Random Amplified Polymorphic DNA Markers Research Articles

RAPD Fingerprinting and Genetic Relationships of Some Wheat Genotypes

The genetic variability and relationships among 5 Egyptian wheat genotypes representing Sakha8, Sakha69, Sakha93, Sids1 and Gemmiza7 were analyzed using 8 random amplified polymorphic DNA (RAPD). A total of 77 loci (73 % polymorphic) in all 5 wheat genotypes was amplified and discriminated all the wheat genotypes. PIC, RP, MI, DP values were evaluated and revealed degree of genetic divergence among the cultivars used. A cluster based on UPGMA (Un-weighted Pair-Group Method with Arithmetic Mean) analysis was used to determine genetic similarities. The five wheat genotypes were divided into two main clusters. Cluster 1 was divided into two groups. In subgroup 1 were included genotype 1 and genotype 2. They seemed very close which might depict sharing of the genetic background among the genotypes. In consequence, the close genetic relationships are entirely alarming and may hinder further plant improvement. Genotype 5 was in subgroup 2. The second cluster was included genotype 3 and genotype 4. The same genotypes were also assessed in field conditions for structural analyses, which were carried out based on six yield components. The dendrogram created was comparatively analyzed with the RAPD dendrogram. This study additionally indicates that RAPD markers are useful for distinguishing and characterizing wheat cultivars. The genetic relatedness among these genotypes could provide useful information for conservation and selection of cross parents in breeding.

Variability among selective guava (Psidium guajava L.) varieties revealed by morphology and RAPD marker

The research was conducted for the assessment of genetic diversity using both morphological and random amplified polymorphic DNA (RAPD) analysis of twelve guava (Psidium guajava L.) varieties growing in Bangladesh. Morphological characterization of guava varieties showed a wide range of variation. The highest variability was observed between Poly and Jelly varieties.Polymerase chain reaction with 5 arbitrary 10-mer and 3 arbitrary 12- mer RAPD primers produced a total of 50 bands of which 75.23 percent were polymorphic. The highest percentage of polymorphic loci (100%) was observed for primer A and the lowest (50%) for A03 primer. The UPGMA dendrogram revealed the segregation pattern and the difference of evolutionary changes. Guava varieties were separated into two main groups, one of them was made up of Chineese, Jelly, Kazi, Apple, L-49, Local-2 and Local-3. The other one was made up of Local-1, Poly, Kashi, Thai and Bombay. The highest genetic distance between Apple and Kazi peyara indicate that these varieties might be interesting in breeding programme for improving trait of interest. This scientific information could be used for further improvement of guava.
 Jahangirnagar University J. Biol. Sci. 7(2): 89-98, 2018 (December)

Molecular diversity assessed amongst high dry rhizome recovery Ginger germplasm (Zingiber officinale Roscoe) from NE-India using RAPD and ISSR markers

Zingiber officinale Roscoe commonly known as ginger is one of the most important spice crop of North East India. This plant has found a wide range of application- as condiments and spice, as flavouring agent, in medicine and as therapeutic uses in pharmaceuticals industries. Different varieties of Zingiber officinale are cultivated in this region but their identification is still lacking till now. Evaluation of genetic diversity is therefore essential for conservation, to avoid duplicity of germplasm and maintenance of this important species. Molecular markers Randomly Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) are tested for eighty high dry recovery genotypes. Selections of genotypes are based on more than 25% dry rhizome recovery. Among 90 primers (40 RAPD and 50 ISSR) initially tested, 26 RAPD and 28 ISSR are used in the study which showed 84.1% and 85.2% polymorphism respectively. Dendrogram generated from UPGMA (Unweighted Pair Group Method with Arithmetic Mean) cluster analysis for both RAPD and ISSR marker was similar. Similar conclusion can be drawn from the result of cluster analysis. These primers could be used for future studies as varietal developmental programme on high dry rhizome recovery lines.

