Shannon's Information Index Research Articles

Assessment of Genetic Diversity in Ethiopian Sesame (Sesamum indicum L.) Germplasm using Random Amplified Polymorphic DNA (RAPD) Markers

Genetic diversity among 128 sesame (Sesamum indicum L.) genotypes representing 10 geographically distinct populations in Ethiopia was assessed at DNA level using RAPD analysis. Eleven RAPD primers used amplified a total of 149 bands, of which 142 (95. 45%) were polymorphic. Each primer generated 7 to 23 amplified fragments with an average of 13.5 bands per primer. Percent of polymorphic loci (P%), number of different (Na) and effective (Ne) alleles along with Shannon information index (I) and Nei’s gene diversity (He) values suggested that the population of Oromia was the most diverse of all populations, while populations from Afar (cultivars) and AM-NSh were found to be the least diverse. Based on average dissimilarity values obtained with RAPD primers, AM-NG-25, SNNP-7 and SNNP-8 were the most distinct of all genotypes, while genotypes ORO-20 and TIGR-5 showed maximum similarity with others. The UPGMA clustering based on the dissimilarity matrix clustered the genotypes into 3 major groups and 11 subgroups, while three genotypes viz., BENSH-6, ORO-14 and SNNP-5 were found out-grouped from the rest and did not join any of the cluster; they are then most divergent genotypes. Generally, both clustering and PCoA patterns revealed that most genotypes located geographically far apart were found to cluster in the same group, while those genotypes from the same origin dispersed. Overall results indicated that RAPD technique revealed a high level of genetic variation among sesame genotypes collected from diverse ecologies of Ethiopia.Â

Genetic patterns investigation of wild Chimonanthus grammatus M.C.Liu by using SSR markers

Chimonanthus grammatus M.C.Liu is an endangered and national-protected medicinal plant species with highly restricted and disjunctive geographical distribution in the border area of Anyuan and Huichang counties of Jiangxi province, China. In this study, six natural populations of the C. grammatus (AY1, AY2, and AY3 from Anyuan; HC1, HC2, and HC3 from Huichang county) and one cultivated population of Chimonanthus praecox (as one outgroup) from Nanchang (NC) city, Jiangxi, were sampled to analyze its genetic diversity and structure using ten microsatellite (SSR) markers. Results showed that Nei's genetic diversity values (He) of seven populations ranged from 0.574 to 0.742, with an average of 0.666±0.028. Values of Shannon's information index (I) per population ranged from 1.215 to 1.832, with an average of 1.535±0.074. For C. grammatus species, AY1 population from Anyuan county harbored the highest genetic diversity (I=1.832±0.195, He=0.742±0.061), while HC3 population from Huichang county had the lowest levels of genetic diversity (I=1.358±0.208, He=0.601±0.078), respectively. The low genetic differentiation (Fst=0.089) was detected in C. grammatus species. UPGMA and PCA analyses classified the seven populations into three branches: AY1, AY2 and AY3 were clustered together; HC1, HC2, and HC3 were grouped together; and NC was clustered by itself. These results revealed that ten SSR markers were effective to investigate the genetic diversity of C. grammatus and to genetically differentiate it from another species in Chimonanthus.

Analysis of genetic variability in endemic medicinal plants of genus Chlorophytum from the Indian subcontinent using amplified fragment length polymorphism marker

The genus Chlorophytum consists of medicinally important species like Chlorophytum borivilianum, C. tuberosum and C. attenuatum. Uncontrolled harvest of this plant from wild habitat due to its high commercial value made the species of this genus be listed in the Red Data Book of Indian plants as an endangered species. In India, approximately nineteen species of Chlorophytum are found; out of these, only C. borivilianum is cultivated commercially. The objective of this study was to measure genetic diversity, population structure and phylogenetic relationship among the species using Amplified Fragment Length Polymorphisms (AFLP). Fifteen pairs of primer (out of 64 primer pairs screened) were used to analyse the genetic diversity in eighteen species of genus Chlorophytum. Cluster analysis, estimation of the gene flow among the species and of the phylogeographic distribution of this genus were carried out using an AFLP data matrix. A high level of genetic diversity was observed on the basis of the percentage of polymorphic bands (99.91%), Shannon's information index (0.3592) and Nei's gene diversity (0.2085) at species level. Cluster analysis of UPGMA dendrogram, principal component analysis and Bayesian method analysis resolved these species in three different clusters, which was supported by morphological information. The Mantel test (r=0.4432) revealed a significant positive correlation between genetic and geographic distances. The collected data have an important implication in the identification, authentication, and conservation of the species of the genus Chlorophytum.

