scholarly journals Enset (Enset ventricosum (Welw.) Cheesman) Breeding for Various Purposes - A Review

2021 ◽  
Vol 10 (2) ◽  
pp. 39
Author(s):  
Getachew Etana Gemechu ◽  
Samrawit Silas Simmon ◽  
Efrem Asfaw
Keyword(s):  
Diversity Index ◽  
Research Effort ◽  
Gene Bank ◽  
Ex Situ ◽  
Staple Food ◽  
Disease Symptoms ◽  
Variability Study ◽  
Two Populations ◽  
Different Parts

Enset (Enset ventricosum (Welw) Cheesman) is a well-known cultivated crop in Ethiopia and a cultural staple food for over 20 million humans in different parts of Ethiopia. It bears flowers that developed into fruits and seeds. It bears seeds and propagated vegetativly. Attempts have been done for maintenance, conservation, improving cultivars, diversity, and variability study. About 623 Enset germplasm were collected from 12 main growing areas and ex-situ conserved at Areka. Seeds of Enset were stored at the millennium gene bank. Seedlings and specimens are held in the garden of Cambridge Cottage and Wakehurst. In the research effort 6 cultivars: 3 early set cultivars: Yanbulle, Gewada, Endale, and 3 late set cultivars: Kelisa, Zerita, Mesena were released. Variability study revealed that corn yields were significantly affected by location, cultivar, and cultivar Vs location. Genotypes: Suite, Warke, Bidu, Astera, and Kekari showed 100% disease symptoms after 30 days of inoculation. Symptoms weren't observed on Meziya, Bedadet, Hiniba, and Nech Enset clones after 90 days of inoculation. ISSRs primers revealed that, in all parameters, Kefficho genotypes have been more diversified than genotypes from Essera areas. The Partitioning of Shannon's diversity index indicated that the major variations were occurred within populations than between the two populations.

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 Geographical patterns of phenotypic diversity and structure of Kenyan wild sorghum populations (Sorghum spp.) as an aid to germplasm collection and conservation strategy

2010 ◽  
Vol 8 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Moses M. Muraya ◽  
Hartwig H. Geiger ◽  
Evans Mutegi ◽  
Ben M. Kanyenji ◽  
Fabrice Sagnard ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Diversity Index ◽  
Flag Leaf ◽  
Germplasm Collection ◽  
Principal Component ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Regional Differentiation ◽  
Wild Sorghum ◽  
Geographical Patterns

Kenya lies within sorghum centre of diversity. However, information on the relative extent of diversity patterns within and among genetically defined groups of distinct ecosystems is lacking. The objective was to assess the structure and phenotypic diversity of wild sorghum populations across a range of geographical and ecological conditions in the country. Sixty-two wild sorghum populations (30 individuals per population) sampled from four distinct sorghum growing regions of Kenya and covering different agroecologies were characterized for ten qualitative traits. Plant height, number of tillers, panicle sizes and flag leaf dimensions were also recorded. Frequencies of the phenotypic classes of each character were calculated. The Shannon diversity index (H′) was used to estimate the magnitude of diversity. Principal component analysis was used to differentiate populations within and between regions. Wild sorghum is widely distributed in Kenya, occurring in sympatric ranges with cultivated sorghum, and both have overlapping flowering windows. All characters considered displayed great phenotypic diversity. Pooled over characters within regions, the mean H′ ranged between 0.60 and 0.93 in Western and Coast regions, respectively. Wild sorghum was found to show a weak regional differentiation, probably reflecting the importance of seed-mediated gene flow in shaping the wild sorghum population structure. Trait distribution was variable among regions, but there was no conspicuous distribution of the traits studied in any given region. Spontaneous hybridization and introgression of genes from cultivated to wild sorghum seems to be likely, and may already have occurred for a long time, although undocumented. Implications for in situ and ex situ genetic resources conservation are discussed.

scholarly journals Unveiling the Fecal Microbiota in Two Captive Mexican Wolf (Canis lupus baileyi) Populations Receiving Different Type of Diets

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 637
Author(s):  
Sergio I. Barraza-Guerrero ◽  
César A. Meza-Herrera ◽  
Cristina García-De la Peña ◽  
Verónica Ávila-Rodríguez ◽  
Felipe Vaca-Paniagua ◽  
...  
Keyword(s):  
United States ◽  
Canis Lupus ◽  
Diversity Index ◽  
Southern United States ◽  
Rrna Gene ◽  
Raw Meat ◽  
Degrading Bacteria ◽  
Mexican Wolf ◽  
Canis Lupus Baileyi ◽  
Two Populations

