scholarly journals Comparative Behavior of Ralstonia solanacearum Biovar 2 in Diverse Plant Species

2008 ◽  
Vol 98 (1) ◽  
pp. 59-68 ◽  
Author(s):  
B. Álvarez ◽  
J. Vasse ◽  
V. Le-Courtois ◽  
D. Trigalet-Démery ◽  
M. M. López ◽  
...  

Ralstonia solanacearum causes bacterial wilt in numerous plant species worldwide. Although biovar 2 mostly affects solanaceous crops, identification of new hosts remains a matter of concern since there is still no clear-cut distinction between host and nonhost plants. In this work we provide data based on histological studies on the status of 20 plant species, most of them of potential interest in crop rotation. Plants were watered with a β-glucuronidase-expressing derivative of R. solanacearum biovar 2, and after a month of incubation, sections of roots and stems were analyzed to localize the pathogen on surface, in cortex and/or xylem. Depending on whether the xylem was colonized or not, plants were classified as hosts or nonhosts, respectively. Hosts generally affected in a few xylem vessels or occasionally in all xylem bundles were classified as tolerant. These included some cabbage, kidney bean, and rutabaga cultivars, and the weed bittersweet nightshade (Solanum dulcamara). Nonhosts were the cultivars tested of alfalfa, barley, black radish, carrot, celery, colocynth, fennel, fiber flax, field bean, field pea, horseradish, maize, and zucchini. However, barley and maize, though nonhosts, may act as reservoirs for the pathogen. The present work constitutes a basis for further studies on cropping systems in fields where R. solanacearum has been detected.

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 451
Author(s):  
Moritz von Cossel ◽  
Lorena Agra Pereira ◽  
Iris Lewandowski

The global demand for plant biomass to provide bioenergy and heat is continuously increasing because of a growing interest among many industrialized and developing countries towards climate sound and renewable energy supply. The exacerbation of land-use conflicts proliferates social-ecological demands on future bioenergy cropping systems. Perennial herbaceous wild plant mixtures (WPMs) represent an approach to providing social-ecologically more sustainably produced biogas substrate that has gained increasing public and political interest only in recent years. The focus of this study lies on three perennial wild plant species (WPS) that usually dominate the biomass yield performance of WPM cultivation. These WPS were compared with established biogas crops in terms of their substrate-specific methane yield (SMY) and lignocellulosic composition. The plant samples were investigated in a small-scale mesophilic discontinuous biogas batch test for determining the SMY. All WPS were found to have significantly lower SMY (241.5–248.5 lN kgVS−1) than maize (337.5 lN kgVS−1). This was attributed to higher contents of lignin (9.7–12.8% of dry matter) as well as lower contents of hemicellulose (9.9–11.5% of dry matter) in the WPS. Only minor, non-significant differences to cup plant and Virginia mallow were observed. Thus, when planning WPS as a diversification measure in biogas cropping systems, their lower SMY should be considered.


2020 ◽  
Vol 8 (7) ◽  
pp. 1056
Author(s):  
Cody Molnar ◽  
Ekaterina Nikolaeva ◽  
Seonghwan Kim ◽  
Tracey Olson ◽  
Devin Bily ◽  
...  

The increasing movement of exotic pathogens calls for systematic surveillance so that newly introduced pathogens can be recognized and dealt with early. A resource crucial for recognizing such pathogens is knowledge about the spatial and temporal diversity of endemic pathogens. Here, we report an effort to build this resource for Pennsylvania (PA) by characterizing the identity and distribution of Phytophthora species isolated from diverse plant species in PA nurseries and greenhouses. We identified 1137 Phytophthora isolates cultured from clinical samples of >150 plant species submitted to the PA Department of Agriculture for diagnosis from 1975 to 2019 using sequences of one or more loci and morphological characteristics. The three most commonly received plants were Abies, Rhododendron, and Pseudotsuga. Thirty-six Phytophthora species identified represent all clades, except 3 and 10, and included a distinct subgroup of a known species and a prospective new species. Prominent pathogenic species such as P. cactorum, P. cinnamomi, P. nicotianae, P. drechsleri, P. pini, P. plurivora, and P. sp. kelmania have been found consistently since 1975. One isolate cultured from Juniperus horizontalis roots did not correspond to any known species, and several other isolates also show considerable genetic variation from any authentic species or isolate. Some species were isolated from never-before-documented plants, suggesting that their host range is larger than previously thought. This survey only provides a coarse picture of historical patterns of Phytophthora encounters in PA nurseries and greenhouses because the isolation of Phytophthora was not designed for a systematic survey. However, its extensive temporal and plant coverage offers a unique insight into the association of Phytophthora with diverse plants in nurseries and greenhouses.


