scholarly journals Study of Associated Fungal Pathogens on Seeds of Eruca sativa Mill., (Gargeer) 

Author(s):  
M.P. Sujata

The aim of the present study is to identification and classification of different associated fungi from the seeds of Eruca sativa. Total 10 species of fungal pathogens belonging to 7 genera are isolated from the Saudi (Ss) and Indian seeds of Eruca sativa. Saudi seeds affected by the fungal pathogens namely, A. niger, A. flavus, A fumigates, Mucor spp., Pencillium spp., while Indian seeds affected by Aspergillus niger, A. flavus, A. fumigates, Aspergillus terreus, Pencillium spp., Mucor spp., Rhizopus stolonifer, Humicola insolens, Colletotrichum gloeosporioides, Fusarium oxysporum. However, many of the soil borne or seed borne associated fungal pathogens spread the diseases in plants as well as in human beings. So the present study reveals that, the proper identification of fungal pathogens and their symptoms are easily recognized. Then the prevention care could be taken during the agriculture and high yield produced before the spread of symptoms and diseases.

Author(s):  
O. O. Kolawole ◽  
C. I. Iloyanomon ◽  
M. O. Ogunlade

Aim: This study was designed to isolate fungal pathogens associated with damping-off of cashew seedlings. Study Design: The cashew seedlings for this study were selected randomly from a number of infected cashew seedlings in the screen house. Methodology: Associated fungal pathogens were grown on potato dextrose agar (PDA) and identified using their characteristics and morphological features observed under the microscope with reference to published identification manuals. Results: The result showed that damping-off of cashew seedling is mostly associated with fungal pathogens such as such as Fusarium spp, Colletotrichum gloeosporioides, Pythium spp., Alternaria sp., Curvularia sp., Aspergillus niger, and Lasiodiplodia theobromae. However, Fusarium spp, and Pythium spp. were predominant and frequently isolated than other pathogens. Conclusion: The knowledge of these pathogens is important for designing strategies to safeguard cashew plant health against diseases in order to ensure sustainable cashew production in Nigeria.


Author(s):  
ABM Ruhul Amin ◽  
MM Rashid ◽  
MB Meah

An experiment was conducted to find out the efficacy of garlic tablets in controlling seed-borne fungal pathogens of cucumber. Suspention of garlic tablet was prepared in water at the concentrations of 1:3, 1:4, 1:5 and 1:6. Seeds of cucumber were treated with the suspentions for 15 minutes. Seeds under control were treated with plain water. Seven fungal pathogens, namely Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Fusarium moniliforme, Penicillium spp., Doratomycetes sp. and Rhizopus stolonifer were found to be associated with the cucumber seeds. Their prevalence ranged from 1.0-8.0, 1.0-4.0, 1.0-15.0, 1.0-8.0, 0.0-9.0, 1.0-17.0 and 0.0-12.0% respectively under different treatments including control. All concentrations of the material caused significant decrease in the prevalence of seed-bornefungi, occurrence of abnormal seedlings and rotten seeds as compared to control. On the other hand, germination increased over control due to seed treatment with garlic tablet. The higher increase in germination and reduction in occurrence of seed-borne fungi, rotten seed and abnormal seedling were corroborated with higher doses of garlic tablet. Key words: Garlic tablet; cucumber seed; seed treatment; fungal pathogens; control. DOI: 10.3329/jard.v7i1.4433 J Agric Rural Dev 7(1&2), 135-138, June 2009


2009 ◽  
Vol 62 ◽  
pp. 402-402
Author(s):  
S.L. Lewthwaite ◽  
P.J. Wright

The predominant diseases of the commercial kumara (Ipomoea batatas) or sweetpotato crop are caused by fungal pathogens The field disease pink rot results from infection by the fungus Sclerotinia sclerotiorum Lesions form on vines but may spread down stems to the roots The widespread nature of this disease in sweetpotato appears peculiar to New Zealand Scurf is a disease caused by Monilochaetes infuscans which occurs in the field but may proliferate amongst stored roots The disease causes a superficial discolouration of the root surface which is mainly cosmetic but can also increase root water loss in storage Infection by Ceratocystis fimbriata produces a disease known as black rot The disease can be transmitted amongst plants at propagation but is particularly rampant amongst roots in storage This disease is readily transmitted and can cause severe economic loss Fusarium oxysporum causes surface rots in stored roots characterised by light to dark brown lesions that tend to be firm dry and superficial The lesions may be circular and centred on wounds caused by insects or mechanical damage at harvest Soft rot caused by Rhizopus stolonifer generally occurs in roots after they are washed and prepared for the market Fungal infection occurs through wounds or bruised tissue producing distinctive tufts of white fungal strands and black spores


Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.