The Mexican wolf (Canis lupus baileyi) was once distributed in southern United States and northern Mexico. It is an endangered subspecies detached from the gray wolf, and likely exemplifies one of the original migration waves of C. lupus into the new world. This is a canine whose individuals survive in specialized facilities, zoos, and museums as part of captive-breeding programs. In order to contribute to the improvement of the management of this species and favor its long-term conservation in Mexico, we aimed to evaluate the diversity and abundance of the fecal bacterial microbiota in two populations exposed to different types of diet: (1) Michilia (23° N, 104° W); kibble daily and raw meat sporadically, and (2) Ocotal (19° N, 99° W); raw meat daily and live animals periodically. Next generation sequencing (V3-V4 16S rRNA gene) by Illumina was implemented. The operational taxonomic units (OTUs) in Michilia resulted in 9 phyla, 19 classes, 34 orders, 61 families, 204 genera, and 316 species, while in Ocotal there were 12 phyla, 24 classes, 37 orders, 69 families, 232 genera, and 379 species. Higher estimated Chao1 richness, Shannon diversity, and core microbiota were observed in Ocotal. Differences (p < 0.05) between populations occurred according to the Bray–Curtis beta diversity index. In the Michilia, dominance of bacteria that degrade carbohydrates (Firmicutes, Lachnospiraceae, Blautia, Clostrodium, Eisenbergiella, Romboutsia, and Ruminococcus) was observed; they are abundant in kibble diets. In contrast, the Ocotal microbiota was dominated by protein-degrading bacteria (Fusobacteria, Fusobacteriaceae, and Fusobacteria), indicating a possible positive relation with a raw meat diet. The information generated in this study is fundamental to support the implementation of better management plans in the two populations considered here, as well as in different facilities of southern United States and Mexico, where this subspecies is kept in captivity for conservation purposes.

Frequency of –163 C > A and 63 C > G single nucleotide polymorphism of cytochrome P450 1A2 in two African populations

2004 ◽  
Vol 42 (8) ◽  
Author(s):  
Collet Dandara ◽  
Patience T. Basvi ◽  
Tashinga E. Bapiro ◽  
Jane Sayi ◽  
Julia A. Hasler
Keyword(s):  
Cytochrome P450 ◽  
Research Effort ◽  
Point Mutations ◽  
Base Change ◽  
Polymorphism Analysis ◽  
Nucleotide Polymorphisms ◽  
Cytochrome P450 1A2 ◽  
Single Nucleotide ◽  
African Populations ◽  
Two Populations

AbstractCytochrome P450 1A2 (CYP1A2) is an important member of the cytochrome P450 superfamily of enzymes because of its involvement in the metabolism of some carcinogens and therapeutically important drugs. As a result, factors affecting the activity of the enzyme are the focus of considerable research effort as they may have important pharmacological or toxicological implications. CYP1A2 has been shown to exhibit a genetic polymorphism with most of the data, however, coming from studies in Caucasian and Oriental populations. In this study therefore, we investigated the frequencies of two point mutations, –163C > A and 63C > G, in two Bantu African populations. A total of 214 healthy subjects were recruited from Zimbabwe (n = 143) and Tanzania (n = 71). The two single nucleotide polymorphisms were detected using polymerase chain reaction-restriction fragment length polymorphism analysis. The frequency of –163A was 57% (95% confidence interval (CI), 54%, 60%) and 49% (95% CI, 45%, 53%) among Zimbabweans and Tanzanians, respectively, but the difference between the two populations was not statistically significant (p = 0.123). The base change 63C > G was not found in any of the subjects from the two populations. We report here a high frequency of –163C > A base change and an absence of the 63C > G change in the two African populations.

Genetic variation in two Chamaecrista species (Leguminosae), one endangered and narrowly distributed and another widespread in the Serra do Espinhaço, Brazil

2007 ◽  
Vol 85 (7) ◽  
pp. 629-636 ◽  
Author(s):  
Reinaldo Moreira da Silva ◽  
G. Wilson Fernandes ◽  
Maria Bernadete Lovato
Keyword(s):  
Genetic Diversity ◽  
Diversity Index ◽  
Random Amplified Polymorphic Dna ◽  
Habitat Destruction ◽  
Conservation Strategies ◽  
Lower Percentage ◽  
Endemic Plant ◽  
Endemic Plant Species ◽  
Two Populations ◽  
Shannon’S Diversity Index

The Serra do Espinhaço in Brazil is under continuous and increasing levels of human disturbance. It has a large number of endemic plant species such as Chamaecrista semaphora (Irwin and Barneby), an endangered species with extremely narrow range. We studied the genetic diversity of C. semaphora and compared it with Chamaecrista mucronata (Spreng.) Irwin and Barneby, a widespread congeneric species distributed over the entire Serra do Espinhaço, in an attempt to provide information for conservation strategies. Two populations of C. mucronata and the only two known populations of C. semaphora from Serra do Cipó were screened for variability using random amplified polymorphic DNA (RAPD) markers. Populations of C. semaphora exhibited a lower percentage of polymorphic markers (16.9%) and Shannon’s Diversity Index (H′pop = 0.124) than C. mucronata populations (43.3% and H′pop = 0.299). Most of the genetic variability of both species studied was distributed within populations; C. semaphora populations (ΦST = 0.198) were less divergent than C. mucronata populations (ΦST = 0.378). The risk of extinction for C. semaphora is large owing to its low level of genetic diversity compared with its widespread congener and because of increasing habitat destruction. Both populations of C. semaphora urgently need protection to maximize the genetic diversity of this species and diminish further substantial loss within the populations.

