scholarly journals Hidden Host Plant Associations of Soilborne Fungal Pathogens: An Ecological Perspective

2013 ◽  
Vol 103 (6) ◽  
pp. 538-544 ◽  
Author(s):  
Glenna M. Malcolm ◽  
Gretchen A. Kuldau ◽  
Beth K. Gugino ◽  
María del Mar Jiménez-Gasco
Keyword(s):  
Host Plant ◽  
Population Biology ◽  
Fungal Pathogens ◽  
Current Knowledge ◽  
Vascular Plant ◽  
Disease Symptoms ◽  
Nonhost Plant ◽  
Plant Associations ◽  
Definition Of ◽  
Forest Plants

Much of the current knowledge on population biology and ecology of soilborne fungal pathogens has been derived from research based on populations recovered from plants displaying disease symptoms or soil associated with symptomatic plants. Many soilborne fungal pathogens are known to cause disease on a large number of crop plants, including a variety of important agronomical, horticultural, ornamental, and forest plants species. For instance, the fungus Verticillium dahliae causes disease on >400 host plants. From a phytopathological perspective, plants on which disease symptoms have not been yet observed are considered to be nonhosts for V. dahliae. This term may be misleading because it does not provide information regarding the nature of the plant–fungus association; that is, a nonhost plant may harbor the fungus as an endophyte. Yet, there are numerous instances in the literature where V. dahliae has been isolated from asymptomatic plants; thus, these plants should be considered hosts. In this article, we synthesize scattered research that indicates that V. dahliae, aside from being a successful and significant vascular plant pathogen, may have a cryptic biology on numerous asymptomatic plants as an endophyte. Thus, we suggest here that these endophytic associations among V. dahliae and asymptomatic plants are not unusual relationships in nature. We propose to embrace the broader ecology of many fungi by differentiating between “symptomatic hosts” as those plants in which the infection and colonization by a fungus results in disease, and “asymptomatic hosts” as those plants that harbor the fungus endophytically and are different than true nonhosts that should be used for plant species that do not interact with the given fungus. In fact, if we broaden our definition of “host plant” to include asymptomatic plants that harbor the fungus as an endophyte, it is likely that the host ranges for some soilborne fungal pathogens are much larger than previously envisioned. By ignoring the potential for soilborne fungal pathogens to display endophytic relationships, we leave gaps in our knowledge about the population biology and ecology, persistence, and spread of these fungi in agroecosystems.

scholarly journals Adaptation of flea beetles to Brassicaceae: host plant associations and geographic distribution of Psylliodes Latreille and Phyllotreta Chevrolat (Coleoptera, Chrysomelidae)

ZooKeys ◽  
2019 ◽  
Vol 856 ◽  
pp. 51-73 ◽  
Author(s):  
Matilda W. Gikonyo ◽  
Maurizio Biondi ◽  
Franziska Beran
Keyword(s):  
Host Plant ◽  
Host Plants ◽  
Current Knowledge ◽  
Flea Beetle ◽  
Chemical Defence ◽  
Plant Associations ◽  
Molecular Phylogenetic ◽  
Related Plant ◽  
Plant Families ◽  
Almost All

The cosmopolitan flea beetle genera Phyllotreta and Psylliodes (Galerucinae, Alticini) are mainly associated with host plants in the family Brassicaceae and include economically important pests of crucifer crops. In this review, the host plant associations and geographical distributions of known species in these genera are summarised from the literature, and their proposed phylogenetic relationships to other Alticini analysed from published molecular phylogenetic studies of Galerucinae. Almost all Phyllotreta species are specialised on Brassicaceae and related plant families in the order Brassicales, whereas Psylliodes species are associated with host plants in approximately 24 different plant families, and 50% are specialised to feed on Brassicaceae. The current knowledge on how Phyllotreta and Psylliodes are adapted to the characteristic chemical defence in Brassicaceae is reviewed. Based on our findings we postulate that Phyllotreta and Psylliodes colonised Brassicaceae independently from each other.

