Effects of salinity and concomitant species on growth of Phragmites australis populations at different levels of genetic diversity

2021 ◽  
Vol 780 ◽  
pp. 146516
Author(s):  
Xin-Sheng Sun ◽  
Yu-Han Chen ◽  
Na Zhuo ◽  
Yuan Cui ◽  
Fang-Li Luo ◽  
...  
mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Jan O. Haerter ◽  
Kim Sneppen

ABSTRACT Even within similar bacterial strains, it has been found that the clustered, regularly interspaced short palindromic repeat (CRISPR) shows a large variability of spacers. Modeling bacterial strains with different levels of immunity to infection by a single virulent phage, we find that coexistence in a well-mixed environment is possible only when these levels are distinctly different. When bacterial strains are similar, one subpopulation collapses. In the case of bacteria with various levels of CRISPR immunity to a range of phages, small differences in spacer composition will accordingly be suppressed under well-mixed conditions. Using a numerical model of populations spreading in space, we predict that it is the Lamarckian nature of CRISPR evolution that combines with spatial correlations to sustain the experimentally observed distribution of spacer diversity.


2012 ◽  
Vol 63 (12) ◽  
pp. 1124 ◽  
Author(s):  
V. Copani ◽  
G. Testa ◽  
A. Lombardo ◽  
S. L. Cosentino

Several morphological and agronomic traits and the genetic diversity of nine Dactylis glomerata L. populations collected throughout Sicily (semi-arid Mediterranean environment) were evaluated for two successive years. Significant differences were recorded for morphological traits (plant height, leaf length, leaf width). In relation to the measurement of summer dormancy, the results suggest the expression of different levels of dormancy (completely dormant, semi-dormant, and non-dormant). For biomass yield, some Sicilian populations (SD63 and SD56) characterised by low levels of summer dormancy show production levels similar to the summer-active control varieties (Medly and Porto). However, SD46, with a much higher level of dormancy, gave biomass yield higher than the summer-dormant control variety (Kasbah). The genetic diversity evaluated by fAFLP analysis confirms the observed morphological and agronomic variability.


Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1292-1301 ◽  
Author(s):  
M. I. Siri ◽  
A. Sanabria ◽  
M. J. Pianzzola

Bacterial wilt, caused by Ralstonia solanacearum, is a major disease affecting potato (Solanum tuberosum) production worldwide. Although local reports suggest that the disease is widespread in Uruguay, characterization of prevalent R. solanacearum strains in that country has not been done. In all, 28 strains of R. solanacearum isolated from major potato-growing areas in Uruguay were evaluated, including 26 strains isolated from potato tubers and 2 from soil samples. All strains belonged to phylotype IIB, sequevar 1 (race 3, biovar 2). Genetic diversity of strains was assessed by repetitive-sequence polymerase chain reaction, which showed that the Uruguayan strains constituted a homogeneous group. In contrast, inoculation of the strains on tomato and potato plants showed, for the first time, different levels of aggressiveness among R. solanacearum strains belonging to phylotype IIB, sequevar 1. Aggressiveness assays were also performed on accessions of S. commersonii, a wild species native to Uruguay that is a source of resistance for potato breeding. No significant interactions were found between bacterial strains and potato and S. commersonii genotypes, and differences in aggressiveness among R. solanacearum strains were consistent with previously identified groups based on tomato and potato inoculations. Moreover, variation in responses to R. solanacearum was observed among the S. commersonii accessions tested.


2021 ◽  
Author(s):  
Furqan Awan ◽  
Muhammad Muddassir Ali ◽  
Muhammad Hassan Mushtaq ◽  
Muhammad Ijaz

Staphylococcus aureus (S. aureus) has been a substantial economic problem due to its antibiotic resistance, persistence inside host and recurrence of disease. It escapes from immunity because of its intra-cellular growth. Moreover, it forms biofilm on both living and in-animate surfaces that leads to recurrent infections and growth in food industry, respectively. Further, S. aureus undergoes the vertical and horizontal evolution that has genetically diversified the bacterial population. All the factors such as point mutations, plasmids, phages etc. have played their roles in diversifying this bacterium. Many bacterial physiological characteristics have been affected by genetic diversity. Biofilm forming ability is also considered as a variable characteristic of S. aureus that can help the bacteria to survive in different environments with different levels of biofilm production. In adapting the environment, S. aureus also forms different types of biofilm for its better survival. How genetic diversity is playing its role in this division of S. aureus is yet to be revealed. This chapter focuses on the factors related to genetic diversity and biofilm formation of S. aureus.


