RAPD Analysis Research Articles

Detection of carbapenem-resistance and biofilm formation genes, and genetic relatedness of Acinetobacter baumannii isolates

Acinetobacter baumannii is one of the most important nosocomial pathogen worldwide. This study aimed to investigate the virulence potential and genomic relatedness of A. baumannii strains isolated from patients hospitalized in the Military Medical Academy (MMA) by detecting OXA-type carbapenemases genes, biofilm-associated genes, and by RAPD analysis. PCR was used to detect the blaoxa genes, ISAba-1 genetic element, and biofilm-associated genes. The genomic relatedness was determined by RAPD analysis using four different primers (AP2, DAF4. M13, and DECA). blaoxa-51-like, blaoxa-23-like, blaoxa-24-like, and blaoxa-58-like were present in 100%, 34.0%, 62.4%, and 3.1% of isolates, respectively. All isolates had the ISAba1 sequence in their genome, in 35.1% of isolates it was associated with the blaoxa-51-like, and in 97.0% with the blaoxa-23-like gene. Biofilm-associated genes bap, ompA, epsA, csuA/BABCDE, and pgaABCD were detected in 93.8%, 95.8%, 88.1%, 98.4%, and 98.9% isolates, respectively. RAPD analysis showed a high degree of genome similarity and clonal dispersion of the isolates. Detection of blaoxa genes, especially biofilm-associated genes, in a high percentage of A. baumannii isolates indicated their great pathogenic potential. RAPD analysis revealed a high level of genomic similarity and clonal dispersion of the majority of isolates through MMA. Further, a continuous introduction of individual strains with different profiles contributes to the genetic diversity of A. baumannii isolates. These results can be useful for further management and tracking nosocomial outbreaks.

SCREENING OF GENETIC VARIANTS, PHYTOCHEMICAL ANALYSIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF Physalis minima FRUITS EXTRACT

Medicinal herbs are playing a major role in the therapeutic field due to the combination of phytochemicals and are the alternatives to chemical drugs. Physalis minima fruit has also exhibited multiple biological activities due to its richness in vitamins, minerals, and antioxidant chemicals. This work investigated the phytochemical variations of the genetic variants collected from four districts around Salem, Namakkal, Erode, and Dharmapuri with the help of polymerase chain reaction and random amplified polymorphic DNA methods. Phytochemicals of the fruits were examined through thin layer chromatography using chloroform, diethyl ether, ethanol, ethyl acetate, and methanol extracts. The polar solvent ethanol crude extract was characterized by FT-IR and GC-MS analysis to identify the functional groups. The antimicrobial activity of ethanolic extracts of Physalis minima fruits was evaluated against Streptococci acidominimus, Pseudomonas aeuriginosa, Penicillium expansum, and Aspergillus fumigatus strains by the cup diffusion method using serially diluted ethanolic extracts of Physalis minima fruit. The sample’s inhibition zones were compared with 25µl of the standards such as tetracyclin and fluconazole. The genetic variants were identified through the RAPD analysis and proved to have both phenotypic and genotypic characteristics in Physalis minima fruits. The thin-layer chromatography outcomes exposed the presence of phytochemicals in an evident manner, and the antimicrobial activity of the fruits exhibited good inhibition against the selected pathogens. The fruit extracts showed good inhibition between 1.5 mm and 5 mm against bacteria. Likewise, 0.5mm to 2.18mm was observed against fungus pathogens.

Полиморфизм ДНК собак. VI. Индивидуализирующие ампликоны

To detect DNA polymorphism in dogs and their wild relatives, a fairly simple method was used in the form of virtual amplification of certain random areas of their genomes using multiplex RAPD analysis with primers with arbitrary nucleotide sequences, which does not require prior knowledge of the sequences of nitrogenous bases of the detected DNA fragments. At the same time, information about the complete genomes of the studied species predicts the expected results, which makes it possible to reject unsuitable primers before conducting "wet" experiments. The multiplex RAPD analysis conducted in silico with 12 decameric primers, the sequences of which exclude the formation of homo- and heterodimers in PCR, showed both genomic similarities and differences between different canid species. If amplicons common to all the studied dog samples are removed from the final results of such virtual amplification, leaving only significant ones that actually act as individualizing, then it is potentially possible to DNA-cataloging each canine specimen with the probability of a random coincidence of their genomic barcodes on average one event per quadrillion.