Addition of fungal diseases of forest plants from Jalna (MS) India

2021 ◽  
Vol 27 (2) ◽  
Author(s):  
Navalsingh J. Todawat
Keyword(s):  
Fungal Pathogens ◽  
Field Survey ◽  
Fungal Disease ◽  
Fungal Diseases ◽  
Diseased Plant ◽  
Plant Leaves ◽  
Disease Symptoms ◽  
Colletotrichum Capsici ◽  
Forest Plants

A survey was carried out in the region of tehsil Badnapur, Jalna to investigate the incidence of fungal disease of plants. Field survey was carried out. Diseased plant leaves were identified using disease symptoms. During the survey, 9 plants were found infected by 6 fungal pathogens causing the disease, viz Cercospora achyranthes, C. balansae, C. gloriosae, C. jamaicensis, Colletotrichum capsici, Marssonina poonensis, Pestalotiopsis carbonacea, Phyllachora euphorbiae and Phyllostictacle rodendri.

scholarly journals TOWARDS A PANEVOLUTIONARY THEORY (PANEVO THEORY), FOLLOWING THE ACADEMIC OF FISIOCRITICI ENZO TIEZZI

2017 ◽  
Vol 8 (1-IT) ◽  
Author(s):  
Mario Tanga ◽  
Giacomo Gelati ◽  
Marco Casazza
Keyword(s):  
Charles Darwin ◽  
Current Knowledge ◽  
Close Contact ◽  
Rachel Carson ◽  
Starting Point ◽  
Science And Culture ◽  
History Of ◽  
Living Species ◽  
Definition Of ◽  
Scientific Fields

6Contemporary science and culture show more and more extended and meaningful signs about the increasing explaining power of evolutionary paradigm. This power overcomes the field of the history of living species. We consider “On the Origin of Species” of 1859 by Charles Darwin as the establishment of this paradigm, but this original and fruitful idea has received the several and different contributions from near and (seemingly) far scientific fields. This process happened according distinguishable waves and leaded the evolutionary theory very far from its starting point, making it something wider and different. The current knowledge of this theory involves many kinds of scholars: biologists, zoologists, botanists, development biologists, genetics/genomics scholars and also scholars of many other disciplines, as statistics, mathematics, ecology, environmental sciences, physics, chemistry, linguistics, sociology, neuro-sciences, epidemiology, informatics, immunology. During the end of XX Century, the study of complexity, of self-organization and of emerging properties has been a decisive factor to extend evolution until beyond the boundaries of Biology. These phenomena, or properties, or features, that are shown by “living” and “not-living” systems (so called basing ourselves on traditional definitions), have deeply modified even the “properly” biologic evolution itself and besides this has demonstrated that, mutatis mutandis, evolutionary processes or phenomena happen also out of biologic dominion, referring “biologic” to “wet-ware world”. This is to say the class of evolutionary phenomena is more widely and more inclusively extended than our opinion. We can mean this as a revolution (according to Kuhn’s definition) that imposes us to restructure the definition of evolution itself and even to redraw the boundaries and the map of Biology itself. Aiming to establish a name of this field of study we propose “PanEvolutionary Theory” (PanEvo Theory). No doubt Prigogine offered an important contribution to this area. The thinking and the work of Enzo Tiezzi can be placed seen in the same perspective. Disregarding direct connections and contacts with the Nobel Prize Prigogine, however the studies of Enzo Tiezzi are neither a fully unexpected work nor a theory lacking of important potentialities: it is not a strange or eccentric academic exercise. Except the close contact and the dense exchanges with Prigogine, we collocate Enzo Tiezzi in the same context of Gregory Chaitin, of Rachel Carson, of John Harte and Robert H. Socolow, of James Paul Wesley, of Sertorio, of Oort and Peixoto, just to cite the most strictly related. Our Academy had the privilege and the honor of having Enzo Tiezzi in its ranks. We think that merits and developments of the thinking of this scholar have to produce important and lasting fruits in the future.

An updated checklist of Iranian Encyrtidae (Hymenoptera, Chalcidoidea)

Zootaxa ◽  
2017 ◽  
Vol 4344 (1) ◽  
pp. 1 ◽  
Author(s):  
MAJID FALLAHZADEH ◽  
GEORGE JAPOSHVILI
Keyword(s):  
Host Plant ◽  
Palaearctic Region ◽  
Plant Family ◽  
Number Of Species ◽  
Plant Associations ◽  
Ooencyrtus Kuvanae ◽  
Current List ◽  
Host Associations

