Interactions between Sclerotinia sclerotiorum and other fungi on the phylloplane of lettuce

1987 ◽  
Vol 65 (8) ◽  
pp. 1633-1637 ◽  
Author(s):  
J. Mercier ◽  
R. D. Reeleder

Selected fungi recovered from the phylloplane of lettuce were assayed, using in vitro and in vivo techniques, to determine their effectiveness as antagonists of ascospores of the lettuce drop pathogen, Sclerotinia sclerotiorum. On leaf discs, Trichoderma viride, Alternaria alternata, and Epicoccum purpurascens significantly reduced ascospore germ-tube elongation by 34.2, 60.6, and 38.3%, respectively. On whole plants, these three fungi significantly reduced infection by 40–93.3%. Isolates of Cladosporium cladosporioides and a red yeast inhibited ascospore elongation significantly in the in vitro leaf disc assay but failed to provide significant protection against infection by S. sclerotiorum in the in vivo whole-plant assay. Observations with the scanning electron microscope indicated that hyphae of T. viride and A. alternata came into close contact with ascospores on the leaf surface, suggesting parasitic relationships. Hyphae of E. purpurascens did not come into direct contact with ascospores and inhibition may have been due to production of antifungal compounds.

2014 ◽  
Vol 49 (1) ◽  
pp. 87-92
Author(s):  
Tatiana-Eugenia Şesan

<em>In vitro </em>relationships between identified seed- and soil-borne fungi from rape samples have been investigated in order to evaluate their antagonistic ability as potential biocontrol agents. The bioproduct obtained from the <em>Trichoderma viride </em>Pers. (strain Td50) has been tested <em>in vivo </em>against the main phytopathogens of rape: <em>Sclerotinia sclerotiorum </em>(Lib.) de Bary, <em>Botrytis cinerea </em>Pers., <em>Alternaria </em>spp. and <em>Fusarium </em>spp. in greenhouse at the Laboratory of Mycology and Plant Pathology, Biology Faculty, University of Bucharest – Romania and in the field at the Agricultural Experimental Research-Development Station Caracal (AERDS), Olt district. The <em>T. viride </em>(strain Td50) bioproduct formulated as a powder for the seed treatment has been effective in the protection of rape plantlets against the above mentioned phytopathogens.


1973 ◽  
Vol 81 (3) ◽  
pp. 533-536 ◽  
Author(s):  
K. W. Moir

SUMMARYIn oven-dried whole plants from three regrowths of four varieties of Panicum maximum, leaf and stem of normal and stunted oats at three stages of first growth, leaf and stem of rape and the whole plant of millet, cell wall ranged from 14 to 77% of the organic matter. In vitro digestible cell wall ranged from 13 to 46% of the organic matter and was closely related to the cell wall (residual standard deviation, ± 2·5). In 16 legume hays the average in vitro digestible cell wall was 22·1% of the forage organic matter compared with an average value of 20·5% found previously from in vivo digestibility experiments with legumes. An unsatisfactory feature of the in vitro digestibility determination was that in silages and low quality grass hays, the digestible cell wall was low relative to known in vivo values for these forage types. The separate determinations of cell wall and in vitro digestible cell wall would add to the confidence that can be placed on estimates of in vivo digestibility from laboratory measurements. Often, the determination of cell-wall content is sufficient for this purpose.


Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 421-428 ◽  
Author(s):  
William L. Patzoldt ◽  
Patrick J. Tranel

In a survey of herbicide responses among Illinois waterhemp half-sib populations, several were observed with differential responses to imazethapyr and thifensulfuron, two acetolactate synthase (ALS)–inhibiting herbicides. Plants from two waterhemp populations were verified resistant to imazethapyr, but susceptible to chlorimuron, using a nondestructive leaf-disc assay. Sequencing of the ALS gene revealed that imazethapyr-resistant waterhemp plants from both populations had inferred amino acid substitutions at position 653 of ALS. Depending on the population, the serine at position 653 of ALS was substituted with either asparagine (S653N) or threonine (S653T). Waterhemp lines were derived from each population to create uniformly imidazolinone-resistant (IR) waterhemp biotypes, designated IR-62 and IR-101. ALS-inhibitor responses of each IR biotype were compared with a previously identified ALS inhibitor–resistant biotype with a tryptophan to leucine substitution at position 574 (W574L) and an herbicide-susceptible control. Whole-plant dose–response experiments with waterhemp biotypes containing W574L, S653N, or S653T mutations indicated that each biotype was resistant to imazethapyr, but only the biotype with a W574L mutation was resistant to thifensulfuron. In vitro ALS-activity assays revealed unique patterns of cross-resistance among protein extracts derived from each biotype in response to imazethapyr, thifensulfuron, cloransulam, and pyrithiobac. In conclusion, three different forms of target-site–based resistance to ALS inhibitors have been identified in waterhemp.