Pulsed Light Mutagenesis of the Willow Bracket Mushroom, Phellinus igniarius (Agaricomycetes), for Enhanced Production of Flavonoids, Laccase, and Fermentation Biomass.

Phellinus igniarius is a medicinal fungus possessing potent therapeutic activity due to the polysaccharides, polyphenols, flavonoids, and other secondary metabolites they contain. Laccases are crucial enzymes involved in lignin degradation in Ph. igniarius and offer great potential to accomplish several bioprocesses. To generate Ph. igniarius strains with high biomass, flavonoid, and laccase activity, we used pulsed light (PL) technology for mutagenesis of Ph. igniarius protoplasts and screened for mutants with high biomass, flavonoid, and laccase activity. At the irradiation power of 100 J, treated distance 8.5 cm, irradiation frequency was 0.5 s/time, three times treatments, after five generations of selection, three mutants were obtained with higher biomass production. Compared with control, the mycelium biomass and the flavonoid production of the screened mutant strain QB72 were increased 20.87% and 53.51%, respectively. The total amount of the accumulated extracellular laccase of the QB72 in the first 6 and 8 days increased 23.38% and 22.37% respectively, and over the total 16 days it increased 9.62%. In addition, RAPD analysis results indicated that the genetic materials of the mutant QB72 were altered. PL mutagenesis method has great potential for developing strains, especially Phellinus.

KAJIAN KERAGAMAN GENETIK ANDALAS (MORUSMACROURA) UNTUK KONSERVASI GENETIK FLORA ASLI SUMATERA BARAT

Conservation managementstrategies for native Sumatran species such as andalas (Morus macroura) are currently being developed through genetic diversitystudies. Theseinformationswill be used to enhance ongoing conservation and regeneration programs and to control the exploitation of these high-valueplant species. This initial study aimed to develop a method for extracting DNA from andalas cambium, to select polymorphic RAPD primers and to study genetic diversity using selected RAPD primers. DNA was successfully extracted usingthe CTAB method from all 32 cambium samples collected from Jambi and West Sumatra. Eighteen RAPD primers were screened and six polymorphic primerswereselected (OPO-6, OPY-6, OPY-15, OPW-1, OPW-3 and OPW-4). RAPD analysis using the sixselected primers resulted in 52 polymorphic loci and thevalue of genetic diversity within the population (Hs) of 0.308 and the value of genetic diversity among populations (DST) of 0.091. The highest genetic diversity was observed in Batipuah,Tanah Datar(0.351) whilethelowest was observed in Halaban,Lima Puluh Kota (0.205).A test with AMOVA shows that the genetic diversity between individuals is greater than the diversity between populations.The dendogram based on the genetic distance between populations showsthat the andalas population in West Sumatra is separated into two groups and both are separated from the Jambi population.The results of this study can be used as a basis for further research on several other andalas populations as well as the basic informationfor conservation strategiesof andalas