2006 ◽  
Vol 31 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Derblai Casaroli ◽  
Danton C. Garcia ◽  
Marlove F. B. Muniz ◽  
Nilson L. de Menezes

O trabalho teve como objetivos avaliar e correlacionar a qualidade sanitária e fisiológica de sementes de abóbora, variedade Menina Brasileira (Cucurbita moschata.). Foram avaliados dois lotes de sementes de abóbora produzidas no sistema agroecológico e quatro no sistema convencional, com e sem tratamento químico. Os lotes foram submetidos aos testes de sanidade, seguindo a metodologia do "Blotter test", com congelamento, germinação e vigor (primeira contagem, índice de velocidade de germinação, envelhecimento acelerado e emergência de plântulas). Os resultados indicaram a separação dos lotes de diferentes origens a partir da qualidade sanitária e fisiológica, onde as maiores incidências de fungos foram observadas nos lotes agroecológicos e o maior potencial fisiológico foi observado nos lotes de origem convencional não tratados. Foram encontrados os fungos Fusarium oxysporum, Alternaria alternata, Cladosporium cucumerinum, Aspergillus niger, Penicillium digitatum, Rhizopus stolonifer e Phoma terrestris. A qualidade sanitária não interferiu na qualidade fisiológica das sementes de abóbora, variedade Menina Brasileira.


2001 ◽  
Vol 64 (5) ◽  
pp. 741-743 ◽  
Author(s):  
DANTE J. BUENO ◽  
JULIO O. SILVA ◽  
GUILLERMO OLIVER

This article reports on the identification of mycoflora of 21 dry pet foods (12 belonging to dogs and 9 to cats) that corresponded to 8 commercial brands made in Argentina and imported. The isolation frequency and relative density of the prevalent fungal genera are compared too. Ten genera and fungi classified as Mycelia sterilia were identified. The predominant genera were Aspergillus (62%), Rhizopus (48%), and Mucor (38%). The most prevalent among Aspergillus was Aspergillus flavus followed by Aspergillus niger and Aspergillus terreus. The predominant Mucor was Mucor racemosus followed by Mucor plumbeus and Mucor globosus. The moisture content of these foods ranged from 5.6 to 10.0% and from 7.2 to 9.9% for dog and cat foods, respectively. A greater moisture content in food for the senior category (9.5 ± 0.2) was observed only in comparison to adult and kitten/puppy. If the moisture content can be maintained at these levels, mold growth would be prevented or at least it would remain at an insignificant level. Some genera and species isolated and identified from the foods analyzed are potentially producing toxins, which are known as mycotoxins. This involves a risk for animal health.


2009 ◽  
Vol 81 (3) ◽  
pp. 367-380 ◽  
Author(s):  
Luis E. C. Andrade

Human beings have taken successive approaches for the understanding and management of diseases. Initially brewed in supernatural concepts and mystical procedures, a vigorous scientific approach has emerged on the grounds of fundamental disciplines such as anatomy, microbiology, biochemistry, physiology, immunology, pathology, and pharmacology. The resulting integrated knowledge contributed to the current classification of diseases and the way Medicine is carried out today. Despite considerable progress, this approach is rather insufficient when it comes to systemic inflammatory conditions, such as systemic lupus erythematosus, that covers clinical conditions ranging from mild pauci-symptomatic diseases to rapidly fatal conditions. The treatment for such conditions is often insufficient and novel approaches are needed for further progress in these areas of Medicine. A recent breakthrough has been achieved with respect to chronic auto-inflammatory syndromes, in which molecular dissection of underlying gene defects has provided directions for target-oriented therapy. Such approach may be amenable to application in systemic auto-immune diseases with the comprehension that such conditions may be the consequence of interaction of specific environmental stimuli and an array of several and interconnected gene polymorphisms. On the bulk of this transformation, the application of principles of pharmacogenetics may lead the way towards a progressively stronger personalized Medicine.