An updated checklist of Iranian Encyrtidae (Hymenoptera, Chalcidoidea) is presented based on literature records from 1947–2016. The current list includes 159 species representing 48 genera. Parasitoid-host associations in Iran and distributional data are also provided. Twelve encyrtid species (7.55%) are known only from Iran but a high number of species (68 species, 42.77%) are widely distributed in the Palaearctic region. Four species previously listed from Iran, Metaphycus angustifrons Compere, 1957, Homalotylus ephippium (Ruschka, 1923), H. sinensis Xu & He, 1997, and Ooencyrtus kuvanae (Howard, 1910) are no longer considered present. Hosts of Iranian encyrtid species are tabulated by order and family, with the majority being Hemiptera (66.98%), followed by Lepidoptera and Coleoptera (each 9.44%), Diptera (6.60%), Hymenoptera (4.71%) and Neuroptera (2.83%). The majority of Encyrtidae known in Iran are parasitoids of the superfamily Coccoidea (46.22%). Host-plant associations of Iranian Encyrtidae are also tabulated, by plant family. 

scholarly journals A Model and Image Based Investigation of X. fastidiosa Within Host Dynamics  

2021 ◽  
Author(s):  
Nancy Walker ◽  
Kathryn Rankin ◽  
Siul Ruiz ◽  
Daniel McKay Fletcher ◽  
Katherine Williams ◽  
...  
Keyword(s):  
Research Effort ◽  
Vascular Plant ◽  
Extracellular Polysaccharide ◽  
Resistance Mechanisms ◽  
Vascular Networks ◽  
Disease Symptoms ◽  
Physical Description ◽  
Olive Cultivars ◽  
Olive Quick Decline Syndrome ◽  
Biofilm Development

<p>Photosynthesis relies on the transport of water and sugars from roots to leaves facilitated by two key tissues: xylem and phloem. Blockages in the xylem/phloem, either by structures formed by the pathogen itself or those formed by the plant as a defence mechanism, disrupt the soil-plant-atmosphere continuum and cause many vascular plant disease symptoms.<em> Xylella fastidiosa </em>(<em>X. fastidiosa</em>) is a bacterium that colonises internal plant vascular networks causing pathogenic effects on several commercially important crops, including those associated with the olive quick decline syndrome causing devastating olive decline in Apulia, Southern Italy.<em> </em>Despite a growing research effort since the recent detection of <em>X. fastidiosa</em> in Europe, the exact processes leading to <em>X. fastidiosa</em> disease symptoms are not fully understood due to difficulties in observing internal plant structures.</p> <p>Our goal is to utilise models to elucidate fundamental processes that lead to olive quick decline syndrome. We are developing a mathematical model describing within-host biofilm development that predicts water-stresses that ultimately inhibit plant functionality. Our approach is centred on the assumption that the biofilm structure is determined by the arrangement of extracellular polysaccharide (EPS) molecules, and as such, our model contains a polymer-physical description of <em>X. fastidiosa</em> biofilm formation dynamics. We used our model, requiring minimal empirical assumptions, to replicate biofilm aggregation observed by microfluidics. We have also produced X-ray Computed Tomography (XCT) images of vascular networks in both resistant and susceptible olive cultivars. We are using these images to test whether susceptibility is correlated with morphological differences that might influence fluid flow through the plant. This work improves the understanding of possible cultivar resistance mechanisms to aid informed breeding and orchard management, and model simulations will provide insights for understanding xylem blockages and their relation to observed symptom severity.</p>

scholarly journals Occurrence of Alternaria dichondrae, Cercospora sp., and Puccinia sp. on Dichondra repens in France and Italy

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1012-1012 ◽  
Author(s):  
L. Cardin ◽  
B. Delecolle ◽  
B. Moury
Keyword(s):  
Fungal Pathogens ◽  
Poa Pratensis ◽  
Rust Fungus ◽  
Lower Surface ◽  
Mycelium Growth ◽  
Disease Symptoms ◽  
Public Gardens ◽  
Perennial Plant ◽  
Young Leaves ◽  
Necrotic Spots

