scholarly journals Were endophytes pre-adapted for defensive mutualism?

2007 ◽  
Vol 13 ◽  
pp. 63-67
Author(s):  
M.S. Torres ◽  
A.P. Singh ◽  
N. Vorsa ◽  
T. Gianfagna ◽  
J.R. Author
Keyword(s):  
Drought Tolerance ◽  
Host Defense ◽  
Phylogenetic Trees ◽  
Ergot Alkaloids ◽  
Disease Suppression ◽  
Defensive Mutualism ◽  
The Family ◽  
Loline Alkaloids ◽  
Selection Of Species ◽  
Selection Of

Defensive mutualism in many grass endophytes involves herbivore deterrence, enhanced disease suppression and drought tolerance. According to our current understanding of the mechanisms, these defensive effects are unique features of the fungi and specific fungal qualities are responsible for each. We examined a selection of species of family Clavicipitaceae for defensive traits including ergot alkaloids and loline production and development of endophytic and epiphytic mycelial states. When features responsible for defensive effects are mapped onto phylogenetic trees showing relationships in the family, it is apparent that all defensive features of endophytic fungi pre-existed evolution of endophytism. We suggest that once endophytism evolved, the alkaloids and other fungal-mediated defensive features switched from previous functions to serve host defense functions. Defensive mutualism in the Clavicipitaceae endophytes naturally evolved through use of pre-existing fungal features after the step to endophytism was made. Keywords: Clavicipitaceae, defensive mutualism, endophytes, ergot alkaloids, loline alkaloids

scholarly journals Serotiny in southern hemisphere conifers

2013 ◽  
Vol 61 (6) ◽  
pp. 486 ◽  
Author(s):  
P. G. Ladd ◽  
J. J. Midgley ◽  
A. P. Nield
Keyword(s):  
Southern Hemisphere ◽  
Fire Regime ◽  
Dry Weight ◽  
Simple Relationship ◽  
Morphometric Measurements ◽  
The Family ◽  
Selection Of Species ◽  
Sterile Seed ◽  
Fertile Seed ◽  
Selection Of

Serotiny is a widespread trait in angiosperms in the southern hemisphere; however, it is less common in conifers and has been little examined in the only two genera of southern conifers (Callitris and Widdringtonia) that have serotinous cones. There is variation across the family in the size of cones, the amount of seed contained and the time over which the cones stay closed on the plant. Cones from most of the species were collected in the field and various morphometric measurements made including cone wet and dry weight, the number of seeds contained and their likely viability. Cones from a selection of species with different cone sizes were heated to increasing temperatures, to investigate the ability of cones to protect the contained seeds from heat. In comparison to the flowering plants, serotiny has developed comparatively recently in southern conifers (in the last 10–20 million years). In Widdringtonia, serotiny is relatively weak, whereas in Callitris, it varies from strong to non-existent. Cone size and fertile-seed production across the two genera varies and the number of fertile seeds produced is positively related to the size of the cone. In some species, there are sterile seed-like bodies. These may have developed to confuse seed predators, so fertile seeds have a better chance of survival. Larger (heavier) cones are more effective in protecting the contained seeds from the heat of fires than are smaller ones. There is no simple relationship between the cone size and type of environment occupied by the species. In regions where fire is unlikely, predictable but mild or completely unpredictable, the species tend to be non-serotinous. In temperate regions where hot fires are likely to have been a selective agent, the species tend to be more strongly serotinous, although fire is not essential to open the cones. The community and environment in which a species has evolved is likely to have influenced the development of the degree of serotiny for each species and this may still be a variable property among populations of some species, depending on the fire regime of the area in which they grow.

scholarly journals Extensive Phylogenetic Analysis of Piscine Orthoreovirus Genomic Sequences Shows the Robustness of Subgenotype Classification

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Marcos Godoy ◽  
Daniel A. Medina ◽  
Rudy Suarez ◽  
Sandro Valenzuela ◽  
Jaime Romero ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Genetic Variation ◽  
Sequence Analysis ◽  
Molecular Phylogeny ◽  
Phylogenetic Trees ◽  
Genomic Segment ◽  
Double Stranded Rna ◽  
The Family ◽  
Original Classification

Piscine orthoreovirus (PRV) belongs to the family Reoviridae and has been described mainly in association with salmonid infections. The genome of PRV consists of about 23,600 bp, with 10 segments of double-stranded RNA, classified as small (S1 to S4), medium (M1, M2 and M3) and large (L1, L2 and L3); these range approximately from 1000 bp (segment S4) to 4000 bp (segment L1). How the genetic variation among PRV strains affects the virulence for salmonids is still poorly understood. The aim of this study was to describe the molecular phylogeny of PRV based on an extensive sequence analysis of the S1 and M2 segments of PRV available in the GenBank database to date (May 2020). The analysis was extended to include new PRV sequences for S1 and M2 segments. In addition, subgenotype classifications were assigned to previously published unclassified sequences. It was concluded that the phylogenetic trees are consistent with the original classification using the PRV genomic segment S1, which differentiates PRV into two major genotypes, I and II, and each of these into two subgenotypes, designated as Ia and Ib, and IIa and IIb, respectively. Moreover, some clusters of country- and host-specific PRV subgenotypes were observed in the subset of sequences used. This work strengthens the subgenotype classification of PRV based on the S1 segment and can be used to enhance research on the virulence of PRV.

