Host Dependent and Geographical Structuring of Citrus Canker Bacteria at Peshawar, Pakistan

Citrus canker disease, caused by Xanthomonas axonopodis pv. Citri (Xac) induces huge losses to citrus, particularly in nurseries. This study assessed the level of genetic diversity and divergence in Xac population prevalent in district Peshawar on various host species, based on isolates collected from different fruit nurseries of Peshawar. Surveillance resulted in collection of 80 samples, out of which 50 bacterial samples were isolated. Genotyping of the isolates using RAPD markers amplified 35 scorable loci with an average of 8.7 loci per primers and level of polymorphism was 100%, i.e., almost all of the isolates genotyped had a different multilocus genotype. The loci GLA-031000 was recorded with the highest gene diversity (0.51) followed by GLB-05_1000 and GLA-03_1100 (0.49). The maximum diversity index (0.50) was recorded for loci GLA-031000, followed by GLB-051000 and GLA-03_1100 (0.48). A high diversity was observed across all locations, with the range of genotypic diversity from 0.778 (detected at Malakandair) to 0.955 (detected at Hayatabad and Tarnab). Divergence between samples collected from different locations was limited as revealed by the PCA, PCoA, phylogenetic tree and network analyses. Samples originated from various hosts also revealed a high diversity across host types with the minimum genotype diversity observed for Eureka Lemon (0.750) and the maximum for sweet lemon (0.966). The divergence for samples collected on various citrus host types was absent. The very small linkage disequilibrium (0.006–0.159) reflected on the potential recombination in the population, which must have direct implications to disease management and resistance exploitation. © 2021 Friends Science Publishers

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Spatial Genetic Structure of a Vector-Borne Generalist Pathogen

Applied and Environmental Microbiology ◽

10.1128/aem.02172-10 ◽

2011 ◽

Vol 77 (8) ◽

pp. 2596-2601 ◽

Cited By ~ 15

Author(s):

Helvécio D. Coletta-Filho ◽

Leonora S. Bittleston ◽

Rodrigo P. P. Almeida

Keyword(s):

Genetic Structure ◽

Riparian Vegetation ◽

Diversity Index ◽

Gene Diversity ◽

Isolation By Distance ◽

Spatial Genetic Structure ◽

Genotypic Diversity ◽

Mantel Test ◽

Content Type ◽

Vector Borne

ABSTRACTVector-borne generalist pathogens colonize several reservoir species and are usually dependent on polyphagous arthropods for dispersal; however, their spatial genetic structure is generally poorly understood. Using fast-evolving genetic markers (20 simple sequence repeat loci, resulting in a total of 119 alleles), we studied the genetic structure of the vector-borne plant-pathogenic bacteriumXylella fastidiosain Napa Valley, CA, where it causes Pierce's disease when it is transmitted to grapevines from reservoir plants in adjacent riparian vegetation. Eighty-three differentX. fastidiosamultilocus microsatellite genotypes were found in 93 isolates obtained from five vineyards, resulting in an index of clonal fraction closer to 0 and a Simpson's genotypic diversity index (D) closer to a maximum value of 1. Moderate values of Nei's gene diversity (HNei; averageHNei= 0.41) were observed for most of theX. fastidiosapopulations. The low Wright's index of genetic diversity among populations calculated by the FSTAT software (Wright'sFSTindex) among population pairs (0.0096 to 0.1080) indicated a weak or absent genetic structure among the five populations; a panmictic population was inferred by Bayesian analyses (with the STRUCTURE and BAPS programs). Furthermore, a Mantel test showed no significant genetic isolation by distance when both Nei (r= −0.3459,P= 0.268) and linearized θ (r= −0.3106,P= 0.269) indices were used. These results suggest that the riparian vegetation from which vectors acquire the pathogen prior to inoculation of grapevines supports a diverse population ofX. fastidiosa.

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Population genetic variation analysis of bitter gourd wilt caused by Fusarium oxysporum f. sp. momordicae in China using inter simple sequence repeats (ISSR) molecular markers

Journal of Plant Pathology ◽

10.1007/s42161-021-00759-8 ◽

2021 ◽

Author(s):

Rui Zang ◽

Ying Zhao ◽

Kangdi Guo ◽

Kunqi Hong ◽

Huijun Xi ◽

...