2020 ◽  
Vol 16 (8) ◽  
pp. 1147-1156
Author(s):  
Ruchi Singh ◽  
Syed M. Hasan ◽  
Amit Verma ◽  
Sanjay K. Panda

Background: A plant is a reservoir of potentially useful active chemical entities which act as drugs as well as intermediates for the discovery of newer molecules and provide newer leads for modern drug synthesis. The demand for new compounds in the field of medicine and biotechnology is centuries old and with a rise in chronic diseases and resistance to existing drugs in the field of anti-infective agents, the chemicals obtained from plant sources have been an area of attraction. The whole plant has possessed multiple pharmacological activities. This is scientifically established by in-vivo and in-vitro studies. Methods: Various electronic databases such as PubMed, Science Direct, Scopus and Google were searched to collect the data of the present review. All the collected information is categorized into different sections as per the aim of the paper. Results: Fifty-six research and review papers have been studied and were included in this review article. After a detailed study, we provide a significant description of various phytochemicals present in Nyctanthes arbor-tristis Linn., which is responsible for various pharmacological activities. Twenty of studied articles gives a general introduction and ethnobotanical information about the plant, two papers contained microscopic detail of leaf and fruit. Twenty papers contained information about the phytoconstituents present in different parts of Nyctanthes arbor-tristis plant and fourteen articles reported pharmacological activities like antioxidant, anti-inflammatory, antiarthritic, antimicrobial and immunobiotic activity. Conclusion: This review explores the published research work comprising the ethnobotanical description of the subjected plant, distribution, phytochemical profile, and arthritis-related pharmacological activities.


BioControl ◽  
2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  

AbstractUtilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.


1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon

1. Two fungi, Coniothyrium minitans Campbell and Trichoderma viride Pers. ex Fr., were grown on autoclaved crushed sclerotia of the species Sclerotinia sclerotiorum, which they parasitize. 2. in vitro the crude culture filtrates would lyse walls isolated from hyphal cells or the inner pseudoparenchymatous cells of the sclerotia, in which a branched β-(1→3)-β-(1→6)-glucan, sclerotan, is a major constituent. 3. Chromatographic fractionation of the enzymes in each culture filtrate revealed the presence of several laminarinases, the most active being an exo-β-(1→3)-glucanase, known from previous studies to attack sclerotan. Acting alone this brought about a limited degradation of the glucan, but the addition of fractions containing an endo-β-(1→3)-glucanase led to almost complete breakdown. A similar synergism between the two enzymes was found in their lytic action on cell walls. 4. When acting alone the endo-β-(1→3)-glucanase had a restricted action, the products including a trisaccharide, tentatively identified as 62-β-glucosyl-laminaribiose. 5. These results are discussed in relation to the structure of the cell walls and of their glucan constituents.


2017 ◽  
Vol 52 (12) ◽  
pp. 1140-1148 ◽  
Author(s):  
Patrícia Elias Haddad ◽  
Luis Garrigós Leite ◽  
Cleusa Maria Mantovanello Lucon ◽  
Ricardo Harakava

Abstract: The objective of this work was to evaluate, in vitro and in vivo, the potential of Trichoderma spp. strains to control Sclerotinia sclerotiorum in soybeans (Glycine max) and to perform the molecular identification of the best perfoming strains. The effect of 120 strains of Trichoderma spp. on the viability of S. sclerotiorum sclerotia was evaluated in vitro through immersion in suspension of conidia from the antagonists and plating in culture medium. The best performing strains were evaluated in vivo, in a greenhouse, for control of the pathogen inoculated on 'Pintado' soybean seeds and plants. Of the 120 strains tested in vitro, 22 strains of Trichoderma spp. caused 100% inhibition of sclerotia germination. In the greenhouse, five strains inhibited the negative effect of the pathogen on seed germination and two strains increased in up to 67% plant dry matter. The best performing strains were identified as T. koningiopsis (3 strains), T. asperelloides (3), T. atroviride (2), and T. virens (1). Trichoderma strains are able to protect soybean plants from the harmful effect of S. sclerotiorum and, at the same time, they can promote the growth of the aerial part in greenhouse conditions.


