A S; Dure-e-Nayab,; Iqbal, M J; Shinwari, Z.K., E-mail: asmumtaz@qau.edu.pk

    2011-10-15

    Genetic diversity was assessed in a set of twelve sugarcane genotypes using Random Amplified Polymorphic DNA (RAPD). A total of thirty-two oligo-primers were employed, sixteen of them revealed amplification at 149 loci, out of which 136 were polymorphic. The genotype SPSG-26 showed the highest number of polymorphic loci, followed by CSSG-668 and HSF-242. Pairwise genetic similarity ranged from 67.2% to 83.3%. The UPGMA cluster analysis resolved most of the accessions in two groups. The clustering pattern did not place all resistant varieties in one or related group which depict diverse resistance source in the present set of sugarcane varieties. Ten primers revealed genotype specific bands among which four primers (K07, H02, K10 and F01) produced multiple genotype specific bands that aid genotype identification especially those with red rot resistance. The present study not only provided information on the genetic diversity among the genotypes but also revealed the potential of RAPD-PCR markers for genotype identification and therefore could be utilized in marker assisted selection for red rot resistance in sugarcane. (author)

  15. The Fusarium crown rot pathogen Fusarium pseudograminearum triggers a suite of transcriptional and metabolic changes in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Powell, Jonathan J; Carere, Jason; Fitzgerald, Timothy L; Stiller, Jiri; Covarelli, Lorenzo; Xu, Qian; Gubler, Frank; Colgrave, Michelle L; Gardiner, Donald M; Manners, John M; Henry, Robert J; Kazan, Kemal

    2017-03-01

    Fusarium crown rot caused by the fungal pathogen Fusarium pseudograminearum is a disease of wheat and barley, bearing significant economic cost. Efforts to develop effective resistance to this disease have been hampered by the quantitative nature of resistance and a lack of understanding of the factors associated with resistance and susceptibility. Here, we aimed to dissect transcriptional responses triggered in wheat by F. pseudograminearum infection. We used an RNA-seq approach to analyse host responses during a compatible interaction and identified >2700 wheat genes differentially regulated after inoculation with F. pseudograminearum . The production of a few key metabolites and plant hormones in the host during the interaction was also analysed. Analysis of gene ontology enrichment showed that a disproportionate number of genes involved in primary and secondary metabolism, signalling and transport were differentially expressed in infected seedlings. A number of genes encoding pathogen-responsive uridine-diphosphate glycosyltransferases (UGTs) potentially involved in detoxification of the Fusarium mycotoxin deoxynivalenol (DON) were differentially expressed. Using a F. pseudograminearum DON-non-producing mutant, DON was shown to play an important role in virulence during Fusarium crown rot. An over-representation of genes involved in the phenylalanine, tryptophan and tyrosine biosynthesis pathways was observed. This was confirmed through metabolite analyses that demonstrated tryptamine and serotonin levels are induced after F. pseudograminearum inoculation. Overall, the observed host response in bread wheat to F. pseudograminearum during early infection exhibited enrichment of processes related to pathogen perception, defence signalling, transport and metabolism and deployment of chemical and enzymatic defences. Additional functional analyses of candidate genes should reveal their roles in disease resistance or susceptibility. Better understanding of host

  16. Gibberella ear rot of maize (Zea mays) in Nepal: distribution of the mycotoxins nivalenol and deoxynivalenol in naturally and experimentally infected maize.

    Science.gov (United States)

    Desjardins, Anne E; Busman, Mark; Manandhar, Gyanu; Jarosz, Andrew M; Manandhar, Hira K; Proctor, Robert H

    2008-07-09

    The fungus Fusarium graminearum (sexual stage Gibberella zeae) causes ear rot of maize (Zea mays) and contamination with the 8-ketotrichothecenes nivalenol (1) or 4-deoxynivalenol (2), depending on diversity of the fungal population for the 4-oxygenase gene (TRI13). To determine the importance of 1 and 2 in maize ear rot, a survey of naturally contaminated maize in Nepal was combined with experiments in the field and in a plant growth room. In the survey, 1 contamination was 4-fold more frequent than 2 contamination and 1-producers (TRI13) were isolated more than twice as frequently as 2-producers (Psi TRI13). In maize ear rot experiments, genetically diverse 1-producers and 2-producers caused ear rot and trichothecene contamination. Among strains with the same genetic background, however, 1-producers caused less ear rot and trichothecene contamination than did 2-producers. The high frequency of 1 contamination and the high virulence of many 1-producers are of concern because maize is a staple food of rural populations in Nepal and because 1 has proven to be more toxic than 2 to animals.

  17. Irpex lacteus, a white-rot fungus with biotechnological potential — review

    Czech Academy of Sciences Publication Activity Database

    Novotný, Čeněk; Cajthaml, Tomáš; Svobodová, Kateřina; Šušla, Martin; Šašek, Václav

    2009-01-01

    Roč. 5, č. 5 (2009), s. 375-390 ISSN 0015-5632 R&D Projects: GA AV ČR IAAX00200901 Institutional research plan: CEZ:AV0Z50200510 Keywords : White-rot fungi * degradation * irpex lacteus Subject RIV: EE - Microbiology, Virology Impact factor: 0.978, year: 2009

  18. Fruits of Black Chokeberry Aronia melanocarpa in the Prevention of Chronic Diseases

    Directory of Open Access Journals (Sweden)

    Tunde Jurikova

    2017-06-01

    Full Text Available In recent years, growing attention has been focused on the utilization of natural sources of antioxidants in the prevention of chronic diseases. Black chokeberry (Aronia melanocarpa represents a lesser known fruit species utilized mainly as juices, purees, jams, jellies and wine, as important food colorants or nutritional supplements. The fruit is valued as a great source of antioxidants, especially polyphenols, such as phenolic acids (neochlorogenic and chlorogenic acids and flavonoids (anthocyanins, proanthocyanidins, flavanols and flavonols, particularly cyanidin-3-galactoside and cyanidin-3-arabinoside, as well as (−-epicatechin units. The berries of A. melanocarpa, due to the presence and the high content of these bioactive components, exhibit a wide range of positive effects, such as strong antioxidant activity and potential medicinal and therapeutic benefits (gastroprotective, hepatoprotective, antiproliferative or anti-inflammatory activities. They could be also contributory toward the prevention of chronic diseases including metabolic disorders, diabetes and cardiovascular diseases, because of supportive impacts on lipid profiles, fasting plasma glucose and blood pressure levels.

