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.).

Science.gov (United States)

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.

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...

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...

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...

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...

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

Science.gov (United States)

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.

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...

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

Science.gov (United States)

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

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

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

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.

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

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.

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

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)

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.

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

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.

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

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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.

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.

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.

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...

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.

New record of Phytophthora root and stem rot of Lavandula angustifolia

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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.

Resistance to Fusarium dry root rot disease in cassava accessions

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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.

Root rot diseases of sugar beet

Directory of Open Access Journals (Sweden)

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.

Comparing methods for inducing root rot of Rhododendron with Phytophthora cinnamomi and P. plurivora

Science.gov (United States)

Root rot, caused by Phytophthora cinnamomi and P. plurivora in containerized Rhododendron, can cause significant losses in the nursery industry. Studies commonly use a 48 h flooding event to stimulate root infection. While flooding rarely occurs in container nurseries, plants may sit in a shallow pu...

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 ...

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...

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 ...

[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.

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)

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.

Trichoderma spp. decrease Fusarium root rot in common bean

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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.

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.

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

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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...

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...

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

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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

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

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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.

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)

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...

Plectosphaerella species associated with root and collar rots of horticultural crops in southern Italy

NARCIS (Netherlands)

Carlucci, A.; Raimondo, M.L.; Santos, J.; Phillips, A.J.L.

2012-01-01

Plectosphaerella cucumerina, most frequently encountered in its Plectosporium state, is well known as a pathogen of several plant species causing fruit, root and collar rot, and collapse. It is considered to pose a serious threat to melon (Cucumis melo) production in Italy. In the present study, an

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...

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)

Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

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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

Relative Efficacy of On-Farm Weeds as Soil-Amendement for Managing Dry Root Rot of Clusterbean in an Arid Environment

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R. Mawar

2006-12-01

Full Text Available The effectiveness of certain on-farm weeds as soil amendments was ascertained against Macrophomina phaseolina, a soil-borne pathogen causing dry root rot of crops grown under rainfed conditions in arid regions. Population changes in M. phaseolina were determined in soils amended separately with residues (1%, w:w of Aerva persica, Celosia argentea, Corchorus depressus, Euphorbia hirta, Heliotropium subulatum and Polycarpaea corymbosa, for a period of 90 days. Significant reductions by 90.4–100% in the population of M. phaseolina were achieved with all the weed residues except P. corymbosa. Celosia and Euphorbia residues completely eradicated viable propagules of M. phaseolina. A strong increase (44–61% in the population of antagonistic actinomycetes was also found in soil amended with Corchorus and Euphorbia. In field tests, soil amended (50 g m2 with Euphorbia, Aerva and Celosia residues significantly reduced dry root rot incidence on clusterbean and also reduced M. phaseolina propagules in the soil. However, dry root rot incidence in Polycarpaea-amended soil (5.8–24.6% was not significantly different from that in non-amended soil (4.3–25.3% in both years of the experiment. P. corymbosa also increased the number of propagules of M. phaseolina in the soil. The results demonstrate that dry root rot of rainfed-cultivated annual crops in arid land can be managed with certain weeds as a soil amendment.

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.

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

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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.

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 ...

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 ...

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

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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

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...

Spatial Distribution of Root and Crown Rot Fungi Associated With Winter Wheat in the North China Plain and Its Relationship With Climate Variables

Science.gov (United States)

Xu, Fei; Yang, Gongqiang; Wang, Junmei; Song, Yuli; Liu, Lulu; Zhao, Kai; Li, Yahong; Han, Zihang

2018-01-01

The distribution frequency of pathogenic fungi associated with root and crown rot of winter wheat (Triticum aestivum) from 104 fields in the North China Plain was determined during the period from 2013 to 2016. The four most important species identified were Bipolaris sorokiniana (24.0% from roots; 33.7% from stems), Fusarium pseudograminearum (14.9% from roots; 27.8% from stems), Rhizoctonia cerealis (1.7% from roots; 4.4% from stems), and Gaeumannomyces graminis var. tritici (9.8% from roots; 4.4% from stems). We observed that the recovered species varied with the agronomic zone. Fusarium pseudograminearum was predominant in regions 1 and 3, whereas F. graminearum, F. acuminatum, and R. cerealis were predominant in regions 2 and 4. The incidence of F. pseudograminearum and R. cerealis was significantly different between regions 1 and 4, while no significant association was found in the distribution of the other species and the agronomic zones. A negative correlation between the frequency of occurrence of F. pseudograminearum and mean annual precipitation during 2013–2016 (r = −0.71; P wheat, two or more root and crown rot species were isolated. The coexistence of Fusarium spp. and B. sorokiniana in one field (65.4%) or in individual plants (11.6%) was more common than for the other species combinations. Moreover, this is the first report on the association between F. sinensis and root and crown rot of wheat. Our results would be useful in the framing guidelines for the management of root and crown rot fungi in wheat in different agronomic zones of the North China Plain. PMID:29887840

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...

Occurrence of the root-rot pathogen, Fusarium commune, in midwestern and western United States

Science.gov (United States)

J. E. Stewart; R. K. Dumroese; N. B. Klopfenstein; M. -S. Kim

2012-01-01

Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries. The pathogen is only reported in Oregon, Idaho, and Washington within United States. Fusarium isolates were collected from midwestern and western United States to determine occurrence of this pathogen. DNA sequences of mitochondrial small subunit gene were used to identify F....

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

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.

Use of homeopathic drugs in combination with fertilizers for the control of root rot fungi

International Nuclear Information System (INIS)

Hanif, A.; Dawar, S.

2015-01-01

This study was conducted to evaluate the fungicidal effectiveness of homeopathic drugs in combination with fertilizers on the growth production and controlling of root rot fungi. Seeds treated with homeopathic drugs in addition of phosphorous and nitrogen fertilizers as soil amendment showed significant inhibitory effect on fungal growth as well as improved the plant growth. Remarkable control of root infecting fungi was shown by the seeds treated with Thuja occidentalis and Arnica montana at rate of 75 percentage v/v concentration and soil amended with urea at rate of 0.1 percentage w/w but greater increased in plant growth was observed by urea at rate of 0.01 percentage in the tested plants viz. mung bean, mash bean, sunflower and okra. Whereas, when A. montana and T. occidentalis at rate of 75 percentage v/v concentration along with the addition of DAP at rate of 0.01 and 0.1 percentage w/w respectively showed maximum suppression of Fusarium spp, R. solani and M. phaseolina and enhanced the plant height and weight followed by A. montana and T. occidentalis at rate of 50 percentage v/v concentration respectively showed a maximum control of root rot fungi and also strengthened the crop plant for better growth. (author)

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

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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.

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...

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...

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...

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

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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.

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...

Spatial Distribution of Root and Crown Rot Fungi Associated With Winter Wheat in the North China Plain and Its Relationship With Climate Variables

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Fei Xu

2018-05-01

Full Text Available The distribution frequency of pathogenic fungi associated with root and crown rot of winter wheat (Triticum aestivum from 104 fields in the North China Plain was determined during the period from 2013 to 2016. The four most important species identified were Bipolaris sorokiniana (24.0% from roots; 33.7% from stems, Fusarium pseudograminearum (14.9% from roots; 27.8% from stems, Rhizoctonia cerealis (1.7% from roots; 4.4% from stems, and Gaeumannomyces graminis var. tritici (9.8% from roots; 4.4% from stems. We observed that the recovered species varied with the agronomic zone. Fusarium pseudograminearum was predominant in regions 1 and 3, whereas F. graminearum, F. acuminatum, and R. cerealis were predominant in regions 2 and 4. The incidence of F. pseudograminearum and R. cerealis was significantly different between regions 1 and 4, while no significant association was found in the distribution of the other species and the agronomic zones. A negative correlation between the frequency of occurrence of F. pseudograminearum and mean annual precipitation during 2013–2016 (r = −0.71; P < 0.01 in the North China Plain and a positive correlation between the mean annual precipitation during 2013–2016 and the frequency of occurrence of F. asiaticum (r = 0.74; P < 0.01 were observed. Several Fusarium species were also found with low frequencies of ~2.1%−3.4 % (F. graminearum, F. acuminatum, and F. sinensis and ~0.1%−1.3% (F. equiseti, F. oxysporum, F. proliferatum, F. culmorum, F. avenaceum, and F. asiaticum. In more than 93% of the fields, from the root and crown tissues of wheat, two or more root and crown rot species were isolated. The coexistence of Fusarium spp. and B. sorokiniana in one field (65.4% or in individual plants (11.6% was more common than for the other species combinations. Moreover, this is the first report on the association between F. sinensis and root and crown rot of wheat. Our results would be useful in the framing

Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L. and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress

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Dilfuza Egamberdieva

2017-09-01

Full Text Available Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non–rhizobial endophytic bacteria from the root nodules of chickpea (Cicer arietinum L., and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1, Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H2O2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani. This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress.

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

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.

Abscisic Acid as a Dominant Signal in Tomato During Salt Stress Predisposition to Phytophthora Root and Crown Rot

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Matthew F. Pye

2018-04-01

Full Text Available Salt stress predisposes plants to Phytophthora root and crown rot in an abscisic acid (ABA-dependent manner. We used the tomato–Phytophthora capsici interaction to examine zoospore chemoattraction and assessed expression of pathogenesis-related (PR genes regulated by salicylic acid (SA and jasmonic acid (JA following a salt-stress episode. Although salt treatment enhances chemoattraction of tomato roots to zoospores, exudates from salt-stressed roots of ABA-deficient mutants, which do not display the predisposition phenotype, have a similar chemoattraction as exudates from salt-stressed, wild-type roots. This suggests that ABA action during predisposing stress enhances disease through effects on plant responses occurring after initial contact and during ingress by the pathogen. The expression of NCED1 (ABA synthesis and TAS14 (ABA response in roots generally corresponded to previously reported changes in root ABA levels during salt stress onset and recovery in a pattern that was not altered by infection by P. capsici. The PR genes, P4 and PI-2, hallmarks in tomato for SA and JA action, respectively, were induced in non-stressed roots during infection and strongly suppressed in infected roots exposed to salt-stress prior to inoculation. However, there was a similar proportional increase in pathogen colonization observed in salt-stressed plants relative to non-stressed plants in both wild-type and a SA-deficient nahG line. Unlike the other tomato cultivars used in this study that showed a strong predisposition phenotype, the processing tomato cv. ‘Castlemart’ and its JA mutants were not predisposed by salt. Salt stress predisposition to crown and root rot caused by P. capsici appears to be strongly conditioned by ABA-driven mechanisms in tomato, with the stress compromising SA-and JA-mediated defense-related gene expression during P. capsici infection.

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)

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

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...

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...

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.

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

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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.

Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

DEFF Research Database (Denmark)

Larsen, John; Graham, James H.; Cubero, Jaime

2012-01-01

Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reduci...

Concentration- and Time-Dependent Effects of Isothiocyanates Produced from Brassicaceae Shoot Tissues on the Pea Root Rot Pathogen Aphanomyces euteiches

NARCIS (Netherlands)

Hossain, S.; Bergkvist, G.; Berglund, K.; Glinwood, R.; Kabouw, P.; Martensson, A.; Persson, P.

2014-01-01

Isothiocyanates (ITCs) hydrolyzed from glucosinolates (GSLs) in Brassicaceae tissue are toxic to soil organisms. In this study, the effect of aliphatic and aromatic ITCs from hydrated dry Brassicaceae shoot tissues on the mycelium and oospores of the pea root rot pathogen Aphanomyces euteiches was

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.

Occurrence of the root-rot pathogen, Fusarium commune, in forest nurseries of the midwestern and western United States

Science.gov (United States)

Mee-Sook Kim; Jane E. Stewart; R. Kasten Dumroese; Ned B. Klopfenstein

2012-01-01

Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries, and this pathogen has been previously reported from Oregon, Idaho, and Washington, USA. We collected Fusarium isolates from additional nurseries in the midwestern and western USA to more fully determine occurrence of this pathogen. We used DNA sequences of the mitochondrial...

Impact of "Roots": Evidence from the National Survey of Black Americans.

Science.gov (United States)

Fairchild, Halford H.; And Others

1986-01-01

Reports on the perceptions of "Roots" among a nationally representative sample of black Americans. Examines viewing patterns and reactions to "Roots" in relation to seven variables: urbanicity, region, gender, age, education, and income. Suggests that, for Blacks, "Roots" was more than entertainment, and that heaviest…

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

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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.

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...

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

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

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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.

Seed priming with extracts of Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L.) plant parts in the control of root rot fungi and growth of plants

International Nuclear Information System (INIS)

Rafi, H.; Dawar, S.; Zaki, M.J.

2015-01-01

Seed priming with plant extracts and chemicals has been used as an important growth enhancement tool in crop plants. In this research, an attempt was made to understand the mechanism of various seed priming treatments on greenhouse-grown okra (Abelmoschus esculentus (L.) Moench.), sunflower (Helianthus annuus L.), peanut (Arachis hypogaea L.) and chickpea (Cicer arietinum L.) for the control of root infecting fungi like Rhizoctonia solani (Kn), Fusarium spp. and Macrophomina phaseolina (Tassi) Goid by plant parts extracts (stem, leaves and seeds) of Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L) at different time intervals (5, 10, 20, 40 minutes). Results showed significant suppression of root rot fungi and significantly enhanced the growth parameters like shoot length, root length, shoot weight and root weight. Seed-priming with A. nilotica and S. mukorossi leaves extract for 10 minutes time interval was found to be effective for the control of root rot fungi and growth of all tested leguminous and non-leguminous plants. (author)

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 ...

A combination of biocontrol agents improves the management of dry root rot (Macrophomina phaseolina in greengram

Directory of Open Access Journals (Sweden)

R. Thilagavathi

2007-08-01

Full Text Available The biocontrol agents Trichoderma viride (strains Tv1 and Tv13, Pseudomonas fluorescens (Pf1 and Py15 and Bacillus subtilis (Bs16 were tested individually and in combination for their effectiveness against root rot of greengram caused by Macrophomina phaseolina. As regards the compatibility of the biocontrol agents with each other, T. viride strains were not compatible with B. subtilis (Bs16, but P. fluorescens strains were compatible with B. subtilis and T. viride. Of the biocontrol agents tested in vitro against M. phaseolina, combinations of P. fluorescens+T. viride (Pf1+Tv1, Pf1+Tv13 and Py15+Tv1 inhibited mycelial growth of the pathogen and they also promoted the growth of the greengram seedlings. A combination of Pf1+Tv1 was most effective in reducing root rot incidence under glass-house and field conditions as compared with other single or combined treatments or the untreated control. The activity of the defense-related enzymes peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase was significantly greater in greengram plants treated with a talc based formulation containing Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1, than in plants receiving other treatments or the untreated control. Moreover, a combination of Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1 significantly increased yield under glass house and field conditions.

Conidioma production of the white root rot fungus [Rosellinia] in axenic culture under near-ultraviolet light radiation

International Nuclear Information System (INIS)

Nakamura, H.; Ikeda, K.; Arakawa, M.; Matsumoto, N.

2002-01-01

Conidiomata of the white root rot fungus were produced in axenic culture under near-ultraviolet light radiation. Pieces of sterilized Japanese pear twigs were placed on 7-day-old oatmeal agar culture in plates. The plates were further incubated for 5 days and then illuminated by near-ultraviolet light. Synnemata developed on the twigs within 5 weeks in 19 of 20 isolates tested, and conidia were observed in 12 of the 19 isolates. The synnemata and conidia produced were morphologically identical to those of Dematophora necatrix

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 ...

Modeling Lolium perenne L. roots in the presence of empirical black holes

Science.gov (United States)

Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this re...

A DNA based method to detect the grapevine root-rotting fungus Roesleria subterranea in soil and root samples

Directory of Open Access Journals (Sweden)

S. Neuhauser

2009-05-01

Full Text Available Roesleria subterranea causes root rot in grapevine and fruit trees. The fungus has long been underestimated as a weak parasite, but during the last years it has been reported to cause severe damages in German vineyards. Direct, observation-based detection of the parasite is time consuming and destructive, as large parts of the rootstocks have to be uprooted and screened for the tiny, stipitate, hypogeous ascomata of R. subterranea. To facilitate rapid detection in vineyards, protocols to extract DNA from soil samples and grapevine roots, and R.-subterranea-specific PCR primers were designed. Twelve DNA-extraction protocols for soil samples were tested in small-scale experiments, and selected parameters were optimised. A protocol based on ball-mill homogenization, DNA extraction with SDS, skim milk, chloroform, and isopropanol, and subsequent purifi cation of the raw extracts with PVPP-spin-columns was most effective. This DNA extraction protocol was found to be suitable for a wide range of soil-types including clay, loam and humic-rich soils. For DNA extraction from grapevine roots a CTAB-based protocol was more reliable for various grapevine rootstock varieties. Roesleria-subterranea-specific primers for the ITS1-5.8S-ITS2 rDNA region were developed and tested for their specifi city to DNA extracts from eleven R. subterranea strains isolated from grapevine and fruit trees. No cross reactions were detected with DNA extracts from 44 different species of fungi isolated from vineyard soils. The sensitivity of the species-specifi c primers in combination with the DNA extraction method for soil was high: as little as 100 fg μl-1 R.-subterranea-DNA was suffi cient for a detection in soil samples and plant material. Given that specifi c primers are available, the presented method will also allow quick and large-scale testing for other root pathogens.

Improved horticultural practices against leaf wilting, root rot and nutrient uptake in mango (mangiferaindica l.)

International Nuclear Information System (INIS)

Nafees, M.; Ahmad, I.; Ahmad, S.; Anwar, R.; Maryyam, A.; Hussnain, R.R.