Keyword(s):

Genetic Variation ◽

Genetic Differentiation ◽

Fusarium Oxysporum ◽

Diversity Index ◽

Gene Diversity ◽

Pcr Amplification ◽

Bitter Gourd ◽

Diseased Plant ◽

Variation Analysis ◽

Group I

AbstractBitter gourd wilt caused by Fusarium oxysporum f. sp. momordicae (FOM) is a devastating crop disease in China. A total of 173 isolates characteristic of typical Fusarium oxysporum with abundant microconidia and macroconidia on white or ruby colonies were obtained from diseased plant tissues. BLASTn analysis of the rDNA-ITS of the isolates showed 99% identity with F. oxysporum species. Among the tested isolates, three were infectious toward tower gourd and five were pathogenic to bottle gourd. However, all of the isolates were pathogenic to bitter gourd. For genetic differences analysis, 40 ISSR primers were screened and 11 primers were used for ISSR-PCR amplification. In total, 127 loci were detected, of which 76 were polymorphic at a rate of 59.84%. POPGENE analysis showed that Nei’s gene diversity index (H) and Shannon’s information index (I) were 0.09 and 0.15, respectively, which indicated that the genetic diversity of the 173 isolates was low. The coefficient of gene differentiation (Gst = 0.33 > 0.15) indicated that genetic differentiation was mainly among populations. The strength of gene flow (Nm = 1.01 > 1.0) was weak, indicating that the population differentiation caused by gene drift was blocked to some degree. The dendrogram based on ISSR markers showed that the nine geographical populations were clustered into two groups at the threshold of genetic similarity coefficient of 0.96. The Shandong and Henan populations were clustered into Group I, while the Guangdong, Hainan, Guangxi, Fujian, Jiangxi, and Hubei populations constituted Group II. Results of the genetic variation analysis showed that the Hunan and Guangxi populations had the highest degree of genetic differentiation, while the Hubei population had the lowest genetic differentiation. Our findings enrich the knowledge of the genetic variation characteristics of FOM populations with the goal of developing effective disease-management programs and resistance breeding programs.

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Modified Monosaccharides Content of Xanthan Gum Impairs Citrus Canker Disease by Affecting the Epiphytic Lifestyle of Xanthomonas citri subsp. citri

Microorganisms ◽

10.3390/microorganisms9061176 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1176

Author(s):

Simone Cristina Picchi ◽

Laís Moreira Granato ◽

Maria Júlia Festa Franzini ◽

Maxuel Oliveira Andrade ◽

Marco Aurélio Takita ◽

...

Keyword(s):

Biofilm Formation ◽

Xanthan Gum ◽

Wild Type Strain ◽

Natural Infection ◽

Citrus Canker ◽

Wild Type ◽

Xanthomonas Citri ◽

Canker Disease ◽

Key Enzyme ◽

Citrus Canker Disease

Xanthomonas citri subsp. citri (X. citri) is a plant pathogenic bacterium causing citrus canker disease. The xanA gene encodes a phosphoglucomutase/phosphomannomutase protein that is a key enzyme required for the synthesis of lipopolysaccharides and exopolysaccharides in Xanthomonads. In this work, firstly we isolated a xanA transposon mutant (xanA::Tn5) and analyzed its phenotypes as biofilm formation, xanthan gum production, and pathogenesis on the sweet orange host. Moreover, to confirm the xanA role in the impaired phenotypes we further produced a non-polar deletion mutant (ΔxanA) and performed the complementation of both xanA mutants. In addition, we analyzed the percentages of the xanthan gum monosaccharides produced by X. citri wild-type and xanA mutant. The mutant strain had higher ratios of mannose, galactose, and xylose and lower ratios of rhamnose, glucuronic acid, and glucose than the wild-type strain. Such changes in the saccharide composition led to the reduction of xanthan yield in the xanA deficient strain, affecting also other important features in X. citri, such as biofilm formation and sliding motility. Moreover, we showed that xanA::Tn5 caused no symptoms on host leaves after spraying, a method that mimetics the natural infection condition. These results suggest that xanA plays an important role in the epiphytical stage on the leaves that is essential for the successful interaction with the host, including adaptive advantage for bacterial X. citri survival and host invasion, which culminates in pathogenicity.