  19. Role of mungbean root nodule associated fluorescent Pseudomonas and rhizobia in suppressing the root rotting fungi and root knot nematodes in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Noreen, R.; Shafique, A.; Haque, S.E.; Ali, S.A.

    2016-01-01

    Three isolates each of fluorescent Pseudomonas (NAFP-19, NAFP-31 and NAFP-32) and rhizobia (NFB- 103, NFB-107 and NFB-109) which were originally isolated from root nodules of mungbean (Vigna radiata) showed significant biocontrol activity in the screen house and under field condition, against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani evaluated on chickpea. Biocontrol potential of these isolates was also evaluated against Meloidogyne incognita, the root knot nematode. Application of Pseudomonas and rhizobial isolates as a soil drench, separately or mixed significantly reduced root rot disease under screen house and field conditions. Nematode penetration in roots was also found significantly less in rhizobia or Pseudomonas treatments used separately or mixed as compared to control. Fluorescent Pseudomonas treated plants produced greater number of nodules per plant than control plants and about equal to rhizobia treated plants, indicating that root nodule associated fluorescent Pseudomonas enhance root nodulation. (author)

  20. Short- and long-term black tea consumption reverses endothelial dysfunction in patients with coronary artery disease.

    Science.gov (United States)

    Duffy, S J; Keaney , J F; Holbrook, M; Gokce, N; Swerdloff, P L; Frei, B; Vita, J A

    2001-07-10

    Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypothesis that tea consumption will reverse endothelial dysfunction, we randomized 66 patients with proven coronary artery disease to consume black tea and water in a crossover design. Short-term effects were examined 2 hours after consumption of 450 mL tea or water. Long-term effects were examined after consumption of 900 mL tea or water daily for 4 weeks. Vasomotor function of the brachial artery was examined at baseline and after each intervention with vascular ultrasound. Fifty patients completed the protocol and had technically suitable ultrasound measurements. Both short- and long-term tea consumption improved endothelium- dependent flow-mediated dilation of the brachial artery, whereas consumption of water had no effect (Peffect on endothelium-independent nitroglycerin-induced dilation. An equivalent oral dose of caffeine (200 mg) had no short-term effect on flow-mediated dilation. Plasma flavonoids increased after short- and long-term tea consumption. Short- and long-term black tea consumption reverses endothelial vasomotor dysfunction in patients with coronary artery disease. This finding may partly explain the association between tea intake and decreased cardiovascular disease events.

  1. Host Resistance and Chemical Control for Management of Sclerotinia Stem Rot of Soybean in Ohio.

    Science.gov (United States)

    Huzar-Novakowiski, Jaqueline; Paul, Pierce A; Dorrance, Anne E

    2017-08-01

    Recent outbreaks of Sclerotinia stem rot (SSR) of soybean in Ohio, along with new fungicides and cultivars with resistance to this disease, have led to a renewed interest in studies to update disease management guidelines. The effect of host resistance (in moderately resistant [MR] and moderately susceptible [MS] cultivars) and chemical control on SSR and yield was evaluated in 12 environments from 2014 to 2016. The chemical treatments evaluated were an untreated check, four fungicides (boscalid, picoxystrobin, pyraclostrobin, and thiophanate-methyl), and one herbicide (lactofen) applied at soybean growth stage R1 (early flowering) alone or at R1 followed by a second application at R2 (full flowering). SSR developed in 6 of 12 environments, with mean disease incidence in the untreated check of 2.5 to 41%. The three environments with high levels of SSR (disease incidence in the untreated check >20%) were used for further statistical analysis. There were significant effects (P Pyraclostrobin increased SSR compared with the untreated check in the three environments with high levels of disease. In the six fields where SSR did not develop, chemical treatment did not increase yield, nor was the yield from the MR cultivar significantly different from the MS cultivar. For Ohio, MR cultivars alone were effective for management of SSR in soybean fields where this disease has historically occurred.

  2. Control of yam tuber rot with leaf extracts of Xylopia aethiopica and ...

    African Journals Online (AJOL)

    JOHN

    Investigation was carried out to test the potency of some plant extracts for the control of yam tuber rot caused by Fusarium ... The extracts of suppressed the growth of these fungi in culture ..... Methodolgy for analysis of Vegetable drug. Practical.

  3. Quorum sensing signaling molecules produced by reference and emerging soft-rot bacteria (Dickeya and Pectobacterium spp..

    Directory of Open Access Journals (Sweden)

    Alexandre Crépin

    Full Text Available Several small diffusible molecules are involved in bacterial quorum sensing and virulence. The production of autoinducers-1 and -2, quinolone, indole and γ-amino butyrate signaling molecules was investigated in a set of soft-rot bacteria belonging to six Dickeya or Pectobacterium species including recent or emerging potato isolates.Using bacterial biosensors, immunoassay, and chromatographic analysis, we showed that soft-rot bacteria have the common ability to produce transiently during their exponential phase of growth the N-3-oxo-hexanoyl- or the N-3-oxo-octanoyl-l-homoserine lactones and a molecule of the autoinducer-2 family. Dickeya spp. produced in addition the indole-3-acetic acid in tryptophan-rich conditions. All these signaling molecules have been identified for the first time in the novel Dickeya solani species. In contrast, quinolone and γ-amino butyrate signals were not identified and the corresponding synthases are not present in the available genomes of soft-rot bacteria. To determine if the variations of signal production according to growth phase could result from expression modifications of the corresponding synthase gene, the respective mRNA levels were estimated by reverse transcriptase-PCR. While the N-acyl-homoserine lactone production is systematically correlated to the synthase expression, that of the autoinducer-2 follows the expression of an enzyme upstream in the activated methyl cycle and providing its precursor, rather than the expression of its own synthase.Despite sharing the S-adenosylmethionine precursor, no strong link was detected between the production kinetics or metabolic pathways of autoinducers-1 and -2. In contrast, the signaling pathway of autoinducer-2 seems to be switched off by the indole-3-acetic acid pathway under tryptophan control. It therefore appears that the two genera of soft-rot bacteria have similarities but also differences in the mechanisms of communication via the diffusible molecules

  4. Quorum Sensing Signaling Molecules Produced by Reference and Emerging Soft-Rot Bacteria (Dickeya and Pectobacterium spp.)