2013-01-01

Poor plant health condition due to various known biotic and abiotic stresses; becoming a disaster in each mango growing country of the world including Pakistan. On the basis of previous researches on the identification of pathogen and several abiotic factors; Soil drenching and foliar spray of various concentrations of Topsin M (TMIC), Aliette (ATP) and Ridomil Gold (ACE) in combination with CuSO/sub 4/(Copper sulphate) was done on mango plants of cv. S.B. (Samar Bahist) Chaunsa showing wilting of leaves and shoots. Foliar application of micro-nutrients (Fe, B and Zn) (Iron, Boron and Zinc) was also practiced to improve general health of experimental plants Month-wise emergence of flushes was significantly higher in all treated plants compared with control. Percentage of wilted leaves and root rot in plants, which received drenching and foliar treatments, was significantly reduced (50%) compared with untreated plants. Nitrogen, phosphorus and potassium (N, P and K) levels in leaves were significantly improved in treated plants compared with control. Sigmoid relatioship was observed between fungicides and copper sulphate concentrations and uptake of N, P and K in treated plants. Application of 250g ATP fungicide by foliar spray plus 125g by soil drench, each along with 50g CuSO/sub 4/proved to be the best against leaf wilting and it improved the N and P level in leaves. While, application of 250g TMIC by foliar spray and 125g by soil drench, each with 50g CuSO/sub 4/, was found to be the best to reduce the spread of root rot in experimental plants. Preliminary spray of TMIC along with Copper sulphate is effective to improve plant health of mango cv. S.B. Chounsa. (author)

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...

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

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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.

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...

Somaclonal variation of sugar beet resistant to pathogenic root rot Fusarium oxysporum var. orthoceras

Directory of Open Access Journals (Sweden)

Urazaliev Kairat

2013-01-01

Full Text Available Sugar beet (Beta vulgaris L. - one of the most important crop in the world. In Kazakhstan, it is a traditional and major source of domestic sugar. The industry of cultivation and production of sugar beet is one of the priority areas of agricultural development of the country. In this paper, we studied the regeneration ability of different genotypes of sugar beet explants on selective media with the culture filtrate of the pathogen fungus F. oxysporum var. orthoceras. From the roots and shoots of sugar beet the pathogen Fusarium root rot was isolated. Was obtained pure cultures of the isolated pathogen. As a result, of morphological and cultural descriptions, as well as microbiological analysis it was revealed that the isolated pathogen is Fusarium Oxysporum. The results showed the pathogenicity of the fungus. For regeneration in vitro of the sugar beet genotypes resistant to the pathogen the culture media was optimized to the culture filtrate of the fungus F. oxysporum var. orthoceras. The frequency of shoot regeneration, depending on the genotype, was 1,0-12,5 %. On these explants the multiple shoot formations were observed.

Impacts of previous crops on Fusarium foot and root rot, and on yields of durum wheat in North West Tunisia

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Samia CHEKALI

2016-07-01

Full Text Available The impacts of ten previous crop rotations (cereals, legumes and fallow on Fusarium foot and root rot of durum wheat were investigated for three cropping seasons in a trial established in 2004 in Northwest Tunisia. Fungi isolated from the roots and stem bases were identified using morphological and molecular methods, and were primarily Fusarium culmorum and F. pseudograminearum. Under low rainfall conditions, the previous crop affected F. pseudograminearum incidence on durum wheat roots but not F. culmorum. Compared to continuous cropping of durum wheat, barley as a previous crop increased disease incidence more than fivefold, while legumes and fallow tended to reduce incidence.  Barley as a previous crop increased wheat disease severity by 47%, compared to other rotations. Grain yield was negatively correlated with the incidence of F. culmorum infection, both in roots and stem bases, and fitted an exponential model (R2 = -0.61 for roots and -0.77 for stem bases, P<0.0001. Fusarium pseudograminearum was also negatively correlated with yield and fitted an exponential model (R2 = -0.53 on roots and -0.71 on stem bases, P < 0.0001 but was not correlated with severity.

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

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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...

The role of defoliation and root rot pathogen infection in driving the mode of drought-related physiological decline in Scots pine (Pinus sylvestris L.).

Science.gov (United States)

Aguadé, D; Poyatos, R; Gómez, M; Oliva, J; Martínez-Vilalta, J

2015-03-01

Drought-related tree die-off episodes have been observed in all vegetated continents. Despite much research effort, however, the multiple interactions between carbon starvation, hydraulic failure and biotic agents in driving tree mortality under field conditions are still not well understood. We analysed the seasonal variability of non-structural carbohydrates (NSCs) in four organs (leaves, branches, trunk and roots), the vulnerability to embolism in roots and branches, native embolism (percentage loss of hydraulic conductivity (PLC)) in branches and the presence of root rot pathogens in defoliated and non-defoliated individuals in a declining Scots pine (Pinus sylvestris L.) population in the NE Iberian Peninsula in 2012, which included a particularly dry and warm summer. No differences were observed between defoliated and non-defoliated pines in hydraulic parameters, except for a higher vulnerability to embolism at pressures below -2 MPa in roots of defoliated pines. No differences were found between defoliation classes in branch PLC. Total NSC (TNSC, soluble sugars plus starch) values decreased during drought, particularly in leaves. Defoliation reduced TNSC levels across tree organs, especially just before (June) and during (August) drought. Root rot infection by the fungal pathogen Onnia P. Karst spp. was detected but it did not appear to be associated to tree defoliation. However, Onnia infection was associated with reduced leaf-specific hydraulic conductivity and sapwood depth, and thus contributed to hydraulic impairment, especially in defoliated pines. Infection was also associated with virtually depleted root starch reserves during and after drought in defoliated pines. Moreover, defoliated and infected trees tended to show lower basal area increment. Overall, our results show the intertwined nature of physiological mechanisms leading to drought-induced mortality and the inherent difficulty of isolating their contribution under field conditions. © The

Impact of "Roots" on Black and White Teenagers

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Hur, K. Kyoon

1978-01-01

Racial attitudes, race, and other demographic factors differentiated viewers' perceptions and reactions to the "Roots" series. The effects on teenagers were apparent in the viewers' immediate perceptions of the series, entertainment and information values of the series, and realistic presentation of black history. (JEG)

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 ...

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.

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber.

Science.gov (United States)

Bradley, Geoffrey G; Punja, Zamir K

2010-11-01

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola, plus 2 biocontrol strains of Pseudomonas fluorescens, were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 10(6) ± 0.73 × 10(6) CFU·(g root tissue)-1 and survival was >107 CFU·(g compost)-1 after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

Phytophthora Root and Crown Rot on Apples in Bulgaria

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Mariana Nakova

2010-01-01

Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

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

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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

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

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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.

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

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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.

Short Rotations in Forest Plantations Accelerate Virulence Evolution in Root-Rot Pathogenic Fungi

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Jean-Paul Soularue

2017-06-01

Full Text Available As disease outbreaks in forest plantations are causing concern worldwide, a clear understanding of the influence of silvicultural practices on the development of epidemics is still lacking. Importantly, silvicultural practices are likely to simultaneously affect epidemiological and evolutionary dynamics of pathogen populations. We propose a genetically explicit and individual-based model of virulence evolution in a root-rot pathogenic fungus spreading across forest landscapes, taking the Armillaria ostoyae–Pinus pinaster pathosystem as reference. We used the model to study the effects of rotation length on the evolution of virulence and the propagation of the fungus within a forest landscape composed of even-aged stands regularly altered by clear-cutting and thinning operations. The life cycle of the fungus modeled combines asexual and sexual reproduction modes, and also includes parasitic and saprotrophic phases. Moreover, the tree susceptibility to the pathogen is primarily determined by the age of the stand. Our simulations indicated that the shortest rotation length accelerated both the evolution of virulence and the development of the epidemics, whatever the genetic variability in the initial fungal population and the asexuality rate of the fungal species

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

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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.

Control of root rot of chickpea caused by Sclerotium rolfsii by different agents and gamma radiation

International Nuclear Information System (INIS)

Rasha Mohammed Fathy El- Said, R.M.F.

2012-01-01

Sclerotium rolfsii causes root rot disease in several crops including chickpea that result in low yield. Artificial infection of chickpea seedlings by S. rolfsii in vitro demonstrated that different tissues of the plant completely disintegrated by fungal infection. In vitro and green house pot experiments demonstrated that inducers in combination with fungicides, oils and bio agents resulted in about 80 % suppression of root rot disease. Treatments have no phyto toxic effect on chickpea seedlings at low doses. Gliocladium virens and Gliocladium deliquescens were effective as biocontrol agents against Sclerotium rolfsii. The percent of survival plants, fresh weight, dry weight and plant height of chickpea plants increased with different treatments with inducers compared with the control. Chlorophyll a, b, and total chlorophyll amounts increased to the maximum values. The activity of two plant enzymes, peroxidase and polyphenol oxidase increased. In this study, gamma irradiation of chickpea seeds at doses 5, 10, 15, 20, 25 and 30 Gy have negative effect on survival, plant height, fresh weight and dry weight of chickpea. The effect of gamma irradiation at doses 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy on the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii were investigated. The results revealed that gamma irradiation increase the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii . Effect of gamma irradiation at doses of 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 5 kGy on the mycelial growth and pathogenicity of S. rolfsii were investigated. The results revealed that gamma irradiation at doses 0.25 up to 3.0 kGy increase the pathogenicity of S. rolfsii but gamma irradiation at dose 5.0 kGy completely inhibited the growth of S. rolfsii. Extracellular polygalacturonase was characterized and purified by precipitation with 70 % ammonium sulfate, dialysis and gel filtration through Sephadex 75

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

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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.

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.

Wheat protection from root rot caused by fusarium culmorum using silver nanoparticles

International Nuclear Information System (INIS)

Rashed, A.O.M.; Mohamed, A.A.R.; Abobakr, M.M.

2016-01-01

Nanomaterials have a positive impact on agriculture. Silver nanoparticles were used to enhance seed germination, plant growth, and as antimicrobial agents to control plant diseases. In the present study, the effectiveness of silver nanoparticles on seed germination of wheat, growth parameters, and control of root rot disease caused by Fusarium culmorum were examined. Three different concentrations (10, 20, and 40 mg/l) were used. Exposure to AgNPs had no significant effects on the seed germination at 10 mg/l and 20 mg/l while at 40 mg/l significant effects were observed compared to that in the control (untreated). Germination was highest (86 percent) after exposure to 20 mg/l of AgNPs. AgNPs, at all concentrations tested, had significant effects on the pre-emergence, post-emergence and survival as compared to the control (infected and untreated with AgNPs); the highest effects were observed after exposure to 40 mg/l of AgNPs (15, 10, and 75 percent respectively). Additionally, our results indicate that plant height, fresh weight, and dry weight were significantly increased at 10 mg/l (23.4 cm, 6 g, and 1.45 g), and 20 mg/l (27.3 cm, 7.5 g, and 1.98 g) respectively, compared with that of the control. However, higher concentration (40 mg/l) of AgNPs decreased the growth parameters. (author)

Localized gene expression changes during adventitious root formation in black walnut (Juglans nigra L.)

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Micah E Stevens; Keith E Woeste; Paula M Pijut

2018-01-01

Cutting propagation plays a large role in the forestry and horticulture industries where superior genotypes need to be clonally multiplied. Integral to this process is the ability of cuttings to form adventitious roots. Recalcitrance to adventitious root development is a serious hurdle for many woody plant propagation systems including black walnut (Juglans...

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.

Rhizopus Soft Rot on Lily Caused by Rhizopus oryzae in Korea

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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.

[Antagonism of Trichoderma spp. to fungi caused root rot of Sophora tonkinensis].

Science.gov (United States)

Qin, Liu-yan; Jiang, Ni; Tang, Mei-qiong; Miao, Jian-hua; Li, Lin-xuan

2011-04-01

To study the antagonism of Trichoderma spp. to fungi S9(Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Antagonism of H2 (Trichoderma harsianum), M6 (Trichoderma viride) and K1 (Trichoderma koningii) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43-2.72 times and 1.43-1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak; the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82.35% respectively, even cultivated S9 for three days in advance. And their inhibition indexes were both reached class I. The inhibition index and inhibition rate of K1 was respectively 46.36% and class IV. The Trichoderma spp. could cause S9 mycelium to appear some phenomenon just like fracture, constriction reduced, digestion, etc. which were observed under the microscope. Trichoderma harsianum and Trichoderma viride showed the further develop prospects in the fight against soil-borne disease on Chinese herbal medicines.

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.

Biological control of Fusarium solani f. sp. phaseoli the causal agent of root rot of bean using Bacillus subtilis CA32 and Trichoderma harzianum RU01

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Saman Abeysinghe

2007-09-01

Full Text Available Root rot, caused by Fusarium solani f. sp. phaseoli, is one of the main root diseases impacting production of common bean in Sri Lanka. Rhizobacteria were screened in dual Petri plate assays to select antagonistic strains against F. solani f. sp. phaseoli. B. subtilis CA32 effectively antagonized the pathogen. T. harzianum RU01 also showed the antagonistic activity. The efficacy of the B. subtilis CA32 and the T. harzianum RU01 were tested in greenhouse pot experiments against F. solani f. sp. phaseoli. Seed bacterization with B. subtilis CA32 and T. harzianum RU01 significantly protected bean seedlings from F. solani f. sp. phaseoli compared to the untreated control plants. Plant protection was more pronounced in T. harzianum RU01 treated plants than bacterized plants. Enhanced root growth was observed only T. harzianum RU01 treated plants, suggesting that the biotic modifications of the mycorrhizosphere as a result of colonization with T. harzianum RU01.

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

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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.

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

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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.

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...

Differential responses of vanilla accessions to root rot and colonization by Fusarium oxysporum f. sp. radicis-vanillae.

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Sayuj eKoyyappurath

2015-12-01

Full Text Available Root and stem rot (RSR disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv is the most damaging disease of vanilla (Vanilla planifolia and V. ×tahitensis, Orchidaceae. Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have i identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, ii thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and iii evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions.Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in-vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in-vitro assay.The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21

Biology, diagnosis and management of Heterobasidion Root Disease of southern pines

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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...

INFLUENCE OF NPK AND LIME APLICATION ON ERVA-MATE GROWTH, ROOT-ROT SEVERITY AND SOIL FUNGI POPULATION1

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Igor Poletto

2011-09-01

Full Text Available The present work evaluated the influence of the application of NPK and liming doses in the soil, on the growth of Erva-mate, the severity of rot-root and the fungi population of the soil. To do so, an experiment was installed at the green house, in the Forest Nursery of UFSM, using an experimental design completely randomized factorial 4x3x4 (Factor F: Fusarium spp. inoculation; Factor C: soil limestone; Factor A: NPK doses , totaling 48 treatments. The seedlings were cultivated in vases containing 2 kg of soil, classified as ‘Red-Yellow Argisoil’ (clay soil. At the end of the experiment was measured the stem diameter, height of the aerial part, leaves number, aerial dry biomass, root dry biomass and total dry biomass of the seedlings. Also, the soil was collected, from each treatment, for the chemical analysis and the counting of the fungi population. It was observed that the association among application of NPK and liming in the soil hampered the development of Erva-mate seedlings. The analysis of some variables suggests that the limestone absence provided greater resistance of seedlings to the attack of Fusarium spp. or the severity of Fusarium spp. was reduced in lower pH. The fungi population of the soil presented varied behavior depending on the applied treatments.

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

Full Text Available O objetivo deste trabalho foi avaliar a intensidade da alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e da podridão negra, causada por Xanthomonas campestris pv. campestris, em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos de várias espécies de brássicas. Foram registradas elevadas prevalências das doenças nos estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto, as médias de severidade de cada doença no conjunto das brássicas não foram diferentes entre os estados, embora as condições climáticas tenham sido nitidamente distintas. A severidade da alternariose variou entre as espécies de brássicas somente em Pernambuco, com a menor severidade registrada em couve-manteiga. Em relação à podridão negra, apenas em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos.The objective of this research was to evaluate the intensity of Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris in organic cultivation of brassicas in Pernambuco and Santa Catarina. The survey was carried aut from November 2001 to February 2002, in 103 fields under

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)

Biocontrol of Fusarium Crown and Root Rot and Promotion of Growth of Tomato by Paenibacillus Strains Isolated from Soil

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Xu, Sheng Jun

2014-01-01

In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant. PMID:25071385

Microbial antagonism as a potential solution for controlling selected root pathogens of crops

Science.gov (United States)

Cooper, Sarah; Agnew, Linda; Pereg, Lily

2016-04-01

Root pathogens of crops can cause large reduction in yield, however, there is a limited range of effective methods to control such pathogens. Soilborne pathogens that infect roots often need to survive in the rhizosphere, where there is high competition from other organisms. In such hot spots of microbial activity and growth, supported by root exudates, microbes have evolved antagonistic mechanisms that give them competitive advantages in winning the limited resources. Among these mechanisms is antibiosis, with production of some significant antifungal compounds including, antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Some of these mechanisms may suppress disease through controlling the growth of root pathogens. In this project we isolated various fungi and bacteria that suppress the growth of cotton pathogens in vitro. The pathogen-suppressive microbes were isolated from cotton production soils that are under different management strategies, with and without the use of organic amendments. The potential of pathogen-suppressing microbes for controlling the black root rot disease, caused by the soilborne pathogen Thielaviopsis basicola, was confirmed using soil assays. We identified isolates with potential use as inoculant for cotton production in Australia. Having isolated a diverse group of antagonistic microbes enhances the probability that some would survive well in the soil and provide an alternative approach to address the problem of root disease affecting agricultural crops.

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

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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

Fine and coarse root parameters from mature black spruce displaying genetic x soil moisture interaction in growth

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John E. Major; Kurt H. Johnsen; Debby C. Barsi; Moira Campbell

2012-01-01

Fine and coarse root biomass, C, and N mass parameters were assessed by root size and soil depths from soil cores in plots of 32-year-old black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) from four full-sib families studied previously for drought tolerance and differential productivity on a dry and wet...

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.

Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp

Energy Technology Data Exchange (ETDEWEB)

Borrego-Benjumea, A.I.; Melero-Vara, J.M.; Basallote-Ureba, M.J.

2015-07-01

Fusarium oxysporum (Fo), F. proliferatum (Fp) and F. solani (Fs) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5), after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubat. (Author)

Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

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Ana I. Borrego-Benjumea

2015-12-01

Full Text Available Fusarium oxysporum (Fo, F. proliferatum (Fp and F. solani (Fs are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM, its pellet (PPM, or olive residue compost (ORC and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days. However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5, after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation. Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubation period and temperature.