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GC-TOF/MS-based metabolomics analysis to investigate the changes driven by N-Acetylcysteine in the plant-pathogen Xanthomonas citri subsp. citri

Scientific Reports ◽

10.1038/s41598-021-95113-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Simone Cristina Picchi ◽

Mariana de Souza e Silva ◽

Luiz Leonardo Saldanha ◽

Henrique Ferreira ◽

Marco Aurélio Takita ◽

...

Keyword(s):

Amino Acids ◽

Cell Proliferation ◽

Plant Pathogen ◽

Model Organism ◽

Citrus Canker ◽

Bacterial Cells ◽

Xanthomonas Citri ◽

Canker Disease ◽

Potential Use

AbstractN-Acetylcysteine (NAC) is an antioxidant, anti-adhesive, and antimicrobial compound. Even though there is much information regarding the role of NAC as an antioxidant and anti-adhesive agent, little is known about its antimicrobial activity. In order to assess its mode of action in bacterial cells, we investigated the metabolic responses triggered by NAC at neutral pH. As a model organism, we chose the Gram-negative plant pathogen Xanthomonas citri subsp. citri (X. citri), the causal agent of citrus canker disease, due to the potential use of NAC as a sustainable molecule against phytopathogens dissemination in citrus cultivated areas. In presence of NAC, cell proliferation was affected after 4 h, but damages to the cell membrane were observed only after 24 h. Targeted metabolite profiling analysis using GC–MS/TOF unravelled that NAC seems to be metabolized by the cells affecting cysteine metabolism. Intriguingly, glutamine, a marker for nitrogen status, was not detected among the cells treated with NAC. The absence of glutamine was followed by a decrease in the levels of the majority of the proteinogenic amino acids, suggesting that the reduced availability of amino acids affect protein synthesis and consequently cell proliferation.

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Genetic Diversity among Calamus brandisii Becc. (Arecaceae) Populations in Kerala Part of Western Ghats

Indian Journal of Forestry ◽

10.54207/bsmps1000-2021-xm8ipx ◽

2021 ◽

Vol 43 (1) ◽

pp. 38-42

Author(s):

Kavungal Priya ◽

◽

Indira . ◽

Vadakkethil Balakrishnan Sreekumar ◽

Renuka . ◽

...

Keyword(s):

Genetic Diversity ◽

Western Ghats ◽

Rapd Markers ◽

Gene Diversity ◽

Issr Markers ◽

High Genetic Diversity ◽

Western Ghats Of India ◽

The Mean ◽

Two Parameters ◽

Two Populations

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.

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Genotypic diversity of S. mutans in dental biofilm formed in situ under sugar stress exposure

Brazilian Dental Journal ◽

10.1590/s0103-64402007000300002 ◽

2007 ◽

Vol 18 (3) ◽

pp. 185-191 ◽

Cited By ~ 6

Author(s):

Rodrigo Alex Arthur ◽

Cínthia Pereira Machado Tabchoury ◽

Renata de Oliveira Mattos-Graner ◽

Altair A. Del Bel Cury ◽

Adriana Franco Paes Leme ◽

...

Keyword(s):

Genotypic Diversity ◽

Negative Control ◽

Stress Exposure ◽

Chain Reaction ◽

Dental Biofilm ◽

Polymerase Chain ◽

Fermentable Carbohydrates ◽

Almost All ◽

Frequent Exposure

In situ dental biofilm composition under sugar exposure is well known, but sugar effect on the genotypic diversity of S. mutans in dental biofilm has not been explored. This study evaluated S. mutans genotypic diversity in dental biofilm formed in situ under frequent exposure to sucrose and its monosaccharide constituents (glucose and fructose). Saliva of 7 volunteers was collected for isolation of S. mutans and the same volunteers wore intraoral palatal appliances, containing enamel slabs, which were submitted to the following treatments: distilled and deionized water (negative control), 10% glucose + 10% fructose (fermentable carbohydrates) solution or 20% sucrose (fermentable and EPS inductor) solution, 8x/day. After 3, 7 and 14 days, the biofilms were colleted and S. mutans colonies were isolated. Arbitrarily primed polymerase chain reaction (AP-PCR) of S. mutans showed that salivary genotypes were also detected in almost all biofilm samples, independently of the treatment, and seemed to reflect those genotypes present at higher proportion in biofilms. In addition to the salivary genotypes, others were found in biofilms but in lower proportions and were distinct among treatment. The data suggest that the in situ model seems to be useful to evaluate genotypic diversity of S. mutans, but, under the tested conditions, it was not possible to clearly show that specific genotypes were selected in the biofilm due to the stress induced by sucrose metabolism or simple fermentation of its monosaccharides.