Genetic differentiation and diversity of Callosobruchus chinensis collections from China.

Callosobruchus chinensis (Linnaeus) is one of the most destructive pests of leguminous seeds. Genetic differentiation and diversity analysis of 345 C. chinensis individuals from 23 geographic populations using 20 polymorphic simple sequence repeats revealed a total of 149 alleles with an average of 7.45 alleles per locus. The average Shannon's information index was 1.015. The gene flow and genetic differentiation rate values at the 20 loci ranged from 0.201 to 1.841 and 11.0-47.2%, with averages of 0.849 and 24.4%, respectively. In the 23 geographic populations, the effective number of alleles and observed heterozygosity ranged from 1.441 to 2.218 and 0.191-0.410, respectively. Shannon's information index ranged from 0.357 to 0.949, with the highest value in Hohhot and the lowest in Rudong. In all comparisons, the fixation index (F ST ) values ranged from 0.049 to 0.441 with a total F ST value of 0.254 among the 23 C. chinensis populations, indicating a moderate level of genetic differentiation and gene flow among these populations. Analysis of molecular variance revealed that the genetic variation within populations accounted for 76.7% of the total genetic variation. The genetic similarity values between populations varied from 0.617 to 0.969, whereas genetic distances varied from 0.032 to 0.483. Using unweighted pair-group method using arithmetical averages cluster analysis, the 23 geographic collections were classified into four distinct genetic groups but most of them were clustered into a single group. The pattern of the three concentrated groups from polymerase chain reactions analysis showed a somewhat different result with cluster.

Microsatellite analysis after long term selection for egg production in Rhode Island Red chicken

This investigation aimed to analyze microsatellites after long term selection for egg production in the selected line (RIRS) of Rhode Island Red chicken and its control line (RIRC) maintained at the institute. Genomic DNA samples isolated from 24 randomly selected birds of RIRS and RIRC line were investigated at 24 microsatellite loci. Microsatellite alleles were separated on 6% urea-PAGE and their sizes were estimated with the help of Gel Doc 2000 system. Allelic data was analyzed. Analysis revealed 2 to 7 alleles in RIRS and 2 to 9 alleles in RIRC line across 24 loci with their sizes ranged from 84 to 276 bp. Observed number of alleles per locus was 4.04±0.23 in RIRS and 4.42±0.33 in RIRC. Allele frequency ranged from 0.083 to 0.667 in RIRS and 0.042 to 0.833 in RIRC. Approximately 34.02% of alleles in RIRS and 39.62% alleles in RIRC were line specific. The frequencies of the specific alleles ranged from 0.083 to 0.667 in RIRS and 0.083 to 0.883 in RIRC. Line specific alleles with higher frequencies can be used in line identification. Corresponding effective number of alleles and Shannon's information index averaged 3.32±0.19 and 1.25±0.06 in RIRS and 3.66±0.32 and 1.30±0.08 in RIRC. These diversity estimates indicated that the control line was more diverse than the selected line and certain specific microsatellite alleles were getting fixed in the selected line.

Analysis of genetic variation in sorghum (Sorghum bicolor (L.) Moench) genotypes with various agronomical traits using SPAR methods