Transcriptome responses of an ungrafted Phytophthora root rot tolerant avocado (Persea americana) rootstock to flooding and Phytophthora cinnamomi.

Science.gov (United States)

Reeksting, B J; Olivier, N A; van den Berg, N

2016-09-22

Avocado (Persea americana Mill.) is a commercially important fruit crop worldwide. A major limitation to production is the oomycete Phytophthora cinnamomi, which causes root rot leading to branch-dieback and tree death. The decline of orchards infected with P. cinnamomi occurs much faster when exposed to flooding, even if flooding is only transient. Flooding is a multifactorial stress compromised of several individual stresses, making breeding and selection for tolerant varieties challenging. With more plantations occurring in marginal areas, with imperfect irrigation and drainage, understanding the response of avocado to these stresses will be important for the industry. Maintenance of energy production was found to be central in the response to flooding, as seen by up-regulation of transcripts related to glycolysis and induction of transcripts related to ethanolic fermentation. Energy-intensive processes were generally down-regulated, as evidenced by repression of transcripts related to processes such as secondary cell-wall biosynthesis as well as defence-related transcripts. Aquaporins were found to be down-regulated in avocado roots exposed to flooding, indicating reduced water-uptake under these conditions. The transcriptomic response of avocado to flooding and P. cinnamomi was investigated utilizing microarray analysis. Differences in the transcriptome caused by the presence of the pathogen were minor compared to transcriptomic perturbations caused by flooding. The transcriptomic response of avocado to flooding reveals a response to flooding that is conserved in several species. This data could provide key information that could be used to improve selection of stress tolerant rootstocks in the avocado industry.

Evaluation of Trichoderma Isolates for Biological Control of Rhizoctonia Root Rot of Bean in Zanjan

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M. Khodae

2016-03-01

Full Text Available Introduction: Rhizoctonia solani is one of the major pathogens causing root rot in the main bean-growing regions in Zanjan province. Under favorable conditions, yield losses in commercial bean fields due to Rhizoctonia root rot have exceeded 50 percent reduction in pod and seed numbers per plants. In 2012 most isolates of the pathogen from severely infected bean fields in Zanjan were assessed to AG-4. R. solani AG-4 can attack other commercial crops such as potato, alfalfa, barley, tomato, cabbage, etc. which are grown in rotation with bean in the area. Thus, the disease is unlikely to be controlled by crop rotation. Moreover, there is no registered resistant bean cultivar against the disease in Iran. Although soil treatment with fungicides is the only effective control method in the region, according to environmental and side effects of fungicides, alternative approaches such as biocontrol method using Trichoderma species is considered. Materials and Methods: The study was conducted using five isolates of Trichoderma (T12-0, T12-N, T19, T6, T95 received from the Department of Plant Pathology, Ferdowsi University of Mashhad (Dr. H. Rouhani and six isolates of Trichoderma (T36,T125, T131, T93, T89, T25 collected in 2011 from rhizosphere of bean plants in the commercial bean fields of Zanjan province (Table 1. Trichoderma isolates were evaluated for their potential to antagonize in vitro the plant pathogenic fungus R. solani using three different tests. In the first test, each isolate of Trichoderma was grown in a dual culture with R. solani AG-4 strain Rh7 on PDA and incubated at 25˚C. Radii of colony of R. solani were measured after 72 h. In the second test the ability of Trichoderma isolates to produce volatile inhibitors was measured. This experiment was conducted in two conditions involving the same time culturing of Trichoderma and Rhizoctonia and isolating 72 h early growing Trichoderma. For both tests the percentage of inhibition was

Reaction of arracacha genotypes to the root soft rot caused by Pectobacterium chrysanthemi Reação de genótipos de mandioquinha-salsa à podridão-mole das raízes causada por Pectobacterium chrysanthemi

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Gilmar Paulo Henz

2005-01-01

Full Text Available The purpose of this paper was to screen thirty-two arracacha genotypes for their reaction to root soft rot. Twenty roots of each genotype were inoculated with two Pectobacterium chrysanthemi isolates in a randomized experiment (10 roots/isolate. After inoculation, roots were individually wrapped with PVC film and kept at 26ºC in closed plastic bags. Soft rot lesions were recorded after 36 hours and genotypes were grouped in four classes of susceptibility by cluster analysis: 10 were less susceptible, 16 intermediate, 3 susceptible and 3 very susceptible. All the tested arracacha genotypes showed only variation in the degree of susceptibility.O objetivo deste trabalho foi avaliar a reação de 32 genótipos de mandioquinha-salsa à podridão-mole das raízes. Vinte raízes de cada genótipo foram inoculadas com dois isolados de Pectobacterium chrysanthemi em um experimento casualizado (10 raízes/isolado. Após a inoculação, as raízes foram embaladas com filmes de PVC e mantidas a 26ºC em sacos de plástico. As lesões de podridão-mole foram avaliadas após 36 horas e os genótipos agrupados em quatro classes de suscetibilidade por análise de agrupamento: 10 foram menos suscetíveis, 16 intermediários, 3 suscetíveis e 3 muito suscetíveis. Todos os genótipos avaliados demonstraram apenas variação no grau de suscetibilidade.

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.

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

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

Science.gov (United States)

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-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

Controlling the root and stem rot of cucumber, caused by Pythium aphanidermatum, using resistance cultivars and grafting onto the cucurbit rootstocks

Directory of Open Access Journals (Sweden)

Fatemeh Rostami

2015-02-01

Full Text Available Cucumber damping off caused by Pythium aphanidermatum is the most important root and stem rot that limits greenhouse cultivations. In this study, relative susceptibility of grafting commercial cucumber cultivars including Alpha, Caspian 340, Storm 5910, Shalim 616, Delta scar, Janette 810, Festibal C5, Royal, Negyn, Soltan and Fadia on two Cucurbita rootstocks were evaluated against P. aphanidermatum . Disease severity, survival and seedling growth were used for the evaluation. The results showed significant differences between the studied cultivars (p≤0.01. Caspian 340 and Alpha with 15.7% and 100% disease severity had more and less tolerant to P. aphanidermatum, respectively. Cucurbita maxima rootstock was more resistant than Cucurbita pepo to P. aphanidermatum. C. pepo had less compatibility with the cucumber and showed little resistance to the pathogen. The study revealed that grafting Caspian340 on the resistant cucurbit rootstock i.e. Cucurbita maxima could be used as disease control strategies in greenhouses.

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.

Combined effect of soil amendment with oil cakes and seed priming in the control of root rot fungi of leguminous and non-leguminous crops

International Nuclear Information System (INIS)

Rafi, H.; Dawar, S.; Tariq, M.

2016-01-01

Organic amendments of soil help in proper aeration, rising of temperature and water holding capacity which results in better uptake of nutrients with root system gets extensive establishment. In this study, effects of soil amendment with oil seed cakes including mustard (Brassica campestris L.), cotton (Gossypium hirsutum L.), almond (Prunus amygdalus L.) and black seed (Nigella sativa L.) cakes at the rate of 0.1 and 1% w/w and priming of seeds with Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L.) leaves extracts and microbial antagonists (Trichoderma harzianum and Rhizobium melilotii) was observed on the growth of plants and in the suppression of root infecting fungi. The results obtained showed that combined effect of bio-priming of seeds with T. harzianum spore suspension and amendment of soil with mustard cake at the rate of 1% was found to be most effective for the growth of leguminous and non-leguminous crop plants (peanut, chickpea, okra and sunflower) and for the reduction of root infecting fungi like Macrophomina phaseolina, Fusarium spp followed by R. meliloti primed seeds in combination with cotton, almond and black seed cakes amendment respectively as compared to control (non treated seeds and soil). (author)

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.

Heterobasidion annosum root rot in Picea abies: Variability in aggressiveness and resistance

Energy Technology Data Exchange (ETDEWEB)

Swedjemark, G.

1995-12-31

In greenhouse experiments 3-4 year-old plants of Picea abies and Pinus sylvestris were inoculated with the root rot fungus Heterobasidion annosum. The growth rates of 25 S and 14 P isolates of the fungus were measured in the sapwood of about 25 rametes each of 98 Norway spruce clones and in 150 seedlings each of Norway spruce and Scots pine. Correlations were determined between fungal sapwood growth and a variety of variables, i.e. the physical stage, growth rhythm, size and condition of the cuttings, provenance and the growth capacity of the clones estimated in field tests. Genetic parameters such as phenotypic and genotypic variance, genotypic coefficient of variance and broad sense heritability were calculated. H. annosum infection incidence was close to 100 % for inoculated Norway spruce clones, and the mortality rate was about 1 %. Fungal growth in sapwood differed significantly among clones and among fungal isolates. The genotypic correlation coefficient was large (30 %) and broad sense heritability was 0.35. This suggests that good selection progress can be achieved in breeding programs. The physical stage (bud-flush, vegetative and post bud-set stage) of the clones contributed significantly to the total variation in fungal growth. The population structure of H. annosum was studied in two 25-year-old, first generation stands of Norway spruce. The stands had been thinned one and seven years earlier, respectively. All stumps and remaining trees were sampled for H. annosum isolates. The isolates were tested with somatic incompatibility to detect single genets and the distribution of genets in the stand was determined. About 70 % of the 7-year-old thinning stumps were colonized by H, annosum, and 50 % of these stumps were colonized by more than one fungal genet. Sixty-three percent of the remaining trees were infected with H. annosum but among them there was only one genet per tree. 104 refs, 12 figs

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.

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 ...

Determination of the Effects of Nutrient sources on Enhancement of Crop Tolerance to Bean Root Rot and Bean Stem Maggot in Western Kenya

International Nuclear Information System (INIS)

Otsyula, R.M.; Nderitu, J.H.

1999-01-01

Field bean phaseolus vulgaris tolerance to root rot (BRR) and bean stem maggot (BSM) is enhanced by improvement of soil nutrients. Organic and inorganic sources of soil nutrients were evaluated in this study to determine their effects on crop tolerance to BRR and BSM. Three variety of GLP 585 susceptible to BRR and BSM; GLP X92 tolerant to BRR and BSM; and KK-8 resistant to BRR and BSM were used. The study was conducted in farmer's field with high level of BRR and BSM over three seasons in a split plot design. Nutrient sources were laid down in main plots while varieties were in subplots. KK-8 gave the highest plant survival and yield over the seasons. GLP 585 had the lowest mean yield and plant survival. Crop tolerance was greatly improved by application of DAP as applied as nutrient sources and varieties for crop tolerance were identified

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

Directory of Open Access Journals (Sweden)

Josefa Blaya

Full Text Available 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-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75% of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

Monitoring cotton root rot by synthetic Sentinel-2 NDVI time series using improved spatial and temporal data fusion.

Science.gov (United States)

Wu, Mingquan; Yang, Chenghai; Song, Xiaoyu; Hoffmann, Wesley Clint; Huang, Wenjiang; Niu, Zheng; Wang, Changyao; Li, Wang; Yu, Bo

2018-01-31

To better understand the progression of cotton root rot within the season, time series monitoring is required. In this study, an improved spatial and temporal data fusion approach (ISTDFA) was employed to combine 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Different Vegetation Index (NDVI) and 10-m Sentinetl-2 NDVI data to generate a synthetic Sentinel-2 NDVI time series for monitoring this disease. Then, the phenology of healthy cotton and infected cotton was modeled using a logistic model. Finally, several phenology parameters, including the onset day of greenness minimum (OGM), growing season length (GLS), onset of greenness increase (OGI), max NDVI value, and integral area of the phenology curve, were calculated. The results showed that ISTDFA could be used to combine time series MODIS and Sentinel-2 NDVI data with a correlation coefficient of 0.893. The logistic model could describe the phenology curves with R-squared values from 0.791 to 0.969. Moreover, the phenology curve of infected cotton showed a significant difference from that of healthy cotton. The max NDVI value, OGM, GSL and the integral area of the phenology curve for infected cotton were reduced by 0.045, 30 days, 22 days, and 18.54%, respectively, compared with those for healthy cotton.

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...

Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

DEFF Research Database (Denmark)

Xu, Lihui; Ravnskov, Sabine; Larsen, John

2012-01-01

the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities...

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.

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.

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...

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.

The bean rhizosphere Pseudomonas aeruginosa strain RZ9 strongly reduces Fusarium culmorum growth and infectiveness of plant roots

Energy Technology Data Exchange (ETDEWEB)

Haddoudi, I.; Sendi, Y.; Batnini, M.; Romdhane, S.B.; Mhadhbi, H.; Mrabet, M.

2017-07-01

A faba bean rhizospheric Pseudomonas aeruginosa isolate RZ9 was used for studying its antifungal activity and protecting effects of faba bean and common bean against the root pathogen Fusarium culmorum strain MZB47. The dual culture tests showed that RZ9 inhibits MZB47 in vitro growth by 56%. When mixing RZ9 cell suspension with MZB47 macroconidia at equal proportion, the macroconidia viability was reduced with 70%. Pathogenicity tests conducted in sterile conditions showed that MZB47 caused an intense root rotting in faba bean ‘Aquadulce’ plantlets and a slight level in common bean ‘Coco blanc’. This was associated to significant decreases in plant growth only in ‘Aquadulce’, reducing shoot dry weight (DW) by 82% and root DW by 70%. In soil samples, MZB47 caused severe root rotting and induced significant decreases in shoot DW (up to 51%) and root DW (up to 60%) for both beans. It was associated to a decrease in nodule number by 73% and 52% for faba bean and common bean, respectively. Biocontrol assays revealed that the inoculation of RZ9 to MZB47-treated plantlets enhanced shoot DWs (25% and 110%) and root DWs (29% and 67%), in faba bean and common bean, respectively. Moreover, root rotting levels decreased and nodule number increased in treated compared to untreated plantlets. Collected data highlighted the disease severity of F. culmorum and demonstrated the potential of using RZ9 in controlling Fusaria root diseases in beans. Thereby, the current study represents the first report on the biocontrol effectiveness of P. aeruginosa against F. culmorum in beans.

The bean rhizosphere Pseudomonas aeruginosa strain RZ9 strongly reduces Fusarium culmorum growth and infectiveness of plant roots

Directory of Open Access Journals (Sweden)

Imen Haddoudi

2017-07-01

Full Text Available A faba bean rhizospheric Pseudomonas aeruginosa isolate RZ9 was used for studying its antifungal activity and protecting effects of faba bean and common bean against the root pathogen Fusarium culmorum strain MZB47. The dual culture tests showed that RZ9 inhibits MZB47 in vitro growth by 56%. When mixing RZ9 cell suspension with MZB47 macroconidia at equal proportion, the macroconidia viability was reduced with 70%. Pathogenicity tests conducted in sterile conditions showed that MZB47 caused an intense root rotting in faba bean ‘Aquadulce’ plantlets and a slight level in common bean ‘Coco blanc’. This was associated to significant decreases in plant growth only in ‘Aquadulce’, reducing shoot dry weight (DW by 82% and root DW by 70%. In soil samples, MZB47 caused severe root rotting and induced significant decreases in shoot DW (up to 51% and root DW (up to 60% for both beans. It was associated to a decrease in nodule number by 73% and 52% for faba bean and common bean, respectively. Biocontrol assays revealed that the inoculation of RZ9 to MZB47-treated plantlets enhanced shoot DWs (25% and 110% and root DWs (29% and 67%, in faba bean and common bean, respectively. Moreover, root rotting levels decreased and nodule number increased in treated compared to untreated plantlets. Collected data highlighted the disease severity of F. culmorum and demonstrated the potential of using RZ9 in controlling Fusaria root diseases in beans. Thereby, the current study represents the first report on the biocontrol effectiveness of P. aeruginosa against F. culmorum in beans.

Examining African self-consciousness and Black racial identity as predictors of Black men's psychological well-being.

Science.gov (United States)

Pierre, Martin R; Mahalik, James R

2005-02-01

This study investigated African self-consciousness and Black racial identity as predictors of psychological distress and self-esteem for Black men. One hundred thirty Black men from a college and community sample completed the African Self-Consciousness Scale, the Racial Identity Attitude Scale-B, the Symptom Checklist 90-Revised, and the Coopersmith Self-Esteem Inventory. Canonical correlation analysis found 2 significant roots with the 1st root indicating that Black men whose attitudes reflected Preencounter and Immersion racial identity attitudes and who do not resist against anti-African/Black forces reported greater psychological distress and less esteem. Results from the 2nd root suggested that Black men whose attitudes reflect greater Internalization racial identity attitudes, greater resistance to anti-African/Black forces, and less identification with Blacks reported greater self-esteem. ((c) 2005 APA, all rights reserved).

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

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%.

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.

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...

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

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...

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.

A novel, multiplexed, probe-based quantitative PCR assay for the soybean root- and stem-rot pathogen, Phytophthora sojae, utilizes its transposable element.

Science.gov (United States)

Haudenshield, James S; Song, Jeong Y; Hartman, Glen L

2017-01-01

Phytophthora root rot of soybean [Glycine max (L.) Merr.] is caused by the oomycete Phytophthora sojae (Kaufm. & Gerd.). P. sojae has a narrow host range, consisting primarily of soybean, and it is a serious pathogen worldwide. It exists in root and stem tissues as mycelium, wherein it can form oospores which subsequently germinate to release motile, infectious zoospores. Molecular assays detecting DNA of P. sojae are useful in disease diagnostics, and for determining the presence of the organism in host tissues, soils, and runoff or ponded water from potentially infested fields. Such assays as published have utilized ITS sequences from the nuclear ribosomal RNA genes in conventional PCR or dye-binding quantitative PCR (Q-PCR) but are not amenable to multiplexing, and some of these assays did not utilize control strategies for type I or type II errors. In this study, we describe primers and a bifunctional probe with specificity to a gypsy-like retroelement in the P. sojae genome to create a fluorogenic 5'-exonuclease linear hydrolysis assay, with a multiplexed internal control reaction detecting an exogenous target to validate negative calls, and with uracil-deglycosylase-mediated protection against carryover contamination. The assay specifically detected 13 different P. sojae isolates, and excluded 17 other Phytophthora species along with 20 non-Phytophthora fungal and oomycete species pathogenic on soybean. A diagnostic limit of detection of 34 fg total P. sojae DNA was observed in serial dilutions, equivalent to 0.3 genome, and a practical detection sensitivity of four zoospores per sample was achieved, despite losses during DNA extraction.