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Assessment of Genetic Diversity of Promising Castor Been (Ricinus communis L.) Genotypes in Nigeria

Notulae Scientia Biologicae ◽

10.15835/nsb11310346 ◽

2019 ◽

Vol 11 (3) ◽

pp. 467-474

Author(s):

Bolaji Zuluqurineen SALIHU ◽

Olamide Ahmed FALUSI ◽

Adeyinka Olufemi ADEPOJU ◽

Ibrahim Wasiu AROLU ◽

Oladipupo Yusuf DAUDU ◽

...

Keyword(s):

Genetic Diversity ◽

Diversity Index ◽

Gene Diversity ◽

Ricinus Communis ◽

Polymorphic Information Content ◽

Block Design ◽

Genetic Material ◽

Morphological Data ◽

Research Attention ◽

Ricinus Communis L

Castor oil plant (Ricinus communis L.) is an important oil crop with little research attention in Nigeria. In the present research, extent of genetic diversity among 20 Nigerian castor genotypes was determined using morphological descriptors and molecular markers. The genotypes were laid out on a randomized complete block design with three replicated plots. Molecular genotyping of the genotypes was carried out using genomic Simple Sequence Repeats (SSR). The genotypes revealed high divergence in seed colour, seed shape, seed mottle, seed caruncle and seed sizes. Seedling establishment varied from 70.18% (in Acc. 006) to 93.25% (Acc. 001) with average mean of 81.53%. Raceme length ranged from 15.90 cm to 29.54 cm with population mean of 20.80 cm. The highest seed yield (1222.98 kg/ha) was recorded in Acc. 001 and the least (611.46 kg/ha) was observed in Acc. 006. Seed oil content varied between 32.15% in Acc. 042 and 54.03% in Acc. 006. Agglomerative cluster dendrogram constructed from morphological data showed random distribution of the genotypes into three cluster groups irrespective of the sources/collection points. The genetic diversity based on SSR Marker Analysis revealed high average expected heterozygosity (0.74), Polymorphic information content (0.68), Nei’s gene diversity index (0.72) and Shannon's Information index (1.43). The dendrogram constructed from molecular data grouped the twenty genotypes into three groups at coefficient of 0.34. From these findings, it showed that the twenty genotypes evaluated are divergent in nature and they could serve as good genetic material for castor breeding in Nigeria.

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Baseline Assessments of Wildlife Biodiversity Within Selected Areas of Central Visayas, Philippines

Journal of Biodiversity Conservation and Bioresource Management ◽

10.3329/jbcbm.v6i2.55244 ◽

2021 ◽

Vol 6 (2) ◽

pp. 27-34

Author(s):

RP Jose ◽

WA Aureo ◽

CI Narido ◽

TD Reyes Jr ◽

MB Sarnowski

Keyword(s):

Species Richness ◽

Species Diversity ◽

Diversity Index ◽

Population Trends ◽

Species Richness And Diversity ◽

Natural Park ◽

Biodiversity Inventories ◽

Baseline Information ◽

High Diversity ◽

Areas Of Protection

A comprehensive inventory of faunal biodiversity was conducted within three Key Biodiversity Areas of Central Visayas. Mt. Bandilaan Natural Park (MBNP), Balinsasayao Twin Lakes Natural Park (BTLNP), and Rajah Sikatuna Protected Landscape (RSPL). Three primary wildlife groups were surveyed: bats, birds and amphibians. Species diversity and population trends were then analyzed to assess areas of biodiversity importance. RSPL generally had the highest species richness and diversity index while MBNP consistently had the lowest. When pooled. The surveyed areas resulted in a high diversity index and rate of endemicity showing the importance of multiple areas of protection. These findings can be utilized to prioritize habitat protection as well as to serve as a baseline information for future biodiversity inventories. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(2): 27-34