2015 ◽  
Vol 16 (1) ◽  
pp. 29-30 ◽  
Author(s):  
Carlye A. Baker ◽  
Scott Adkins

To the best of our knowledge, this is the first report of TCSV infection of H. wayetii and S. truncata from any location, although other tospoviruses are known to infect these and related plant species. The identification of these two diverse plant species as the first reported natural ornamental hosts of TCSV has implications for TCSV epidemiology and management in ornamental and vegetable crops, which frequently share production space. Accepted by publication 15 January 2015. Published 25 February 2015.


2018 ◽  
Vol 23 (10) ◽  
pp. 2033
Author(s):  
Ivana Marić ◽  
Irena Međo ◽  
Slobodan Jovanović ◽  
Radmila Petanović ◽  
Dejan Marčić

Despite economic importance of Tetranychidae, knowledge regarding diversity of spider mites in the Balkan Peninsula and Southeast Europe is incomplete, especially in protected natural areas. This study presents diversity of spider mites (Acari: Tetranychidae) collected over five growing seasons at 296 locations in 38 protected natural areas of Serbia. A total of 31 spider mite species were found, 10 from Bryobiinae and 21 from Tetranychinae. The species Eotetranychus fagi Zacher was recorded as new to Serbia and this record was also the first one for Southeast Europe. Spider mites were found on host plants in five basic types as well as many subtypes of terrestrial habitats, with woodland as the most dominant one. A total of 151 plant species from 44 families were recorded as hosts for spider mites including new world records: 60 new hosts for family Tetranychidae and 41 new hosts for 21 spider mite species. Host plants from Rosaceae family harbored the highest number of spider mite species (16). A considerable number of species was found on host plants from the families Betulaceae (11), Asteraceae (10) and Sapindaceae (10). Two cosmopolitan spider mites, Tetranychus urticae Koch and Tetranychus turkestani Ugarov & Nikolskii, were clearly distinguished with 67 (7 new) and 43 (13 new) recorded host species, respectively; among newly recorded hosts for Tetranychidae family, these two mite species were found on 27 and 12 hosts, respectively. After the two most common species, the most striking was the presence of Bryobia praetiosa Koch with 24 (4 new) recorded host plants, followed by Amphitetranychus viennensis (Zacher), Eotetranychus carpini (Oudemans) and Bryobia rubrioculus (Scheuten), with 21 (7 new), 20 (6 new) and 16 (2 new) hosts, respectively. The remaining tetranychids were found on 1–9 host plant species. This study provided the first insight into diversity of tetranychids in Serbian protected areas. Further research in this field should focus on mites from host plants representative of specific areas and habitats, including endangered, endemic and relict species.


2020 ◽  
Vol 29 (2) ◽  
pp. 111-155
Author(s):  
Snežana Jarić ◽  
Zorana Mataruga ◽  
Dimitrije Sekulić ◽  
Marija Pavlović ◽  
Dragana Pavlović ◽  
...  

The main aim of the conducted research was to determine the presence of allochthonous plants in the area of the protected natural reserve - The Great War Island. The research was conducted during the vegetation season of 2020. Thirty four allochthonous plant species were recorded and classified into 19 families. Asteraceae (8 species), Fabaceae Poaceae and Sapindaceae (3 species each) had the highest species diversity. Phytogeographic analysis of their primary distribution areas has shown that most belong to the category of floral elements of the "adventitious" areal type. The chorological spectrum is dominated by species of North American origin (58.8%), while in the biological spectrum the most common are therophytes (38.2%). Chronological spectrum analysis has shown the highest prevalence of neophytes (64.7%). Seventeen species have the status of invasive, 16 naturalized, while one species (Morus alba) is characterized as ephemerophyte. The most frequent neophytes on the Great War Island are Acer negundo, Ailanthus altissima, Amorpha fruticosa, Fraxinus pennsylvanica, while among neotophytes, Echinocystis lobata and Symphyotrichum lanceolatus stand out in terms of frequency of occurrence. The geographical position of the Great War Island, due to which it is exposed to periodic floods, high levels of groundwater, strong influence of anthropogenic factors and the biological characteristics of allochthonous species are the main factors enabling them to inhabit this area. Results of this research should be the basis for the development of a strategy for monitoring the condition and planning control measures for the unwanted plant species, in order to protect the indigenous flora. Only careful and responsible management of landscapes of outstanding features such as The Great War Island and taking appropriate preventive measures can prevent the settlement, domestification and further spread of allochthonous plants.