STUDY OF GENETIC DIVERSITY AND ANALYSIS OF THE DEGREE OF SIMILARITY IN SOME APPLE AND PLUM VARIETIES USING RAPD MARKERS

Molecular evaluation of germplasm is an important step in breeding programs, and the application of molecular biological techniques has led to important results in terms of both within- and between-species variability of traits. The RAPD technique has been successfully used to reveal allelic polymorphism as well as to measure genetic similarity. In this study, the genetic diversity of 25 genotypes and cultivars for apple species and 26 genotypes and cultivars for plum species was assessed with six RAPD markers. All these cultivars belong to the ex situ collection of apple and the ex situ collection of plum at the Research Institute for Fruit Growing Pitesti. The average number of amplified bands was 19.2 for apple and 17.66 for plum. Statistical analysis of intraspecific allelic polymorphism was expressed using the PIC (Polymorphic Information Content) index, which takes into account the allelic frequency. Two statistical indices were used to quantify genetic diversity: the Shannon index and the Simpson index. The degree of similarity between varieties was analyzed using the NTSYSpc version 2.1. Following RAPD analyses, the allele sizes of the analyzed varieties were within the range quoted in the literature, the genetic profiles of the studied varieties suggesting a medium to high genetic diversity, except for markers OPBC-04 and OPBB-05 for plum species, which expressed a high genetic diversity. Genetic distances calculated based on polymorphism of migrated bands in agarose gel confirmed the known genealogies of the apple and plum varieties studied. Thus, the smallest genetic distance for apple species was found between 'Jonagold' and 'Golden Delicious', 'Pionier' and 'Rustic', 'Jonathan' and 'Idared', 'Wagener Premiat' and 'Granny Smith', 'Remar' and 'Aura', 'Romus 3' and 'Rome Beauty', and the largest between Malus floribunda and the other genotypes studied. In plum, the smallest genetic distance was found between 'Dani' and 'Tita', 'Roman' and 'Tuleu gras', 'Dara' and 'Haganta', 'Romanța' and 'Stanley', 'Anna Spath' and 'Renclod Violet', and the largest between 'Lama', 'Black Diamond' and the other genotypes studied.

Genetic relationship and polymorphism of selected medicinal plants of Asclepiadaceae using RAPD molecular analysis method

Present study was aimed to assess the genetic similarity among the medicinal plants of Asclepiadaceae family members such as Ceropegia juncea, Gymnema sylvestre, Oxystelma esculentum, Pentatropis capensis and Wattakaka volubilis , by using RAPD based molecular analysis. Sixteen primers (OPA, OPC, OPF and OPG series) were used to screen the genetic variation between the selected Ascleipidaceae members. RAPD analysis revealed the presence of 936 bands in which 466 were monomorphic and 256 were polymorphic bands. In particular, 49.78% were monomorphic and 27.35% were polymorphic with an average of 16% polymorphism per primer from the 936 amplified products. The highest number of bands was observed in Ceropegia juncea (198) followed by Pentatropis capensis (190), Oxystelma esculentum (189), Gymnema sylvestre (182) and Wattakaka volubilis (177). Among the primers used OPC 05 (17 bands), OPC 16 (17 bands) and OPC 03 (18 bands) produced maximum number of bands in Wattakaka volubilis , Pentatropis capensis and Gymnema sylvestre respectively. UPGMA cluster analysis revealed that presence of Wattakaka volubilis and Gymnema sylvestre in a same cluster (cluster 1) and Pentatropis capensis and Oxystelma esculentum in same cluster (cluster 2) had close relationship with each other. Findings revealed that presence of Ceropegia juncea in separate sub cluster (2) clearly evidences that species is so distant from other species of Asclepiadaceae. It may be concluded that RAPD tool will be very much helpful for the taxonomist to identify the plant members and place them in the appropriate family through molecular data.

Yeasts from Chinese strong flavour Daqu samples: isolation and evaluation of their potential for fortified Daqu production

In total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified among these isolates including Saccharomyces cerevisiae, Hanseniaspora vineae, Pichia kluyveri, Trichosporon asahii, Wickerhamomyces anomalus, Kluyveromyces lactis, Yarrowia lipolytica, Wickerhamomyces mori, Galactomyces geotrichum, Dabaryomyces hansenii, and Saccharomyces kudriavzevii. To understand the impact of these yeast strains on the quality and flavour of Daqu, we then assessed volatile compounds associated with Daqu samples fermented with corresponding strains. These analyses revealed strain YE006 exhibited the most robust ability to produce ethanol via fermentation but yielded relatively low quantities of volatile compounds, whereas strain YE010 exhibited relatively poor fermentation efficiency but produced the greatest quantity of volatile compounds. These two yeast strains were then utilized in a mixed culture to produce fortified Daqu, with the optimal inoculum size being assessed experimentally. These analyses revealed that maximal fermentation, saccharifying, liquefying, and esterifying power as well as high levels of volatile compounds were achieved when using a 2% inoculum composed of YE006/YE010 at a 1:2 (v/v) ratio. When the liquor prepared using this optimized fortified Daqu was compared to unfortified control Daqu, the former was found to exhibit significantly higher levels of flavour compounds and better sensory scores. Overall, our findings may provide a reliable approach to ensuring Daqu quality and improving the consistency and flavour of Chinese strong-flavour liquor through bioaugmentation.