2020 ◽  
Author(s):  
Desalegn D. Serba ◽  
Ghislain Kanfany ◽  
Davina Rhodes ◽  
Paul St. Amand ◽  
Amy Bernardo ◽  
...  

Abstract Background: Genetic improvement of pearl millet is lagging behind most of the major crops. Development of genomic resources is expected to expedite breeding for improved agronomic traits, stress tolerance, yield, and nutritional quality. Genotyping a breeding population with high throughput markers enables exploration of genetic diversity, population structure, and linkage disequilibrium (LD) which are important preludes for marker-trait association studies and application of genomic-assisted breeding. Results: Genotyping-by-sequencing (GBS) libraries of 309 inbred lines derived from landraces and improved varieties from Africa and India generated 54,770 high quality single nucleotide polymorphism (SNP) markers. On average one SNP per 29 Kb was mapped in the reference genome, with the telomeric regions more densely mapped than the pericentromeric regions of the chromosomes. Population structure analysis using 30,208 SNPs evenly distributed in the genome divided 309 accessions into five subpopulations with different levels of admixture. Pairwise genetic distance (GD) between accessions varied from 0.09 to 0.33 with the average distance of 0.28. Rapid LD decay implied low tendency of markers inherited together. Genetic differentiation estimates were the highest between subgroups 4 and 5, and the lowest between subgroups 1 and 2. Conclusions: Population genomic analysis of pearl millet inbred lines derived from diverse geographic and agroecological features identified five subgroups mostly following pedigree differences with different levels of admixture. It also revealed the prevalence of high genetic diversity in pearl millet, which is very useful in defining heterotic groups for hybrid breeding, trait mapping, and holds promise for improving pearl millet for yield and nutritional quality. The short LD decay observed suggests an absence of persistent haplotype blocks in pearl millet. The diverse genetic background of these lines and their low LD make this set of germplasm useful for traits mapping.


2011 ◽  
Vol 48 (5) ◽  
pp. 1305-1313 ◽  
Author(s):  
Karin M. Kettenring ◽  
Melissa K. McCormick ◽  
Heather M. Baron ◽  
Dennis F. Whigham

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Rongmin Guo ◽  
Lihua Zhou ◽  
Hongbo Zhao ◽  
Fadi Chen

OpisthopappusShih is endemic to the Taihang Mountains, China. It grows in the crevice of cliffs and is in fragmented distribution. This genus consists of two species, namely,O. taihangensis(Ling) Shih andO. longilobusShih, which are both endangered plants in China. This study adopted intersimple sequence repeat markers (ISSR) to analyze the genetic diversity and genetic structure from different levels (genus, species, and population) in this genus. A total of 253 loci were obtained from 27 primers, 230 of which were polymorphic loci with a proportion of polymorphic bands (PPB) of up to 90.91% at genus level. At species level, bothO. taihangensis(PPB=90.12%,H=0.1842, andI=0.289) andO. longilobus(PPB=95.21%,H=0.2226, andI=0.3542) have high genetic diversity. Their respective genetic variation mostly existed within the population. And genetic variation inO. longilobus(84.95%) was higher than that inO. taihangensis(80.45%). A certain genetic differentiation among populations inO. taihangensiswas found (Gst=0.2740,Φst=0.196) and genetic differentiation inO. longilobuswas very small (Gst=0.1034,Φst=0.151). Gene flow in different degrees (Nm=1.325and 4.336, resp.) and mating system can form the existing genetic structures of these two species. Furthermore, genetic differentiation coefficient (Gst=0.0453) between species and the clustering result based on the genetic distance showed that interspecific differentiation betweenO. taihangensisandO. longilobuswas not significant and could occur lately.


2014 ◽  
Vol 163 (7-8) ◽  
pp. 543-553 ◽  
Author(s):  
Rodrigo V. Costa ◽  
Laércio Zambolim ◽  
Luciano V. Cota ◽  
Dagma D. Silva ◽  
Douglas F. Parreira ◽  
...  

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