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RAPD ANALYSIS OF GENETIC VARIATION IN NATURAL POPULATIONS OF AEGILOPS SP. FROM SOUTH ADRIATIC

AGROFOR ◽

10.7251/agreng1801035d ◽

2018 ◽

Vol 3 (1) ◽

Author(s):

Miodrag DIMITRIJEVIĆ ◽

Sofija PETROVIĆ ◽

Borislav BANJAC ◽

Goran BARAĆ

Keyword(s):

Genetic Variation ◽

Food Production ◽

Rapd Markers ◽

Rapd Analysis ◽

Gene Diversity ◽

Rapd Marker ◽

Natural Populations ◽

Genetic Structuring ◽

Potential Source ◽

Novel Approach

New challenges that food production is facing, requires novel approach inagricultural strategy. The scissors of growing demand for food and the limits of theEarth's resources are forcing plant breeders to run for the new borders, utilizing allthe available genetic variation in order to create fruitful and economically soundcultivars. Aegilops sp. (Poaceae) is a potential source of genetic variation for wheatimprovement. RAPD marker analysis was used in order to distinguish and evaluatedifferent genotypes of Aegilops sp. population samples from the collectiongathered during few years’ expeditions in South Adriatic, along the coastal, littoraland the inland parts of Montenegro. Ten randomly amplified polymorphic DNAmarkers (RAPDs) were tested: OPA-05, OPA-08, OPB-06, OPA-02, OPA-07,OPA-25, OPB-07, OPB-18, OPC-06, OPC-10 to examine genetic structuring on 18samples of 6 populations of different Aegilops sp. According to global AMOVA,75% of total gene diversity was attributable mostly to diversity within population(ΦPT =0.205 p=0.001), indicating that the groups of studied goat grass populationswere seemingly to differing genetically. In contrast, 25% of the variation camefrom variation among populations. According to PCoA, the distribution of 18 goatgrass accessions by Principal Coordinate Analysis shows 3 distinct groups. PCoaxis 1, PCo axis 2, and PCo axis 3 account for 20.8%, 18.2% and 14.1% of thevariation, respectively. The results showed that RAPD markers could be aconvenient tool for investigating genetic variation and for detecting geneticstructuring of populations. Genetic variability formed under natural selection wasentrenched.

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Diversity Analysis of Endophytic Bacterial Community in Two Citrus Cultivars With Different Resistance to Citrus Canker

10.21203/rs.3.rs-347972/v1 ◽

2021 ◽

Author(s):

Bing Liu ◽

Jiahao Lai ◽

Simeng Wu ◽

Junxi Jiang ◽

Weigang Kuang

Keyword(s):

Bacterial Community ◽

Endophytic Bacteria ◽

Citrus Canker ◽

Navel Orange ◽

Xanthomonas Citri ◽

Canker Disease ◽

Satsuma Mandarin ◽

Endophytic Bacterial Community ◽

Dominant Bacteria ◽

The Relationship

Abstract The selective infection of Xanthomonas citri pv. citri to citrus cultivars is universally known, but it is not clarified whether there is a relationship between endophytic bacteria and the resistance of host variety to canker disease. In order to explore the relationship, Satsuma mandarin and Newhall navel orange were collected respectively as samples of resistant or susceptible cultivars to citrus canker disease, and endophytic bacterial community of two citrus cultivars were analyzed by using a next-generation, Illumina-based sequencing approach. Simultaneously, the seasonal dynamics of endophytic bacterial community and dominant genera were analyzed. The results showed that there were four dominant groups including Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes in all samples at phylum level. Endophytic bacteria were the most abundant in spring samples, then in summer and autumn samples. There were some differences between endophytic bacterial community of resistant citrus and that of susceptible citrus to canker disease, and the endophytic bacteria of Satsuma mandarin are more abundant than that of Newhall navel orange. According to the analysis of dominant bacteria in two citrus cultivars, it was found that some endophytic bacteria with antagonistic characteristics existed universally in all samples, although the dominant bacteria in different seasonal sample were different. However, in Newhall navel orange of susceptible citrus to canker disease, there were not only some bacteria against Xanthomonas citri pv. citri, but also some cooperative bacteria of canker occurrence like Stenotrophomonas.

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