Short Communication: Genetic diversity among Fusarium isolates from cereals in Iran assessed using RAPD marker

Siahpoush S, Darvishnia M. 2019. Short Communication: Genetic diversity among Fusarium isolates from cereals in Iran assessed using RAPD marker. Biodiversitas 20: 292-296. Fusarium species cause important disease on many crops including cereals, and accurate identification and then proper management of this disease will be helpful to reduce economic losses. In this paper, 13 Fusarium isolates from root and crown of cereals in western Iran were identified by morphological and molecular methods. Sequencing of translation elongation factor 1-alpha revealed 8 species as follows: Fusarium acuminatum, F. avenaceum, F. culmorum, F. equiseti, F. proliferatum, F. reticulatum, F. solani, and F. tricinctum. Species diversity was analyzed by random amplified polymorphic DNA (RAPD). Four primers were used as Rfu9, Rfu10, Rfu23, and Rfu25 which all of them produced distinct and reproducible bands. A dendrogram was developed by UPGMA. Generated polymorphic bands were observed in all 13 different species by 4 primers. Rfu9 by 13 bands and Rfu23 by 10 ones, produced the most and the least bands respectively. Genetic similarity coefficient was between 0.00-0.9. RAPD analysis showed that these isolates were genetically varied and two clusters were formed with Fusarium isolates.

DETERMINATION OF GENETIC VARIATION OF EGYPTIAN COWPEA (VIGNA UNGUICULATA (L.) WALP.) USING RAPD-PCR PATTERNS

Cowpea (Vigna unguiculata (L.) Walp.) is the most important grain legume crop grown in tropical and subtropical regions. Seeds of cowpea have a high nutritional value containing high amount of protein (23–29%). Seeds of 19 landraces of cowpea (Vigna unguiculata) were obtained from gene bank of Cairo University (11 landraces) and from Agricultural Research Station Kafr El-Sheikh (Sakha) (8 varieties). The seeds planted till maturity. Random amplified polymorphic DNA (RAPD) was assayed to determine the genetic variation of 19 varieties of cowpea cultivated in different regions of Egypt. A total of five random primers were used in the study. Amplification of genomic DNA of Egyptian cowpea landraces with these RAPD primers yielded 54 fragments that could be scored, of which 45 were polymorphic. Number of amplified fragments with random primers ranged from 4 (OP 856) to 14 (OP 880). Percentage polymorphism ranged from 75% (OP 856) to a maximum of 100% (OP 889, OP 868, Op 808 and OP 880), with an average of 95%. A dendrogram produced by the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Jaccard‟s similarity coefficient revealed that the cowpea varieties divided into two groups which showed variability that may be exploited for crop improvement. The overall range of genetic similarities ranged from 0.48 to 0.93 in 19 landraces of cowpea which indicates there was high variability among the varieties. Based on genetic distance in RAPD analysis the landraces no. 9 and 12 appeared as most divergent and could be used in breeding programme of cowpea. It could be concluded that RAPD markers are important tools for genetic analysis for cowpea(Vigna unguiculata (L.) Walp.).

Somatic embryogenesis and evaluation of genetic fidelity in Amorphophallus paeoniifolius (Dennst.) Nicolson

ABSTRACT Amorphophallus paeoniifolius (Dennst.) Nicolson (elephant foot yam) is a well-known vegetable tuber plant that belongs to medicinally important family Araceae. The present study reports on establishment of somatic embryogenesis using shoot apices as explants and assessment of genetic fidelity of regenerated plants using random amplified polymorphic DNA (RAPD) markers. Highest somatic embryo formation (100%) was obtained on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP) (13.31 µM) and 3% sucrose, whereas lowest percentage of somatic embryos was recorded on medium supplemented with different concentrations of indole-3-acetic acid and 2,4-dichlorophenoxyacetic acid (2,4-d). Mature somatic embryos germinated readily on MS basal medium supplemented with coconut water (15%) and BAP (4.43 µM) and developed into normal plantlets after 4 weeks under dark conditions. Well-rooted plants were successfully acclimatized on half-strength MS medium; survival rate was 85%. The assessment of genetic fidelity and stability of regenerated plantlets from somatic embryos using RAPD markers resulted in monomorphic banding pattern that confirmed the genetic homogeneity of the regenerated plantlets. The protocol for somatic embryogenesis and regeneration of plantlets with low risk of genetic instability of A. paeoniifolius reported here is highly reproducible. This represents the first report on in vitro regeneration and RAPD assessment in A. paeoniifolius.