Transatlantic Roots of Prostate Cancer Disparities in Black Men: The CaPTC Program | Division of Cancer Prevention

Science.gov (United States)

Speaker | "Transatlantic Roots of Prostate Cancer Disparities in Black Men: The CaPTC Program" will be presented by Folakemi Odedina, PhD Professor, Pharmacotherapy & Translational Research and Director, UF Health Cancer Center Cancer Health Disparities at the University of Florida College of Pharmacy in Orlando, FL. Date: March 13, 2018; Time: 11:00am - 12:00pm; Location: NCI

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...

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

African Journals Online (AJOL)

Isolations from diseased squash roots revealed the presence of Alternaria tenuis, Aspergillus niger, Fusarium oxysporum, F. solani and Rhizoctonia solani. The last two fungi were more frequent than any of the other fungi. Pathogenicity tests proved that squash plants were highly vulnerable to attack by Fusarium solani and ...

Incorporation of plant materials in the control of root pathogens in muskmelon

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Andréa Mirne de Macêdo Dantas

2013-12-01

Full Text Available The effect of plant materials[Sunn Hemp (Crotalaria juncea, Castor Bean (Ricinus communis L., Cassava (Manihot esculenta Crantz and Neem (Azadirachta indica] and the times of incorporation of these materials in regards to the incidence of root rot in melon was evaluated in Ceará state, Brazil. The experiment was conducted in a commercial area with a history of root pathogens in cucurbitaceae. The randomized block design was used, in a 5 x 3 factorial arrangement with four repetitions. The treatments consisted of a combination of four plant materials (sunn hemp, castor beans, cassava and neem and a control with no soil incorporation of plant material and three times of incorporation (28, 21, and 14 days before the transplanting of the seedlings. Lower incidence of root rot was observed in practically all of the treatments where materials were incorporated at different times, with variation between the materials, corresponding with the time of incorporation, in relation to the soil without plant material. The pathogens isolated from the symptomatic muskmelon plants were Fusarium solani, Macrophomina phaseolina, Monosporascus cannonballus and Rhizoctonia solani, F. solani being encountered most frequently.

Measuring of -1,3 Glucanase Activity in Trichoderma Virens Isolates and Selection of the Best Isolates for Biological Control of Cucumber Root Rot

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Fatemeh Zavvari

2013-02-01

Full Text Available In this study four isolates of  Trichoderma virens (T.virens 414, T.virens 414.8, T.virens 304 and  T.virens 404.4 were compared based on extra cellular β-1,3 glucanase production and biological control of root rot cucumber (Phytophthora drerchsleri in laboratory and green house experiments.The in vitro potential of those isolates were evaluated against  P.drechsleri  through production of volatile and dual culture. The pH (3, 5, 7, 8, 9 and temperature effects(5, 15, 20, 25, 30, 40˚C on Trichoderma mycelial growth were also evaluated. Colony growth rate of thease isolates were also studied in water agar culture medium containing carboxy methyle cellulose (CMC and showed direct correlation with β-1,3 glucanase secretion. According to results T. virens 304 and T. virens 414.8  were the best isolates in biocontrol of . drechsleri. Result also showed direct correlation between β-1,3 glucanase secretion and inhibition growth of phytophthora  mycelium and reduction of phytophthora infection.

German science and black racism--roots of the Nazi Holocaust.

Science.gov (United States)

Haas, François

2008-02-01

The Nazi's cornerstone precept of "racial hygiene" gave birth to their policy of "racial cleansing" that led to the murders of millions. It was developed by German physicians and scientists in the late 19th century and is rooted in the period's Social Darwinism that placed blacks at the bottom of the racial ladder. This program was first manifested in the near-extermination of the African Herero people during the German colonial period. After WWI, the fear among the German populace that occupying African troops and their Afro-German children would lead to "bastardization" of the German people formed a unifying racial principle that the Nazis exploited. They extended this mind-set to a variety of "unworthy" groups, leading to the physician-administered racial Nuremberg laws, the Sterilization laws, the secret sterilization of Afro-Germans, and the German euthanasia program. This culminated in the extermination camps.

Aggressive root pathogen Phellinus noxius and implications for western Pacific Islands

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Sara M. Ashiglar; Phil G. Cannon; Ned B. Klopfenstein

2015-01-01

Phellinus noxius is an aggressive root rot pathogen affecting tropical and subtropical forests. Causing much damage in tropical Asia, Africa, Taiwan, Japan and the Pacific Islands, its wide host range encompasses more than 200 plant species representing 59 families (Ann et al. 2002). It can devastate agricultural plantations of tea, rubber, cocoa, avocados,...

Race Characterization of Phytophthora root rot on Capsicum in Taiwan as a Basis for Anticipatory Resistance Breeding.

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Barchenger, Derek W; Sheu, Zong-Ming; Kumar, Sanjeet; Lin, Shih-Wen; Burlakoti, Rishi R; Bosland, Paul W

2018-02-27

Peppers (Capsicum sp.) are an increasingly important crop because of their use as a vegetable, spice, and food colorant. The oomycete Phytophthora capsici is one of the most devastating pathogens to pepper production worldwide, causing more than $100 million in losses annually. Developing cultivars resistant to P. capsici is challenging because of the many physiological races that exist and new races that are continuously evolving. This problem is confounded by the lack of a universal system of race characterization. As a basis to develop a global anticipatory breeding program, New Mexico Recombinant Inbred Lines (NMRILs) functioned as a host differential for Phytophthora root rot to characterize the race structure of P. capsici populations in Taiwan. Using the NMRILs, 24 new races were identified, illustrating the utility and usefulness of the NMRILs for anticipatory breeding. Virulence of P. capsici was observed to be geographically specific and in two virulence clusters. Interestingly, all but two isolates collected in 2016 were the A2 mating type, which is a shift from the predominantly A1 mating type isolates collected prior to 2008. The NMRILs host differential provides an approach for scientists to work together on a global scale when breeding for resistance as well as on a local level for regional gene deployment. Additionally, we propose that the current race numbering system, which has no biological meaning, be supplemented with the virulence phenotype, based on the susceptible NMRILs to a given isolate. This work provides insights into the population dynamics of P. capsici and interactions within the highly complex Capsicum-Phytophthora pathosystem, and offers a basis for similar research in other crops.

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.

antagonistic effect of native bacillus isolates against black root rot

African Journals Online (AJOL)

ACSS

A number of fungi and bacteria are known to be very effective .... Round. Convex. Smooth. Wrinkled. Slow. BS024. Irregular and spreading. Flat. Wavy .... Antibiotic effect of bacterial antagonist ..... antagonistic Bacillus and Trichoderma isolates ...

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 ...

[Phosphorus transfer between mixed poplar and black locust seedlings].

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He, Wei; Jia, Liming; Hao, Baogang; Wen, Xuejun; Zhai, Mingpu

2003-04-01

In this paper, the 32P radio-tracer technique was applied to study the ways of phosphorus transfer between poplar (Populus euramericana cv. 'I-214') and black locust (Robinia pseudoacacia). A five compartment root box (18 cm x 18 cm x 26 cm) was used for testing the existence of the hyphal links between the roots of two tree species when inoculated with vesicular-arbuscular (VA) mycorrhizal fungus (Glomus mosseae). Populus I-214 (donor) and Robinia pseudoacacia (receiver) were grown in two terminal compartments, separated by a 2 cm root-free soil layer. The root compartments were lined with bags of nylon mesh (38 microns) that allowed the passage of hyphae but not roots. The top soil of a mixed stand of poplar and black locust, autoclaved at 121 degrees C for one hour, was used for growing seedlings for testing. In 5 compartment root box, mycorrhizal root colonization of poplar was 34%, in which VA mycorrhizal fungus was inoculated, whereas 26% mycorrhizal root colonization was observed in black locust, the other terminal compartment, 20 weeks after planting. No root colonization was observed in non-inoculated plant pairs. This indicated that the mycorrhizal root colonization of black locust was caused by hyphal spreading from the poplar. Test of tracer isotope of 32P showed that the radioactivity of the treatment significantly higher than that of the control (P mycorrhizal fungus was inoculated in poplar root. Furthermore, mycorrhizal interconnections between the roots of poplar and black locust seedlings was observed in situ by binocular in root box. All these experiments showed that the hyphal links was formed between the roots of two species of trees inoculated by VA mycorrhizal fungus. Four treatments were designed according to if there were two nets (mesh 38 microns), 2 cm apart, between the poplar and black locust, and if the soil in root box was pasteurized. Most significant differences of radioactivity among four treatments appeared 44 days after feeding

Draft genome sequence of Bacillus velezensis 2A-2B strain: a rhizospheric inhabitant of Sporobolus airoides (Torr.) Torr., with antifungal activity against root rot causing phytopathogens.

Science.gov (United States)

Martínez-Raudales, Inés; De La Cruz-Rodríguez, Yumiko; Alvarado-Gutiérrez, Alejandro; Vega-Arreguín, Julio; Fraire-Mayorga, Ahuitz; Alvarado-Rodríguez, Miguel; Balderas-Hernández, Victor; Fraire-Velázquez, Saúl

2017-01-01

A Bacillus velezensis strain from the rhizosphere of Sporobolus airoides (Torr.) Torr . , a grass in central-north México, was isolated during a biocontrol of phytopathogens scrutiny study. The 2A-2B strain exhibited at least 60% of growth inhibition of virulent isolates of phytopathogens causing root rot. These phytopathogens include Phytophthora capsici , Fusarium solani , Fusarium oxysporum and Rhizoctonia solani . Furthermore, the 2A-2B strain is an indolacetic acid producer, and a plant inducer of PR1, which is an induced systemic resistance related gene in chili pepper plantlets. Whole genome sequencing was performed to generate a draft genome assembly of 3.953 MB with 46.36% of GC content, and a N50 of 294,737. The genome contains 3713 protein coding genes and 89 RNA genes. Moreover, comparative genome analysis revealed that the 2A-2B strain had the greatest identity (98.4%) with Bacillus velezensis.

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.

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.

A Review of Our Roots: Blacks in Gerontology

Science.gov (United States)

Brown, Candace S.; Baker, Tamara A.; Mingo, Chivon A.; Harden, J. Taylor; Whitfield, Keith; Aiken-Morgan, Adrienne T.; Phillips, Karon L.; Washington, Tiffany

2014-01-01

The historical underpinnings in the field of gerontology rest on the contributions of scholars across a myriad of racial and ethnic backgrounds. With the increasing diversity of the adult population, there is a need to increase the number of researchers who study older adults from diverse racial and ethnic populations in general and Black elderly people in particular. Furthermore, it is important to document the participation of Black older adults in our earliest and continuing research efforts. Understanding the historical context and the foundational influence of Black scholars in this field is critical. To realize its humble beginnings, one must become aware of the contributions by Black scholars who have a vested interest in the aging process. With universal similarities and unique differences among older adults, there is a need to acknowledge the past and current scholarship of those who study the aging processes of Blacks while marveling over the future possibilities. The purpose of this review is to elucidate the legacy and current contributions, philosophies, and research of Black scholars in the field of gerontology. In addition, exploration of the theoretical and conceptual frameworks used to establish national and organizational initiatives is reviewed. The impetus in initiating and continuing this work requires a “knowledge of our roots” while moving into the future. It is important to learn the history and significance of Black scholars in gerontology, the contributions of older Blacks, and appreciate the resiliency and marveled life course of this unique population. PMID:24022695

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.

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.

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

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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.

Effect of composts on microbial dynamics and activity, dry root rot severity and seed yield of cowpea in the Indian arid region

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Meenu BAREJA

2011-01-01

Full Text Available Nutrient-deficient sandy soil, having poor moisture retention, favors  Macrophomina phaseolina, a soil-borne plant pathogen, occurring in severe form on many important crops grown in the Indian arid region. In a 2-year field experiment, five composts (4 ton/ha prepared from residues of Calotropis procera, Prosopis juliflora, Azadirachta indica, Acacia nilotica, and on-farm weeds were tested on cowpea (Vigna unguiculata to determine their effectiveness in limiting the  severity of charcoal rot caused by M. phaseolina in relation to the microbial population dynamics, microbial activity and the seed yield of cowpea.  In general, compost-amended plots retained 8.9% higher moisture than unamended plots. The microbial population increased in amended plots during the crop season. Populations of total fungi and actinomycetes were heighest in Calotropis compost-amended soil, while total bacteria were maximum in weed- compost amended soil. Microbial activity in amended plots was  26.3% higher than in unamended plots. Among trace elements,  uptake of Zn, Mn, Fe and Cu was  heighest  in plants grown in weed-compost amended soil followed by A. nilotica compost-amended soil. Soil amendment with the composts significantly reduced  plant mortality due to charcoal rot. The lowest mortality was recorded in plants amended with A. nilotica compost (5.5% followed by P. juliflora compost (5.8, while the  highest plant mortality (11.5% from charcoal rot occurred in the unamended control on the basis of the pooled average of two years. There was a significant inverse correlation between microbial activity and charcoal rot incidence in cowpea at 20 days after planting. Composts also had a beneficial effect on yield, with a 28.3% increase in seed yield in P. juliflora compost-amended plots. These results suggest that in resource-deficient farming , certain on-farm wastes can be effectively utilized for managing soil-borne pathogens, as well as  for �

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

Botanicals to Control Soft Rot Bacteria of Potato

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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.

BIOMODIFICATION OF KENAF USING WHITE ROT FUNGI

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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.

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

Science.gov (United States)

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...

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

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.

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.

Management of root rot and root knot disease of mungbean with the application of mycorrhizospheric fluorescent pseudomonas under field condition

International Nuclear Information System (INIS)

Bokhari, S.S.; Tariq, S.; Ali, S.A.

2014-01-01

The mycorrhizosphere is the region around a mycorrhizal fungus in which nutrients released from the hyphae increases microbial population and its activities. In this study five mycorrhizospheric fluorescent Pseudomonas (MRFP) were evaluated for biocontrol potential under field condition using mungbean (Vigna radiata) as test plant. MRFP-249 significantly reduced Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina. Whereas MRFP246 and MRFP-247 were also found effective against M. phaseolina. Mycorrhizospheric fluorescent Pseudomonas were also found effective against root knot nematode by reducing the galls on roots and nematode's penetration in roots. Highest fresh shoot weight and plant height was produced by MRFP-248. Plants grown in soil treated with Pseudomonas showed higher number of VAM spores around the mungbean roots than untreated control plants. The mycorrhizal symbiosis should not be considered merely as bipartite, plant-fungus interaction, but should instead include the associated microorganisms, particularly fluorescent Pseudomonas. (author)

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...

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.

Comparative transcriptome profiling of the early infection of wheat roots by Gaeumannomyces graminis var. tritici.

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Lirong Yang

Full Text Available Take-all, which is caused by the fungal pathogen, Gaeumannomyces graminis var. tritici (Ggt, is an important soil-borne root rot disease of wheat occurring worldwide. However, the genetic basis of Ggt pathogenicity remains unclear. In this study, transcriptome sequencing for Ggt in axenic culture and Ggt-infected wheat roots was performed using Illumina paired-end sequencing. Approximately 2.62 and 7.76 Gb of clean reads were obtained, and 87% and 63% of the total reads were mapped to the Ggt genome for RNA extracted from Ggt in culture and infected roots, respectively. A total of 3,258 differentially expressed genes (DEGs were identified with 2,107 (65% being 2-fold up-regulated and 1,151 (35% being 2-fold down-regulated between Ggt in culture and Ggt in infected wheat roots. Annotation of these DEGs revealed that many were associated with possible Ggt pathogenicity factors, such as genes for guanine nucleotide-binding protein alpha-2 subunit, cellulase, pectinase, xylanase, glucosidase, aspartic protease and gentisate 1, 2-dioxygenase. Twelve DEGs were analyzed for expression by qRT-PCR, and could be generally divided into those with high expression only early in infection, only late in infection and those that gradually increasing expression over time as root rot developed. This indicates that these possible pathogenicity factors may play roles during different stages of the interaction, such as signaling, plant cell wall degradation and responses to plant defense compounds. This is the first study to compare the transcriptomes of Ggt growing saprophytically in axenic cultures to it growing parasitically in infected wheat roots. As a result, new candidate pathogenicity factors have been identified, which can be further examined by gene knock-outs and other methods to assess their true role in the ability of Ggt to infect roots.

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

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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.

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.