Genetic variation among 45 genotypes of sorghum (Sorghum bicolor L.) representing seven subpopulations was assessed using three single primer amplification reaction (SPAR) methods viz., inter-simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD) and directed amplification of minisatellite-region DNA (DAMD). Totally 15 ISSR, 8 RAPD and 7 DAMD primers generated 263 amplification products, accounting for 84.6% polymorphism across all the genotypes. The Mantel's test of correlation revealed the best correlation between ISSR and cumulative data with a correlation coefficient (r) of 0.84. Assessment of population diversity indicated that the maximum intra population genetic diversity was recorded among high FeZn lines (HFL) having maximum values of Nei's genetic diversity (h) (0.244), Shannon information index (I) (0.368) and the percentage of polymorphic loci (Pp) (72.65%) while the corresponding lowest values of 0.074, 0.109 and 17.95% respectively were observed among the members of MDT subpopulation. The mean coefficient of gene differentiation (GST) and the gene flow (Nm) between populations were observed to be 0.396 and 0.7680 respectively. The analysis of molecular variance (AMOVA) suggested that maximum genetic variation exists within populations (95%) than among populations (5%). Thus the information obtained from this study could be utilized in sorghum breeding programmes for the development of varieties with improved nutrition and agronomic values in future.

Genetic diversity of grapevine (Vitis vinefera L.) from Tanzania as revealed by ISSR markers

Grapevine (Vitis vinifera L.) is a perennial horticultural crop which is used worldwide for production of wine, table grapes, dried fruits and grape juice. In spite of its importance as a cash crop, the purity of each variety and genetic diversity of this crop has not been identified. The study therefore, was conducted to assess the purity and genetic diversity among and within 10 varieties of grapevines represented by a total of 43 individual plants. By using nine ISSR primers, a total of 56 polymorphic bands were generated. Within variety diversity based on polymorphic bands ranged from 26.79% for Ruby seedless to 73.21% for Alphoncelavallee with a mean of 55.18 %, Neis genetic diversity of 0.089 0.308 with a mean of 0.202, Shannon information index of 0.137–0.445 with a mean of 0.302 and analysis of molecular variation (AMOVA) of 76.767% within varieties were detected. With all diversity parameters, the highest diversity was obtained from Regina, Alphoncelavallee, Syrah and Makutupora white varieties, whereas the lowest was from Ruby seedless. AMOVA showed a 23.23% between varieties variability was less than that of within varieties variation. Varieties differentiation with Fixation index (FST) was 0.23. From Jaccards pairwise similarity coefficient, Makutupora red and Chancellor were most related varieties exhibiting 0.976 meanwhile Queen of vineyard and Ruby seedless were most distantly related varieties with similarity of 0.408. Alphoncelavallee and Makutupora white varieties exhibited the highest genetic diversity. Therefore, these varieties should be considered for further improvement of this species.

Mining simple sequence repeats inPicrorhiza kurroatranscriptomes for assessing genetic diversity among accessions varying for picrosides contents

Picrorhiza kurroa(family Scrophulariaceae) is a high value medicinal herb used in herbal drug formulations like picroliv, picrolax, etc. It has been collected recklessly from its natural habitat posing endangered status for its existence, thereby necessitating characterization of genetic diversity for its sustainable utilization and conservation. In this study, picrosides content and genetic profiles of 26 accessions ofP. kurroafrom different locations in north-western Himalayas have been analysed. Picroside-I (P-I) content ranged from 0.37 to 2.7% in fresh shoots whereas total picrosides content (P-I+P-II) ranged from 3.7 to 10.9% in dry rhizomes. High picrosides content accession PKS-1 was identified, both for shoots and rhizomes. To study genetic diversity and correlate picrosides content with their genetic factors, genetic profiling was done using simple sequence repeats (SSRs) identified fromP. kurroatranscriptomes. Out of 361 SSR primers tested on 26 accessions, 35 primers yielded polymorphic profiles. Overall low genetic diversity was observed inP. kurroaaccessions. The highest polymorphism information content (PIC) of 0.55 was given by SSR marker PKSTS-P9 (TGGTG)4. Mean allele number was 2.97. Mean observed and expected heterozygosities were 0.597 and 0.452, respectively. Among all accessions Nei's genetic diversity (H) was 0.39 and Shannon's information index (I) was 0.58. Cluster analysis of STRUCTURE was comparable to DARWIN. Microsatellite markers would be helpful in the development of DNA diagnostics for the authentication of quality plant material as well as planning a genetic improvement strategy.

