scholarly journals Studies on Biology, Seed dispersal and Host interaction of Dendrophthoe falcata (L.f.) Etting. - A stem parasite of Mangifera indica L. (Mango)

2020 ◽  
Vol 8 (3) ◽  
pp. 097-103
Author(s):  
Subhashini Kuramana ◽  
Gaddeyya Gandipilli ◽  
P. K. Ratna Kumar

The hemiparasitic plant, Dendrophthoe falcata (L.f.) Etting. known as Loranthus is a stem parasite, mostly prefers Mangifera indica L. (mango) as its host. Remarkable damage of the mango crop due to the adverse effect of Loranthus was identified in the field area. The occurrence and host preference of the D. falcata was systematically studied at eight field sites of Vizianagaram District. The vegetative, reproductive and parasitic characteristics of D. falcata were recorded periodically. The effective management strategies to control Loranthus were not employed in the study area because of the lack of knowledge on the host-parasite interaction. Keeping in mind, the investigation was conducted (October 2018 to June, 2019) in mango fields of Vizianagaram District of Andhra Pradesh to explore the biology, the host specificity, the occurrence, the pollination, the bird-host-parasite interaction and the effective control methods of D. falcata.

Author(s):  
Guohong Zeng ◽  
Jin Li ◽  
Yuxiu Ma ◽  
Qian Pu ◽  
Tian Xiao ◽  
...  

AbstractSaponins are kinds of antifungal compounds produced by Panax notoginseng to resist invasion by pathogens. Ilyonectria mors-panacis G3B was the dominant pathogen inducing root rot of P. notoginseng, and the abilities to detoxify saponins were the key to infect P. notoginseng successfully. To research the molecular mechanisms of detoxifying saponins in I. mors-panacis G3B, we used high-throughput RNA-Seq to identify 557 and 1519 differential expression genes (DEGs) in I. mors-panacis G3B with saponins treatments for 4H (Hours) and 12H (Hours) compared with no saponins treatments, respectively. Among these DEGs, we found 93 genes which were simultaneously highly expressed in I. mors-panacis G3B with saponins treatments for 4H and 12H, they mainly belong to genes encoding transporters, glycoside hydrolases, oxidation–reduction enzymes, transcription factors and so on. In addition, there were 21 putative PHI (Pathogen–Host Interaction) genes out of those 93 up-regulated genes. In this report, we analyzed virulence-associated genes in I. mors-panacis G3B which may be related to detoxifying saponins to infect P. notoginseng successfully. They provided an excellent starting point for in-depth study on pathogenicity of I. mors-panacis G3B and developed appropriate root rot disease management strategies in the future.


Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 724-730 ◽  
Author(s):  
S. A. Pereyra ◽  
R. Dill-Macky ◽  
A. L. Sims

Survival and inoculum production of Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum (Schwabe)), the causal agent of Fusarium head blight of wheat and barley, was related to the rate of wheat (Triticum aestivum L.) residue decomposition. Infested wheat residue, comprising intact nodes, internodes, and leaf sheaths, was placed in fiberglass mesh bags on the soil surface and at 7.5- to 10-cm and 15- to 20-cm depths in chisel-plowed plots and 15 to 20 cm deep in moldboard-plowed plots in October 1997. Residue was sampled monthly from April through November during 1998 and every 2 months through April to October 1999. Buried residue decomposed faster than residue placed on the soil surface. Less than 2% of the dry-matter residue remained in buried treatments after 24 months in the field, while 25% of the residue remained in the soil-surface treatment. Survival of G. zeae on node tissues was inversely related to the residue decomposition rate. Surface residue provided a substrate for G. zeae for a longer period of time than buried residue. Twenty-four months after the initiation of the trial, the level of colonization of nodes in buried residue was half the level of colonization of residue on the soil surface. Colonization of node tissues by G. zeae decreased over time, but increased for other Fusarium spp. Ascospores of G. zeae were still produced on residue pieces after 23 months, and these spores were capable of inducing disease. Data from this research may assist in developing effective management strategies for residues infested with G. zeae.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 994
Author(s):  
Alina S. Puig ◽  
Sarah Wurzel ◽  
Stephanie Suarez ◽  
Jean-Philippe Marelli ◽  
Jerome Niogret

Theobroma cacao is affected by viruses on every continent where the crop is cultivated, with the most well-known ones belonging to the Badnavirus genus. One of these, cacao mild mosaic virus (CaMMV), is present in the Americas, and is transmitted by several species of Pseudococcidae (mealybugs). To determine which species are associated with virus-affected cacao plants in North America, and to assess their potential as vectors, mealybugs (n = 166) were collected from infected trees in Florida, and identified using COI, ITS2, and 28S markers. The species present were Pseudococcus jackbeardsleyi (38%; n = 63), Maconellicoccus hirsutus (34.3%; n = 57), Pseudococcus comstocki (15.7%; n = 26), and Ferrisia virgata (12%; n = 20). Virus acquisition was assessed by testing mealybug DNA (0.8 ng) using a nested PCR that amplified a 500 bp fragment of the movement protein–coat protein region of CaMMV. Virus sequences were obtained from 34.6 to 43.1% of the insects tested; however, acquisition did not differ among species, X2 (3, N = 166) = 0.56, p < 0.91. This study identified two new mealybug species, P. jackbeardsleyi and M. hirsutus, as potential vectors of CaMMV. This information is essential for understanding the infection cycle of CaMMV and developing effective management strategies.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jaya Kaushik ◽  
◽  
Sandeep Shankar ◽  
Anargh V ◽  
Renu M ◽  
...  