The genetic potential of Taxus sumatrana medicinal plants in Kerinci Regency

Taxus -a taxol-producing medicinal plant that mostly found in highland area- is a species in genus Taxus and family Taxaceae. This study was aimed to determine the genetic diversity within and between population of T. sumatrana in Kerinci Regency, i.e. Mount Kerinci and Mount Tujuh, based on altitude. The genetic diversity was analyzed with RAPD analysis. The altitude was categorized as low (<2000 m asl) and high (>2000 m asl). The cambium extraction was carried out based on CTAB method. DNA amplification was conducted in RAPD method on machine of PCR System 9700 Applied Biosystems. Nine RAPD primers were used in this study. The results revealed that the average of polymorphic locus was 53.89%. Genetic diversity within population was fairly high with value of 0.1799 and Shannon index of 0.2746. Among the four populations, the population of High Tujuh showed the highest level of variability (He=0.2044). The Nei genetic distance between populations was ranging from 0.0567 to 0.1302. The potential of High Tujuh population is still large enough so that it can still be explored for genetic conservation and cultivated as a taxol-producing material which is useful for medicine.

English

The African forest, which was and still is the heart of biodiversity, is fast losing its bio-components due to natural disasters and human encroachment. A catalogue of the bio-components of the African forest is imminent so that conservation programs can be established to safeguard rare germplasm(s) from extinction. The population density of wild Auricularia (Mushroom) of Southwestern Nigeria was the focus of this research. DNA primers were obtained from Operon Technology, Alameda, California, USA. Characterization was done using phenotype, PCR and electrophoresis gel (RAPD). OPB-11 to OPB-21, OPH-3 to OPH-15, and OPT-1 to OPT-19 primers formed polymorphic bands with DNA samples of the specimens. Three (3) distinct species of Auricularia were identified in the forest of Southwest Nigeria based on PCR and RAPD analyses. Geospatial analysis showed that Auricularia auricula was present in the forests of Ekiti, Osun, Ogun, Oyo and Lagos states, but none was identified in Ondo State. On the contrary, Auricularia polytricha was only identified in the tropical rainforest and grassland vegetation of Ondo, Lagos and Oyo states. &nbsp; Key words: Auricularia, mushrooms, population density, Southwestern Nigeria, phenotypic description, genome similarity index.

The Emergence of New Aggressive Leaf Rust Races with the Potential to Supplant the Resistance of Wheat Cultivars.

Simple SummaryThe pathogen that causes wheat leaf rust, Puccinia triticina, possesses numerous aggressive races that can erode the resistant genes in its host. This study presents the recognition of the new physiological races of P. triticina, their distribution, and their resistance genes in wheat cultivars, which are critical for directing and improving wheat breeding programs for resistance to leaf rust. Winds often transport the pathogen’s initial inoculum from one country to another. Our findings trigger an alert to the whole world about developing races capable of supplanting leaf rust resistance.Characterization of the genetic structure and the physiological races of Puccinia triticina is a growing necessity to apply host genetic resistance against wheat leaf rust as a successful control strategy. Herein, we collected and identified about 130 isolates of P. triticina from 16 Egyptian commercial wheat cultivars grown at different locations, over two seasons (2019/2020 and 2020/2021). The 130 isolates of P. triticina were segregated into 17 different physiological races. TTTST and TTTKS were the most common virulent races, whereas TTTST and MTTGT were the most frequent races. The races were classified into three groups, based on their distinct DNA band sizes (150 bp, 200 bp, and 300 bp) after RAPD analysis. The new wheat cultivars (Sakha-94, Sakha-95, and Shandweel-1) infected with the most virulent race (TTTST), Gemmeiza-12, and Misr-3 were resistant to all physiological races. The resistance of these cultivars was mostly due to the presence of Lr19- and Lr28-resistant genes. Our results serve as a warning about emerging aggressive races capable of supplanting resistance to leaf rust, and help in the understanding of the pathotype–cultivar–location association and its role in the susceptibility/resistance of new wheat cultivars to P. triticina.