Counseling Parents of Children With Behavior Problems: The Use of Extinction and Time-Out Techniques

PEDIATRICS ◽  
1977 ◽  
Vol 59 (1) ◽  
pp. 78-85
Author(s):  
Ronald S. Drabman ◽  
Greg Jarvie
Keyword(s):  
Problem Behaviors ◽  
Inappropriate Behavior ◽  
Time Intervals ◽  
Alternative Behavior ◽  
Home Setting ◽  
Time Out ◽  
Behavior Response ◽  
Disciplinary Problems ◽  
The Family ◽  
Selection Of

The pediatrician is the professional most frequently sought out for advice concerning disciplinary problems with children in the home. Behavioral psychologists have advocated the use of contingent ignoring and time-out procedures to help reduce problem behaviors; however, practicing pediatricians have found that these two procedures are often not successful. In fact, sometimes the two procedures seem to exacerbate inappropriate behavior. This paper documents the difficulties found in using the ignoring and/or time-out procedures in the home setting. Potential pitfalls in the use of ignoring, including not specifying the target behavior, not taking a baseline, inadvertently, intermittently reinforcing the inappropriate behavior, response bursts, spontaneous recovery, and not reinforcing an appropriate alternative behavior, are described. In addition, several pitfalls in the use of the time-out procedure, including selection of isolation area, inappropriate selection of time intervals, interference from others in the family, and escape attempts on the part of the child are discussed. For each potential problem a remedy is suggested.

On the authorship and publication dates of Theraphosa and Theraphosidae (Araneae, Mygalomorphae): a clarification

Bionomina ◽  
2021 ◽  
Vol 24 (1) ◽  
Author(s):  
RAINER BREITLING
Keyword(s):  
19Th Century ◽  
Relevant Literature ◽  
Historical Context ◽  
Publication Date ◽  
Diverse Group ◽  
Early 19Th Century ◽  
The Family ◽  
Minority View ◽  
Case Based ◽  
Selection Of

The genus Theraphosa was established by Thorell (1870) as the type genus of the simultaneously published family Theraphosidae, the most diverse group of mygalomorph spiders. This authorship and publication date have long been accepted by the majority of authors. However, there has been a long-standing minority view that the genus name should be attributed to Walckenaer (1805), and the publication date of the family name changed to 1869.             A thought-provoking recent publication has examined this case. Based on a limited selection of the relevant literature, the authors struggled to make sense of their sources and prematurely concluded that the minority opinion might indeed be correct. They overlooked the potentially destabilising implications of this reattribution.             This paper revisits the evidence in the light of a much wider range of relevant publications, places it in its important historical context and, on the basis of the current rules of nomenclature, concludes that the traditional consensus has indeed been correct.                 Thus, Theraphosa Thorell, 1870 is the type genus of Theraphosidae Thorell, 1870 and a nomen protectum, while Theraphosa Schinz, 1823 is a nomen oblitum, mostly limited to the German textbook literature of the early 19th century. Teraphosa Eichwald, 1830 and Teraphosa Gistel, 1848 are junior synonyms of Avicularia Lamarck, 1818 (syn. nov.). Theraphosa Walckenaer, 1805 is a suprageneric name of the class-series (synonymous to Mygalomorphae) and not available at the genus level.

scholarly journals Phylogenetic relationships within the family Halobacteriaceae inferred from rpoB′ gene and protein sequences

2007 ◽  
Vol 57 (10) ◽  
pp. 2289-2295 ◽  
Author(s):  
Madalin Enache ◽  
Takashi Itoh ◽  
Tadamasa Fukushima ◽  
Ron Usami ◽  
Lucia Dumitru ◽  
...  
Keyword(s):  
16S Rrna ◽  
Molecular Marker ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Protein Sequences ◽  
Rpob Gene ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
The Family