Objective: To formulate a protocol for safe and effective management of an ophthalmologic practice in a hospital or a clinic during the Covid - 19 pandemic. Methods and analysis: Literature was reviewed regarding Covid-19 pandemic and ophthalmology. The following key words were used. Covid-19, telemedicine, challenges, management strategy. Result: An efficient protocol for ophthalmology practice during the Covid-19 pandemic was established which covered various protective measures that are essential and vital in the Covid-19 pandemic. Conclusion: An evidence-based protocol was formulated which may be modified in future as per the latest developments and trends in the ongoing pandemic.


1985 ◽  
Vol 75 (3) ◽  
pp. 501-518 ◽  
Author(s):  
Sarah E. Randolph ◽  
Gordon M. Steele

AbstractThe experimental manipulation of separate, but originally identical, populations of Ixodes ricinus (L.) by applying three conventional tick control measures in different enclosures on naturally infested moorland in Wales allowed the elements of the tick-host interaction to be analysed quantitatively and the effectiveness of the control methods to be compared. From the relationship between the sheep stocking density and the numbers of questing ticks picked up by fortnightly blanket-dragging in each enclosure, the death rate of ticks during their activity season and the rate of contact between sheep and ticks were calculated. From this, it was possible to investigate the effect of different stocking densities on the feeding success of ticks. A major factor determining the much lower contact rate for larvae than for nymphs was the different spatial distribution of questing ticks, clumped for larvae and random for nymphs. The non-random use by sheep of the three different vegetation zones in the paddock resulted in the highest contact rate between sheep and ticks in the pasture area, but tick survival was apparently highest in the bog area. Combining these factors resulted in the prediction that the bracken area was the least favourable habitat for ticks. In the two enclosures where the sheep were not treated with acaricide the mean tick loads on the sheep were similar, but the lower overall use of the pasture by the sheep in the low stocking density enclosure (2/ha) resulted in slightly lower tick loads there compared with those in the high stocking density enclosure (4/ha). The numbers of ticks counted in the second year showed that pasture spelling was the most effective control method, acaricide treatment was less effective, and the benefits of halving the stocking density were marginal. The implications of these results for control strategies are discussed.


2018 ◽  
Vol 373 (1745) ◽  
pp. 20170101 ◽  
Author(s):  
David J. Civitello ◽  
Brent E. Allman ◽  
Connor Morozumi ◽  
Jason R. Rohr

Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological consequences of supplementation, highlighting the similarities and differences between food provisioning and two widespread forms of nutrient input: agricultural fertilization and aquatic nutrient enrichment. We then review an aquatic disease system and a general model to assess whether predator and competitor species can enhance or overturn the direct effects of enrichment. All forms of supplementation can directly affect epidemics by increasing host population size or altering parasite production within hosts, but food provisioning is most likely to aggregate hosts and increase parasite transmission. However, if predators or competitors increase in response to supplementation, they could alter resource-fuelled outbreaks in focal hosts. We recommend identifying the traits of hosts, parasites or interacting species that best predict epidemiological responses to supplementation and evaluating the relative importance of these direct and indirect mechanisms. Theory and experiments should examine the timing of behavioural, physiological and demographic changes for realistic, variable scenarios of supplementation. A more integrative view of resource supplementation and wildlife disease could yield broadly applicable disease management strategies. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.


The impending jeopardies relating to dearth of water in performing the techno economic activity of production of electricity in power industries ushered gainful insights for this research paper for pursuing to reckon and quantify the renewable electric energy consumption of water by gauging at the foot prints. This research paper presses the need of the hour to persistently stimulate the electric generation industries to integrate the multidimensional anomalies of seasonal changes of monsoonal fresh water in the arena of Environmental micro and macro climate strategies. Taking cue of electric energy water sequential linkages using water foot printing technology this paper empirically estimated that, minimum water foot print was recorded in selected biomass and natural gas based electricity producing industries to yield 1000 kilowatt of electricity vis-à-vis selected Hydel power station, which has voracious appetite. This research has been performed with a field level investigation of assessing the magnitude of water scarcity by performing a documentation of exemplary investigative case study approach in selected regions of Andhra Pradesh.


2014 ◽  
Author(s):  
Andreas Schröder ◽  
Joel E Dimsdale

Somatic symptoms that cannot be attributed to organic disease account for 15 to 20% of primary care consultations and up to 50% in specialized settings. About 6% of the general population has chronic somatic symptoms that affect functioning and quality of life. This chapter focuses on the recognition and effective management of patients with excessive and disabling somatic symptoms. The clinical presentation of somatic symptoms is categorized into three groups of patients: those with multiple somatic symptoms, those with health anxiety, and those with conversion disorder. The chapter provides information to assist with making a diagnosis and differential diagnosis. Management includes ways to improve the physician–patient interaction that will benefit the patient, a step-care model based on illness severity and complexity, and psychological and pharmacologic treatment. The chapter is enhanced by figures and tables that summarize health anxiety, symptoms, differential diagnoses, and management strategies, as well as by case studies and examples. This review contains  5 highly rendered figures, 10 tables, and 235 references.


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