Genetic Diversity and Population Structure Patterns in Chinese Cherry (Prunus pseudocerasus Lindl) Landraces

Chinese cherry (Prunus pseudocerasus Lindl.) is an ancient fruit crop with highly economic and ornamental values. It originated in China and the cultivation history can be traced back to 3,000 - 4,000 years ago. Over such a long-term domestication process, a large number of genetic variations have been accumulated in different landraces. However, their utilization for cultivar improvement is limited by the scarcity of information involving genetic diversity and population structure. Here, 17 populations comprised of 140 individuals were collected from four geographic areas: Sichuan Basin (SC), Qinglin Mountain (QL), Yungui Plateau (YG) and North of China (NC), and analyzed using a set of 20 microsatellite markers. In total, 126 polymorphic loci were generated, with 6.3 loci per primer. The global expected heterozygosity (He = 0.63) and Shannon information index (I = 1.23) implied a moderately high level of genetic variation. Two major clusters (cluster 1 and cluster 2) were demonstrated based on population structure analysis, which implied the presence of two potential domestication sites of Chinese cherry landraces. Individuals from SC were assigned to cluster 1 and those from QL, YG and NC were grouped into cluster 2. Samples from QL region contained the most plentiful admixture genetic components, implied the possibility of being one transition region of genetic variation. Moreover, botanical characteristics, such as long lifespan, inbreeding preference as well as vegetative propagation, might lead to a relatively low level but significant genetic divergence among populations. Finally, conservation strategies were proposed to protect these valuable natural germplasm based on these results.

Genetic diversity and phylogenetic relationships among five endemic Pinus taxa (Pinaceae) of China as revealed by SRAP markers

The genetic diversity and phylogenetic relationships among five endemic Pinus taxa of China (Pinus tabulaeformis, P. tabulaeformis var. mukdensis, P. tabulaeformis f. shekanensis, Pinus massoniana and Pinus henryi) were studied by SRAP markers. Using 10 SRAP primer pairs, 247 bands were generated. The percent of polymorphic bands (94.8%), Nei's genetic diversity (0.2134), and Shannon's information index (0.3426) revealed a high level of genetic diversity at the genus-level. At the taxon level, P. tabulaeformis f. shekanensis and P. henryi showed a higher genetic diversity than the others. The coefficient of genetic differentiation among taxa (0.3332) indicated a higher level of genetic diversity within taxon, rather than among taxa. An estimate of gene flow among taxa was 1.0004 and implied a certain amount of gene exchange among taxa. The results of neighbor-joining cluster analysis and principal co-ordinate analysis revealed that P. tabulaeformis, P. tabulaeformis var. mukdensis and P. tabulaeformis f. shekanensis were conspecific, which was in agreement with the traditional classification. Phylogenetic relationships analysis also indicated that P. henryi might be a distinct species closely related to P. tabulaeformis.

Genetic diversity of oil-tea camellia germplasms revealed by ISSR analysis

Genetic diversity of 51 oil-tea camellia germplasms was analyzed using the optimized inter-simple sequence repeat (ISSR)–PCR reaction system with 22 primers screened from a set of 100 ISSR primers. The results showed that 493 discernible loci with distinct electrophoretic bands were obtained, of which, 478 loci (96.78%) were polymorphic. This indicated that oil-tea germplasms possess abundant genetic diversities. By clustering analysis performed using softwares of NTSYS 2.10 and Winboot, 51 oil-tea germplasms were divided into two groups: Group I had 48 lines of Camellia oleifera Abel, while Group II had three C. oleifera Abel related species and their similarity coefficient was 0.62. Group I was further divided into Group I-1 and Group I-2, and their similarity coefficient (Gs) was 0.634. All members of Group I-1 originated from Hunan Province, while Group I-2 included the rest of Hunan lines and those originated from other regions of China. Analyzed by software POPGENE 1.32, the Shannon's information index (I*) of genetic polymorphism was 0.3852, the genetic diversity among different region populations (Ht) was 0.2537, the genetic diversity within populations (Hs) was 0.15545, the differentiation coefficient of genetic diversity among populations (Gst) was 0.3967, and the gene flow among populations (Nm*) was 0.8262. The Nei's genetic distances between the Hunan population and the populations originated from other regions of China implied that geographic isolation strongly influenced genetic differentiation among populations. Meanwhile, seedling rootstock grafting and high grafting for tree crown produced genetic variations among clonal offsprings.

