Genetic diversity of <Emphasis Type="Italic">Guizotia abyssinica</Emphasis> (L. f.) Cass. (Asteraceae) from Ethiopia as revealed by random amplified polymorphic DNA (RAPD)

Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing regions in Ethiopia was investigated using random amplified polymorphic DNA (RAPD) to reveal the extent of its populations genetic diversity. Ninety-seven percent of the loci studied was revealed to be polymorphic for the whole data set. The within population diversity estimated by Shannon diversity index and Nei gene diversity estimates was revealed to be 0.395 and 0.158, respectively. The extent of genetic variation of populations from major niger producing regions was significantly lower than that of populations from other regions; however, it is distributed regardless of altitude of growth. Genetic differentiation between populations was estimated with Shannon index as G^′ _ST (0.432), Nei’s G _ST (0.242) and AMOVA based F _ST (0.350) and appears to be equivalent to the average values calculated from various RAPD based studies on outcrossing species. Higher proportion of the variation detected by AMOVA resided within populations (64.58%) relative to the amount of variation among populations (35.42%). UPGMA cluster analysis showed that most of the populations were clustered according to their region of origin. However, some populations were genetically distant from the majority and seem to have unique genetic properties. It is concluded that the crop has a wide genetic basis that may be used for the improvement of the species through conventional breeding and/or marker assisted selection. Collection of germplasm from areas not yet covered and/or underrepresented is the opportunity to broaden the genetic basis of genebank collection.     

Genetic diversity of wild banana (<Emphasis Type="Italic">Musa balbisiana</Emphasis> Colla) in China as revealed by AFLP markers

Wild banana Musa balbisiana Colla is one of the progenitors of cultivated bananas and plantains. It is native to Southeast Asia and the western Pacific. South China represents the northern limit of its distribution range. The genetic diversity of Musa balbisiana was assessed by the amplified fragment length polymorphism (AFLP) fingerprinting in 15 populations of China. Four primer pairs produced 199 discernible loci. High levels of genetic diversity were detected, with P = 78.5%, H _E = 0.241, and H _pop = 0.3684 at population level, and P = 100%, H _T = 0.3362 and H _sp = 0.5048 at species level. Significant genetic differentiation among populations was detected based on Hickory’s analysis (27.6%), Shannon’s diversity index (27.0%) and AMOVA (27.1%). The AFLP results are discussed and compared with data obtained by microsatellites method. The estimates of genetic diversity and differentiation between each pair of populations computed with microsatellites and AFLP markers were not significantly correlated. Conservation strategies for Musa balbisiana in China are proposed.     

Genetic Structure of Wild and Domesticated Populations of Capsicum annuum (Solanaceae) from Northwestern Mexico Analyzed by RAPDs

Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in wild populations and 34.7% in domesticated populations. Mean and total genetic diversity were 0.069 and 0.165 for wild populations and 0.081 and 0.131 for domesticated populations. Parameters of genetic diversity estimated from 54 bands with frequencies ≥1 − (3/n) (n = sample size) showed that 56.7% of the total variation was within and 43.3% among wild populations, whereas 67.8% of the variation was within and 32.2% among domesticated populations. AMOVA indicated that total genetic diversity was equally distributed within (48.9 and 50.0%) and among (50.0 and 51.1%) populations in both wild and domesticated samples. Wild and domesticated populations were clearly resolved in a UPGMA dendrogram constructed from Jaccard’s distances (average GD = 0.197), as well as by AMOVA (17.2% of variance among populations types, p = 0.001) and by multidimensional scaling analysis. Such differentiation can be associated with domestication as well as different origin of gene pools of the wild (Northwestern Mexico) and cultivated (more probably Central Mexico) samples analyzed. The considerable genetic distances among cultivars (average GD = 0.254) as well as the high number of diagnostic bands per cultivar (33 out of 126 bands), suggest that genetic changes associated with domestication could have resulted from artificial selection intervening in different directions, but the inclusion of more domesticated samples might clarify the nature of distinctions detected here.     