2010 ◽  
Vol 2 (3) ◽  
pp. 72-76 ◽  
Author(s):  
Bilal Ahmad PADDER ◽  
Prem Nath SHARMA ◽  
Renu KAPIL ◽  
Anju PATHANIA ◽  
Om Prakash SHARMA

Three bioagents (Trichoderma viride, T. harzianum and Gliocladium virens) and five biopesticides (Achook, Neemgold, Wannis, Spictaf and Neemazal) were evaluated under in vitro and in vivo conditions against Colletotrichum lindemuthianum. All the three antagonistic fungi caused significant inhibition of mycelial growth, maximum being with T. viride (69.21%) followed by T. harzianum (64.20%). Among the biopesticides tested at four concentrations, Wanis applied @ 1000 ?l/ml caused maximum inhibition of 82.12 per cent followed by Spictaf (52.85%). T. viride and Wanis @ 1000 ?l/ml were most effective in reducing the seed borne infection. Integration of bioagents with Bavistin showed that disease can be effectively managed with seed dressing either with Bavistin or biopesticide followed by foliar treatment with fungicide or biopesticide.


2018 ◽  
Vol 10 (4) ◽  
pp. 279-284
Author(s):  
Zh. Ivanova ◽  
K. Vasileva ◽  
N. Velkov ◽  
S. Grozeva

Abstract. Powdery mildew, caused by Podosphaera xanthii and Golovinomyces cichoracearum, is an economically important disease in melon worldwide. Genetic resistance is one of the most suitable strategies to control powdery mildew. During the last few years several races of the pathogens have been reported. The need to develop resistant varieties is a challenge for each breeding program. Leaf disc assay was used in phytopathology and breeding programs as a rapid and reliable method for evaluation of disease resistance in a large number of plant materials. The purpose of this study was to establish species and races of powdery mildew in Plovdiv region, South Central Bulgaria; to develop a suitable system of pathogen isolation and cultivation; to determine the resistance levels in different melon genotypes available in Maritsa Vegetable Crops Research Institute (MVCRI) - Plovdiv collection by the leaf disc assay. Fifty-three melon genotypes, including lines, varieties, hybrids and ten differential lines were tested. The data showed that causal agent of powdery mildew was race 1 of P. xanthii in Plovdiv region. Our experimental results indicated that for the long-term storage of powdery mildew it is preferable to keep a whole plant under in vitro conditions. This allows the preservation of powdery mildew for two months before transferring on a new tissue. Thirty-four of the tested melon genotypes reacted as immune or resistant and nineteen as susceptible. Resistant melon genotypes are a suitable source in initiating a new breeding program aimed to increase resistance to powdery mildew.


2009 ◽  
Vol 3 (2) ◽  
pp. 48-64
Author(s):  
Kadhim M. Ibrahim ◽  
Shaimaa A. Yousir

Several experiments were carried out to study heavy metal tolerance in tissue cultures or whole plants of S. grandiflora., Callus was induced and maintained on modified Murashige and Skoog, 1962 medium (MS) supplemented with (0.5)mg/l benzyl adenine and (2)mg/l 2,4-phenoxy acetic acid . Heavy metals (Cd, Co, Cu, Cr or Zn) were added to the culture medium at different concentrations as contamination agents. In order to asses the effect of these heavy metals on seed germination; seeds were sown in soil contaminated with different concentrations of heavy metals for 3 weeks. Atomic Absorption Spectrophotometer was used for analysis of samples taken from whole plants and callus cultures. Results showed that callus fresh weight decreased with increasing heavy metal concentration in cultural medium. Germination percentages and plant heights increased over time. However, a reduction occurred in these parameters with increasing heavy metal levels. Percentages of metals accumulated in calli were (0.001, 0.011, 0.012 and 0.013%) at (0.0, 0.05, 0.075 and 0.1)mg/l Cd respectively; (0.001, 0.008, 0.016 and 0.006%) at (0.0, 0.1, 0.25 and 0.5)mg/l Co respectively; (0.001, 0.020, 0.034 and 0.015%) at (0.0, 0.075, 0.2 and 0.5)mg/l Cu respectively; (0.001, 0.013, 0.012 and 0.010%) at (0.0, 0.25, 0.4 and 0.5)mg/l Cr respectively and (0.027, 0.051, 0.059 and 0.056%) at (0.0 , 0.75, 1.0 and 1.5)mg/l Zn respectively. Percentages of metals accumulated in whole plants were (0.08, 0.55, 1.11, 0.83 and 0.44%) at (0.0, 1.0, 2.0, 3.0 and 4.0)mg/Kg soil Cd respectively; (0.11, 0.22, 0.55, 0.47 and 0.44%) at (0.0, 15.0, 30.0 45.0 and 60.0)mg/Kg soil Co respectively; (0.01, 0.10, 0.57, 0.58 and 0.72%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cu respectively. (0.08, 0.80, 1.28, 1.31 and 0.88%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cr respectively and (0.06, 1.11, 1.20, 1.83 and 2.22%) at (0.0, 100.0, 200.0, 300.0 and 400.0)mg/Kg soil Zn respectively.


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