    Science.gov (United States)

    Crépin, Alexandre; Barbey, Corinne; Beury-Cirou, Amélie; Hélias, Valérie; Taupin, Laure; Reverchon, Sylvie; Nasser, William; Faure, Denis; Dufour, Alain; Orange, Nicole; Feuilloley, Marc; Heurlier, Karin; Burini, Jean-François; Latour, Xavier

    2012-01-01

    Background Several small diffusible molecules are involved in bacterial quorum sensing and virulence. The production of autoinducers-1 and -2, quinolone, indole and γ-amino butyrate signaling molecules was investigated in a set of soft-rot bacteria belonging to six Dickeya or Pectobacterium species including recent or emerging potato isolates. Methodology/Principal Findings Using bacterial biosensors, immunoassay, and chromatographic analysis, we showed that soft-rot bacteria have the common ability to produce transiently during their exponential phase of growth the N-3-oxo-hexanoyl- or the N-3-oxo-octanoyl-l-homoserine lactones and a molecule of the autoinducer-2 family. Dickeya spp. produced in addition the indole-3-acetic acid in tryptophan-rich conditions. All these signaling molecules have been identified for the first time in the novel Dickeya solani species. In contrast, quinolone and γ-amino butyrate signals were not identified and the corresponding synthases are not present in the available genomes of soft-rot bacteria. To determine if the variations of signal production according to growth phase could result from expression modifications of the corresponding synthase gene, the respective mRNA levels were estimated by reverse transcriptase-PCR. While the N-acyl-homoserine lactone production is systematically correlated to the synthase expression, that of the autoinducer-2 follows the expression of an enzyme upstream in the activated methyl cycle and providing its precursor, rather than the expression of its own synthase. Conclusions/Significance Despite sharing the S-adenosylmethionine precursor, no strong link was detected between the production kinetics or metabolic pathways of autoinducers-1 and -2. In contrast, the signaling pathway of autoinducer-2 seems to be switched off by the indole-3-acetic acid pathway under tryptophan control. It therefore appears that the two genera of soft-rot bacteria have similarities but also differences in the

  5. Morphological and molecular identification of Fusarium tricinctum and Fusarium acuminatum as causal agents of garlic bulbs rot in Serbia

    Directory of Open Access Journals (Sweden)

    Ignjatov Maja V.

    2017-01-01

    Full Text Available Garlic (Allium sativum L. is considered to be one of the oldest crops in the world. During 2016, infected garlic bulbs occurred in storages on several localities of the Province of Vojvodina. Symptomatic cloves showed typical rot symptoms such as softened and spongy areas covered with white fungal growth with deep lesions formed on the cloves which became dry over time. A total of 36 isolates of Fusarium species were obtained from diseased cloves of garlic. Colony morphology and microscopic properties of isolated Fusarium species were recorded from the cultures grown on PDA and CLA, respectively. Identification of two chosen isolates was performed by sequencing the EF-1α gene. The TEF sequence of isolate JBL12 showed 100% similarity with several F. tricinctum sequences and sequence of JBL539 showed 99% identity with several F. acuminatum sequences and they were deposited in the NCBI GenBank. Based on the results of the morphological and molecular identification, isolates JBL12 and JBL539 were identified as F. tricinctum and F. acuminatum, respectively, as new causal agents of garlic bulbs rot in Serbia. Specific primers were designed for the PCR identification of the F. tricinctum. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31030

  6. Biodiversity of Fusarium species causing ear rot of maize in Germany

    NARCIS (Netherlands)

    Görtz, A.; Oerke, E.C.; Steiner, U.; Waalwijk, C.; Vries, de P.M.; Dehne, H.W.

    2008-01-01

    In Germany, maize is one of the most important agriculture commodities, a major component in animal feed as well as an essential substrate producing biogas. Maize car rot poses a major impact worldwide as it is caused by several Fusarium spp., most of which have the ability to produce mycotoxins.

  7. Rhizoctonia disease of tulip : characterization and dynamics of the pathogens

    NARCIS (Netherlands)

    Schneider, J.H.M.

    1998-01-01

    Rhizoctonia disease causes severe losses during the production cycle of tulip. The complex nature of the disease requires a precise characterization of the causal pathogens. Typical bare patches are caused by R. solani AG 2-t. Bulb rot symptoms are, apart from AG 2-t isolates, caused by R.

  8. Identification of Pathogenic Fusarium spp. Causing Maize Ear Rot and Poten tial Mycotoxin Production in China

    Directory of Open Access Journals (Sweden)

    Canxing Duan

    2016-06-01

    Full Text Available Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B1, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China.

  9. Producción artesanal del rotífero Philodina sp. y de algas para la alimentación de post-larvas de bocachico

    Directory of Open Access Journals (Sweden)

    Victoria Eugenia Quintero P

    2009-01-01

    Full Text Available El cultivo de algas mixtas se realizó en el Instituto de Piscicultura Tropical de la Corporación Autónoma Regional del Valle del Cauca (Buga 25 ºC y 969 m.s.n.m. utilizando fertilizantes inorgánicos en baldes plásticos, se produjeron en promedio 386 x 10³ células/ml de cultivo. En el cultivo de Philodina en frascos de vidrio alimentado con algas y levadura, se obtuvieron 410 rotíferos/ml de cultivo. Se evaluaron tres tratamientos: rotíferos enriquecidos con aceite de pescado; rotíferos más algas (Chlorella, Scenedesmus, Pediastrum, Spyrogira y Anabaena y Artemia salina + Spirulina, usando 100 post-larvas de bocachico/acuario, alimentadas dos veces al día según biomasa sembrada. El mayor porcentaje de sobrevivencia, peso y talla se obtuvo con el alimento constituido por rotíferos enriquecidos con aceite de pescado (93 %,3.2mg, 6.86mm, seguido de rotíferos + algas (80.67 %,2 mg, 6.1mm y Artemia+ Spirulina (60.6 %,1.6mg, 6.06mm respectivamente

  10. Effect of climate on the distribution of Fusarium spp. causing crown rot of wheat in the Pacific Northwest of the United States.