The Vigna angularis complex: Genetic variation and relationships revealed by RAPD analysis, and their implications for in situ conservation and domestication

The present study, using RAPD analysis, was undertaken to characterize genetic variation in three forms of V. angularis, cultivated, wild and weedy forms, and their relationships. The materials used consisted of 171 individuals (plants) or cultivars from 23 populations including 5 wild populations, 6 weedy populations, 6 cultivated populations and 6 populations with plants having wild and weedy or intermediate morphology, denoted here as complex populations. The materials used were collected on Honshu Island, Japan and seeds collected directly from the field were germinated for DNA extraction. In addition, 6 landrace accessions of V. angularis from the genebank were also analyzed. Genetic variation was highest in the wild form (H_g= 0.132; GD = 0.388), followed by the weedy form (H_g= 0.124; GD = 0.341) and the least in the cultivated form (H_g= 0.079; GD = 0.274). Intra-population genetic variation was high in the weedy and in the wild populations. However, inter-population was greater than intra-population genetic variation for all groups of populations studied in the V. angularis complex. 93% of the total diversity in the present study was exhibited by plants from complex populations and specific RAPD bands were found in these populations. Our results provide evidence that complex populations would be a logical focus for efforts to conserve the V. angularis complex in situ. Our results suggest that weedy populations are usually an ecotype of the wild form adapted to a different habitat.     

Comparison of the genetic structure of populations of wild emmer wheat, <Emphasis Type="Italic">Triticum turgidum</Emphasis> ssp. <Emphasis Type="Italic">dicoccoides</Emphasis>, from Israel and Turkey revealed by AFLP analysis

The aim of the present study was to assess the genetic variation in several Israeli and Turkish populations of wild emmer wheat, Triticum turgidum ssp. dicoccoides, the progenitor of most domesticated wheat. Single spikes were collected in 2002 from 60 plants that grew in six different habitats in Ammiad, northeastern Israel (8–12 plants from each habitat), and in 1998 from 56 plants that grew in seven different habitats in Diyarbakir, southeastern Turkey (8 plants from each habitat). Seeds were planted in a nursery and DNA was extracted from every plant and analyzed by the fluorescent-based amplified fragment length polymorphism (AFLP) method. Seven primer combinations produced 788 discernible loci of which 48.6% were polymorphic in Israel and 40.5% in Turkey. The genetic diversity estimates P (frequency of polymorphic loci) and He (gene diversity) were higher in Ammiad than in Diyarbakir (means of P = 0.34 and He = 0.13 in Ammiad vs. P = 0.20 and He = 0.08 in Diyarbakir). Ammiad populations contained more unique alleles than Diyarbakir populations. The relative genetic diversity estimates (θ) values were 0.188 in Ammiad and 0.407 in Diyarbakir, suggesting better differentiation of the populations in Turkey. Genetic distance was larger between Israeli and Turkish populations than between populations of each country. The data indicate that the Israeli and Turkish populations are considerably diverged and that the Israeli populations are more polymorphic than the Turkish ones, having a larger within-populations genetic variation than among-populations one. The significance of the results in relation to the differentiation pattern of wild emmer in the Near East is discussed.     

RAPD and AFLP assessment of genetic variation in a landrace of pepper (Capsicum annuum L.), grown in North-West Italy

In several regions of Italy as well as other parts of southern Europe, the heterogeneity of the land, the climate and the soil favour the survival in cultivation of a large number of landraces specifically adapted to local conditions. Knowledge on the level and distribution of their genetic variation can help to develop appropriate strategies, in order to suistainably manage in situ these germplasm resources at risk of genetic erosion. C. annuum is an herbaceous diploid species and is considered to be self-pollinating, although different rates of out-crossing have been recorded. We used random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers to assess genetic diversity within and between five populations of a landrace of Capsicum annuum L., grown in a limited area in north-west Italy and locally known as Cuneo pepper. Partitioning the genetic variation with Shannon's diversity index revealed that 41.6% occurred between and 58.4% within populations. Analogous results were obtained when the analysis was based only on RAPD or AFLP markers. However, AFLP was more reliable, since a lower range of variation was observed among primer combinations in detecting the two components of genetic variation. Notwithstanding the rather high level of within genetic variation detected, the five populations were clearly differentiated and differed in the frequency of alleles exclusive and/or present at very low frequencies. Our results show the need for accurate estimation of allele frequencies, in order to identify populations to which priority should be given for dynamic conservation of landraces.     