In order to clarify the current phylogeny of the haloarchaea, particularly the closely related genera that have been difficult to sort out using 16S rRNA gene sequences, the DNA-dependent RNA polymerase subunit B′ gene (rpoB′) was used as a complementary molecular marker. Partial sequences of the gene were determined from 16 strains of the family Halobacteriaceae. Comparisons of phylogenetic trees inferred from the gene and protein sequences as well as from corresponding 16S rRNA gene sequences suggested that species of the genera Natrialba, Natronococcus, Halobiforma, Natronobacterium, Natronorubrum, Natrinema/Haloterrigena and Natronolimnobius formed a monophyletic group in all trees. In the RpoB′ protein tree, the alkaliphilic species Natrialba chahannaoensis, Natrialba hulunbeirensis and Natrialba magadii formed a tight group, while the neutrophilic species Natrialba asiatica formed a separate group with species of the genera Natronorubrum and Natronolimnobius. Species of the genus Natronorubrum were split into two groups in both the rpoB′ gene and protein trees. The most important advantage of the use of the rpoB′ gene over the 16S rRNA gene is that sequences of the former are highly conserved amongst species of the family Halobacteriaceae. All sequences determined so far can be aligned unambiguously without any gaps. On the other hand, gaps are necessary at 49 positions in the inner part of the alignment of 16S rRNA gene sequences. The rpoB′ gene and protein sequences can be used as an excellent alternative molecular marker in phylogenetic analysis of the Halobacteriaceae.

scholarly journals Prioritization and Selection of High Biomass Energy Producing Plant Species at Boset District, Central Ethiopia: An Ethnobotanical Approach 

2021 ◽  
Author(s):  
Tinsae Bahru Yifru ◽  
Berhane Kidane ◽  
Amsalu Tolessa
Keyword(s):  
Plant Species ◽  
Sustainable Use ◽  
Biomass Energy ◽  
Calotropis Procera ◽  
Sampled Data ◽  
High Biomass ◽  
Structured Interviews ◽  
Acacia Senegal ◽  
Selection Of Species ◽  
Selection Of

Abstract Background: In Ethiopia, about 92.3% of all the biomass energy is consumed by domestic households and the demand is growing from 10-14%. However, there are little/no practical experiences or documented indigenous knowledge on how traditional people identify and select high biomass producing plant species with short rotation periods at Boset District. Therefore, the present study was aimed at: (1) selecting and documenting high biomass energy producing plant species at Boset District; (2) identifying major predictor variables that influence the prioritization and selection of species; and (3) develop a Generalized Linear Model (GLM) to predict the selection of species. Methods: A total of 96 informants comprising 59 men and 37 women between the ages of 18 and 81 were sampled. Data were collected using structured interviews, guided field walk, discussions and field observations. Results: Collected data indicated that 88.5% of the informants involved in firewood collection, while 90% practiced charcoal making. A total of 1533.60 Birr per household on average was earned annually from this activity. A total of 25 firewood and/or charcoal plant species were identified and documented at Boset District. Of these, Acacia senegal, Acacia tortilis and Acacia robusta were the three best prioritized and selected indigenous high biomass producing species. Prosopis juliflora, Parthenium hysterophorus, Azadirachta indica, Calotropis procera, Cryptostegia grandiflora, Lantana camara and Senna occidentalis further grouped under introduced fuelwood species. Prediction of GLM assured sampled Kebeles and source of income generated from fuelwood species positively and significantly (p<0.001) related to selection of species. Higher efficiency to provide energy and heat; little or no smoke or soot; easier to cut and split the wood and easier availability were some of the main selection criteria. Conclusions: This study provides valuable information in selection and documenting of high biomass producing plant species for proper management and sustainable use at Boset District. The three most selected species (A. senegal, A. tortilis and A. robusta) should be further evaluated at laboratory to determine their energy values.

scholarly journals The most prominent educational problems faced by teachers of Arabic language in the schools of education for middle-aged government in Riyadh: أبرز المشكلات التدريسية التي تواجه معلمي اللغة العربية في مدارس تعليم الكبار المتوسطة الحكومية بمدينة الرياض

2017 ◽  
Vol 1 (4) ◽  
Author(s):  
Abdul Aziz bin Othman Al Humeida
Keyword(s):  
Writing Skills ◽  
Arabic Language ◽  
Literacy Skills ◽  
Male Students ◽  
Educational Resource ◽  
Schools Of Education ◽  
Resource Center ◽  
The Family ◽  
Descriptive Method ◽  
Selection Of

The study aimed to identify the most prominent problems faced by teachers of Arabic language, and ways to address them. The researcher used the descriptive descriptive method. The study tool consisted of a questionnaire distributed to a sample of (55) all male students in the middle school for boys in Riyadh in the second semester of 1433-1434H. The teaching of the students is: The weakness of the student in the literacy skills, the obligations of the family learner do not help him to study. The most important problems related to the curricula are: the lack of curricula dedicated to the large student, the lack of participation in the selection of curricula, the lack of development and change constantly, not appropriate time to complete. The most important problems related to the environment are: There is no suitable library for adults, there is no suitable educational means, no furniture suitable for the age of the students, no educational resource center and a building of its own. There were no statistically significant differences at (α0.05) between the responses of the study members according to the following variables: qualification, experience. In the light of the results, the researcher made a number of recommendations: To promote the learner's knowledge of reading and writing skills, to take care of homework assignments, to develop special curricula for the great student and to involve the teacher in her selection; to create an appropriate library for adults;

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