    Science.gov (United States)

    Poole, Grant J; Smiley, Richard W; Walker, Carl; Huggins, David; Rupp, Richard; Abatzoglou, John; Garland-Campbell, Kimberly; Paulitz, Timothy C

    2013-11-01

    Fusarium crown rot (FCR) is one of the most widespread root and crown diseases of wheat in the Pacific Northwest (PNW) of the United States. Our objectives were to characterize crown rot severity and distribution throughout the PNW by conducting a survey of 210 fields covering the diverse dryland wheat-producing areas of Washington and Oregon and to utilize a factor analysis statistical approach to determine the effects of climate and geography on species distribution and disease severity. Climatic variables were based on 30-year averages and 2008 and 2009 separately (the 2 years of the survey). Mean annual temperature, mean temperature in the coldest month, mean temperature in the warmest month, mean annual precipitation, snowfall, elevation, soil type, and cropping intensity were highly intercorrelated. The factor analysis of the climate variables resulted in the development of two latent factors that could be used as predictor variables in logistic regression models for the presence or absence of Fusarium spp. and of FCR disease scores. Isolates of Fusarium spp. were recovered from 99% of 105 fields sampled in 2008 and 97% of fields in 2009. There were differences between years for responses of FCR and nodes scores, and isolations of Fusarium pseudograminearum with more significant results in 2008, due to warmer drier weather. Results of the factor analysis showed that the distribution of F. pseudograminearum occurred in a greater frequency in areas of the PNW at lower elevations with lower moisture and higher temperatures in 2008, whereas F. culmorum occurred in greater frequency in areas at higher elevations with moderate to high moisture and cooler temperatures consistently across both years. Disease scores increased with increasing levels of factors 1 (primarily temperature) and 2 (primarily precipitation). Both the frequency of pathogen species and disease scores were influenced by the year, indicating that soilborne pathogens are responsive to short

  11. The occurence of black spot disease in Astyanax aff. fasciatus(characiformes: characidae in the Guaíba Lake basin, RS, Brazil

    Directory of Open Access Journals (Sweden)

    F Flores-Lopes

    Full Text Available Black spot disease is common in freshwater fish and is usually caused by the metacercaria stage of digenetic trematodes, normally from the Diplostomidae family. The present study evaluated the prevalence and intensity of this disease in Astyanax aff. fasciatus(Teleostei: Characiformes in the Guaíba Lake basin (RS, Brazil, including body parts assessment and the points of sampling with higher occurrence of black spots. Fish samples were taken seasonally from December 2002 until October 2004. The samples were collected with the use of a seine net at eleven points. The specimens were fixed in 10% formalin and stored in 70% ethanol. Black spot disease showed a low frequency in the Guaíba lake basin (2.07% and no specificity to the species Astyanax aff. fasciatus was observed. A high prevalence among the individuals and high intensity of infection levels was found in the ventral and dorsal regions in relation to other body parts (e.g., pectoral, pelvic and anal regions. Among the sampling points studied, we observed a higher prevalence on samples collected at points Gasômetro, Saco da Alemoa and Sinos, located in open areas with less occurrence of mollusks.

  12. Diseases of the Date Palm: Present Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    M. Djerbi

    1998-01-01

    Full Text Available While date palm is affected by many diseases, bayoud remains the most serious one. It is caused by a soil born pathogen, Fusarium oxyspurum f .sp. albedinis. It has affected practically all Moroccan palm groves as well as those of western and central Algerian sahara, where it has respectively killed more than 12 million in Morocco and three million in Algeria and has accelerated the desertification phenomenon. External and internal symptoms as well as identification methods of F.o. f. sp. albedinis by pathogenicity test, cultural characteristics, and vegetative compatibility were reviewed and discussed. Small distance contamination occurs by root contact between diseased trees and healthy ones, and at large distances through the movement of contaminated planting material (offshoots, symptomless carriers and infested soil and irrigation water. Prophylactic measures as well as chemical, cultural, biological and genetic controls were reviewed. It appears that the most productive mean lies in research into resistant cultivars. Hundreds of genotypes have been selected and introduced for micro-propagation and planted in infested areas to rehabilitate date palm oasis ravaged by bayoud. Among other date palm diseases Khamedj (Mauginiella scaettae, fruit rot (due to numerous fungi, Black scorch (Thielaviopsis paradoxa, Belaat (Phytophtora sp. are of minor importance and of sporadic occurrence. However, they become serious and cause heavy losses under favorable conditions and when proper sanitation is not applied. Two serious and fatal diseases of unknown causes (AI Wijam and the Brittle leaf disease as well as many other diseases and physiological disorders of minor importance were also reviewed.

  13. Biochemical and physiological responses of oil palm to bud rot caused by Phytophthora palmivora.

    Science.gov (United States)

    Moreno-Chacón, Andrés Leonardo; Camperos-Reyes, Jhonatan Eduardo; Ávila Diazgranados, Rodrigo Andrés; Romero, Hernán Mauricio

    2013-09-01

    In recent years, global consumption of palm oil has increased significantly, reaching almost 43 million tons in 2010. The sustainability of oil palm (Elaeis guineensis) cultivation has been compromised because of the bud rot disease whose initial symptoms are caused by Phytophthora palmivora. There was a significant incidence of the disease, from an initial stage 1 of the disease to the highest stage 5, that affected photosynthetic parameters, content of pigments, sugars, polyamines, enzymatic antioxidant activities, phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) and β-(1,3) glucanase (β-Gluc, EC 3.2.1.39). In healthy palms photosynthesis was 13.29 μmol CO2 m(-2) s(-1) in average, while in stage 5 the average photosynthesis was around 3.66 μmol CO2 m(-2) s(-1). Additionally, total chlorophyll was reduced by half at the last stage of the disease. On the contrary, the contents of putrescine, spermine and spermidine increased three, nine and twelve times with respect to stage 5, respectively. Antioxidant enzyme activities, as well as the phenylalanine ammonia-lyase and β-(1,3) glucanase showed an increase as the severity of the disease increased, with the latter increasing from 0.71 EAU in healthy palms to 2.60 EAU in plants at stage 5 of the disease. The peroxidase (POD, EC 1.11.1.7) enzymatic activity and the content of spermidine were the most sensitive indicators of disease. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Effect of dietary pigment on growth performance and disease resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius

    Directory of Open Access Journals (Sweden)

    Boonyaratpalin, M.