Efficient invitro plant regeneration from cotyledon-derived callus cultures of sesame (Sesamum indicum L.) and genetic analysis of True-to-Type regenerants using RAPD and SSR markers

Sesame (Sesamum indicum L.) is an important oilseed crop which is rich in unsaturated fatty acids, proteins and natural antioxidants. Reports on tissue culture methods involving regeneration through callus phase are scanty, genotype dependent and have been reported with low regeneration frequency. This recalcitrant nature will impede the application of modern biotechnological tools for genetic advancement studies in sesame. An efficient protocol for invitro shoot organogenesis from callus cultures has been established using cotyledon explants excised from 1-week-old seedlings of sesame cv. TMV 3. Maximum frequency of greenish white friable compact (GWFC) callus (72.0%) was obtained on Murashige and Skoog (MS) medium supplemented with 4.54 μM of 2, 4-dichlorophenoxyacetic acid (2, 4-D). Organogenic GWFC callus cultured on MS medium containing 4.4 μM of 6-benzylaminopurine (BAP) and 10 μM of silver nitrate (AgNO3) showed the optimum frequency of shoot regeneration (66%) and produced 4.6 shoots per 150 mg callus. Optimum rooting of 70.2%, an average of 6.02 ± 0.8 roots per shoot was achieved on MS medium fortified with 5.6 μM of indole-3-acetic acid (IAA). The rooted plantlets were acclimatized successfully in a greenhouse with a 65.8% survival rate. Non significant phenotypic aberrations were observed among the ex vitro transferred plantlets. The genetic stability of regenerants was assessed by using Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) markers. PCR amplification using 10 RAPD and 10 SSR primers generated 71 distinct and scorable DNA bands. DNA banding patterns reveal the absence of somaclonal variation among the plantlets regenerated through indirect organogenesis compared to that of mother plant and confirms the genetic purity of the invitro raised plants. The developed protocol could be effectively employed for obtaining genetic traits invitro through genetic transformation studies.

Genetic Variation and Phylogenetic Relationship among four Parrotfishes (genus Scarus) in Hurghada, Red Sea Coast, Egypt Based on RAPD Markers

Random amplified polymorphic DNA (RAPD) fingerprints were obtained for 4 Parrotfishes (genus Scarus) namely, Scarus collana Ruppell 1835; Scarus frenatus Lacepede 1802; Scarus (Chlorurus) sordidus Forsskal 1775 andScarus niger Forsskal 1775 using RAPD-PCR typing technique. A total of 111 bands (ranging from 200 to 2000 base pair) were produced, 13 monomorphic (common) and 98 polymorphic (88.29% level of polymorphism). The Scarus frenatus recorded highest band frequencies among studied species. Under phenetic approaches clustering using unweighted pair group method average (UPGMA) based on Nei-72 genetic distance, principal coordinate analysis (PCOA), and neighbour joining (NJ) based on pairwise mean character differences, the studied scarids formed two groups as sister taxa and most likely to have the most common ancestor. There is a close genetic relatedness among group members [Scarus collana/Scarus niger and Scarus frenatus/Scarus sordidus]. According to parsimony (Cladistic) analysis, RAPD markers obtained are reliable and phylogenetically instructive. The four parrotfishes are related, but S. frenatus, S. sordidus, and S. niger have a close evolutionary relationships. Splitting of Scarus collana as basal group suggested a common ancestor having unique features (synapomorphies) be inherited in the studied parrotfishes. This study’s results possibly provide useful information about the genetic variation and phylogenetic relationships among parrotfishes.