Author(s):  
Pawan Gupta

Seventy per cent of patients who present to the ED have pain as their main complaint—and most of the time as a sign of injury or inflammation. Therefore, early assessment by scoring at the point of triage and offering the appropriate analgesia are the first steps towards the management of such patients. The College of Emergency Medicine guidelines suggest that at least 98% of patients in severe pain (pain score of 7–10) should be offered appropriate analgesia within 60min of arrival, or triage, whichever is earlier. In 90% of these patients, the status of pain should be re-evaluated within 60min of receiving the first dose of the analgesic. Despite this clear-cut standard and the availability of a wide variety of analgesics, achieving such a target remains, occasionally, elusive. It must also be realized that a positive experience for the patient largely depends on relief of pain as early as possible. Consequently, one of the primary areas for a new FY1 to focus on is the pain management. Remember it is simple and straightforward in most circumstances. GA may be required in the ED for various clinical indications, for example, cardioversion, facial trauma or burns, and acute respiratory failure (such as in asthma). In an emergency situation it may be a challenging procedure even for an experienced anaesthetist and could be dangerous for the patients. An FY1/2 will never be expected to perform this, but it is important to know when to call for help when the situation demands. Local anaesthesia is widely used in the ED, and is one of the skills foundation trainees learn in the early days. It is comparatively safe if the doctor is aware of how to perform the procedure and the upper limit of the dose for a particular patient. Finally, conscious sedation is also widely used in the ED for reducing fractures and/or dislocations and minor operations. However, it carries the same risks as GA and should be carried out by a doctor who is trained in the procedure as well as in resuscitation. A risk assessment should be performed as a patient with high risks (previous cardiac or respiratory diseases) must be sedated with extreme caution.


2019 ◽  
Vol 20 (23) ◽  
pp. 5887 ◽  
Author(s):  
Heshan Du ◽  
Changlong Wen ◽  
Xiaofen Zhang ◽  
Xiulan Xu ◽  
Jingjing Yang ◽  
...  

The soilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt (BW), a major disease of pepper (Capsicum annuum). The genetic basis of resistance to this disease in pepper is not well known. This study aimed to identify BW resistance markers in pepper. Analysis of the dynamics of bioluminescent R. solanacearum colonization in reciprocal grafts of a resistant (BVRC 1) line and a susceptible (BVRC 25) line revealed that the resistant rootstock effectively suppressed the spreading of bacteria into the scion. The two clear-cut phenotypic distributions of the disease severity index in 440 F2 plants derived from BVRC 25 × BVRC 1 indicated that a major genetic factor as well as a few minor factors that control BW resistance. By specific-locus amplified fragment sequencing combined with bulked segregant analysis, two adjacent resistance-associated regions on chromosome 10 were identified. Quantitative trait (QTL) mapping revealed that these two regions belong to a single QTL, qRRs-10.1. The marker ID10-194305124, which reached a maximum log-likelihood value at 9.79 and accounted for 19.01% of the phenotypic variation, was located the closest to the QTL peak. A cluster of five predicted R genes and three defense-related genes, which are located in close proximity to the significant markers ID10-194305124 or ID10-196208712, are important candidate genes that may confer BW resistance in pepper.


2016 ◽  
Vol 42 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Anatoliy A. Khapugin ◽  
Tatyana B. Silaeva ◽  
Anastasia A. Semchuk ◽  
Elena N. Kunaeva

Abstract Population-based studies of endangered plant species are key methods for assessment of the status for these plants at any territory. Plant species of the Orchidaceae family are sensitive components in natural ecosystems. That is why determination of the status for their populations can be considered as indicators for the status of natural ecosystem position as a whole. Investigations of three Orchidaceae species populations (Orchis militaris L., Epipactis palustris (L.) Crantz, Malaxis monophyllos (L.) Swartz) were carried out in Central Russia (Republic of Mordovia). Abundance, density, structure and dynamics of populations of these species were studied. Species composition of accompanying flora was established for each rare species. Some morphometrical parameters of individuals for the studied species were measured. Features of ontogenetic spectrum for Orchis militaris and Epipactis palustris populations were shown.


2019 ◽  
Vol 46 (8) ◽  
pp. 732 ◽  
Author(s):  
Binh T. T. Tran ◽  
Stephanie J. Watts-Williams ◽  
Timothy R. Cavagnaro

The formation of arbuscular mycorrhizas (AM) can result in positive, neutral or negative responses in the growth and mineral nutrition of host plants, particularly that of P, Zn and other micronutrients. This study examined the growth and nutritional responses of 15 agriculturally important plant species, including cereals, legumes and vegetables, with and without inoculation with the AM fungus (AMF) Rhizophagus irregularis. Furthermore, we explored whether the responses differed between different functional groups of plants such as monocots and dicots, C3 and C4 plants, and N-fixing and non-N-fixing plants. We found that that mycorrhizal colonisation of roots, plant growth and plant nutrient responses differed between plant species. Among the species analysed, leek (Allium ampeloprasum L. var. porrum) was the most mycorrhiza-responsive, displaying the highest mycorrhizal colonisation and biomass response, and the greatest increases in most mineral nutrients. In other plant species, the concentration of P, Cu, Zn and S were generally enhanced by inoculation with AMF. Furthermore, ionomes differed more greatly between plant species than in response to inoculation with AMF. This research further improves our understanding of the responses of different and diverse plant species to the formation of AM in terms of growth and ionomics under standardised growth conditions. The results of this study may be used in further studies and to inform agricultural practices.


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