    2005-02-01

    Full Text Available Effects of dietary pigment on survival and disease (white spot syndrome virus: WSSV resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius (PL15 for a 30-day period were studied. The results showed that not only was mean survival of black tiger shrimp (PL15 fed with supplementation of Lucarotene or Betatene at 125 mg/kg diet significantly higher (P<0.05 but also the body color was increased. There were no effects of dietary pigment on mean weight, percent weight gain and WSSV resistance. However, mean WSSV resistance of black tiger shrimp (PL15 fed diet containing Lucantin pink 50 mg/kg diet, Spirulina 30 g/kg diet or Betatene 125 mg/kg diet was higher than that of control.

  15. Combating a global threat to a clonal crop: banana black sigatoka pathogen pseudocercospora fijiensis (synonym mycosphaerella fijiensis) genomes reveal clues for disease control

    Science.gov (United States)

    Mycosphaerella fijiensis is the fungal pathogen that causes black Sigatoka or leaf streak disease of banana. Control of this disease requires weekly applications of fungicides in most cultivation areas. Major problems for disease management are fungicide resistance and the lack of effective genes fo...

  16. Molecular Detection of Monilinia fructigena as Causal Agent of Brown Rot on Quince

    Directory of Open Access Journals (Sweden)

    Jovana Hrustić

    2012-01-01

    Full Text Available Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is importanthost for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phytopathological methods. Pathogenicity of eight obtained isolates was tested by artificial inoculation of injured apple fruits. Identification was performed according to pathogenic, morphological and ecological properties, and was confirmed by Multiplex polimeraze chain reaction, PCR. All the isolates studied caused brown rot on inoculated apple fruits. The isolates form light yellow colonies with lobate margins,with single-celled, transparent, elliptical or oval conidia in chains, regardless temperature or light presence. Sclerotia are observed in 14 days old cultures. The highest growth rate of most of the isolates is at 27°C and in dark. Based on studied pathogenic, morphological and ecological characteristics, it was found that the Monilinia fructigena is causal agent of brown rot of quince. Using specific primers (MO368-5, MO368-8R, MO368-10R, Laxa-R2for detection of Monilinia species in Multiplex PCR reaction, the expected fragment 402 bp in size was amplified, which confirmed that the studied isolates belonged to the speciesM. fructigena.

  17. Response of cultivars of malanga (Xanthosoma sagittifolium (L. Schott to dry rot

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa Cuéllar

    2017-01-01

    Full Text Available Malanga (Xanthosoma sagittifolium (L. Schott is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT. We determined the incidence and severity of damage, yields and percent of losses at harvest. The lowest values of incidence and the highest total return was achieved in clons ‘INIVIT MX-95-2’, ‘INIVIT MX-95-1’ and ‘INIVIT MX-2007’. Clones of malanga Xanthosoma belonging to the group purple, showed lower incidence that of white and yellow groups. These results will allow selecting cultivars of malanga with greater resistance to the dry rot and with this to diminish the losses in the harvest.

  18. Fungicidal activity of essential oils of Cinnamomum zeylanicum (L.) and Syzygium aromaticum (L.) Merr et L.M. Perry against crown rot and anthracnose pathogens isolated from banana.

    Science.gov (United States)

    Ranasinghe, L; Jayawardena, B; Abeywickrama, K

    2002-01-01

    To develop a post-harvest treatment system against post-harvest fungal pathogens of banana using natural products. Colletotrichum musae was isolated and identified as the causative agent responsible for anthracnose peel blemishes while three fungi, namely Lasiodiplodia theobromae, C. musae and Fusarium proliferatum, were identified as causative agents responsible for crown rot. During the liquid bioassay, cinnamon [Cinnamomum zeylanicum (L.)] leaf, bark and clove [Syzygium aromaticum (L.)] oils were tested against the anthracnose and crown rot pathogens. The test oils were fungistatic and fungicidal against the test pathogens within a range of 0.03-0.11% (v/v). Cinnamon and clove essential oils could be used as antifungal agents to manage post harvest fungal diseases of banana. Cinnamon and clove essential oil could be used as alternative post-harvest treatments on banana. Banana treated with essential oil is chemically safe and acceptable to consumers. Benomyl (Benlate), which is currently used to manage fungal pathogens, can cause adverse health effects and could be replaced with volatile essential oils.

  19. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Science.gov (United States)

    Rahman, M. M.; Ali, M. E.; Khan, A. A.; Akanda, A. M.; Uddin, Md. Kamal; Hashim, U.; Abd Hamid, S. B.

    2012-01-01

    A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers. PMID:22645446

  20. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5% antagonistic effect of E-65 was observed in the Granola and the lowest (32.7% of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

  1. Effect of cropping system and age of plant at harvest on tuber rot and performance of elite cassava varieties in derived savannah

    Directory of Open Access Journals (Sweden)

    Joy N Odedina

    2017-09-01

    Full Text Available Devastated tuber rot disease among farmers prompted the evaluation of the elite improved varieties in the intercrop and the practice of delaying harvesting when there is glut in the market necessitated this study. Trial was carried out at the Federal University of Agriculture, Abeokuta between 2011 and 2014 to evaluate yield performance of 21 elite cassava varieties planted as sole crop verse intercropped and harvested at different age. The 2 x 21 x 3 factorial experiment was laid out in randomized complete block design and replicated three times. The tuber yield obtained from sole plot in 2011/2012 cropping season was significantly higher than intercrop whereas those of 2012/2014 cropping season were similar. Land Equivalent Ratio was above one in both cropping seasons indicating that the performance of the improved varieties in intercrop was efficient. The pooled mean tuber yield showed that TMS 30572, 92/0326, 95/0211, 01/1371, 00/0338, 01/0046, 00/0098, 01/1097, 01/0085, 98/0581 and 98/510 were among the top eight varieties. Harvesting could be delayed up to 15 months after planting to reduce tuber rot.

  2. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage.