Isolation, Antibiogram and Molecular Characterization of Group B Streptococci Isolates from Bovine Mastitis

Background: Group B streptococcus (GBS) or Streptococcus agalactiae is an important pathogen associated with bovine mastitis. The organism is also of public health consequences and may cause variety of infections ranging from neonatal sepsis, pneumonia and meningitis to localized infections and urinary tract infection or arthritisin adult humans. Widespread use of antibiotics in veterinary medicine has led to development of resistance among the pathogens. So there is need for surveillance of antimicrobial resistance to ensure effective treatment. Methods: Milk samples collected from mastitis affected animals were processed for isolation of Streptococcus agalactiae. The isolates were tested for antimicrobial susceptibility. Molecular characterisation was carried out by PCR to study the occurrence of resistance marker genes and virulence marker genes. RAPD was carried out to study genetic diversity among the isolates. Result: Six isolates of S. agalactiae were obtained from 182 milk samples. Highest resistance was observed against co-trimoxazole and tetracycline followed by ampicillin. tetM gene and tetO genes could be amplified in four and three isolates, respectively. None of the isolates showed amplification for ermA, ermB, mefA and mefE genes. Three isolates were positive for the five virulence genes tested (glnA, cfb, hylB, scaA and cyl). RAPD analysis demonstrated great intraspecific genetic diversity among the streptococcal isolates.

Estimation of the Coefficient of Variation and Some Genetic Parameters of Some Landraces of Cowpea

The present investigation was carried out during two successive summer seasons of years 2019 and 2020 at the Faculty of Agriculture (Saba Basha), Alexandria University and the laboratory of the vegetable seed of Sabahya Horticulture Research Station, Alexandria Governorate, Egypt to evaluate six local cultivars and landraces of cowpea for some morphological characters, yield and its components as well as estimate some genetic parameters. Results reflected obvious differences among the six genotypes of cowpea for most of the studied characters. The coefficient of variation (C.V.) was less than 10 % for all the studied traits in all genotypes of cowpea. These results indicate that the six genotypes of cowpea are genetically identical concerning these traits. Analysis of variance showed that variances of genotypes were highly significant in all studied traits. These findings refer to that there were highly variations between genotypes under study. Generally, the data prove that all of the studied traits could be improved through the selection method, but with different degrees of the improving depending upon the amount of variation present in each population. Meanwhile, mean squares of years were significant only in height of the first flower, this can be interpreted as this property being affected by the different environmental conditions in both years of the study. Cluster analysis, based on RAPD plus ISSR analysis, divided the 6 studied genotypes into 3 major groups. The first contained Geza and Kareem7 Cvs. with similarity of (30%), the second consisted of Fowa Lr. and Kaha Cv., and the third one contained the ones of Behira Lr. and Kafr Elshikh Cv.

Sympatric threatened Iberian leuciscids exhibit differences in Aeromonas diversity and skin lesions' prevalence.

Assessments regarding health aspects of Iberian leuciscids are limited. There is currently an information gap regarding effects of infectious diseases on these populations and their role as a possible conservation threat. Moreover, differences in susceptibility to particular agents, such as Aeromonas spp., by different species/populations is not clear. To understand potential differences in Aeromonas diversity and load, as well as in the prevalence and proportion of skin lesions, in fishes exposed to similar environmental conditions, an observational study was implemented. Using a set of 12 individuals belonging to two sympatric Iberian leuciscid species (Squalius pyrenaicus and Iberochondrostoma lusitanicum), the skin lesion score in each individual was analyzed. Furthermore, a bacterial collection of Aeromonas spp. isolated from each individual was created and isolates' load was quantified by plate counting, identified at species level using a multiplex-PCR assay and virulence profiles established using classical phenotypic methods. The similarity relationships of the isolates were evaluated using a RAPD analysis. The skin lesion score was significantly higher in S. pyrenaicus, while the Aeromonas spp. load did not differ between species. When analyzing Aeromonas species diversity between fishes, different patterns were observed. A predominance of A. hydrophila was detected in S. pyrenaicus individuals, while I. lusitanicum individuals displayed a more diverse structure. Similarly, the virulence index of isolates from S. pyrenaicus was higher, mostly due to the isolated Aeromonas species. Genomic typing clustered the isolates mainly by fish species and skin lesion score. Specific Aeromonas clusters were associated with higher virulence indexes. Current results suggest potential differences in susceptibility to Aeromonas spp. at the fish species/individual level, and constitute important knowledge for proper wildlife management through the signalization of at-risk fish populations and hierarchization of conservation measures.