Development of seven novel specific SCAR markers for rapid identification of Phytophthora sojae: the cause of root- and stem-rot disease of soybean

Phytophthora sojae is a devastating pathogen that causes soybean Phytophthora root and stem rot. In this study, we developed seven pairs of polymerase chain reaction primers derived from sequence-characterized amplified regions (SCAR). These seven SCAR markers allowed discrimination of P. sojae from 17 different Phytophthora species and three other soilborne pathogens (Pythium ultimum, Fusarium solani and Rhizoctonia sp.) which also induce root rot in soybean. Among those 17 Phytophthora species, P. melonis has approximately 98% similarity in ITS sequences; P. drechsleri requires an annealing temperature up to 66 °C with an ITS-targeting diagnostic marker (PS primers) developed by Wang et al. (2006) for P. sojae; and P. sansomeana is a newly described soybean-infecting Phytophthora species. These three Phytophthora species could be specifically distinguished against P. sojae by these seven SCAR markers. After screening 100 random amplified polymorphic DNA (RAPD) primers, eight primers clearly produced specific bands only for P. sojae rather than other Phytophthora species tested. Subsequently, seven of eight P. sojae-specific RAPD markers were successfully converted into SCAR markers, namely, Scar276, Scar304, Scar333, Scar37, Scar519, Scar57 and Scar78. These SCAR markers were used to detect 75 isolates of P. sojae specifically, while no products were obtained for 29 additional isolates representing 17 other Phytophthora species and three other soilborne pathogens. Furthermore, Scar333 successfully allowed the detection with a sensitivity of 100 pg from genomic DNA of P. sojae, Scar276 had a higher sensitivity of 10 pg, and four specific SCAR primers (Scar304, Scar37, Scar519 and Scar78) had a sensitivity of 100 fg, which is the highest for detecting P. sojae until now. Six of the seven SCAR markers, with the exception of Scar57, were also used to detected P. sojae in artificial or naturally infected soybean seedlings and infested soil. Our findings demonstrate that SCAR markers provide a rapid and sensitive molecular diagnostic tool for the detection of P. sojae in plants, and will play a key role in effective management of the disease.

Genetic Fingerprinting of Two Species of Averrhoa Using RAPD and SRAP Markers

Random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) marker analyses were conducted in two underutilized fruit trees of the family, Oxalidaceae, namely Averrhoa bilimbi and A. carambola, commonly known as cucumber tree and starfruit tree respectively. The current study focused on the utility of 23 RAPD primers and 31 SRAP primers. The RAPD primer, OPD-07 produced the greater number of amplified fragments, exhibited higher level of polymorphism and could differentiate between almost all the collections on the basis of the efficiency of different primer parameters. The most competent SRAP primer combination for the characterization of Averrhoa collections was ME2/EM6. Cluster and PCA analyses on both RAPD and SRAP data differentiated the A. bilimbi and A. carambola collections. Both markers showed that A. bilimbi collections, Ab2, Ab3 and Ab4 were distinct from the rest. Both SRAP and integrated data were capable of distinguishing sour and sweet collections of A. carambola. The present study provides the first in-depth report on the molecular diversity between the two species of the genus Averrhoa with regard to RAPD and SRAP markers. Both RAPD and SRAP could discriminate the species, and collections of Averrhoa. SRAP are the preferred choice because it differentiates various collections and possess good amplification, stability and polymorphism.