    Science.gov (United States)

    Liu, Yiqing; Wisniewski, Michael; Kennedy, John F; Jiang, Yusong; Tang, Jianmin; Liu, Jia

    2016-10-20

    The ability of chitosan and oligochitosan to enhance ginger (Zingiber officinale) resistance to rhizome rot caused by Fusarium oxysporum in storage was investigated. Both chitosan and oligochitosan at 1 and 5g/L significantly inhibited rhizome rot, with the best control at 5g/L. Chitosan and oligochitosan applied at 5g/L also reduced weight loss, measured as a decrease in fresh weight, but did not affect soluble solids content or titratable acidity of rhizomes. The two compounds applied at 5g/L induced β-1,3-glucanase and phenylalanine ammonia-lyase enzyme activity and the transcript levels of their coding genes, as well as the total phenolic compounds in rhizome tissues. Therefore, the ability of chitosan and oligochitosan to reduce rot in stored rhizomes may be associated with their ability to induce defense responses in ginger. These results have practical implications for the application of chitosan and oligochitosan to harvested ginger rhizomes to reduce postharvest losses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effects of Silicon Amendment on Soilborne and Fruit Diseases of Avocado

    Directory of Open Access Journals (Sweden)

    Elizabeth K. Dann

    2017-10-01

    Full Text Available The effects of silicon (Si amendment have been studied in several plant/pathogen interactions; however, studies in horticultural tree crops are limited. Effects of amendment with soluble potassium silicate (AgSil®32, approximately 30% available Si, or milled cement building board by-products (Mineral Mulch (MM or Mineral Dust (MD, containing 5% available Si were investigated in field and greenhouse trials with avocado. Orchard soil drench applications with potassium silicate improved yield and quality of fruit, but visual health of trees declining from Phytophthora root rot (PRR was not affected. Orchard spray or trunk injection applications with potassium silicate were ineffective. Amendment of potting mix with MM and MD reduced root necrosis of avocado seedlings after inoculation with Calonectria ilicicola, an aggressive soilborne pathogen causing black root rot. Application of MM to mature orchard trees declining with PRR had a beneficial effect on visual tree health, and Si accumulation in leaves and fruit peel, after only 10 months. Products that deliver available Si consistently for uptake are likely to be most successful in perennial tree crops.

  4. Efficacy of Heat Treatment for the Thousand Cankers Disease Vector and Pathogen in Small Black Walnut Logs

    Science.gov (United States)

    A. E. Mayfield; S. W. Fraedrich; A. Taylor; P. Merten; S. W. Myers

    2014-01-01

    Thousand cankers disease, caused by the walnut twig beetle (Pityophthorus juglandis Blackman) and an associated fungal pathogen (Geosmithia morbida M. Kolarõ´k, E. Freeland, C. Utley, and N. Tisserat), threatens the health and commercial use of eastern black walnut (Juglans nigra L.), one of the most economically...

  5. Bacteriophages of Soft Rot Enterobacteriaceae-a minireview.

    Science.gov (United States)

    Czajkowski, Robert

    2016-01-01

    Soft rot Enterobacteriaceae (Pectobacterium spp. and Dickeya spp., formerly pectinolytic Erwinia spp.) are ubiquitous necrotrophic bacterial pathogens that infect a large number of different plant species worldwide, including economically important crops. Despite the fact that these bacteria have been studied for more than 50 years, little is known of their corresponding predators: bacteriophages, both lytic and lysogenic. The aim of this minireview is to critically summarize recent ecological, biological and molecular research on bacteriophages infecting Pectobacterium spp. and Dickeya spp. with the main focus on current and future perspectives in that field. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Modification of wheat straw lignin by solid state fermentation with white-rot fungi

    NARCIS (Netherlands)

    Dinis, M.J.; Bezerra, R.M.F.; Nunes, F.; Dias, A.A.; Guedes, C.; Ferreira, L.M.M.; Cone, J.W.; Marques, G.S.M.; Barros, A.R.N.; Rodrigues, M.A.M.

    2009-01-01

    The potential of crude enzyme extracts, obtained from solid state cultivation of four white-rot fungi (Trametes versicolor, Bjerkandera adusta, Ganoderma applanatum and Phlebia rufa), was exploited to modify wheat straw cell wall. At different fermentation times, manganese-dependent peroxidase

  7. Draft Genome Sequences of Dickeya sp. Isolates B16 (NIB Z 2098) and S1 (NIB Z 2099) Causing Soft Rot of Phalaenopsis Orchids.

    Science.gov (United States)

    Alič, Špela; Naglič, Tina; Llop, Pablo; Toplak, Nataša; Koren, Simon; Ravnikar, Maja; Dreo, Tanja

    2015-09-10

    The genus Dickeya contains bacteria causing soft rot of economically important crops and ornamental plants. Here, we report the draft genome sequences of two Dickeya sp. isolates from rotted leaves of Phalaenopsis orchids. Copyright © 2015 Alič et al.

  8. Optimization of Laccase Production using White Rot Fungi and Agriculture Wastes in Solid State Fermentation

    Directory of Open Access Journals (Sweden)

    Hendro Risdianto

    2012-07-01

    Full Text Available Laccase has been produced in a solid state fermentation (SSF using white rot fungi and various lignocellulosic based substrates. White rot fungi used were Marasmius sp, Trametes hirsuta, Trametes versicolor and Phanerochaete crysosporium. The solid substrates employed in this research were collected from agriculture waste which were empty fruit bunches (EFB, rice straw, corn cob, and rice husk. The objective of this research was to determine the most promising fungus, the best solid substrate and the optimal conditions for the production of laccase. The results showed that Marasmius sp. on all solid substrates displayed higher laccase activity than that of any other strain of white rot fungi. Marasmius sp. and solid substrate of rice straw demonstrated the highest laccase activity of 1116.11 U/L on day 10. Three significant factors, i.e. pH, temperature and yeast extract concentration were studied by response surface method on laccase production using Marasmius sp and rice straw. The optimized conditions were pH, temperature and yeast extract concentration of 4.9, 31ºC and 0.36 g/L respectively. The fermentation of Marasmius sp. in SSF on agricultural waste shows a great potential for the production of laccase.

  9. Control of postharvest Botrytis fruit rot of strawberry by volatile organic compounds of Candida intermedia.

    Science.gov (United States)

    Huang, R; Li, G Q; Zhang, J; Yang, L; Che, H J; Jiang, D H; Huang, H C

    2011-07-01

    A study was conducted to identify volatile organic compounds or volatiles produced by Candida intermedia strain C410 using gas chromatography-mass spectrometry, and to determine efficacy of the volatiles of C. intermedia in suppression of conidial germination and mycelial growth of Botrytis cinerea and control of Botrytis fruit rot of strawberry. Results showed that, among 49 volatiles (esters, alcohols, alkenes, alkanes, alkynes, organic acids, ketones, and aldehydes) identified from C. intermedia cultures on yeast extract peptone dextrose agar, two compounds, 1,3,5,7-cyclooctatetraene and 3-methyl-1-butanol, were the most abundant. Synthetic chemicals of 1,3,5,7-cyclooctatetraene; 3-methyl-1-butanol; 2-nonanone; pentanoic acid, 4-methyl-, ethyl ester; 3-methyl-1-butanol, acetate; acetic acid, pentyl ester; and hexanoic acid, ethyl ester were highly inhibitory to conidial germination and mycelial growth of B. cinerea. Inhibition of conidial germination and mycelial growth of B. cinerea by volatiles of C. intermedia was also observed. Meanwhile, results showed that incidence and severity of Botrytis fruit rot of strawberry was significantly (P intermedia cultures or C. intermedia-infested strawberry fruit. These results suggest that the volatiles of C. intermedia C410 are promising biofumigants for control of Botrytis fruit rot of strawberry.