Population structure and core collection construction of apricot (Prunus armeniacaL.) in North Africa based on microsatellite markers

North Africa enclosed original apricot genetic resources with the cohabitation of grafting and seed-propagated accessions. In this study, we assessed the genetic diversity and population structure of 183 apricot accessions using 24 microsatellite markers distributed evenly in thePrunusgenome. A total of 192 alleles and a high level of gene diversity (0.593) were detected among the whole panel. Genetic structure analysis revealed the presence of four genetic clusters. We also found that both geographical origin and mode of propagation are important factors structuring genetic diversity in apricot species. Results confirmed the presence of gene exchange between the northern and southern countries of the Mediterranean Basin. Subsequently, a core collection of 98 accessions based on M (maximization) strategy showing 99.47% of allele retention ratio was constructed. No significant differences for Shannon's information index and Nei's diversity index were observed between the core and entire collections. Our results provide an effective aid for future germplasm preservation and conservation strategies as well as genetic association studies development in relation to phenotypic data.

Heterozygosis deficit of polymorphic markers linked to the β-globin gene cluster region in the Iranian population.

Iran is considered as one of the high-prevalence areas for β-thalassemia with a rate of about 10% carrier frequency. Molecular diagnosis of the disease is performed both by direct sequencing and indirectly by the use of polymorphic markers present in the beta globin gene cluster. However, to date there is no reliable information on the application of the markers in the Iranian population. Here we report the results of an extended molecular analysis of five RFLP markers, XmnI, HindIIIA, HindIIIG, RsaI and HinfI, located within the β-globin gene cluster region in four subpopulations of Iran. A total of 552 blood samples taken from the Iranian subpopulations including Isfahan, Chaharmahal-O-Bakhtiari, Khuzestan and Hormozgan were genotyped using PCR-RFLP and sequencing. The allele frequency, the expected and observed heterozygosity, and Shannon's information index (I) of these markers were calculated. Distribution of the allele frequencies for XmnI, HindIIIA, HindIIIG, RsaI and HinfI polymorphic markers did not differ significantly among the subpopulations examined. Overall observed heterozygosity ranged from 0.1706 for HindIIIA to 0.4484 for RsaI. The Shannon index was <1 for all the polymorphic markers in the populations studied. The data indicated that heterozygosity of these markers was low in the Iranian population. The results suggested that genotyping of these markers is not informative enough once used as single markers for prenatal diagnosis and carrier detection of β-thalassemia in the Iranian population. However, haplotyping of these markers may provide more useful data in linkage analysis and prenatal diagnosis as well as carrier detections for β-thalassemia in Iranians.

Genetic diversity of Styrax obassia Sieb. et Zucc. based on AFLP markers

Styrax obassia Sieb. et Zucc. is an industrially important landscape tree that produces storax, a resin with pharmacological properties. Studies were initiated to analyze the genetic diversity and relationships of 76 individuals of S. obassia from five natural populations using amplified fragment length polymorphism (AFLP) markers in Shandong Province, China. Eight AFLP primers selected from 64 primers were used to generate 1343 discernible DNA bands, of which 1338 (99.6%) were polymorphic. High genetic diversity was revealed at the species level (number of different alleles Na = 1.9960, number of effective alleles Ne = 1.2782, Nei's gene diversity H = 0.1764, Shannon's information index I = 0.2883) and at the population level (H = 0.1451, I = 0.2289). At a similarity coefficient threshold of 0.57, all individuals were divided into three groups. The population KY1 localized in Mt. Kunyu harbored the most abundant genetic diversity. Most of the genetic differentiation existed within populations, while genetic differentiation among populations was 11.5% with P > 0.05. There was no significant correlation (r = 0.4727, P = 0.9106) between genetic distance and geographical distance among the populations. On the basis of these results, we propose a strategy for the conservation of S. obassia germplasm.