Genetic diversity in <Emphasis Type="Italic">Eremostachys superba</Emphasis> Royle ex Benth. (Lamiaceae), an endangered Himalayan species,as assessed by RAPD

Eremostachys superba Royle ex Benth. (Lamiaceae) has undergone a severe decline in population size since its discovery in the North-western Himalayas in late 19th century. One hundred and seventy-two plants from six populations in the Indian states of Uttar Pradesh and Jammu & Kashmir, located between 0.45 km and 455.72 km apart from each other were evaluated for RAPD polymorphism. Sixteen random primers generated 92 bands overall, 77 of which were polymorphic. Shannon’s index of genetic diversity within populations (H _o) ranged between 0.305 and 0.421; the average within-population diversity (H _pop) was 0.389; and the total species diversity (H _sp) was 0.478. The population from Mohand (representing the type locality) had the fewest plants, at 18, and was genetically the most depauperate. Among the other populations, ranging in size between 52 and 1,022 individuals, no relation between population size and genetic diversity was evident. It is suggested that these six populations represent relics of a larger, extended population, in which the presence of perennating rootstocks has helped preserve historic patterns of genetic diversity. AMOVA revealed that 83.01% of the variation exists within populations, which was consistent with earlier studies on the reproductive biology of E. superba, which indicated this species is predominantly allogamous. FST distances between all populations were significant, indicating geographic differentiation despite some of them being closely separated. Habitat restoration and protection from indiscriminate harvesting are proposed as primary strategies for conserving E. superba. Rejuvenation of the Mohand population through intrapopulation crossing between plants bearing diverse molecular phenotypes is also suggested.     

Levels and distribution of allozyme and RAPD variation in populations of Elymus fibrosus (Schrenk) Tzvel. (Poaceae)

To study the magnitude and nature of genetic variation in E. fibrosus, the levels and distribution of allozyme and RAPD variations were investigated in populations collected from Finland and Russia. The results obtained from the allozyme and RAPD studies were compared to each other in 10 of the populations. The allozyme analysis showed that 6 of 12 presumed loci (50%) were polymorphic within the species, while the mean number of polymorphic loci within populations was 4.8%. The mean number of allele per locus for the species was 1.5 and 1.05 across the populations. Genetic diversity at the species level was low (H _es = 0.025), and the mean population genetic diversity was even lower (H _ep = 0.007). Both these values were much lower than the average for other Elymus and self-fertilising species. The largest proportion of the total allozyme diversity was found among, rather than within the populations (G _ST = 0.70). The allozyme genetic distances between the populations did not reflect geographic distances. Cluster and principal coordinates analyses revealed the same allozyme relationship patterns among the populations. A comparison of allozyme and RAPD variation in 10 of the populations showed differences in the amount of genetic variation. The RAPD analysis revealed higher levels of variation (A _p = 1.19, P _p = 20.3 and H _ep = 0.09) than the allozyme one) A _p = 1.06, P _p = 5.8 and H _ep = 0.008). For both markers, the largest proportion of the total gene diversity was found among the populations studied (G _st = 0.63 for RAPDs and G _st = 0.65 for allozyme). In contrast to the allozyme analysis, the RAPD based genetic distances did reflect geographic distances. The cluster and principal coordinates analyses showed different grouping of populations for each data set. There was a positive, but not significant, correlation (r = 0.41) between the genetic distance matrices resulting from these markers. Regional comparison revealed that the Finnish populations had a higher diversity than the Russian ones. Generally, this study indicates that E. fibrosus contains low genetic variation in its populations. The results are discussed in the context of conservation of the species.     