  10. Fourier Transform Infrared Radiation Spectroscopy Applied for Wood Rot Decay and Mould Fungi Growth Detection

    Directory of Open Access Journals (Sweden)

    Bjørn Petter Jelle

    2012-01-01

    Full Text Available Material characterization may be carried out by the attenuated total reflectance (ATR Fourier transform infrared (FTIR radiation spectroscopical technique, which represents a powerful experimental tool. The ATR technique may be applied on both solid state materials, liquids, and gases with none or only minor sample preparations, also including materials which are nontransparent to IR radiation. This facilitation is made possible by pressing the sample directly onto various crystals, for example, diamond, with high refractive indices, in a special reflectance setup. Thus ATR saves time and enables the study of materials in a pristine condition, that is, the comprehensive sample preparation by pressing thin KBr pellets in traditional FTIR transmittance spectroscopy is hence avoided. Materials and their ageing processes, both ageing by natural and accelerated climate exposure, decomposition and formation of chemical bonds and products, may be studied in an ATR-FTIR analysis. In this work, the ATR-FTIR technique is utilized to detect wood rot decay and mould fungi growth on various building material substrates. An experimental challenge and aim is to be able to detect the wood rot decay and mould fungi growth at early stages when it is barely visible to the naked eye. Another goal is to be able to distinguish between various species of fungi and wood rot.

  11. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    Energy Technology Data Exchange (ETDEWEB)

    Shirakashi, Ryo, E-mail: aa21150@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); Mischke, Miriam [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fischer, Peter [Physiologische Chemie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Memmel, Simon [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Krohne, Georg [Abteilung fuer Elektronenmikroskopie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fuhr, Guenter R. [Lehrstuhl fuer Biotechnologie und Medizintechnik, Universitaet des Saarlandes, Saarbruecken (Germany); Zimmermann, Heiko [Lehrstuhl fuer Molekulare und Zellulaere Biotechnologie, Universitaet des Saarlandes, Saarbruecken (Germany); Sukhorukov, Vladimir L., E-mail: sukhorukov@biozentrum.uni-wuerzburg.de [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.

  12. Mutant lines of currant tomato, valuable germplasm with multiple disease resistance

    International Nuclear Information System (INIS)

    Govorova, G.F.; Khrustaleva, V.V.; Shcherbakov, V.K.

    1987-01-01

    Studies were carried out for two years on eight mutant lines of currant tomato at the Krymsk Experimental Breeding Station of the N.I. Vavilov All-Union Scientific Research Institute of Plant-Growing (VIR). The station is situated in an area of commercial field tomato growing (Krasnodar region). The mutant lines of currant tomato (VIR specimen No. k-4053) were obtained through chronic gamma-irradiation. A disease resistance evaluation of the mutants was carried out for Verticillium wilt (Verticillium albo-atrum Rein. and Berth.), for black bacterial spotting (Xanthomonas vesicatoria Dows.), for tobacco mosaic virus Nicotiana 1 Smith), for streak virus (Nicotiana 1), for the combination TMV with X and Y potato viruses, for cucumber virus (Cucumis 1), and also for top rot. Fifty plants of each mutant line were evaluated and checks were made three times in each season. A comparison of the currant tomato mutants with the standard tomato varieties demonstrates the better resistance shown by the mutant germplasm to the main pathogens. The degree to which some currant tomato mutants were affected by Verticillium was lower than that of the most VerticiIlium-resistant samples of tomato evaluated between 1975 and 1981. The mutants of currant tomato should therefore be of interest as germplasm in breeding tomatoes for improved multiple disease resistance

  13. Caracterização de isolados de Xanthomonas campestris pv campestris de sistemas de produção orgânico e reação de brássicas à podridão-negra Characterization of strains of Xanthomonas campestris pv campestris from organic farming systems and reaction of brassicas to black rot

    Directory of Open Access Journals (Sweden)

    Liliana Andréa dos Santos

    2008-12-01

    .3%, resistance to amoxicilin (70%, gentamicin (40.0% and norfloxacin (45.5% and medium sensitivity (44.4% or resistance (44.4% to neomycin. Fifty-five strains of Xcc were resistant to copper sulfate at 50 mg mL-1 and all of them to 200 mg mL-1; 92.22% of the strains showed esterase activity. Strains were grouped in seven similarity groups by the Euclidean analysis-single linkage. The reaction of 14 genotypes of brassicas to strain "B21" of Xcc was also studied. The genotypes significantly differed among them in relation to incubation period, incidence and disease severity. The highest disease severity was recorded on broccoli "Ramoso", cauliflower "Bola de Neve" and "Piracicaba de Verão", and cabbage "Chato de Quintal", classified as highly susceptible to black rot. The Chinese cabbage hybrids "AF 70", "AF 72", "AF 69" and "AF 66" were highly resistant to black-rot, while broccolis "Ramoso" and "Piracicaba Precoce", cauliflower "Piracicaba de Verão" and "Híbrido Cindy" and cabbage "60 Dias" showed intermediate resistance.

  14. Fungal pathogen complexes associated with rambutan, longan and mango diseases in Puerto Rico

    Science.gov (United States)

    Different fungi have been associated with diseased inflorescences, leaves, and fruits of mango, rambutan and longan. During a fungal disease survey conducted between 2008 and 2013 at six orchards of rambutan and longan, and one orchard of mango in Puerto Rico, symptoms such as fruit rot, infloresc...