Reação de cultivares de abacateiro à podridão de raízes Reaction of avocado cultivars to avocado root rot

Directory of Open Access Journals (Sweden)

Ciro Hideki Sumida

2009-07-01

Full Text Available As cultivares de abacateiro (Persea americana Mill 'Margarida', 'Fortuna' e 'Hass' têm muita importância econômica no mercado nacional e internacional. Em função disso, este trabalho teve como objetivo avaliar a reação dessas cultivares frente à Phytophthora cinnamomi Rands., agente causal da podridão das raízes. A inoculação do patógeno foi feita por meio de implantação de tecidos de raízes sintomáticas. Foram inoculadas quatro raízes em três árvores diferentes, uma de cada cultivar, em três pontos diferentes da raiz. Em cada cultivar, das quatro raízes, uma foi utilizada como testemunha, nas quais foram implantados tecidos sadios. A avaliação foi realizada aos 120 dias após a inoculação, observando-se as raízes externamente quanto à alteração da coloração e presença de estruturas de patógenos na região da superfície da casca nos pontos inoculados. Internamente, foram removidas as cascas para visualização das alterações a partir do ponto inoculado, sendo observadas alterações de coloração dos tecidos e realizada mensuração da extensão do escurecimento (lesão aparente. Nas extremidades das lesões foram retirados segmentos de raízes e implantados em meio de cultivo farinha de milho-ágar e incubados, para verificação da colonização na área sem escurecimento, ou seja, a colonização não- aparente. Das cultivares avaliadas, a 'Hass' foi a menos suscetível ao P. cinnamomi, quando comparada às cultivares 'Fortuna' e 'Margarida'. O patógeno P. cinnamomi pode apresentar desenvolvimento ou colonização nos tecidos radiculares além da área sintomática.Cultivars of the avocado (Persea americana Mill 'Margarida', 'Fortuna' and 'Geada' have importance in the national and international markets. The present paper had as objective to evaluate the reaction of such cultivars to Phytophthora cinanamomi Rands, the causal agent of avocado root rot. They were inoculated four roots in three different

In-Vitro Evaluation of Fungicides and Fungicide Combinations Against Fusarium Root-Rot Fungal Pathogens of French Beans(Phaseolus Vulgaris L. c v. Monel

International Nuclear Information System (INIS)

Wagichunge, A.G.R; Owino, P.O; Waudo, S.W; Seif, A.A

1999-01-01

Laboratories studies were undertaken to evaluate In-vitro efficacy of captan, thiram, pyrazophos, triforine and metalaxyl + mancozeb fungicides against Fusarium solani (Mart.) Appel and Wollenw fsp. phaseoli (Burk) Synder and Hansen Fusarium oxysporum Schlecht fsp. phaseoli kend and Synder root-rot fungal pathogens of French beans. Five fungicides and four combinations were tested for their antifungal activity. Fungicides treatments significantly (P=0.05) inhibited mycelial growth and spore germination. Fungicides suppressed the growth of F. oxysporum fsp. Phaseoli more than that of F. solani fsp. phaseoli. All fungicides except metalaxyl + mancozeb failed to suppress sporulation of the two fungi In-vitro. In the case of thiram the sporulation capacity of F. oxysporum fsp. phaseoli 3.43 times higher than in the control. Although, no fungicides treatment was seen to inhibitor of all the three measures of fungitoxicity, the ranking of the best three fungicide treatments would be, thiram 50 + captan so > triforine > metalaxyl + mancozeb. The relatively higher inhibitory effect of fungicides on the growth of F. oxysporum Ssp. Phaseoli than that of F. solani fsp. Phaseoli suggested that F. oxysporum Esp. Phaseoli was more sensible to fungicide treatments. Such differences may reflect inherent variations in accessibility of the active toxicants within the fungal systems. The ability attributed to the low growth rate, N depletion temperature and oxygen

Root diseases, climate change and biomass productivity

International Nuclear Information System (INIS)

Warren, G.R.; Cruickshank, M.

2004-01-01

Tree growth and yield in eastern boreal spruce fir forests are both greatly affected by root and butt rots. These pests are also prevalent in western coniferous species and boreal-sub-boreal forests. Infections are difficult to detect, but reduced growth, tree mortality, wind throw and scaled butt cull contribute to considerable forest gaps. Harvesting and stand tending practices in second growth stands are creating conditions for increased incidence. Tree stress is one of the major factors affecting the spread of root disease. It is expected that climate change will create abnormal stress conditions that will further compound the incidence of root disease. A comparison was made between natural and managed stands, including harvesting and stand practices such as commercial thinning. Studies of Douglas-fir forests in British Columbia were presented, with results indicating that managed forests contain one third to one half less carbon biomass than unmanaged forests. It was concluded that root diseases must be recognized and taken into account in order to refine and improve biomass estimates, prevent overestimation of wood supply models and avoid potential wood fibre losses. 40 refs., 2 figs.

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...

Fear of a Black femme: The existential conundrum of embodying a Black femme identity while being a professor of Black, queer, and feminist studies.

Science.gov (United States)

Story, Kaila Adia

2017-10-02

Although a Black femme identity has been defined and embodied by many as an identity with Black feminist roots and revolutionary potentials, Black femmes are still rendered hypervisible and invisible through racist and heteronormative politics. Similarly, embodying a Black femme identity as a professor in academia often engenders these same pretenses of hypervisibility and invisibility. This essay explores what this existential conundrum has been for me as both a Black femme and professor of Black queer and feminist studies, while illuminating the mix of forces within academia that have attempted to stifle my chosen sexual identity and gendered performance.

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.

( 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 ...

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...

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.

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 ...

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 ...

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.

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

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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.

Genome sequences of two Phytophthora species responsible for Sudden Oak Death and Soybean Root Rot provide novel insights into their evolutionary origins and mechanisms of pathogenesis

Energy Technology Data Exchange (ETDEWEB)

Tyler, Brett M.; Tripathi, Sucheta; Aerts, Andrea; Bensasson, Douda; Dehal, Paramvir; Dubchak, Inna; Garbelotto, Matteo; Gijzen, Mark; Huang, Wayne; Ivors, Kelly; Jiang, Rays; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt; McDonald, Hayes; Medina, Monica; Morris, Paul; Putnam, Nik; Rash, Sam; Salamov, Asaf; Smith, Brian; Smith, Joe; Terry, Astrid; Torto, Trudy; Grigoriev, Igor; Rokhsar, Daniel; Boore, Jeffrey

2005-12-01

The approximately 60 species of Phytophthora are all destructive pathogens, causing rots of roots, stems, leaves and fruits of a wide range of agriculturally and ornamentally important plants (1). Some species, such as P. cinnamomi, P. parasitica and P. cactorum, each attack hundreds of different plant host species, whereas others are more restricted. Some of the crops where Phytophthora infections cause the greatest financial losses include potato, soybean, tomato, alfalfa, tobacco, peppers, cucurbits, pineapple, strawberry, raspberry and a wide range of perennial tree crops, especially citrus, avocado, almonds, walnuts, apples and cocoa, and they also heavily affect the ornamental, nursery and forestry industries. The economic damage overall to crops in the United States by Phytophthora species is estimated in the tens of billions of dollars, including the costs of control measures, and worldwide it is many times this amount (1). In the northern midwest of the U.S., P. sojae causes $200 million in annual losses to soybean alone, and worldwide causes around $1-2 billion in losses per year. P. infestans infections resulted in the Irish potato famine last century and continues to be a difficult and worsening problem for potato and tomato growers worldwide, with worldwide costs estimated at $5 billion per year.

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

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.

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.

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.

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...

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

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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.

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 ...

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...

Evaluating Genetic Association between Fusarium and Pythium ...

African Journals Online (AJOL)

Resistance to Fusarium root rot (Fusarium solani f.s.p phaseoli) has been reported in common bean (Phaseolus vulgaris L.) sources and is usually associated with Pythium root rot resistance. Pythium root rot (Pythium ultimum var ultimum) resistance is controlled by a single dominant gene, marked by a SCAR marker ...

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...

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.

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.

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

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.

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...

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

Detection and characterization of broad-spectrum antipathogen activity of novel rhizobacterial isolates and suppression of Fusarium crown and root rot disease of tomato.

Science.gov (United States)

Zhang, L; Khabbaz, S E; Wang, A; Li, H; Abbasi, P A

2015-03-01

To detect and characterize broad-spectrum antipathogen activity of indigenous bacterial isolates obtained from potato soil and soya bean leaves for their potential to be developed as biofungicides to control soilborne diseases such as Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Thirteen bacterial isolates (Bacillus amyloliquefaciens (four isolates), Paenibacillus polymyxa (three isolates), Pseudomonas chlororaphis (two isolates), Pseudomonas fluorescens (two isolates), Bacillus subtilis (one isolate) and Pseudomonas sp. (one isolate)) or their volatiles showed antagonistic activity against most of the 10 plant pathogens in plate assays. Cell-free culture filtrates (CF) of five isolates or 1-butanol extracts of CFs also inhibited the growth of most pathogen mycelia in plate assays. PCR analysis confirmed the presence of most antibiotic biosynthetic genes such as phlD, phzFA, prnD and pltC in most Pseudomonas isolates and bmyB, bacA, ituD, srfAA and fenD in most Bacillus isolates. These bacterial isolates varied in the production of hydrogen cyanide (HCN), siderophores, β-1,3-glucanases, chitinases, proteases, indole-3-acetic acid, salicylic acid, and for nitrogen fixation and phosphate solubilization. Gas chromatography-mass spectrometry analysis identified 10 volatile compounds from 10 isolates and 18 compounds from 1-butanol extracts of CFs of five isolates. Application of irradiated peat formulation of six isolates to tomato roots prior to transplanting in a Forl-infested potting mix and field soil provided protection of tomato plants from FCRR disease and enhanced plant growth under greenhouse conditions. Five of the 13 indigenous bacterial isolates were antagonistic to eight plant pathogens, both in vitro and in vivo. Antagonistic and plant-growth promotion activities of these isolates might be related to the production of several types of antibiotics, lytic enzymes, phytohormones, secondary

Tobacco Rotated with Rapeseed for Soil-Borne Phytophthora Pathogen Biocontrol: Mediated by Rapeseed Root Exudates

Directory of Open Access Journals (Sweden)

Yuting Fang

2016-06-01

Full Text Available Black shank, caused by Phytophthora parasitica var. nicotianae, is a widespread and destructive disease of tobacco. Crop rotation is essential in controlling black shank. Here, we confirmed that rotating black shank-infested fields with rapeseed (Brassica napus suppressed the incidence this disease. Further study demonstrated that rapeseed roots have a strong ability to attract zoospores and subsequently stop the swimming of zoospores into cystospores. Then, rapeseed roots secrete a series of antimicrobial compounds, including 2-butenoic acid, benzothiazole, 2-(methylthiobenzothiazole, 1-(4-ethylphenyl-ethanone, and 4-methoxyindole, to inhibit the cystospore germination and mycelial growth of P. parasitica var. nicotianae. Thus, rapeseed rotated with tobacco suppresses tobacco black shank disease through the chemical weapons secreted by rapeseed roots.

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

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...

Impact of soil salinity on the plant-growth – promoting and biological control abilities of root associated bacteria

Directory of Open Access Journals (Sweden)

Dilfuza Egamberdieva

2017-11-01

Full Text Available The effectiveness of plant growth – promoting bacteria is variable under different biotic and abiotic conditions. Abiotic factors may negatively affect the beneficial properties and efficiency of the introduced PGPR inoculants. The aim of this study was to evaluate the effect of plant growth – promoting rhizobacteria on plant growth and on the control of foot and root rot of tomatoes caused by Fusarium solani under different soil salinity conditions. Among the five tested strains, only Pseudomonas chlororaphis TSAU13, and Pseudomonas extremorientalis TSAU20 were able to stimulate plant growth and act as biological controls of foot and root rot disease of tomato. The soil salinity did not negatively affect the beneficial impacts of these strains, as they were able to colonize and survive on the roots of tomato plants under both saline and non-saline soil conditions. The improved plant height and fruit yield of tomato was also observed for plants inoculated with P. extremorientalis TSAU20. Our results indicated that, saline condition is not crucial factor in obtaining good performance with respect to the plant growth stimulating and biocontrol abilities of PGPR strains. The bacterial inoculant also enhanced antioxidant enzymes activities thereby preventing ROS induced oxidative damage in plants, and the proline concentrations in plant tissue that play an important role in plant stress tolerance.

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.

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.

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

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

"Roots": Medium and Message.

Science.gov (United States)

Kinnamon, Keneth

A national telephone survey indicated that audiences rated the television production of "Roots" positively in terms of the following: realistic portrayal of the people and the times; relevance for contemporary race relations; perceived emotional effect; and increased understanding of the psychology of black people. However, a comparison…

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 ...

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.

Interactions between biosurfactant-producing Pseudomonas and Phytophthora species

OpenAIRE

Tran, H.

2007-01-01

Fluorescent Pseudomonas bacteria produce a wide variety of antimicrobial metabolites, including soap-like compounds referred to as biosurfactants. The results of this thesis showed that biosurfactant-producing Pseudomonas bacteria are effective in controlling Phytophthora foot rot disease of black pepper in Vietnam and promote root and shoot development of the ‘King of Spices’. Biosurfactant-producing P. fluorescens strain SS101 was also effective in controlling tomato late blight caused by P...

Draft Genome Sequence of Bacillus velezensis 3A-25B, a Strain with Biocontrol Activity against Fungal and Oomycete Root Plant Phytopathogens, Isolated from Grassland Soil.

Science.gov (United States)

Martínez-Raudales, Inés; De La Cruz-Rodríguez, Yumiko; Vega-Arreguín, Julio; Alvarado-Gutiérrez, Alejandro; Fraire-Mayorga, Atzin; Alvarado-Rodríguez, Miguel; Balderas-Hernández, Victor; Gómez-Soto, José Manuel; Fraire-Velázquez, Saúl

2017-09-28

Here, we present the draft genome of Bacillus velezensis 3A-25B, which totaled 4.01 Mb with 36 contigs, 3,948 genes, and a GC content of 46.34%. This strain, which demonstrates biocontrol activity against root rot causal phytopathogens in horticultural crops and friendly interactions in roots of pepper plantlets, was obtained from grassland soil in Zacatecas Province, Mexico. Copyright © 2017 Martínez-Raudales et al.

Root uptake and phytotoxicity of nanosized molybdenum octahedral clusters

Energy Technology Data Exchange (ETDEWEB)

Aubert, Tangi [Solid State Chemistry and Materials Group, UMR CNRS 6226 Sciences Chimiques de Rennes, University of Rennes 1, 263 av. du General Leclerc, Campus de Beaulieu, 35042 Rennes (France); Burel, Agnes [Electronic Microscopy Department, University of Rennes 1, 2 av. du Professeur Leon-Bernard, Campus de Villejean, 35043 Rennes (France); Esnault, Marie-Andree [Mechanisms at the Origin of Biodiversity Team, UMR CNRS 6553 Ecobio, University of Rennes 1, 263 av. du General Leclerc, Campus de Beaulieu, 35042 Rennes (France); Cordier, Stephane; Grasset, Fabien [Solid State Chemistry and Materials Group, UMR CNRS 6226 Sciences Chimiques de Rennes, University of Rennes 1, 263 av. du General Leclerc, Campus de Beaulieu, 35042 Rennes (France); Cabello-Hurtado, Francisco, E-mail: francisco.cabello@univ-rennes1.fr [Mechanisms at the Origin of Biodiversity Team, UMR CNRS 6553 Ecobio, University of Rennes 1, 263 av. du General Leclerc, Campus de Beaulieu, 35042 Rennes (France)

2012-06-15

Highlights: Black-Right-Pointing-Pointer We investigated the effect of nanosized Mo{sub 6} clusters on the growth of rapeseed plants. Black-Right-Pointing-Pointer The aggregation state of the clusters depends on the dispersion medium. Black-Right-Pointing-Pointer The concentration-dependant toxicity of the clusters depends on aggregation state. Black-Right-Pointing-Pointer We took into account the possible contribution to toxicity of dissolved ionic species. Black-Right-Pointing-Pointer The root uptake of the clusters was followed by NanoSIMS. - Abstract: Here are examined the root uptake and phytotoxicity of octahedral hexamolybdenum clusters on rapeseed plants using the solid state compound Cs{sub 2}Mo{sub 6}Br{sub 14} as cluster precursor. [Mo{sub 6}Br{sub 14}]{sup 2-} cluster units are nanosized entities offering a strong and stable emission in the near-infrared region with numerous applications in biotechnology. To investigate cluster toxicity on rapeseed plants, two different culture systems have been set up, using either a water-sorbing suspension of cluster aggregates or an ethanol-sorbing solution of dispersed nanosized clusters. Size, shape, surface area and state of clusters in both medium were analyzed by FE-SEM, BET and XPS. The potential contribution of cluster dissolution to phytotoxicity was evaluated by ICP-OES and toxicity analysis of Mo, Br and Cs. We showed that the clusters did not affect seed germination but greatly inhibited plant growth. This inhibition was much more important when plants were treated with nanosized entities than with microsized cluster aggregates. In addition, nanosized clusters affected the root morphology in a different manner than microsized cluster aggregates, as shown by FE-SEM observations. The root penetration of the clusters was followed by secondary ion mass spectroscopy with high spatial resolution (NanoSIMS) and was also found to be much more important for treatments with nanosized clusters.

Biodegradation of Hevea brasiliensis wood by Rigidoporus lignosus and Phellinus noxius

Energy Technology Data Exchange (ETDEWEB)

Geiger, J.P.; Rio, B.; Nicole, M.; Nandris, D.

1986-01-01

In vitro wood slats degradation assays reveal that both the white root rot fungus R. lignosus and the brown root rot fungus P. noxius cause a white rot of wood. In vivo (infected tap roots) they cause the same type of decay. Nevertheless lignin determination show the rubber-tree ability to react against the parasite aggression by increased lignification of tissues.

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,...

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

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.

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.

X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions.

Science.gov (United States)

Paya, Alexander M; Silverberg, Jesse L; Padgett, Jennifer; Bauerle, Taryn L

2015-01-01

Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D) using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen) and Picea mariana (black spruce) seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for 2 months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals) and paired seedlings (inter- or intra-specific), than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

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...

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...

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,...

The Relationship between Black Point and Fungi Species and Effects of Black Point on Seed Germination Properties in Bread Wheat

OpenAIRE

TOKLU, Faruk; AKGÜL, Davut Soner; BİÇİCİ, Mehmet; KARAKÖY, Tolga

2014-01-01

This study was undertaken to investigate the relationship between some fungi species and black point incidence and the effect of black point on seed weight, germination percentage, seedling emergence, seedling establishment, number of embryonic roots, and coleoptile length under field conditions in bread wheat. In this research, black-pointed and black point-free kernel samples of 5 bread wheat cultivars, namely Ceyhan-99, Doğankent-1, Yüreğir-89, Seyhan-95, and Adana-99 - commonly grown unde...

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

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

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

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

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

Detection and quantification of Leptographium wageneri, the cause of black-stain root disease, from bark beetles (Coleoptera: Scolytidae) in North California using regular and real-time PCR

Science.gov (United States)

Wolfgang Schweigkofler; William J. Otrosina; Sheri L. Smith; Daniel R. Cluck; Kevin Maeda; Kabir G. Peay; Matteo Garbelotto

2005-01-01

Black-stain root disease is a threat to conifer forests in western North America. The disease is caused by the ophiostomatoid fungus Leptographium wageneri (W.B. Kendr.) M.J. Wingf., which is associated with a number of bark beetle (Coleoptera: Scolytidae) and weevil species (Coleoptera: Curculionidae). We developed a polymerase chain reaction test...

Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot.

Science.gov (United States)

Borrego-Benjumea, Ana; Basallote-Ureba, María J; Melero-Vara, José M; Abbasi, Pervaiz A

2014-04-01

Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninety-three Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple-sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil.

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

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. ...

Cadmium accumulation and strategies to avoid its toxicity in roots of the citrus rootstock Citrumelo

Energy Technology Data Exchange (ETDEWEB)

Podazza, Griselda [Instituto de Ecologia, Fundacion Miguel Lillo, Miguel Lillo 251, CP 4000, Tucuman (Argentina); Arias, Marta [Catedra de Anatomia Vegetal, Facultad de Ciencias Naturales e IML, Miguel Lillo 205, CP 4000, Tucuman (Argentina); Prado, Fernando E., E-mail: prad@arnet.com.ar [Catedra de Fisiologia Vegetal, Facultad de Ciencias Naturales e IML, Miguel Lillo 205, CP 4000, Tucuman (Argentina)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Cd induces oxidative stress, increasing the H{sub 2}O{sub 2} and O{sub 2}{center_dot}{sup -} generation. Black-Right-Pointing-Pointer SOD, G-POD, CAT activities are enhanced by Cd. Black-Right-Pointing-Pointer G-POD activity participates in Cd-induced lignin synthesis. Black-Right-Pointing-Pointer Cd mainly accumulates in exodermis and vascular cylinder. Black-Right-Pointing-Pointer Cd is mostly immobilized in roots, limiting its transport to aerial parts. - Abstract: In order to assess implications of Cd-induced oxidative stress in roots of the citrus rootstock Citrumelo, seedlings were hydroponically exposed to two relatively realistic Cd concentrations during 7 days. Our results showed that increasing Cd concentrations in external solution were associated with higher Cd accumulations in roots. At 5 {mu}M Cd the accumulation of Cd in roots was over 70-f higher than in aerial part (stem + leaves). Malondialdehyde (MDA), superoxide radical (O{sub 2}{center_dot}{sup -}), hydrogen peroxide (H{sub 2}O{sub 2}) and lipoxygenase activity (LOX) increased in Cd-exposed roots, suggesting a metal-induced oxidative stress. The Cd treatment enhanced the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and guaiacol-type peroxidase (G-POD), as well as the content of secondary metabolites i.e. soluble phenolics (SPs) and lignin. Histochemical analyses of roots showed that Cd, H{sub 2}O{sub 2}, (O{sub 2}{center_dot}{sup -}), lignin and G-POD displayed a similar location pattern. Almost all analyzed parameters showed a similar dynamic tendency with increases under 5 {mu}M Cd followed by decreases under 10 {mu}M Cd, suggesting that a complex coordinated Cd-defensive mechanism is operating in Citrumelo roots exposed to environmental realistic Cd concentrations.

Combined effects of biocontrol agents and soil amendments on soil microbial populations, plant growth and incidence of charcoal rot of cowpea and wilt of cumin

Directory of Open Access Journals (Sweden)

Vijeta SINGH

2012-09-01

Full Text Available Field experiments were conducted for 2 years to determine the effectiveness of combined use of two biocontrol agents, Bacillus firmus and Aspergillus versicolor for control of Macrophomina phaseolina induced charcoal rot of cowpea and Fusarium oxysporum f. sp. cumini induced wilt of cumin. The lowest level of plant mortality (3‒4% due to charcoal rot of cowpea was recorded when bacterium coated seeds were sown in radish compost amended soil compared to the non-amended soil (13.8‒20.5%, but this was not significantly better than some other treatments. Cowpea roots from B. firmus coated seeds had better nodulation than any of the individual A. versicolor treatments. Although B. firmus coated seeds + A. versicolor + farmyard manure resulted in maximum nodulation this was not significantly different to B. firmus seed coating. Root colonization by the combined biocontrol agent treatments was better than the individual biocontrol agent treatments. Combining A. versicolor with farmyard manure supported the maximum populations of total fungi and actinomycetes. In both winter seasons, the lowest incidence of wilt (1.0‒5.2% on cumin was recorded when A. versicolor was amended with neem compost compared to the non-amended soil (5.7‒10.5%. Maximum colonization of A. versicolor on roots was observed in B. firmus + A. versicolor + farmyard manure amended plots. During both years, the treatment combination of A. versicolor in neem compost amended plots resulted in maximum populations of fungi, bacteria and A. versicolor in the soil, which was greater than in the non-amended soil. Significant increases in disease control were not recorded after single or repeated delivery of A. versicolor. These results suggest that combining B. firmus as seed coatings with A. versicolor as soil applications gives improved control of M. phaseolina and Fusarium induced diseases on legume and seed spice crops in arid soils.

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. ...

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。

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

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

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...

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.

Effect of inoculation with arbuscular mycorrhizas on rooting, weaning and subsequent growth of micropropagated Malus (L. Moench

Directory of Open Access Journals (Sweden)

Marjatta Uosukainen

1994-05-01

Full Text Available The importance of different rooting methods and the effects of arbuscular mycorrhizal (AMF inoculation on the rooting rate, weaning survival and subsequent growth of microcuttings of Malus rootstock YP and the Finnish crab apple cultivars Hanna and Marjatta were studied in four experiments conducted at the Laukaa Research and Elite Plant Unit, Finland. Sucrose in the in vitro rooting medium gave the best support to weaning survival in comparision with glucose and fructose. Directly rooted microcuttings had a higher survival rate than in vitro rooted microcuttings. AMF inoculation did not improve the rooting rate in direct rooting. However, the Glomus hoi strain V98 caused severe rotting of microcuttings and thus lowered the rooting rate of cv. Hanna, AMF inoculation increased the mean shoot height of established plants, particularly inoculation with G. hoi V98, G. claroideum V43a or G. fistulosum V128. This effect, however, varied considerably in different host-fungus combinations. Some AMF strains, e.g. G. hoi V1O4, caused strong growth retardation. After the rooting and weaning stage, many uninoculated plants lapsed into arrest of growth. This phenomenon was less frequent in AMF inoculated plants. Optimal timing of AMF inoculation and nutritional level of rooting and weaning substrate are discussed.

Touchdowns and Honor Societies: Expanding the Focus of Black Male Excellence

Science.gov (United States)

Morris, Jerome E.; Adeyemo, Adeoye O.

2012-01-01

The athletic/academic paradox for black males is historically rooted in rank-and-file notions of black people primarily as workers rather than thinkers. Policymakers, educators, and administrators should think more deeply about how societal perceptions of black males as "natural" athletes, rather than intelligent students adversely influences how…

Ultrastructural changes of compressed lumbar ventral nerve roots following decompression

International Nuclear Information System (INIS)

El-Barrany, Wagih G.; Hamdy, Raid M.; Al-Hayani, Abdulmonem A.; Jalalah, Sawsan M.; Al-Sayyad, Mohammad J.

2006-01-01

To study whether there will be permanent lumbar nerve rot scanning or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain. The study was performed at the Department of Anatomy, Faulty of Medicine, king Abdulaziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study. One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyentilated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The enoneurium was filed of myelinated and unmyelinated nerve fibers and collagen fibrils. Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve and nerve recovery without endoneurial scarring. (author)

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)

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

Burkholderia ginsengiterrae sp. nov. and Burkholderia panaciterrae sp. nov., antagonistic bacteria against root rot pathogen Cylindrocarpon destructans, isolated from ginseng soil.

Science.gov (United States)

Farh, Mohamed El-Agamy; Kim, Yeon-Ju; Van An, Hoang; Sukweenadhi, Johan; Singh, Priyanka; Huq, Md Amdadul; Yang, Deok-Chun

2015-04-01

Strain DCY85(T) and DCY85-1(T), isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85(T) as well as DCY85-1(T) belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023(T) (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85(T) and DCY85-1(T) were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85(T) and DCY85-1(T) was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85(T) and DCY85-1(T) was putrescine. Although both DCY85(T) and DCY85-1(T) have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA-DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85(T) and DCY85-1(T) are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85(T) and DCY85-1(T) showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85(T) (KCTC 42054(T) = JCM 19888(T)) and DCY85-1(T) (KCTC 42055(T) = JCM 19889(T)).

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.

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.

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.

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.

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-...

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...

Overkill: Black Lives and the Spectacle of the Atlanta Cheating Scandal

Science.gov (United States)

Royal, Camika; Dodo Seriki, Vanessa

2018-01-01

This article examines the 2015 Atlanta cheating scandal trials and sentencing. Using critical race theory, the authors argue that cheating is a natural outgrowth of market-based school reform and that racial realism will always lead to scrutiny of Black performance. The sentences of these Black educators is overkill, rooted in anti-Blackness, and…

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

Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

NARCIS (Netherlands)

Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

2011-01-01

Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from

Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

NARCIS (Netherlands)

Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

2012-01-01

Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from

Geometrical Method for Thermal Instability of Nonlinearly Charged BTZ Black Holes

International Nuclear Information System (INIS)

Panahiyan, Shahram; Hendi, Seyed Hossein; Eslam Panah, Behzad

2015-01-01

We consider three-dimensional BTZ black holes with three models of nonlinear electrodynamics as source. Calculating heat capacity, we study the stability and phase transitions of these black holes. We show that Maxwell, logarithmic, and exponential theories yield only type one phase transition which is related to the root(s) of heat capacity, whereas, for correction form of nonlinear electrodynamics, heat capacity contains two roots and one divergence point. Next, we use geometrical approach for studying classical thermodynamical behavior of the system. We show that Weinhold and Ruppeiner metrics fail to provide fruitful results and the consequences of the Quevedo approach are not completely matched to the heat capacity results. Then, we employ a new metric for solving this problem. We show that this approach is successful and all divergencies of its Ricci scalar and phase transition points coincide. We also show that there is no phase transition for uncharged BTZ black holes.

Gnomoniopsis castanea is the main agent of chestnut nut rot in Switzerland

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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

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

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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.

First report of root rot caused by Phytopythium helicoides on pistachio rootstock in California

Science.gov (United States)

We examined pathogenicity of Phytopythium helicoides on UCB-1 rootstock to investigate its role in root disease and collapse observed on potted pistachio plants. Approximately 25 potted 2-year-old pistachio rootstock trees in a Kern County, CA, research plot maintained outdoors and irrigated to cont...

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

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...

Molecular genetic studies in Fragaria species : agrobacterium-mediated transformation and fine mapping of the Phytophthora fragariae resistance gene Rpfl.

NARCIS (Netherlands)

Haymes, K.M.

1997-01-01

The fungus Phytophthora fragariae, is able to cause red stele root rot in the strawberry. Symptoms of the disease is discolouration of the stele of the roots, rotting away of the infected roots, dwarfism, wilting, and finally plant death. Chemical control of red stele

Scholarly context not found: one in five articles suffers from reference rot.

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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.

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.

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.

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.

Soil Structure and Mycorrhizae Encourage Black Walnut Growth on Old Fields

Science.gov (United States)

Felix Jr. Ponder

1979-01-01

Examination of black walnut seedlings grown in forest and field soils showed all root systems were infected with mycorrhizae; the amount of infection was influenced by treatments. Mean height and dry weight of tops and roots were greater for seedlings grown in forest than field soil. Seedling height growth was not increased by disturbing either soil; but, root dry...

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.

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....

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...

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

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.

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.

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

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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.

Interactions of Phytophthora capsici with Resistant and Susceptible Pepper Roots and Stems.

Science.gov (United States)

Dunn, Amara R; Smart, Christine D

2015-10-01

Using host resistance is an important strategy for managing pepper root and crown rot caused by Phytophthora capsici. An isolate of P. capsici constitutively expressing a gene for green fluorescent protein was used to investigate pathogen interactions with roots, crowns, and stems of Phytophthora-susceptible bell pepper 'Red Knight', Phytophthora-resistant bell pepper 'Paladin', and Phytophthora-resistant landrace Criollos de Morelos 334 (CM-334). In this study, the same number of zoospores attached to and germinated on roots of all cultivars 30 and 120 min postinoculation (pi), respectively. At 3 days pi, significantly more secondary roots had necrotic lesions on Red Knight than on Paladin and CM-334 plants. By 4 days pi, necrotic lesions had formed on the taproot of Red Knight but not Paladin or CM-334 plants. Although hyphae were visible in the crowns and stems of all Red Knight plants observed at 4 days pi, hyphae were observed in crowns of only a few Paladin and in no CM-334 plants, and never in stems of either resistant cultivar at 4 days pi. These results improve our understanding of how P. capsici infects plants and may contribute to the use of resistant pepper cultivars for disease management and the development of new cultivars.

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...

Effects of cell suspension and cell·free culture filtrate of Pseudomonas aeruginosa in the control of root rot-root kont disease complex of tomato (Lycopersicon esculentum Mill.

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I. A. Siddiqui

2013-12-01

Full Text Available The plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6 was tested for antagonistic activity towards Meloidogyne javanica, the root-knot nematode and soilbome root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani under laboratory and greenhouse conditions. Cell-free culture filtrate of the bacterium caused significant reduction in egg hatching of M.javanica and inhibited radial growth of fungi in vitro. Cell-free culture filtrate also caused lyses in mycelium of F.solani. Under greenhouse conditions, soil drenches with the aqueous cell suspension or cell-free culture resulted in a considerable reduction in nematode population densities in soil and subsequent root-knot development due to M.javanica. In addition to nematode control, rhizobacterium application also inhibited root-infection caused by soilborne root~infecting fungi with significant enhancement of growth of tomato seedlings.

Comparative efficacy of a red alga solieria robusta, chemical fertilizers and pesticides in managing the root diseases and growth of soybean

International Nuclear Information System (INIS)

Sultana, V.; Haque, S.E.; Baloch, G.N.; Ara, J.

2011-01-01

Application of seaweed as soil amendment for the control of soil borne plant diseases has increased in recent years due to their environment friendly role. In screen house study, a red seaweed Solieria robusta used as soil amendment showed better suppressive effect on root rotting fungus Fusarium solani than Topsin-M, a fungicide, but was found less effective than Topsin-M against Macrophomina phaseolina and Rhizoctonia solani on soybean. Solieria robusta showed similar suppressive effect on root knot nematode as did carbofuran, a nematicide. Seaweed showed slightly better effect on plant growth than urea or potash by producing taller plants, better root length and number of flowers per plant. However, mixed application of S.robusta and Topsin-M produced greater number of flowers per plant and tallest plants. (author)

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...

Behavior of hybrid corn crop as second rot incidence in West Region Paraná

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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.

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

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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.

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...

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

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.

Root hair mutants of barley

International Nuclear Information System (INIS)

Engvild, K.C.; Rasmussen, K.

2005-01-01

Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

Association of Pectolytic Fluorescent PSeudomonas with Postharvest Rots of Onion

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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.

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

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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.

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.

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

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.

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.

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...

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.

Fusarium rot of onion and possible use of bioproduct

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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.

Historic and Cultural Roots of Apartheid.

Science.gov (United States)

Chonco, Seshi

1987-01-01

Reviews the historical and cultural roots of the South African system of apartheid. Covers early Dutch settlement, the Anglo-Boer War, the Native Land Act of 1913, and the rise of the National Party. Concludes with a discussion of the different perspectives held by black and white South Africans on the "progress" made in recent years.…

Molecular characterization of a novel thermostable laccase PPLCC2 from the brown rot fungus Postia placenta MAD-698-R

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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.

Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

Science.gov (United States)

Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

2016-01-01

Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

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Xiaomei Xu

Full Text Available Phytophthora root rot caused by Phytophthora capsici (P. capsici is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS. Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334 and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399 were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3 was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA and Specific Length Amplified Fragment sequencing (SLAF-seq provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away and P52-11-41 (1.1 cM. A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

Incorporation of disease resistance from Lycopersicon peruvianum L. to cultivated tomatoes, 1: Breeding of new varieties ''Ryugyoku'' etc., having resistance to Fusarium root rot and tobacco mosaic virus inherited from L. peruvianum

International Nuclear Information System (INIS)

Yamakawa, K.; Yasui, H.; Mochizuki, T.; Hida, K.; Komochi, S.

1987-01-01

Fusarium crown and root rot (FCR) resistance and Tobacco Mosaic Virus (TMV) resistance (Tm-2) of a wild tomato (Lycopersicon peruvianum) were incorporated into cultivated tomatoes (L. esculentum). With this material, F1 hybrid varieties 'Kagyoku, Ryugyoku' and their parental lines 'Tomato parental lines No. 4, -No. 5' were developed. In addition, 'Kagyoku, Ryugyoku' possess Fusarium wild (J1), Nematode (Meloidogyne incognita) and TMV (Tm-2a) resistance introduced from the other varieties. Among the resistances introduced from L. peruvianum, TMV resistance is simply inherited and stable enough. FCR resistance is basically monogenic, but the strong influence of the genetic background hinders the development of FCR resistant varieties with high quality and yield. Whereas 'Ryugyoku' which is highly resistant to FCR has less attractive fruit characters, 'Kagyoku' yields fruits of high quality with a comparatively low FCR resistance. In this report, the breeding process from interspecific hybridization to the development of F1 varieties and the methods of selection applied were described. Also the difficulties which arose in the process of incorporation of the resistance from the wild species were discussed

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...

Educational Lynching: Critical Race Theory and the Suspension of Black Boys

Science.gov (United States)

Payne, Macheo

2010-01-01

Looking at the disproportionate suspension of African American, Black male students through the lens of critical race theory, this presents arguments from a CRT how the disproportionate suspension of Black male students is rooted in white supremacy and racist policy in the United States. Local recommendations are offered for Oakland Unified School…

Interaction between N-fertilizer and water availability on borer-rot complex in sugarcane

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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.

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; ...

Heroes and villains: Research identifies harmful and beneficial microbes in nursery soil

Science.gov (United States)

Phytophthora and Pythium species are common pathogens in nursery systems that can cause rhododendron root rot. Plants with root rot are often stunted, and may wilt and die, thus directly reducing nursery profit. Rhododendrons are an important crop in Pacific Northwest nurseries, but are highly susc...