Genetic Characterization of Swamp Eel of Bangladesh Through Dna Barcoding and Rapd Techniques

The freshwater air-breathing swamp eel Monopterus spp. are native to the freshwater of Bangladesh and throughout the Indian subcontinent. To identify the different swamp eel species and to check the genetic diversity among them, a total of twelve swamp eel specimens were collected from four districts (Tangail, Bogura, Bagerhat and Sylhet) representing the four division of Bangladesh. The extracted DNA from twelve fish samples was amplified by the PCR technique for DNA barcoding and RAPD analysis. Among 12 specimens, 8 specimens showed a 95-100% similarity with M. cuchia species published in the NCBI GenBank database and BOLD system. The studied mct3 (collected from Tangail region), mcs1, mcs2 and mcs3 (collected from Sylhet region) specimens showed about 83% homology with Ophisternon sp. MFIV306-10 as per BLAST search; whereas BOLD private database showed 99% similarity with Ophisternon bengalense (Bengal eel). From the phylogenetic tree analysis, 8 samples were clustered with M. cuchia and 4 samples showed similarity with Ophisternon sp. MFIV306-10 and Ophisternon bengalense _ANGBF45828-19. In RAPD-PCR based analysis, it was found that the maximum genetic distance (1.6094) was observed between mcba2 and mcs3, while between mct1 and mct2, the minimum genetic distance was 0.000. A total of 192 bands, of which 35 were polymorphic with 17.88% polymorphisms among swamp eel species and the size of the amplified DNA fragments ranged from 250 to 1800 bp. The information on DNA barcoding and RAPD analysis help measure the genetic diversity among swamp eel species, ensure the reliability of the published taxonomic information, and initiate proper management programs to conserve these vulnerable species to meet future export demand.&#x0D; Asiat. Soc. Bangladesh, Sci. 46(2): 117-131, December 2020

Biodiversity assessment of African locust bean (Parkia biglobosa) accessions from Savanna and Forest zones of Nigeria as revealed by seed storage proteins and RAPD markers

Understanding the level and distribution of genetic diversity in African locust bean (Parkia biglobosa) would strengthen breeding and conservation programmes towards domestication and sustainable use of this species. Sixteen accessions of P. globosa were assessed for variability based on seed morphology, seed protein and DNA profiling. Significant variation in seed characteristics were observed across locations. Seed protein profiling by SDS-PAGE revealed homogeneity as most bands were found common in all accessions, indicating that the protein profiles are highly conserved. Protein profiling separated the 16 accessions into four major clusters at 0.93 similarity coefficient. Most accessions grouping into Cluster 1 had a similarity coefficient of close to 100% and were from the Derived Savanna suggesting the presence of duplicates. Accessions NH/2016/P14, NH/2016/P03 and NH/2016/P04 grouped into clusters II, III and IV; respectively. Sixteen RAPD markers generated a total of 256 bands of which 63.67% were polymorphic. Gene diversity ranged from 0.41 to 0.93 and Polymorphic Information Content (PIC) from 0.39 to 0.93. The RAPD-based dendrogram separated accessions into six groups at 0.68 similarity coefficient. Based on a polymorphic seed storage protein marker a genetically distinct accession NH/2016/P04 could be exploited for breeding purposes. The homogeneity of alleles and narrow genetic base as revealed by RAPD and SDS-PAGE analyses suggests possible loss of intraspecific genetic diversity. Thus, intensification of germplasm collections across the different agroecological zones and characterization using specific markers will give a better understanding of diversity of P. biglobosa in order to enhance selection towards conservation, breeding and sustainable utilization.