  15. Molecular identification and potential of an isolate of white rot fungi in bioremediation of petroleum contaminated soils

    Directory of Open Access Journals (Sweden)

    Maryam Mohammadi-sichani

    2017-06-01

    Full Text Available Introduction:Elimination or reduction of petroleum hydrocarbons from natural resources such as water and soil is a serious problem of countries, particularly oil-rich countries of the world. Using white rotting fungi compost for bioremediation of soils contaminated by petroleum hydrocarbons is effective. The aim of this study is molecular identification and potential of anisolate of white rot fungi in bioremediation of petroleum contaminated soils. Materials and methods: Spent compost of white rotting fungi was inoculated with petroleum contaminated soil into 3%, 5% and 10% (w/w. Treatments were incubated at 25-23 °C for 3 months. Reduction of petroleum hydrocarbons in treated soil was determined by gas chromatography. Ecotoxicity of soil was evaluated by seed germination test. Results: Based on the genome sequence of 18s rRNA, it is revealed that this isolate is Ganoderma lucidum and this isolate is deposited as accession KX525204 in the Gene Bank database. Reduction of petroleum hydrocarbons in soil treated with compost (3, 5 and 10% ranged from 42% to 71%. The germination index (% in ecotoxicity tests ranged from 20.8% to 70.8%. Gas chromatography results also showed a decrease in soil Hydrocarbons compounds. Discussion and conclusion: The compost of Ganoderma lucidum, a white rot fungus, has a potential ability to remove petroleum hydrocarbons in contaminated soil. Removal of hydrocarbons was increased with increase in compost mixed with contaminated soil. Petroleum contaminated soil amended with spent compost of G.lucidum 10% during three months is appropriate to remove this pollutant.

  16. Treatment of micropollutants in municipal wastewater using white-rot fungi

    OpenAIRE

    Margot, Jonas; Vargas, Micaela; Contijoch, Andreu; Barry, David Andrew; Holliger, Christof

    2014-01-01

    Treatment of micropollutants such as pharmaceuticals and pesticides in municipal wastewater is challenging due to their very low concentrations (ng/l to µg/l), their relatively low biodegradability, and their different physico-chemical characteristics. One potential way to improve micropollutant biodegradation in wastewater treatment plant (WWTP) effluent is by using microorganisms such as white-rot fungi that produce powerful unspecific oxidative exo-enzymes (laccase, peroxidase) that are ab...

  17. Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

    Directory of Open Access Journals (Sweden)

    Giovanna GILARDI

    2014-09-01

    Full Text Available Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al to control crown and root rot of tomato incited by Phytophthora nicotianae. The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma, B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

  18. Characterization of the causal organism of blackleg and soft rot of potato, and management of the disease with balanced fertilization

    International Nuclear Information System (INIS)

    Ali, H.F.; Bibi, A.; Ahmad, M.; Junaid, M.; Ali, A.; Alam, S.

    2014-01-01

    Based upon colony morphology, physio-biochemical tests and polymerase chain reaction (using species or subspecies-specific primers) studies, 20 isolates (out of a total of 42) were found to be Erwinia carotovora subspecies atroseptica (Eca), 19 were identified as Erwinia carotovora subspecies carotovora (Ecc), and 3 as Erwinia chrysanthemi (Ech). Results of the subspecies-differentiating biochemical tests indicated that majority of the candidate Ecc isolates did not produce acid from methyle glucoside (as expected) but their reaction to the production of reducing substances from sucrose was variable. Likewise, some of our Eca and Ecc strains (unexpectedly) were sensitive to erythromycin. Also, most of our Eca strains unexpectedly grew at 36 degree C. Our strains slightly deviate from the standard description in some of their minor characteristics but they still remain the valid members of the Eca, Ecc or Ech group as similar variations in minor characteristics have been found by other workers. The occurrence of intermediate forms of Eca and Ecc (sharing some of the characteristics of both the groups) indicates variability happening among these strains. This variability indicates the potential ability of the pathogen to break the resistance of the host. The results of the effect of balanced nutrition in controlling blackleg and soft rot of potatoes indicated that the fertilizer combination of N3P1K3 (262/252/262 kg.ha-1) which is slightly higher than the normally practiced dose (247/247/247 kg.ha-1) was the best in bringing the disease to a minimum and subsequently increasing the yield. (author)

  19. Pathogenicity of Nectriaceous Fungi on Avocado in Australia.

    Science.gov (United States)

    Parkinson, Louisamarie E; Shivas, Roger G; Dann, Elizabeth K

    2017-12-01

    Black root rot is a severe disease of young avocado trees in Australia causing black necrotic roots, tree stunting, and leaf drop prior to tree death. Nectriaceous fungi (Nectriaceae, Hypocreales), are commonly isolated from symptomatic roots. This research tested the pathogenicity of 19 isolates from Calonectria, Cylindrocladiella, Dactylonectria, Gliocladiopsis, and Ilyonectria, spp. collected from young avocado trees and other hosts. Glasshouse pathogenicity tests with 'Reed' avocado (Persea americana) seedlings confirmed that Calonectria ilicicola is a severe pathogen of avocado, causing stunting, wilting, and seedling death within 5 weeks of inoculation. Isolates of C. ilicicola from peanut, papaya, and custard apple were also shown to be aggressive pathogens of avocado, demonstrating a broad host range. An isolate of a Calonectria sp. from blueberry and avocado isolates of Dactylonectria macrodidyma, D. novozelandica, D. pauciseptata, and D. anthuriicola caused significant root rot but not stunting within 5 to 9 weeks of inoculation. An isolate of an Ilyonectria sp. from grapevine closely related to Ilyonectria liriodendri, and avocado isolates of Cylindrocladiella pseudoinfestans, Gliocladiopsis peggii, and an Ilyonectria sp. were not pathogenic to avocado.

  20. Black Teenage Pregnancy

    Directory of Open Access Journals (Sweden)

    Loretta I. Winters

    2012-01-01

    Full Text Available This article examines the relative importance of race and socioeconomic status (SES in determining whether Black and White teenagers report having ever been pregnant. Data gathered from 1999 to 2006 by the National Center for Health Statistics of the Center for Disease Control and Prevention included 1,580 Black and White females aged 15 to 19 years. Results supported the effects of race and SES, with SES having the stronger effect. However, the effects of race and SES differ when controlling for the state of the economy. No difference between Blacks and Whites was found during better economic times. During 2003-2004, the period of greatest economic stress, race was determined to be the only predictor of teenage pregnancy. In particular, during 2005-2006, the reduction in pregnancy rates for Black minors (15-17 fell below those for White minors within their respective SES categories. Policy implications are discussed in light of these findings.