Assessment of Genetic Diversity of Argania spinosa L. Growing in Arid and Semi-arid Areas of Morocco as Revealed by Inter-Simple Sequence Repeats

Argania spinosa L. (Sapotaceae family), endemic to Morocco, is a multipurpose tree with an important ecological and socio-economical interest. Nevertheless, the sustainability of the agro-forestry system is now threatened by overgrazing and over-exploitation leading to an alarming decline in the number of trees. In the present study, inter-simple sequence repeats (ISSR) markers were used to evaluate the genetic variation and to assess the genetic diversity distribution within and among 17 argan populations growing naturally under semi-arid and arid climate. Thus, a total of seven primers generated 260 well-defined bands, with an average of 37.14 bands per primer. Studied populations showed a relatively high level of genetic diversity at species level and low level of genetic diversity at population level. The percentage of polymorphic bands, Nei's gene diversity and Shannon's information index at population and species level were 30.15%, 0.164, 0.217 and 98.8%, 0.172, 0.293, respectively. A relative low level of genetic differentiation (Gst = 0.39) was in agreement with the results obtained from the analysis of molecular variance (AMOVA). Estimated gene flow was Nm = 0.781 among populations. Mantel test revealed a non-significant correlation between genetic and geographic distance (r = 0.065, P < 0.05), suggesting that the geographic distribution is not the major factor that shaped the present population genetic structure. The results can help preserve A. spinosa L. tree as an endangered species, however, refining these finding using co-dominant markers is recommended in order to establish conservation strategies.

Assessment of genetic variations of silver lime (Tilia tomentosa Moench.) by RAPD markers in urban and forest ecosystems

In the present study, the genetic diversity analysis of Tilia tomentosa plants was performed by using random amplified polymorphic DNA (RAPD) primers. Twenty eight plant samples, collected from urban (25 members) and forest (3 members) ecosystems, were used in this study. A total of 53 bands were obtained from eight RAPD primers, of which 48 (90.6%) were polymorphic. The percentage of polymorphic loci (P) was found to be 94.29%, the observed number of alleles (Na) was 1.94, the effective number of alleles (Ne) was 1.60, Nei's gene diversity (h) was 0.34 and Shannon's information index (I) was 0.50. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis revealed two major groups. Members of the urban and forest ecosystems showed high genetic similarity (28%–92%) and they did not separate from each other in UPGMA tree. Furthermore, urban and forest genotypes clustered together in principal component analysis.

English

Nigella sativa L. (commonly known as black cumin) belonging to family Rannunculaceae is an important medicinal plant with worldwide distribution. In Ethiopia, N. sativa occurs in all regions and agro-ecologies at different altitudinal ranges. This plant has a lot of importance in Ethiopia. However, there is no information available on molecular genetic diversity of this crop in respect to Ethiopia. Therefore, the aim of this study was to investigate the genetic diversity of black cumin populations collected from Amhara, Oromia, Tigray, Benshangul and South Nation&rsquo;s Nationality People regions of Ethiopia using ISSR marker. A total of 84 black cumin accessions were obtained from Institute of Biodiversity Conservation (IBC). The ISSR marker was used for computing gene diversity, percent polymorphism, Shannon diversity index and AMOVA. Overall, accessions from Oromia showed the highest gene diversity (H = 0.35) and Shannon information index (I= 0.52), followed by Amhara with gene diversity and Shannon index values of (0.35) and (0.51), respectively. NJ and UPGMA results showed strong grouping among accessions collected from the Oromia and Amhara region. The five geographical regions of Ethiopia showed different levels of genetic variation. Thus, conservation priority should be given for those regions that have low genetic diversity. &nbsp; Key words: Conservation, indigenous, molecular markers, primers.

English

Lepidium sativum L. (family Brassicaceae), is underutilized medicinal plant with worldwide distribution. In Ethiopia, L. sativum occurs in all regions and agro-ecologies at different altitudinal ranges. The study was conducted to assess the genetic diversity of L. sativum populations from Ethiopia using molecular marker and agronomic traits. Molecular data generated from inter simple sequence repeat bands recorded was used for computing gene diversity, percent polymorphism, Shannon diversity index and analysis of molecular variance. Moreover, the inter simple sequence repeat data was used to construct unweighted pair group method with arithmetic mean, neighbor joining trees and principal co-ordinate plot using Jaccard’s coefficient. Tigray and Amhara L. sativum populations showed higher gene diversity (0.24) and Shannon information index (0.35). Both unweighted pair group method with arithmetic mean and principal co-ordinate analysis showed very weak grouping among individuals collected from the same regions. Generally, Tigray and Amhara regions showed moderate to high diversity in inter simple sequence repeat analysis. Different geographical regions of Ethiopia, showed different levels of variation; thus, conservation priority should be given to those regions that have genetic diversity. This result also indicates the presence of genetic diversity that can be exploited to improve the productivity of L. sativum in Ethiopia. Key words: Genetic diversity, inter simple sequence repeat (ISSR), Lepidium sativum, morphology.