Dichondra repens (kidneyweed or ponysfoot), family Convolvulaceae, is a perennial plant with persistent leaves and is grown alone or in association with turfgrass in subtropical and Mediterranean regions. Because of its prostrate growth habit, it does not need to be mowed. It is also used as a potted plant for house decoration. During surveys of lawns in public gardens of the Franco-Italian Riviera conducted from 1993 to 2003, we noticed 0.1- to 0.5-cm-diameter, brownish, necrotic spots on leaves of D. repens in Antibes, Cannes, Menton, Nice, and Vallauris (France) and in Arma di Taggia, Diano Marina, Imperia, La Mortola, Ospedaletti, San Remo, and Ventimiglia (Italy). Symptoms were more intense in the spring on young leaves but lesions remained all year on older leaves. Two species of fungal pathogens were frequently isolated from these spots. One fungus produced brown, erect conidiophores with brown, pear-shaped conidia and bifid, subhyaline beaks. Conidia formed singly, were composed of 8 to 10 cells with transverse and longitudinal crosswalls, and had one to four hyaline spurs frequently longer than the conidia. Conidia measured 90 to 260 × 16 to 29 μm. The pathogen, identified as Alternaria dichondrae (1), was previously characterized in Italy, New Zealand, and Argentina. The second fungus species produced clumps of erect, brown conidiophores with hyaline, filiform conidia composed of 10 to 20 cells. These conidia measured 90 to 310 × 3 to 3.5 μm. This fungus was identified as a Cercospora sp. (2), a genus not previously reported on D. repens. For both fungi, necrotic spots similar to those observed in natural infections were obtained after spraying a suspension of mycelium and conidia onto leaves of D. repens seedlings that had two to four expanded leaves that had been pricked with a pin. The plants were maintained under high humidity. Assays of mycelium growth on agar media containing various fungicides showed that 1 ppm of pyremethanil completely inhibited the growth of A. dichondrae, whereas a mixture of 10 ppm of diethofencarb and 10 ppm of carbendazine completely inhibited Cercospora sp. growth. Telia were also observed on the lower surface of D. repens leaves, sometimes in association with disease symptoms of A. dichondrae and Cercospora sp. Disease symptoms of the rust were yellowing and curling of the leaf surface with erect petiole, whereas healthy plants were prostrate with plane leaf surfaces. The two-celled teliospores had smooth cell walls, a single germinative pore per cell, and measured 32 to 34 × 12 to 13 μm with a thin unattached pedicel. This rust fungus was consequently classified in the genus Puccinia (2), also not previously reported as a pathogen of D. repens. It is possible that Poaceae plants such as Poa pratensis grown in association with D. repens were the inoculum source. Whereas A. dichondrae and Cercospora sp. do not induce severe diseases and are not widespread, the prevalence of Puccinia sp. tends to increase over time, requiring appropriate treatments to manage infected turf grasses. References: (1) P. Gambogi et al. Trans. Br. Mycol. Soc. 65:322, 1975. (2) G. Viennot-Bourgin. Les Champignons Parasites des Plantes Cultivées, Masson ed. Paris, 1949.

scholarly journals Diet and Metabolic Syndrome: Where Does Resistant Starch Fit In?

2004 ◽  
Vol 87 (3) ◽  
pp. 756-760 ◽  
Author(s):  
Linda C Tapsell
Keyword(s):  
Metabolic Syndrome ◽  
Heart Disease ◽  
Resistant Starch ◽  
Current Knowledge ◽  
Appetite Control ◽  
Major Health ◽  
Fat Utilization ◽  
The Metabolic Syndrome ◽  
Definition Of

Abstract Metabolic syndrome is a term linking the clinical profiles of some of the world's major health problems today: obesity, heart disease, and diabetes. It is predicated on dietary patterns, and particularly on the delivery of fuel. The effects may be seen first in the development of abdominal obesity and insulin resistance leading to Type 2 diabetes mellitus and coronary heart disease. This review examines the role resistant starch might play in the prevention and management of these conditions. Beginning with a definition of resistant starch, a critical review of the scientific literature is presented. Current knowledge suggests that resistant starch in the diet may assist in the prevention and management of conditions associated with the metabolic syndrome via its potential effects on delaying the delivery of glucose as fuel with subsequent fat utilization and appetite control benefits. There is still a great deal of research to be undertaken in this area, but it is clearly warranted, given the position of starches in the global food supply and the potential impact on population health.

Drosophila sonorae (Diptera, Drosophilidae), a new species in the repleta species group from Mexico

Zootaxa ◽  
2008 ◽  
Vol 1725 (1) ◽  
pp. 27 ◽  
Author(s):  
WILLIAM B. HEED ◽  
SERGIO CASTREZANA
Keyword(s):  
New Species ◽  
Host Plant ◽  
Species Group ◽  
Plant Associations ◽  
Species Complexes ◽  
A New Species

We describe a new species, D. sonorae Heed and Castrezana from Sonora, Mexico in the repleta species group of Drosophila (Drosophilidae, Diptera). This species is morphologically similar to other members of the newly established D. longicornis complex, and the well-established D. longicornis cluster. Host plant associations, biogeography, and distributions of species in both the longicornis and mulleri species complexes are discussed here.

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