2009 ◽  
Vol 76 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Dominik Mojzita ◽  
Marilyn Wiebe ◽  
Satu Hilditch ◽  
Harry Boer ◽  
Merja Penttilä ◽  
...  

ABSTRACT d-Galacturonic acid can be obtained by hydrolyzing pectin, which is an abundant and low value raw material. By means of metabolic engineering, we constructed fungal strains for the conversion of d-galacturonate to meso-galactarate (mucate). Galactarate has applications in food, cosmetics, and pharmaceuticals and as a platform chemical. In fungi d-galacturonate is catabolized through a reductive pathway with a d-galacturonate reductase as the first enzyme. Deleting the corresponding gene in the fungi Hypocrea jecorina and Aspergillus niger resulted in strains unable to grow on d-galacturonate. The genes of the pathway for d-galacturonate catabolism were upregulated in the presence of d-galacturonate in A. niger, even when the gene for d-galacturonate reductase was deleted, indicating that d-galacturonate itself is an inducer for the pathway. A bacterial gene coding for a d-galacturonate dehydrogenase catalyzing the NAD-dependent oxidation of d-galacturonate to galactarate was introduced to both strains with disrupted d-galacturonate catabolism. Both strains converted d-galacturonate to galactarate. The resulting H. jecorina strain produced galactarate at high yield. The A. niger strain regained the ability to grow on d-galacturonate when the d-galacturonate dehydrogenase was introduced, suggesting that it has a pathway for galactarate catabolism.


2004 ◽  
pp. 147-176
Author(s):  
Stanimir Rakic

In this paper I examine compound names of plants, animals, human beings and other things in which at least one nominal component designates a part of the body or clothes, or some basic elements of houshold in Serbian and English. The object of my analysis are complex derivatives of the type (adjective noun) + suffix in Serbian and componds of the type noun's + noun, noun + noun and adjective + noun in English. I try to show that there is a difference in metaphorical designation of human beings and other living creatures and things by such compound nouns. My thesis is that the metathorical designation of human beings by such compounds is based on the symbolic meaning of some words and expressions while the designation of other things and beings relies on noticed similarity. In Serbian language such designation is provided by comples derivatives praznoglavac 'empty-headed person', tupoglavac 'dullard' debolokoiac 'callos person', golobradac 'young, inexperienced person' zutokljunac 'tledling' (fig), in English chicken liver, beetle brain birdbrain, bonehead, butterfingers, bigwig, blackleg, blue blood bluestocking, eat's paw, deadhead,fat-guts,fathead, goldbrick (kol) hardhat, hardhead, greenhorn, redcoat (ist), redneck (sl), thickhead, etc. Polisemous compounds like eat's paw lend support for this thesis because their designation of human beings is based on symbolic meaning of some words or expressions. I hypothesize that the direction and extend of the possible metaphorization of names may be accounted for by the following hierarchy (11) people - animals - plants - meterial things. Such hierarchy is well supported by the observations of Lakoff (1987) and Taylor (1995) about the role of human body in early experience and perception ofthe reality. Different restrictions which may be imposed in the hierarchy (11) should be the matter of further study, some of which have been noted on this paper. The compounds of this type denoting people have metaphorically meaning conected with some pejorative uses. These compounds refer to some psychological or characteral features, and show that for the classification of people such features are much more important than physical properties. While the animals and plants are classified according to some charecteristics of their body parts, people are usually classified according to psychollogical characteristics or their social functions. I have also noted a difference in structure between compounds designation animals and those designating plants and other things. The designation of animals relies more on metonymy, and that of plants and other things on metaphor based on comparision of noticed similarities. In the compounds designating animals, the nominal component relatively seldom refers to the parts of plants or other things. I guess that the cause may be the fact that the anatomy of plants is very different from the anatomy of animals. As a consequence the structure adjective + noun is much more characteristic of the compounds designating animals in English than the structure noun's + noun, and the same holds, although in a lesser degree for the compounds designating humans. It is also noticeable that in English compounds whose second component a part of body or clothes the first component rarely designates animals. On the other hand the compounds (9), in which the nominal head refers to some superordinate species, the first component often designates animal species, but usually of a very different kind. These data seem to lend support for Goldvarg & Gluksberg's thesis (1998) that metaforical interpretation is favoured if the nominal constituents denote quite different entities.


Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 815-815 ◽  
Author(s):  
B. A. Latorre ◽  
S. C. Viertel ◽  
I. Spadaro

Severe outbreaks of bunch rots (BR) have occurred recently during harvest of table grapes (Vitis vinifera L.) in Chile. Previously, BR was almost exclusively associated with Botrytis cinerea Pers.:Fr. (2,3); however, in 2000 to 2002, BR symptoms were associated with black molds and possibly nonfilamentous yeasts and bacteria. Cvs. Thompson Seedless, Flame Seedless, Ruby Seedless, and Red Globe were severely affected. Symptoms start at the pedicels as soft, watery rots that partially or completely decay infected berries. Longitudinal cracks are produced, a black mold usually develops along the crack fissures, and the skin of the berry turns light gray. Isolations on potato dextrose agar acidified with 1 N lactic acid (APDA) at 0.5 ml/liter, consistently yielded Rhizopus stolonifer (Ehrenb. ex Fr.) Vuillemin and Aspergillus niger Tiegh. R. stolonifer on APDA produced a white-to-gray aerial and nonseptate mycelium, black and globose sporangia with an elliptical collumela, one-celled, globose to oval, striated, almost hyaline sporangiospores, rhizoids, and stolons. A. niger produced septate mycelium. Single-celled, black, rough walled, globose conidia developed on short chains on the second phialides at the tip of globose, upright conidiophores. Mature (soluble solids >16%) detached berries of cv. Thompson Seedless were inoculated with sporangiospores (≈107 spores per ml) of R. stolonifer isolates RS6, RS52, RS73, and RS79 and conidia (≈108 conidia per ml) of A. niger isolates AN12, AN69, and AN75. When berries were aseptically punctured with a sterile hypodermic syringe prior to inoculation, 60 to 86.7% and 42.5 to 100% of berries were infected with R. stolonifer and A. niger, respectively, and both developed BR symptoms (significantly different from control berries) after 48 h in humid chambers at 23°C. Injuries were needed for infection since no infection or only 23.3% of noninjured berries were infected with R. stolonifer and A. niger, respectively. For both pathogens, there was a significant (P < 0.043) interaction between isolates and the presence or absence of injuries. Both pathogens were successfully reisolated on APDA. Fungicide sensitivity tests were performed on detached cv. Thompson Seedless berries challenged by placing an ≈6 μl-drop of inoculum suspension (106 or 107 spores per ml of R. stolonifer isolate RS52 and A. niger isolate AN12, respectively) on injured berries. Pyraclostrobin (0.067 mg/ml) mixed with nicobifen at 0.134 mg/ml (BAS 516 01 F at 0.201 mg a.i./ml, BASF) and copper oxide at 1.2 mg/ml (Cuprodul 60 WP, Quimetal Chile) significantly (P < 0.01) inhibited infection (100% control) by R. stolonifer and A. niger. R. stolonifer was completely controlled by dicloran at 1.88 mg/ml (Botran 75 WP) and partially controlled by captan at 1.6 mg/ml (Captan 80 WP), but A. niger was not controlled by either fungicide. To our knowledge this is the first report of R. stolonifer causing BR of table grape in Chile (4). The severe outbreaks may be associated with warm weather conditions during harvest and injuries caused by birds, insects, or cultural practices. Infection caused by R. stolonifer or A. niger may be followed by sour rot organisms (yeasts or bacteria), as has been suggested elsewhere (1,2). References: (1) E. Gravot et al. Phytoma 543:36, 2001. (2) W. B. Hewitt Page 26 in: Compendium of Grape Diseases, American Phytopathological Society, St. Paul, MN, 1994. (3) B. A. Latorre and G. Vásquez. Aconex (Chile) 52:16, 1996. (4) F. Mujica and C. Vergara. Flora Fungosa Chilena. Universidad de Chile, Facultad de Agronomiacute;a, Santiago, Chile, 1980.


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