Analysis of selected medicinal plants used in the treatment of malaria and typhoid fever in Ebonyi State, Nigeria

The study was aimed at evaluating selected medicinal plants used in the treatment of malaria and typhoid fever. Materials used include medicinal plants used locally in treating malaria and typhoid fever sourced from different villages in Ebonyi State. The analysis of the medicinal plants was conducted using random amplified polymorphic DNA (RAPD) markers and NTSYSpc software version 2.02. Different RAPD markers including OPB-1, OPB-2, OPB-3, OPB-5, OPB-12 and OPH-12 were used to amplify the DNA of these plants. These markers were found to be polymorphic except OPB-3 which did not produce any band. It was observed that RAPD markers can effectively amplify DNA sequences of different medicinal plants. The data matrix of RAPD profiles obtained from fragments of each amplicon were scored as 1 (presence of alleles) or 0 (absence of alleles). A dendrogram of the plants using unweighted pair group mean (UPGMA) clustered the genotypes into groups. The dissimilarity values were 0.26 and 1 as minimum and maximum with an edge length of 1.32. Principal component analysis of the generated amplicons resulted to clusters with unique genetic identity. The polymorphism detected among the plants genotypes will be useful in selecting genetically diverse species in future breeding programme. Keywords: Medicinal plants, Malaria/Typhoid, RAPD, Ebonyi State, Nigeria

Molecular characterization of <i>Auricularia</i> spp from south-western Nigeria using Random Amplified Polymorphic DNA (RAPD) markers

This study was conducted to investigate the genetic diversity in 48 samples of Auricularia species randomly collected from secondary forests in Osun (11), Oyo (10), Ondo (9), Ekiti (8), Ogun (8) and Lagos States (8) of Nigeria. Fourteen Random Amplified Polymorphic DNA (RAPD) markers were used for molecular characterization of Auricularia species. Phylogenetic relations were determined by cluster analysis and Polymorphic Information Content (PIC) and gene diversity determined using standard procedures. The Auricularia species were grouped into 6 distinct clusters based on morphological traits. The PIC value ranged from 0.5594 (OPH-15) to 0.7819 (OPB-12) and gene diversity from 0.5930 (OPH-15) to 0.7977 (OPB-12). Primer OPB-12 was the most informative for genetic diversity of Auricularia species. However, primer OPB-21 gave the highest number of alleles while OPB-12 showed the highest range of gene diversity and accounted for the diversity of the Auricularia species. The dendrogram and the principal coordinate analysis exhibited similar clustered patterns, revealing that all the tested strains could be divided into six distinct groups, each of which correlated with different geographical regions. Molecular characterisation is essential in genetic diversity studies and has proven useful in the classification of Auricularia spp. Keywords: Auricularia spp, Cluster analysis, Genetic diversity, Mushroom cultivation, Principal coordinate analysis, Polymorphic information content, RAPD markers

RAPD markers reveal genetic variation between Cichorium spinosum L. and Taraxacum sp.; a substantial medicinal plants of Greece

Fifteen Random Amplified Polymorphic DNA (RAPD) markers were used to measure genetic diversity and genetic relationships between five endemic genera of Mediterranean basin (Greece). Three species of Cichorium spinosum were collected; two from island Crete (Greece) and one from island Kythnos, and other two species of Taraxacom sp. (Asteraceae); are from Orhomenos and Athens. Two hundred-forty amplified products and 163 RAPD bands were scored with an average of 67.91% of them revealing polymorphism across accessions. In this research OPD-05 primer with 24 bands showed the highest number of bands, while the OPM-18 and OPB-16, both of them with 8 bands showed the least number of bands. Also OPV-06 primer with 18 polimorphic bands showed the highest number of bands. The least number of polymorphic bandswere found in OPX-18. UBC-292, OPAN-01, OPB-16, OPM-18, OPD-05 primers. Subsequently, OPD-05 primer with 29.16% showed the least percentage of polymorphism degree, whereas OPM-18 and OPB-16 primers with 87.50% showed the highest percentage of polymorphism. UPGMA clustering based on data from polymorphic RAPD bands revealed two distinct group which joined to form one major cluster at 32% level of similarity. Also Cichorium spinosum, Crete and Cichorium spinosum, Kythnos, varieties with 100% similarity are synonyms. The similarity indices of the RAPD dendrogram ranged between 30% and 100% averagely high enough to suggest useful variability for genetic diversity and plant breeding.