Antagonistic properties of Trichoderma viride on post harvest ...

African Journals Online (AJOL)

The effective in vitro screening tests of Trichoderma viride for antagonism against post harvest pathogens of cassava roots (Manihot esculenta Crantz) rot together with its competitive and mycoparasitic abilities informs its selection as the most promising candidate for the biocontrol of post harvest cassava root rot pathogens.

Diversity of black Aspergilli and mycotoxin risks in grape, wine and dried vine fruits

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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.

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

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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.

High-Q Fabry–Pérot Micro-Cavities for High-Sensitivity Volume Refractometry

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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.

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

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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.

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.

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

Aluminium-induced excessive ROS causes cellular damage and metabolic shifts in black gram Vigna mungo (L.) Hepper.

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Chowra, Umakanta; Yanase, Emiko; Koyama, Hiroyuki; Panda, Sanjib Kumar

2017-01-01

Aluminium-induced oxidative damage caused by excessive ROS production was evaluated in black gram pulse crop. Black gram plants were treated with different aluminium (Al 3+ ) concentrations (10, 50 and 100 μM with pH 4.7) and further the effects of Al 3+ were characterised by means of root growth inhibition, histochemical assay, ROS content analysis, protein carbonylation quantification and 1 H-NMR analysis. The results showed that aluminium induces excessive ROS production which leads to cellular damage, root injury, stunt root growth and other metabolic shifts. In black gram, Al 3+ induces cellular damage at the earliest stage of stress which was characterised from histochemical analysis. From this study, it was observed that prolonged stress can activate certain aluminium detoxification defence mechanism. Probably excessive ROS triggers such defence mechanism in black gram. Al 3+ can induce excessive ROS initially in the root region then transported to other parts of the plant. As much as the Al 3+ concentration increases, the rate of cellular injury and ROS production also increases. But after 72 h of stress, plants showed a lowered ROS level and cellular damage which indicates the upregulation of defensive mechanisms. Metabolic shift analysis also showed that the black gram plant under stress has less metabolic content after 24 h of treatment, but gradually, it was increased after 72 h of treatment. It was assumed that ROS played the most important role as a signalling molecule for aluminium stress in black gram.

Evaluation of microbial products for the control of zucchini foot and root rot caused by Fusarium solani f. sp. cucurbitae race 1

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Roberta ROBERTI

2012-09-01

for an effective management of zucchini Fusarium foot and root rot through rhizosphere competence and several mechanisms exerted by their microbial ingredients.

The Black Aspergillus Species of Maize and Peanuts and Their Potential for Mycotoxin Production

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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

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

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

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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.

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.

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...

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...

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.

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

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...

Identification of sources of resistance to anthracnose stalk rot in maize

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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.

A genomics-informed, SNP association study reveals FBLN1 and FABP4 as contributing to resistance to fleece rot in Australian Merino sheep

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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

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis fruits in Vietnam.

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Ivana Puglisi

Full Text Available Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis, a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana rootstocks grafted with 'King' mandarin (Citrus nobilis and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi, sweet orange (Citrus x sinensis and bergamot (Citrus x bergamia as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata. This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam.

Science.gov (United States)

Puglisi, Ivana; De Patrizio, Alessandro; Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano; Cacciola, Santa Olga

2017-01-01

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

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...

DETERMINATION OF THE SEEDLINGS QUALITY CLASSES OF BLACK LOCUST (Robinia pseudoacacia L. ORIGINS

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İbrahim Turna

2000-04-01

Full Text Available classification criteria is the assesment of height and root-colar diameter together. newly seedling quality classification (YS have highly first grade seedlings. The most important According to the results of this study, all the origins determined with respect to either TSE or determined by using factor analysis. Furthermore the morphological characteristics that affect the seedling quality classification were diameter. The resulting seedling quality classification were controlled by using discriminant analysis. determined according to height, root-colar diameter and combination of both height and root-colar provenances were soved in KTÜ Nursery. One year later, these seedlings were lifted. Quality norms in KTÜ Nursery were used. Eighteen different origin seeds of Black locust of which eleven are egzotic In this present study, 1+0 Black Locust ( Robinia pseudoacacia L. seedlings grown

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.

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....

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.

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

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

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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.

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,...

Improvement of Agrobacterium-mediated transformation and rooting of black cherry

Science.gov (United States)

Ying Wang; Paula M. Pijut

2014-01-01

An improved protocol for Agrobacterium-mediated transformation of an elite, mature black cherry genotype was developed. To increase transformation efficiency, vacuum infiltration, sonication, and a combination of the two treatments were applied during the cocultivation of leaf explants with Agrobacterium tumefaciens strain EHA105...

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...

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 ...

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.

Poinsettia Growth and Development Response to Container Root Substrate with Biochar

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Yanjun Guo

2018-01-01

Full Text Available A greenhouse study was conducted to evaluate the growth and development of poinsettia ‘Prestige Red’ (Euphorbia pulcherrima grown in a commercial peat-based potting mix (Sunshine Mix #1 amended with biochar at 0%, 20%, 40%, 60%, 80%, or 100% (by volume at four different fertigation regimes: F1: 100 to 200 mg·L−1 nitrogen (N, F2: 200 to 300 mg·L−1 N (control, F3: 300 to 400 mg·L−1 N, or F4: 400 to 500 mg·L−1 N. The experiment was a two-factor factorial design with 10 replications for each combination of biochar by fertigation. As the percentage of biochar increased, root substrate pore space and bulk density increased, while container capacity decreased. Root rot and red bract necrosis only occurred in F4 combined with 100% biochar. Plants grown in 40% biochar had a similar growth and development to those in 0% biochar. Up to 80% biochar, plants exhibited no significant change, except in terms of dry weight, which decreased at higher biochar percentages (60% and 80%. In summary, at a fertigation rate of 100 mg·L−1 N to 400 mg·L−1 N, up to 80% biochar could be used as an amendment to peat-based root substrate with acceptable growth reduction and no changes in quality.

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)

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

The Use of Gas-Sensor Arrays in the Detection of Bole and Root Decays in Living Trees: Development of a New Non-invasive Method of Sampling and Analysis

Directory of Open Access Journals (Sweden)

Manuela BAIETTO

2015-10-01

Full Text Available Wood rot is a serious fungal disease of trees. Wood decay fungi penetrate and gain entry into trees through pruning cuts or open wounds using extracellular digestive enzymes to attack all components of the cell wall, leading to the destruction of sapwood which compromises wood strength and stability. On living trees, it is often difficult to diagnose wood rot disease, particularly during extreme weather conditions when trees can fail, causing tree parts to fall onto people and property. Today, tree stability evaluation and inner decay detection are performed visually and by the use of commercial instruments and methods that are often invasive, time-consuming and sometimes inadequate for use within the urban environment. Moreover, most conventional instruments do not provide an adequate evaluation of decay that occurs in the root system. A long-term research project, initiated in 2004, was aimed at developing a novel approach for diagnosing inner tree decays by detecting differences in volatile organic compounds (VOCs released by wood decay fungi and wood from healthy and decayed trees. Different commercial electronic noses (ENs were tested under laboratory conditions and directly in the field, on healthy and artificially-inoculated stem wood chips, and root fragments. The first stage of the research was focused on testing different commercially available electronic noses (e-noses for the capabilities of discriminating between different strains and species of wood decay fungi as well as sapwood belonging to different tree species. In the second stage, sapwood of different tree species was artificially inoculated with decay fungi to test the diagnostic ability of the e-noses to detect differences in aroma bouquets emitted by healthy and inoculated woods. Root fragments were then inoculated with specific root decaying fungi and incubated under different types of soils to assess whether soil odors could influence the ability of the e-nose to

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.

Black God and white devil in the urban ghettos of America: Religion and black nationalism of the Nation of Islam

Directory of Open Access Journals (Sweden)

Zbigniew Marcin Kowalewski

2013-01-01

Full Text Available The Nation of Islam, commonly known as the Black Muslim movement,appeared during the Great Depression in the black ghettos of the big urban andindustrial centers in the northern United States. It was founded by W. Fard Muhammad,one of the probably most mysterious figures in the history of Black America,in whom his followers saw the incarnation of Allah. Its doctrine was a combinationof an extremely heterodox or “heretical” Islam and a separatist variety of blacknationalism. A quarter of century later, the marginal sect led by Elijah Muhammadas Messenger of Allah became the most important new religious movement to emerge in the U.S. in the twentieth century. It has proved to be the largest and longest-lived nationalist movement among the American blacks. Its activities, including the preaching of “black internationalism”, were seen by the federal authorities as a threat to national security. The outstanding revolutionary leader Malcolm X emerged from its bosom. Rooted in the lowest layers of the black working class, the Nation of Islam durably and successfully questions the liberal middle-class leadership of the northern black communities, which aspires toward integration into white society.

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, ...

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 ...

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.)

Black holes thermodynamics, information, and firewalls

CERN Document Server

Mann, Robert B

2015-01-01

This book reflects the resurgence of interest in the quantum properties of black holes, culminating most recently in controversial discussions about firewalls. On the thermodynamic side, it describes how new developments allowed the inclusion of pressure/volume terms in the first law, leading to a new understanding of black holes as chemical systems, experiencing novel phenomena such as triple points and reentrant phase transitions. On the quantum-information side, the reader learns how basic arguments undergirding quantum complementarity have been shown to be flawed; and how this suggests that a black hole may surround itself with a firewall: a violent and chaotic region of highly excited states. In this thorough and pedagogical treatment, Robert Mann traces these new developments from their roots to our present-day understanding, highlighting their relationships and the challenges they present for quantum gravity.

Tissue culture of black pepper (piper nigrum l.) in Pakistan

International Nuclear Information System (INIS)

Hussain, A.; Naz, S.; Nazir, H.; Shinwari, Z.K.

2011-01-01

Black pepper (Piper nigrum L.) the 'King of Spices' is a universal table condiment. It is extensively used in Pakistani cuisines and herbal medicines and imported in bulk from neighboring countries. The black pepper vine is generally cultivated by seed because other vegetative propagation methods are slow and time consuming. Therefore the tissue culture technique is considered more efficient and reliable method for rapid and mass propagation of this economically important plant. The present study was initiated to develop protocol for micro-propagation of black pepper vine. The stem, leaf and shoot tip explants from mature vine were cultured on MS medium supplemented with different concentrations of plant growth regulators (2,4-D, BA, IBA). Best callus was produced on MS medium with 1.5 mg/l BA by shoot tip explant. Shoot regeneration was excellent on MS medium with 0.5 mg/l BA. The plantlets formed were rooted best on 1.5 mg/l IBA. The rooted plants were transplanted in soil medium and acclimatized in growth room. The plants raised were test planted under the local conditions of Hattar. (author)

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.

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

The black Arab as a substitution for sin and guilt

Directory of Open Access Journals (Sweden)

Petrović Radmilo

2009-01-01

Full Text Available The figure of the Black Arab as a form of guilt and sin is a well-established memorial pattern throughout the Mediterranean world, having already existed for more than 3000 years. This text is focused on two different types of interpretation of the Black Stone and its semantic relation with the symbolized figure of Black Arab in the oral traditions of Mediterranean peoples - Jewish religion and Islamic eschatology. The transformation of the signification of the Black Stone was transferred to the Islamic religion in the act of pilgrimage. The Jewish practice of transferring sin and guilt is related with the Iranian-Manichean Ahura Mazda-Ahriman, and the ancient Greek goddess Hecate. All manifestations of the Black Arab left a deep trace on Slavic spiritual life through the Slavic gods Chernobog, Triglav and Toyan and consequently on the deeply rooted conception of all Slavic peoples that the Black Arab was a black demon of death and the underworld.

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.

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.

Variability of some morphological traits of one-year old red oak, black walnut, birch and wild pear seedlings in the nurseries of Jastrebac region

Directory of Open Access Journals (Sweden)

Krstić Milun

2002-01-01

Full Text Available Five morphological and quantitative characteristics of one-year old seedlings of Red oak (Quercus rubra L, Black walnut (Juglans nigra L, Wild pear (Pyrus pygrowser Borkh and Birch (Betula verrucosa Ehrh were studied. The seedlings were produced and cultivated in the controlled conditions of the nursery in the region of Jastrebac, by the classical method. Aboveground seedling height, root collar diameter, root length, number of secondary roots and the leaf assimilation area were analysed. Intraspecific and interspecific variability of morphological features of the above species were assessed by the comparative analysis and statistical methods The comparative analysis shows the great individual variability of seedlings, which can indicate their genetic potential, adaptation to environment conditions, further spontaneous selection and the development in natural conditions. This justifies the need of the quality assessment and the first selection already in the nursery, in order to ensure the quality planting material and to reduce the risk of afforestation failure One-year old birch seedlings have the lowest average height (18.8 cm. Black walnut and Wild pear seedlings are approximately twice as high, and Red oak about 2.5 times higher. At the same time Red oak seedlings have for about one-fourth greater height than Black walnut, and for one-third greater height than Wild pear. Wild pear seedlings attain the averagely twice larger root collar diameter than Birch (2.8 cm, Red oak seedlings about 2.5 times larger diameter, and Black walnut 3.5 times larger diameter. Black walnut has a larger root collar diameter than Red oak for about one third, and almost twice larger than Wild pear. Birch, Red oak and Wild pear have almost twice longer root (1.8-1.9 times, Black walnut about 2.25 times longer. The total assimilation area of a Birch seedling is averagely 89.0 cm2. Compared to birch, wild pear has approximately double assimilation area per tree, Red

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.

With Black Athena into the third millenium CE

NARCIS (Netherlands)

Binsbergen, van W.M.J.; Docter, R.F.; Moormann, E.M.

1998-01-01

In 1987 and 1991 Martin Bernal published two volumes on the Afroasiatic roots of classical civilization. His theory that ancient Greek culture derived from Egypt and Phoenicia opened a discussion known as the debate on 'Black Athena'. This article sorts out whatever lasting contribution Bernal has

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.

Seedling-sapling growth variation in a southern Illinios black walnut provenance/progeny test

Science.gov (United States)

George Rink; J. W. Van Sambeek

1987-01-01

Nursery root and shoot measurements and annual height, basal diameter and survival data for the 5 years after outplanting were used to describe black walnut growth variation in southern Illinois. At age 5 sapling height narrow-sense heritability was found to be 0.49 for 131 open-pollinated families from across the black walnut comercial range. Greatest height and...

Root distribution pattern of flue-cured tobacco in light and heavy soils

International Nuclear Information System (INIS)

Nagaraj, G.; Gopalachari, N.C.

1977-01-01

Root distribution of flue-cured tobacco (variety : Kanakaprabha) in clayey and loamy sand soils was studied with the help of 32 P wick feeding technique. About 90 percent of the roots of tobacco plant in black soil on 40th day and in light soil on 60th day are present in a soil core of diameter 40 cm and depth 30 cm. On the 90th day of growth stage, no significant differences were observed in the root distribution of tobacco between the two types of soil. About 85 percent of the roots were present in a soil core of diameter 40 cm and depth 30 cm on 90th day in both the soils. (author)

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

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.

Derivation of Mutants of Erwinia carotovora subsp. betavasculorum Deficient in Export of Pectolytic Enzymes with Potential for Biological Control of Potato Soft Rot

Science.gov (United States)

Costa, José M.; Loper, Joyce E.

1994-01-01

Erwinia carotovora subsp. betavasculorum Ecb168 produces an antibiotic(s) that suppresses growth of the related bacterium Erwinia carotovora subsp. carotovora in culture and in wounds of potato tubers. Strain Ecb168 also produces and secretes pectolytic enzymes and causes a vascular necrosis and root rot of sugar beet. Genes (out) involved in secretion of pectolytic enzymes by Ecb168 were localized to two HindIII fragments (8.5 and 10.5 kb) of Ecb168 genomic DNA by hybridization to the cloned out region of E. carotovora subsp. carotovora and by complementation of Out- mutants of E. carotovora subsp. carotovora. Out- mutants of Ecb168, which did not secrete pectate lyase into the culture medium, were obtained when deletions internal to either HindIII fragment were introduced into the genome of Ecb168 through marker exchange mutagenesis. Out- mutants of Ecb168 were complemented to the Out+ phenotype by introduction of the corresponding cloned HindIII fragment. Out- mutants of Ecb168 were less virulent than the Out+ parental strain on potato tubers. Strain Ecb168 and Out- derivatives inhibited the growth of E. carotovora subsp. carotovora in culture, indicating that the uncharacterized antibiotic(s) responsible for antagonism was exported through an out-independent mechanism. Strain Ecb168 and Out- derivatives reduced the establishment of large populations of E. carotovora subsp. carotovora in wounds of potato tubers and suppressed tuber soft rot caused by E. carotovora subsp. carotovora. PMID:16349316

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.

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...

Effect of the planting material on the incidence of dry rot in Colocasia esculenta (L. Schott and Xanthosoma spp.

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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.

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.

Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

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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®.

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

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)

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.

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

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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.

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

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.

GENETIC RESOURCES OF ROOT VEGETABLES CROPS IN CENTRAL REGION OF RUSSIA

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V. E. Yudaeva

2017-01-01

Full Text Available As a result of the research carried out in 2013-2016, the viability and originality of 1157 accessions of root vegetables have been preserved. 250 breeding accessions of carrot, beetroot and radish have been assessed for different economically valuable traits in open field and laboratory tests. Out of them, 65 accessions were selected out as sources of economically valuable traits. The early-maturing accessions of radish, such as ‘Korsar’, ‘Francuzsky Zavtrak’, ‘Mikhnevsky 1’, ‘18 Dney’, ‘Koroleva Margo’, ‘Polyna’, ‘Rozovo-Krasny s Belym Konchikom’, ‘Sofit’, ‘Kvarta’, ‘Saksa’, ‘Variant’ were regarded. The carrot accessions, such as ‘Scarlet’, ‘Koroleva Oseni’, ‘Dlinnaya Krasnaya’ were distinguished as sources of high yield capacity. The sources of high root yield in beetroot were varieties: ‘Valenta’, ‘Mestnaya iz Madagaskara’, Goldiers Super Black Beet, Zwaans Early Red Chief. The long shelf-life during wintertime was observed in beetroot varieties: ‘Slowiblot’, ‘Valenta’, ‘Lomarina’. The varieties: ‘Nevezhes’, ‘Neger Schwarz Halblange’, ‘Goldiers Super Black Beet’ were distinguished by high root marketability. With the use of world plant collection at VIR, the following varieties of root vegetables: ‘Dar Podmoskovya’ in carrot; ‘Osennya Princessa’ in beetroot; ‘Mikhnevskiy 1 ‘in garden radish; ‘Osenniy Krasavets’ in daikon; ‘Albina’ in root parsley; ‘Atlant’ in parsnip; Moscowskiy Krasavets in celery, and ‘Oseniya Udacha’ in wild radish were developed. It was also shown those varieties that had high yield capacity and root marketability were distinguished by small epidermal cell structure and large number of stomata per unit of leaf surface. It may be supposed that the large number of stomata per unit of leaf surface and small epidermal cell structure was the evidence of adaptive capacity of accessions taken for the study. 