English

Molecular characterization of 16 mustard ( Brassica spp.) genotypes by using 12 RAPD markers revealed that three primers GLA-11, OPB-04 and OPD-02 showed good technical resolution and sufficient variations among different genotypes. A total of 40 RAPD bands were scored of which 38 (94.87%) polymorphic amplification products were obtained. Besides, the primer OPD-02 amplified maximum number of polymorphic bands (100.00%) while the primer GLA-11 and OPB-04 generated the least (92.31%) polymorphic bands, which were minimal in number. The present study produced 13.33 scorable bands per primer and 12.67 polymorphic bands per primer. Frequencies of maximum number of polymorphic loci were found to be high with the exception of GLA-11(0.750), OPB-04 (0.875) and OPD-02 (0.750). The estimate of Nei's genetic diversity for the entire genotypes of mustard was 0.3596 and Shannon's information index was 0.535. There was a high level of genetic variation among the mustard genotypes studied from the proportion of polymorphic loci point of view. The values of pair-wise comparison of Nei’s genetic distance between genotypes were computed from combined data for the three primers; ranged from 0.1054 to 0.9862. BINA Sarisha-3 and BINA Sarisha-4 showed the lowest genetic distance of 0.1054 where Tori-7 and NAP-0758-2 showed highest genetic distance of 0.9862. The 16 mustard genotypes were differentiated into three main clusters: BARI Sarisha-14, BARI Sarisha-9, BARI Sarisha-15, BINA Sarisha-4, BINA Sarisha-3, BARI Sarisha-8, Sampad and Tori-7 in cluster A, NAP-0763, NAP-0721-1, BARI Sarisha-4, BARI Sarisha-6, NAP-0762-2 and NAP-0848-2 in cluster B and NAP-0838 and NAP-0758-2 were grouped into cluster C by making dendrogram based on Nei’s genetic distance using unweighted pair group method of arithmetic means (UPGMA). Keywords: Mustard, diversity analysis, RAPD marker, genetic distance, cluster analysis. Abbreviation: UPGMA, Unweighted pair group method of arithmetic means; RFLP, restriction fragment length polymorphism; RAPDs, random amplified polymorphic DNAs; AFLP, amplified fragment length polymorphism; SSRs, simple sequence repeats; CTAB, cetyl trimethyl ammonium bromide.

English

Lepidium sativum L. (family Brassicaceae), is an underutilized medicinal plant with worldwide distribution. In Ethiopia, L. sativum occurs in all regions and agro-ecologies at different altitudinal ranges. The study was conducted to assess the genetic diversity of L. sativum population from Ethiopia using inter simple sequence repeat (ISSR) marker. Molecular data generated from ISSR bands recorded was used for computing gene diversity, percent polymorphism and Shannon diversity index and AMOVA. Moreover, the ISSR data was used to construct unweighted pair group method with arithmetic mean (UPGMA) and principal coordinated analysis (PCO) plot using Jaccard&rsquo;s coefficient. &nbsp;Tigray and Amhara population showed higher gene diversity (0.24) and Shannon information index (0.35). All UPGMA, neighbor-joining (NJ) and PCO analysis showed very weak grouping among individuals collected from the same regions. Generally, Tigray and Amhara regions showed moderate to high diversity in ISSR analysis. Different geographical regions of Ethiopia, showed different level of variation; thus conservation priority should be given for those regions that have high genetic diversity. This result also indicates the presence of genetic diversity that can be exploited to improve the productivity of L. sativum in Ethiopia. &nbsp; Key words: Genetic diversity, ISSR, Lepidium sativum.