Genetic characterization of Indian little millet (Panicum sumatrense) genotypes using random amplified polymorphic DNA markers

Initially, 60 primers were screened among 32 genotypes of little millet (Panicum sumatrense), from which 36 primers were selected on the basis of a sharp and clear banding pattern for final random amplified polymorphic DNA (RAPD) analysis. The PCR reaction was carried out using a single decamer primer at a time. In total, 175 RAPD marker loci were amplified of which 155 were polymorphic (88.58%). The band size of amplified markers was in the range 100–1900 bp. Ten bands were the maximum scored (for primer OPH-19) whereas two bands were the minimum scored (for primer OPC-13). On average, 4.86 bands per primer and 4.31 polymorphic bands per primer were recorded. The polymorphism information content ranged from 0.102 (OPAI-01) to 0.517 (OPE-04). A dendrogram divided the genotypes into two major and further into sub-groups according to their collection center geographical regions. This was the first report on molecular diversity analysis of a large collection of little millet germplasm. Diverse genotypes may be used in breeding programmes for P. sumatrense improvement.

Genetic and ecogeographical diversity of rye (Secale L.) species growing in Iran, based on morphological traits and RAPD markers

Assessing the genetic diversity is an essential step for breeding programs and the optimal use of genetic resources. In this study genetic and phenotypic diversity of 70 rye (Secale L.) populations collected from different regions of Iran were evaluated based on 14 qualitative morphological traits and Random Amplified Polymorphic DNA (RAPD) markers. Among the evaluated traits spike shattering, leaf pubescence and stem and auricle color showed a high taxonomic value. Based on the morphological diversity assessed using descriptive statistics and discriminant function analysis, 38 S. cereale L. subsp. cereale, 28 S. cereale L. subsp. ancestrale Zhuk., eight S. strictum C. Presl, subsp. strictum, and three populations of S. strictum C. Presl, var. ciliatoglume (Boiss.) Fred. et Peters. were identified. Genetic diversity of 20 populations of identified species by RAPD markers confirmed the results of morphological evaluation. The rate of polymorphism was 45.26% of total amplified DNA fragments. Cluster analysis of RAPD data effectively separated the two species of rye (S. cereale L. and S. strictum C. Presl).

Estimating the Genetic Relationship in Various Warm Season Turfgrass Genotypes Using RAPD and ISSR Markers

The genetic diversity of 13 warm season turfgrass genotypes were studied in which 7 genotypes is of Cynodon dactylon and one each of C. dactylon × C. transvaalensis, Zoysia matrella, Zoysia tenuifolia, Stenotaphrum secundatum, Axonopus compressus and Eremochola ophiuroides were assessed using PCR based Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. Out of 150 primers of RAPD and 18 primers of ISSR screened, six each of RAPD and ISSR primers, were used to generate polymorphism for all genotypes. The dendrogram obtained from UPGMA cluster analysis of Jaccard’s similarity values ranged from 0.029 to 0.395 for RAPD and from 0.085 to 0.750 for ISSR primers. Based on above markers the genotypes were grouped into six distinct clusters.

Genetic diversity and structure of Betula utilis accessions of North-western Himalaya based on RAPD and ISSR markers

Betula utilis, commonly known as Himalayan birch is an important tree species of fragile ecosystem of Himalayas placed in endangered category. In the present study genetic diversity, structure and interrelationships of B. utilis accessions from North-western Himalayan regions were analyzed using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. 15 RAPD and 16 ISSR primers collectively amplified 109 polymorphic fragments with an average of 3.51 fragments in a size range of 300–1300 bp. Polymorphism Information Content (PIC) ranged from 0.21 to 0.5 with an average of 0.43. Dendrogram grouped all the accessions into two major clusters. Factorial analysis showed three groups for all the analyzed accessions. Bayesian clustering using STRUCTURE grouped all the accessions in two clusters and separated majority of accessions belonging to Jammu & Kashmir Himalaya (cluster-II) from other accessions of Himachal Pradesh and Uttarakhand Himalaya (cluster-I). Exceptionally, four accessions namely, Sinth-12, Sinth-20, Son-06 and Son-16 from Kashmir grouped in Cluster-I. Structure analysis showed that two genetic stocks were contributing in genetic makeup of all the analyzed accessions. Results of the present study can be useful for selection of diverse accessions as well as can be useful in designing conservation and management strategies in North-western Himalayan regions.