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.

26 - 30 Kutama

African Journals Online (AJOL)

DR. AMINU

wood popularly known as white rot. Wood and root rot basidiomycetes are occasional problem in desert plants including cliff rose, Canotia (Canotia holacantha) e.t.c (P.D.P, 2011). Also cacti which have a large amount of solid wood tissues may be invaded and decayed by wood rotting basidiomycetes (Uno et al., 2008).

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

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

Two-dimensional Root Phenotyping System Based on Root Growth on Black Filter Paper and Recirculation Micro-irrigation

Czech Academy of Sciences Publication Activity Database

Rattanapichai, W.; Klem, Karel

2016-01-01

Roč. 52, č. 2 (2016), s. 64-70 ISSN 1212-1975 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : image analysis * nutrient deficiency * root system architecture * spring barley Subject RIV: EH - Ecology, Behaviour Impact factor: 0.532, year: 2016

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.

Behavioural response of Heterorhabditis megidis towards plant roots and insect larvae

NARCIS (Netherlands)

Boff, M.I.C.; Tol, van R.W.H.M.; Smits, P.H.

2002-01-01

The behavioural response of infective juveniles (IJs) of Heterorhabditis megidis (strain NLH-E87.3) to cues from roots of strawberry (Fragaria x ananassa Duch.), thuja (Thuja occidentalis L.) and to larvae of the black vine weevil, Otiorhynchus sulcatus, was studied. Choice assays were conducted in

Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

Science.gov (United States)

Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

2014-05-01

Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses. Copyright © 2014. Published by Elsevier GmbH.

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

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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.

Carbon Dioxide and Methane Formation in Norway Spruce Stems Infected by White-Rot Fungi

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Ari M. Hietala

2015-09-01

Full Text Available Globally, billions of tons of carbon sequestered in trees are annually recycled back to the atmosphere through wood decomposition by microbes. In Norway, every fifth Norway spruce shows at final harvest infection by pathogenic white-rot fungi in the genera Heterobasidion and Armillaria. As these fungi can mineralize all components of wood, we predicted that they have a significant carbon footprint. Gas samples taken from infected stems were analyzed for CO2 and CH4 concentrations, and wood samples from different parts of the decay columns were incubated under hypoxic (4% O2 and anoxic laboratory conditions. In spring and summer the stem concentrations of CO2 were generally two times higher in trees with heartwood decay than in healthy trees. For most of the healthy trees and trees with heartwood decay, mean stem concentrations of CH4 were comparable to ambient air, and only some Armillaria infected trees showed moderately elevated CH4. Consistently, low CH4 production potentials were recorded in the laboratory experiment. Up-scaling of CO2 efflux due to wood decay in living trees suggests that the balance between carbon sequestration and emission may be substantially influenced in stands with high frequency of advanced root and stem heartwood decay.

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

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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.

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.

Producción artesanal del rotífero Philodina sp. y de algas para la alimentación de post-larvas de bocachico

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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

The Deconstruction of the Cartesian Dichotomy of Black and Whitein William Blake’s The Little Black Boy

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Ali Gunes

2015-12-01

Full Text Available The Deconstruction of the Cartesian Dichotomy of Black and Whitein William Blake’s The Little Black Boy Abstract This paper discusses English Romantic Poet William Blake’s anti-racial views in his poem The Little Black Boy. In so doing, it focuses upon how Blake attempts to deconstruct the Cartesian dichotomy of Western world view, a dichotomy which has usually been based on “the theory that the universe has been ruled from its origins by two conflicting powers, one good and one evil, both existing as equally ultimate first causes.” In this binary and hierarchal relationship, there are two essential terms in which one term is absolutely regarded as primary or fundamental in its essence, whereas the other term is considered secondary or something that lacks originality and presence. Once this equation is applied to the relationship between black and white people, it will easily be seen in the Western world that white people are always primary or fundamental to black-skinned people, and thus the perception behind this binary and hierarchal relationship seems the root of all the racial problems between black and white. This paper argues that Blake strives to deconstruct radically in The Little Black Boy the basis of this binary and hierarchal relationship which has been carried out for centuries in the Western world to segregate and then control the lives of black people. Finally, the paper maintains that Blake also shows a strong aspiration for creating an egalitarian society free of discrimination and injustices at a time when anti-slavery campaigns hit the top on both sides of Atlantic.

Historical Dialectics of Black Nationalist Movements in America.

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Turner, James E.

1977-01-01

The development of Africa-oriented social movements is divided into five periods: (1) the genesis of the return-to-Africa movement, 1790-1840; (2) the quest for nationality, 1845-1861; (3) the roots of Pan-Africanism, 1870-1915; (4) the Garvey movement, 1916-1930; and (5) the recent Black liberation movement, inspired by Malcolm X and operating in…

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.

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)

Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

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Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

2013-04-01

In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

Relational Teaching with Black Boys: Strategies for Learning at a Single-Sex Middle School for Boys of Color

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Nelson, Joseph Derrick

2016-01-01

Background/Context: Positive teacher-student relationships are critical for Black boys' learning across single-sex and coeducational environments. Limited attention to these relationships by school professionals is rooted in deficit-oriented conceptions of boyhood and Black masculinity. The popular message of deficiency and pathology is clear:…

How Does Salinity Shape Bacterial and Fungal Microbiomes of Alnus glutinosa Roots?

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Thiem, Dominika; Gołębiewski, Marcin; Hulisz, Piotr; Piernik, Agnieszka; Hrynkiewicz, Katarzyna

2018-01-01

Black alder (Alnus glutinosa Gaertn.) belongs to dual mycorrhizal trees, forming ectomycorrhizal (EM) and arbuscular (AM) root structures, as well as represents actinorrhizal plants that associate with nitrogen-fixing actinomycete Frankia sp. We hypothesized that the unique ternary structure of symbionts can influence community structure of other plant-associated microorganisms (bacterial and fungal endophytes), particularly under seasonally changing salinity in A. glutinosa roots. In our study we analyzed black alder root bacterial and fungal microbiome present at two forest test sites (saline and non-saline) in two different seasons (spring and fall). The dominant type of root microsymbionts of alder were ectomycorrhizal fungi, whose distribution depended on site (salinity): Tomentella, Lactarius, and Phialocephala were more abundant at the saline site. Mortierella and Naucoria (representatives of saprotrophs or endophytes) displayed the opposite tendency. Arbuscular mycorrhizal fungi belonged to Glomeromycota (orders Paraglomales and Glomales), however, they represented less than 1% of all identified fungi. Bacterial community structure depended on test site but not on season. Sequences affiliated with Rhodanobacter, Granulicella, and Sphingomonas dominated at the saline site, while Bradyrhizobium and Rhizobium were more abundant at the non-saline site. Moreover, genus Frankia was observed only at the saline site. In conclusion, bacterial and fungal community structure of alder root microsymbionts and endophytes depends on five soil chemical parameters: salinity, phosphorus, pH, saturation percentage (SP) as well as total organic carbon (TOC), and seasonality does not appear to be an important factor shaping microbial communities. Ectomycorrhizal fungi are the most abundant symbionts of mature alders growing in saline soils. However, specific distribution of nitrogen-fixing Frankia (forming root nodules) and association of arbuscular fungi at early stages of

Effect of sterilization on mineralization of straw and black carbon

OpenAIRE

Bobul'ská, Lenka; Bruun, Sander; Fazekašová, Danica

2013-01-01

The study was aimed at investigating the role of microorganisms in the degradation of BC (black carbon). CO evolution was measured under sterilized and non-sterilized soil using BC and straw amendments. Black carbon and straw were produced from homogenously C labelled roots of barley (Hordeum vulgare) with a specific activity 2.9 MBq g C. Production of BC was implemented at 300 °C for 24 h in a muffle oven, incubated in soil and C in the evolved CO was measured after 0.5, 1, 2, 4, 8, 16, 26 a...

Molecular Detection of Monilinia fructigena as Causal Agent of Brown Rot on Quince

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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.

Poly-γ-glutamic acid productivity of Bacillus subtilis BsE1 has positive function in motility and biocontrol against Fusarium graminearum.

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Wang, Luyao; Wang, Ning; Mi, Dandan; Luo, Yuming; Guo, Jianhua

2017-07-01

In this study, we investigate the relationship between γ-PGA productivity and biocontrol capacity of Bacillus subtilis BsE1; one bacterial isolate displayed 62.14% biocontrol efficacy against Fusarium root rot. The γ-PGA yield assay, motility assay, wheat root colonization assay, and biological control assay were analysed in different γ-PGA yield mutants of BsE1. The pgsB (PGA-synthase-CapB gene) deleted mutant of BsE1 reduced γ-PGA yield and exhibited apparent decline of in vitro motile ability. Deletion of pgsB impaired colonizing capacity of BsE1 on wheat root in 30 days, also lowered biocontrol efficacies from 62.08% (wild type BsE1) to 14.22% in greenhouse experiment against Fusarium root rot. The knockout of pgdS and ggt (genes relate to two γ-PGA degrading enzymes) on BsE1, leads to a considerable improvement in polymer yield and biocontrol efficacy, which attains higher level compared with wild type BsE1. Compared with ΔpgsB mutant, defense genes related to reactive oxygen species (ROS) and phytoalexin expressed changes by notable levels on wheat roots treated with BsE1, demonstrating the functional role γ-PGA plays in biocontrol against Fusarium root rot. γ-PGA is not only important to the motile and plant root colonization ability of BsE1, but also essential to the biological control performed by BsE1 against Fusarium root rot. Our goal in this study is to reveals a new perspective of BCAs screening on bacterial isolates, without good performance during pre-assays of antagonism ability.

EFIKASI TRICHODERMA HARZIANUM DENGAN BERBAGAI BAHAN ORGANIK DALAM PENGENDALIAN PENYAKIT BUSUK PANGKAL BATANG PADA LADA

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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.

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...

Primeira ocorrência de Pythium sp. E Rhizoctonia sp. causando podridão-de-raízes em ervais no Rio Grande do Sul

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Igor Poletto

2007-01-01

Full Text Available In 2004, some plantations of Ilex paraguariensis A. St.-Hil. In Taquari Valley, state of Rio Grande do Sul, started presenting growth stagnation, yellowing, leaf drop and necrosis in the root system, typical symptoms of root rot. Roots samples were collected in farms of two cities and sent for analysis at the Plant Disease Laboratory at the Department of Plant Protection/CCR/UFSM. The presence of Rhizoctonia and Pythium was diagnosed and these were pathogenic when inoculated in plants of erva-mate. This is the first observation of these two fungi causing root rot in erva-mate plantations in the state of Rio Grande do Sul, Brasil.

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

Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

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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.

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.

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.

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

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.

Optimization of Laccase Production using White Rot Fungi and Agriculture Wastes in Solid State Fermentation

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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.

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.

Fourier Transform Infrared Radiation Spectroscopy Applied for Wood Rot Decay and Mould Fungi Growth Detection

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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.

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.

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...

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.

Molecular identification and potential of an isolate of white rot fungi in bioremediation of petroleum contaminated soils

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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.

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.

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...

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

Efficacy of screening methods used in breeding for black pod ...

African Journals Online (AJOL)

The disease affects the pods, beans, flower cushions, leaves, stems and roots. The objective of this study was to evaluate the efficacy of resistance screening methods used in breeding black pod disease resistance in cocoa. The resistance of cocoa leaves and pods to Phytophthora palmivora was investigated in twenty five ...

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.

Chemical Characterization of Different Sumac and Pomegranate Extracts Effective against Botrytis cinerea Rots

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Flora V. Romeo

2015-06-01

Full Text Available Pomegranate (Punica granatum L. peel and sumac (Rhus coriaria L. fruit and leaf extracts were chemically characterized and their ability to inhibit table grape (cv. Italia rots caused by Botrytis cinerea was evaluated on artificially inoculated berries. Different extraction methods were applied and extracts were characterized through Ultra Fast High Performance Liquid Chromatography coupled to Photodiode array detector and Electrospray ionization Mass spectrometer (UPLC-PDA-ESI/MSn for their phenol and anthocyanin contents. The concentrated pomegranate peel extract (PGE-C was the richest in phenols (66.97 g gallic acid equivalents/kg while the concentrated sumac extract from fruits (SUF-C showed the highest anthocyanin amount (171.96 mg cyanidin 3-glucoside equivalents/kg. Both phenolic and anthocyanin profile of pomegranate and sumac extracts were quite different: pomegranate extract was rich in cyanidin 3-glucoside, pelargonidin 3-glucoside and ellagic acid derivatives, while sumac extract was characterized by 7-methyl-cyanidin 3-galactoside and gallic acid derivatives. The concentrated extracts from both pomegranate peel and sumac leaves significantly reduced the development of Botrytis rots. In particular, the extract from pomegranate peel completely inhibited the pathogen at different intervals of time (0, 12, and 24 h between treatment and pathogen inoculation on fruits maintained at 22–24 °C and high relative humidity (RH. This extract may represent a valuable alternative to control postharvest fungal rots in view of its high efficacy because of the low cost of pomegranate peel, which is a waste product of processing factories.

Controls on Ecosystem and Root Respiration in an Alaskan Peatland

Science.gov (United States)

McConnell, N. A.; McGuire, A. D.; Harden, J. W.; Kane, E. S.; Turetsky, M. R.

2010-12-01

Boreal ecosystems cover 14% of the vegetated surface on earth and account for 25-30% of the world’s soil carbon (C), mainly due to large carbon stocks in deep peat and frozen soil layers. While peatlands have served as historical sinks of carbon, global climate change may trigger re-release of C to the atmosphere and may turn these ecosystems into net C sources. Rates of C release from a peatland are determined by regional climate and local biotic and abiotic factors such as vegetation cover, thaw depth, and peat thickness. Soil CO2 fluxes are driven by both autotrophic (plant) respiration and heterotrophic (microbial) respiration. Thus, changes in plant and microbial activity in the soil will impact CO2 emissions from peatlands. In this study, we explored environmental and vegetation controls on ecosystem respiration and root respiration in a variety of wetland sites. The study was conducted at the Alaskan Peatland Experiment (APEX; www.uoguelph.ca/APEX) sites in the Bonanza Creek Experimental Forest located 35 km southwest of Fairbanks Alaska. We measured ecosystem respiration, root respiration, and monitored a suite of environmental variables along a vegetation and soil moisture gradient including a black spruce stand with permafrost, a shrubby site with permafrost, a tussock grass site, and a herbaceous open rich fen. Within the rich fen, we have been conducting water table manipulations including a control, lowered, and raised water table treatment. In each of our sites, we measured total ecosystem respiration using static chambers and root respiration by harvesting roots from the uppermost 20 cm and placing them in a root cuvette to obtain a root flux. Ecosystem respiration (ER) on a μmol/m2/sec basis varied across sites. Water table was a significant predictor of ER at the lowered manipulation site and temperature was a strong predictor at the control site in the rich fen. Water table and temperature were both significant predictors of ER at the raised

Molecular phylogeny of Laetiporus and other brown rot polypore genera in North America

Science.gov (United States)

Daniel L. Lindner; Mark T. Banik

2008-01-01

Phylogenetic relationships were investigated among North American species of Laetiporus, Leptoporus, Phaeolus, Pycnoporellus, and Wolfiporia using ITS, nuclear large subunit and mitochondrial small subunit rDNA sequences. Members of these genera have poroid hymenophores, simple septate hyphae and cause brown rots in a variety of...

Biological control of strawberry soil-borne pathogens Macrophomina phaseolina and Fusarium solani, using Trichoderma asperellum and Bacillus spp.

Directory of Open Access Journals (Sweden)

Ana María PASTRANA

2016-05-01

Full Text Available In south-western Spain, Macrophomina phaseolina and Fusarium solani were found to be associated in strawberry plants with, respectively, charcoal rot, and crown and root rot symptoms. For management of both fungal diseases, the antagonistic effects of two commercial formulations, one based on Trichoderma asperellum T18 strain (Prodigy® and the other on Bacillus megaterium and B. laterosporus (Fusbact®, were evaluated in vitro and under controlled environment and field conditions. Two inoculation methods (root-dipping and soil application and two application times (pre- and post-pathogen inoculation, as preventive and curative treatments, respectively were assessed. Dual plate confrontation experiments demonstrated the antagonistic effects of T. asperellum and Bacillus spp. by inhibiting radial growth of M. phaseolina and F. solani by more than 36%. Preventive application of T. asperellum by root-dipping reduced the incidence of charcoal rot (up to 44% in a growth chamber and up to 65% under field conditions and also reduced disease progression, the percentage of crown necrosis, as well as the level of infection measured as ng of pathogen DNA g-1 plant by quantitative real-time PCR. This treatment was also the most effective for reduction of crown and root rot caused by F. solani (up to 100% in a greenhouse and up to 81% under field conditions. These results were nearly comparable with the control achieved using chemical fungicides. The Bacillus spp.-based formulation was also effective for control of charcoal rot and showed variable results for control of F. solani, depending on the growth conditions.

The Fictional Black Blues Figure: Blues Music and the Art of Narrative Self-Invention

OpenAIRE

Mack, Kimberly

2015-01-01