Strategies and priorities in field collections for ex situ conservation: the case of the Israel Plant Gene Bank

2016 ◽  
Vol 64 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Oz Barazani ◽  
Einav Mayzlish-Gati ◽  
Dikla Lifshitz ◽  
Rivka Hadas ◽  
Alexandra Keren-Keiserman ◽  
...  
Keyword(s):  
Ex Situ Conservation ◽  
Gene Bank ◽  
Ex Situ ◽  
Plant Gene

scholarly journals Bacteriophage typing inSalmonella bareilly

1994 ◽  
Vol 112 (1) ◽  
pp. 45-49
Author(s):  
N. C Sharma ◽  
R. Bhatia ◽  
S. Singh ◽  
P. C. John ◽  
S. Kumar ◽  
...  
Keyword(s):  
Diversity Index ◽  
Bacteriophage Typing ◽  
Phage Types ◽  
A Value ◽  
Different Parts

SummaryA total of 675 stdrains ofSalmonella bareillyreceived from different parts of India and France during 1959–92 were phage typed using six bacteriophages. Overall ttypability achieved was 90·8% with 23 distinctphage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson's coefficient was applied for diversity index having a value of 0·839. This system was found to be reproducible, stable and epidemiologically useful.

scholarly journals Genetic Diversity, Population Structure and Relationship of Ethiopian Barley (Hordeum vulgare L.) Landraces as reveled by Simple Sequence Repeat (SSR) Markers

2021 ◽  
Author(s):  
Allo Aman Dido ◽  
B.J.K. Singh ◽  
Ermias Assefa ◽  
M.S.R. Kr ◽  
Dawit Degefu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Simple Sequence Repeat ◽  
Diversity Index ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Sequence Repeat ◽  
Genetic Rescue ◽  
Hordeum Vulgare L ◽  
Barley Genotypes ◽  
Simple Sequence

Abstract Characterization of genetic resources maintained at genebanks has important implications for future utilization and collection activities. A total of 49 simple sequence repeat (SSR) or microsatellite markers were used to study genetic diversity and relationships among 376 barley landraces collected from different barley producing parts of Ethiopia and eight cultivars. Overall, 478 alleles with an average of 9.755 alleles per locus were obtained of which 97.07% of the loci were observed to be polymorphic. Nei’s genetic diversity index (h) was 0.654, and the Shannon diversity index (I) was 0.647, indicating that the genetic diversity in barley genotypes studies was moderately high. At the population level, the percentage of polymorphic loci (PPL) averaged 98.37%, h = averaged 0.388, and I = averaged 0.568. The highest level of genetic diversity was observed in the AR population (PPL =100%, h = 0.439, I = 0.624); the lowest was observed in the JM population (PPL = 75.51%, h = 0.291, I =0.430). AMOVA revealed significant genetic differentiation within and between populations (P < 0.001), with 84.21% of the variation occurring within populations and 15.79% occurring among populations. Genetic variation analysis showed a coefficient of gene differentiation of 0.053 and a gene flow value of 4.467 among populations. The 384 barley genotypes were divided into seven genetic clusters according to STRUCTURE, Neighbour joining tree and principal coordinate analysis, correlating significantly with geographic distribution. These results will assist with the formulation of conservation strategies, such as genetic rescue and on-farm in situ and ex situ conservation.

scholarly journals Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species

2019 ◽  
Vol 20 (3) ◽  
pp. 704-711
Author(s):  
KAROLINE APARECIDA FELIX RIBEIRO ◽  
CRISTIAN MADEIRA DE MEDEIROS ◽  
JOSÉ ÁNGEL SÁNCHEZ-AGUDO ◽  
JOSÉ SÁNCHEZ-SÁNCHEZ
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
Ex Situ Conservation ◽  
Seed Viability ◽  
Potassium Nitrate ◽  
Ex Situ ◽  
Cold Stratification ◽  
Different Temperatures ◽  
Two Populations

Abstract. Ribeiro KAF, Madeira de Medeiros C, Agudo JAS, Sánchez JS. 2019. Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species. Biodiversitas 20: xxxx. Strategies to halt the decline of biodiversity include: in-situ and ex-situ conservation, the latter already considered at the global level essential in conservation programs. The results of the germinative responses of Carex lainzii Luceño, E. Rico & T. Romero (Cyperaceae), an endemic Spanish endangered species, are presented in this work, to different trials carried out in the laboratory with seeds harvested in the two known populations of that community. Treatments with and without 0.2% potassium nitrate (KNO3) were tested for four, six and eight months in cold stratification at 5 °C in two germination chambers at different temperatures (22/10 °C and 27/15 °C with a photoperiod of 12/12 hours). The results indicate that there is a large difference in germination rates between the two populations. The use of KNO3 did not increase germination rates in any case, but differences were found between periods of cold stratification, with six months being the most effective. On the other hand, the germination rates of both populations remain low (17.58% and 2%) compared to the obtained rate of seed viability. With this first approach to the understanding of the germination requirements of C. lainzii, it becomes clear that new essays are needed to obtain better results, in order to effectively implement the protection plans of C. lainzii populations.

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