Genetic differentiation within Vetiveria zizanioides: selection and breeding of commercial perfumery grass Vetiver

ABSTRACTEighteen Vetiveria zizanioides accessions were analyzed for genetic diversity by Random Amplified Polymorphic DNA (RAPD) including CIM-Vridhi, an elite released variety. Twenty MAP primers were used to detect the DNA polymorphism and a total of 152 bands were obtained, out of which 45 were monomorphic, 137 polymorphic, 15 unique bands and 73.1% polymorphism were estimated. The average polymorphic information content (PIC) value obtained with RAPD markers was 0.44; marker index (MI), effective multiplex ratio (EMR), and resolving power (RP) were 2.39, 5.09, and 22.3, respectively. Principal component analysis (PCA) derived for RAPD markers illustrated the first three principal coordinate components accounted for 76.75% of the genetic similarity variance.

English

To assay the efficiency of graphite nanoparticles (GtNPs) in sterilizing tissues and their role in enhancing genetic diversity, sweet potato is considered an important crop; hence its explants were used. In this experiment, GtNPs of 200, 400 and 800 ppm concentrations were used for sterilization of MS callus induction and regeneration media in Abees cultivar. The results showed that GtNPs had a good potential for removing bacterial contaminants without having side effects on the explant viability during the sterilization of sweet potato tissue in all their concentrations. Also, the percentage of callus induction increased from 98.67% in control to 100% in all GtNPs concentrations. The number of shoots per callus was enhanced at 400 ppm concentration. RAPD molecular markers and SDS-PAGE analysis were used to assess the genetic diversity of the sweet potato selected plants obtained from somaclonal variations in combination with GtNPs. Five decamer random amplified polymorphic DNA (RAPD) primers generated a total of 96 DNA fragments from the selected variants and their parent. Out of them, 82 polymorphic bands appeared with 85.42% polymorphism. The levels of DNA and protein patterns polymorphism within each treatment varied. RAPD and protein markers revealed that the concentration of 800 ppm showed the lowest similarity average among the ten selected variants and their parent. The obtained results indicated that somaclonal variation with GtNPs can be combined to increase the induced mutations frequency. Key words: Graphite nanoparticles, somaclonal variation, random amplified polymorphic DNA (RAPD), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

English

The genetic and morphological diversity of soybean germplasms was studied using random amplified polymorphic DNA (RAPD) markers and morphological traits such as plant height, height of cotyledon leaves, basal leaf length, basal leaf width, basal leaf area, terminal leaflets number, terminal leaflet length, terminal leaflet width, terminal leaflet area and basal leaf petiole length. A total of 30 germplasms were investigated. The number of amplification products obtained ranged between 6 and 9. An average of five bands was obtained per primer set. The RAPD analysis of the 30 soybean germplasms revealed a total of 23 bands, amplified by 14 different oligonucleotide primers. Sixteen of these bands were highly polymorphic with percentage polymorphism at 70%, indicating the germplasms investigated had a high level of genetic diversity. The consensus tree generated from the genetic diversity analysis placed the soybean germplasms into five groups at an agglomerate coefficient of 0.6 (similarity level). Similarly, cluster analysis from the morphological characterisation revealed 5 clades with an average distance between clusters of 0.75. There was a significant lack of correlation between the RAPD markers and the morphological traits evaluated. Although, both analyses grouped the soybean genotypes into 5 clades, the composition of the individual clusters were very variable and divergent with the correlation between the largest clusters in the molecular and morphological characterisation at only 35-42%. Key words: Soybean, germplasm, random amplified polymorphic DNA (RAPD), genetic diversity, morphological variability, polymorphism.