Assessment of Genetic Diversity in Promising Sugarcane Mutants Developed Through Chemical Mutagenesis

Sugarcane is an important cash crop gaining importance as ideal raw material for bioenergy production. Conventional sugarcane improvement is carried out through intensive crossing and selection breeding within the Saccharum complex. Being highly polyploidy crop the mutation breeding is also integrated for specifically improving the desired genetic trait in sugarcane varieties developed through conventional breeding. In the present work RAPD markers based assessment of genetic diversity and kinship relationships of six promising mutants developed using CoC 671 has been reported. The banding pattern of the PCR amplified products showed polymorphism with the RAPD profile in all six mutants. Mutants CoC 671, TC 2813, TC 2819, TC 2826, TC 2875 formed a separate cluster, and TC 906, TC 922, and TC 906 B formed a separate cluster distinct from the earlier one with the parent (CoC 671) and the standard Check (Co 86023). The genetic distance between the groups was found to be only marginally higher than the respective group distances and the overall mean genetic distance. The similarity indices indicated that there was 15 % genetic dissimilarity between CoC 671 and Co 86032. This may be because CoC 671 was one of the parents for Co 86032. In the present investigation, the genetic similarity value ranged from 0.97 to 0.78 among the mutants. A total of 34 band positions were scored, out of which 15 RAPD bands were polymorphic. From the genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost more than 78% similar to the mother plant. Thus the level of similarity between varieties seemed to be not very high but the mutants could be distinguished from each other easily. RAPD analysis indicated EMS-induced point mutations resulting in specific rectifications without much change in the genetic backbone of genotype CoC 671. Since this analysis was carried out on mutants after multiplying in field for three successive generations, we presume that these mutants/genotypes are stable and express the stable genetic variations.

Assessment of polymorphism using RAPD in the generalized hemiparasitic plant Helicanthes elasticus (Desv.)Danser collected from six different hosts

RAPD analysis was carried out to determine genetic diversity that occurred among the selected accessions of H.elasticus obtained from six different hosts. All together 10 random primers were used for the RAPD assay, of which primer S11 produced 12 amplified bands in which 10 are polymorphic. Primer S9 produced the least number of amplified fragments. 10 primers together resulted in 88 amplified fragments, of which 26 are found to be polymorphic. Considerable polymorphism was shown by 3 primers that can be represented in a descending order S11&gt;S79&gt;S10. Accessions of H.elasticus obtained from Anacardium occidentale and Citrus maxima produced more polymorphic bands with S11. The overall polymorphism obtained in the selected samples of this hemiparasite was 29.54 indicating that genetic similarity was more among these samples rather than genetic diversity.

RAPD analysis and field screening of bread wheat and barley accessions for resistance to cereal leafminer Syringopais temperatella

RAPD analysis and field screening of bread wheat and barley accessions for resistance to cereal leafminer Syringopais temperatella

Detection of Erysiphe necator, the Causal Agent of Powdery Mildew on Grapevine, and Determination of their Mating Types in Southern Syria Using Some Molecular Markers

Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of grapevine throughout the world. This study aimed to identify the mating types of this pathogen in Syria using molecular markers. Three DNA extraction methods: Promega Kit, phenol chloroform isoamyl alcohol (PCI) and SDS were compared. The amount and quality of DNAs obtained by the SDS method were suitable for PCR amplification and other molecular assays. PCR amplification using specific primers (Uncin 144 and Uncin 511) was performed and the expected amplicon of 300-400 bp was obtained from 29 isolates of E. necator collected from different geographical locations and from different grapevine cultivars. Results obtained showed that E. necator may cause atypical symptoms similar to those of downy mildew, in some grapevine cultivars according to the environmental conditions and training system used. Isolates of E. necator were classified into four groups according to geographical locations and grapevine cultivar, based on the observed variation in banding pattern with E07 primer and the constructed phenogram by using UPGMA. RAPD analysis of 39 E. necator isolates using the primer E07 showed the presence of two mating types, and the frequency of each varied depending on the geographical location, with a predominance of the - mating type which did not produce a 1000 bp band using the PCR primer E07. Keywords: Powdery mildew, Erysiphe necator, RAPD, mating type, DNA extraction.