Exploration of intra- and inter-population genetic diversity in <Emphasis Type="Italic">Hedysarum coronarium</Emphasis> L. by AFLP markers

Amplified fragment length polymorphism (AFLP) markers were used to characterize the genetic diversity within and among natural populations and cultivars of Hedysarum coronarium. Twelve populations within Tunisia were evaluated with three AFLP primer combinations. A total of 207 reproducible bands was detected of which 178 (86%) were polymorphic. The great discriminative power of AFLP markers and their ability to represent genetic relationships among Hedysarum plants was demonstrated. Genetic diversity within and among populations was assessed through Principal Component Analysis (PCA) and cluster analysis by using the Neighbor-joining clustering algorithm. AFLP technology has provided evidence of a high degree of intra- and inter-population genetic diversity in H. coronarium. AFLP banding patterns provided molecular markers correlated with the plants’ geotropism. In addition, AFLP markers can differentiate wild accessions from cultivars. Moreover, geographical origins did not correspond to population clustering.     

AFLP Fingerprinting in Pigeonpea (Cajanus cajan (L.) Millsp.) and its Wild Relatives

Detection of DNA polymorphism in cultivated pigeonpea (Cajanus cajan) and two of its wild relatives Cajanus volubilis and Rhynchosia bracteata is reported here for the first time using amplified fragment length polymorphism (AFLP) fingerprinting. For this purpose, two EcoRI (three selective nucleotides) and 14 MseI (three selective nucleotides) primers were used. The two wild species shared only 7.15% bands with the pigeonpea cultivars, whereas 86.71% common bands were seen among cultivars. Similarly, 62.08% bands were polymorphic between C. volubilis and pigeonpea cultivars in comparison to 63.33% polymorphic bands between R. bracteata and pigeonpea cultivars, and 13.28% polymorphic bands among pigeonpea cultivars. The cluster analysis revealed low polymorphism among pigeonpea cultivars and very high polymorphism between cultivated pigeonpea and its wild relatives. The AFLP analysis also indicated that only one primer combination (EcoRI + ACT and MseI + CTG), at the most any four primer pair combinations, are sufficient for obtaining reliable estimation of genetic diversity in closely related cultivars like pigeonpea material analyzed herein. AFLP analysis may prove to be a useful tool for molecular characterization of pigeonpea cultivars and its wild relatives and for possible use in genome mapping.     

Analysis of genetic diversity in Turkish sesame (Sesamum indicum L.) populations using RAPD markers⋆

The genetic diversity of 38 cultivated populations of Sesamum indicum L. from four different regions of Turkey was estimated at the DNA level with the random amplified polymorphic DNA (RAPD) technique. Sixty-one bands were obtained for all populations 78% of which were polymorphic. Analysis of molecular variance (AMOVA) was used to investigate the genetic diversity of the populations which yielded highly significant differences among populations within regions (91.9% of the total genetic diversity). According to AMOVA and Shannon's index that were performed separately for each region, the highest value of genetic variation was observed among Northwest region populations (CV = 7.7; H₀ = 0.304) and lowest in the Southeast regions' populations (CV = 2.6; H₀ = 0.068). Nei and Li's similarity index was calculated and phylogenetic tree was established using the neighbor-joining algorithm. This phenetic analysis grouped 35 of 38 accessions in six groups leaving three highly diverse accessions outside. Wagner phylogenetic method was used to assess the phylogenetic relationships among the populations. In the majority-rule consensus tree, only 7 of the 32 forks showed above 60% occurrence. Using Principal Coordinate Analysis (PCO) of the RAPD data set, the groups were clearly separated along the first three axis. These results indicate that RAPD technique is useful for sesame systematics, and should be valuable for the maintenance of germplasm banks and the efficient choice of parents in breeding programs.     

An Assessment of the Genetic Diversity within a Collection of Wild Cranberry (<Emphasis Type="Italic">Vaccinium macrocarpon</Emphasis> Ait.) Clones with RAPD-PCR

Forty-three wild cranberry (Vaccinium macrocarpon Ait.) clones collected from four Canadian provinces and five cranberry cultivars were assessed for genetic variability by using random amplified polymorphic DNA (RAPD)-PCR. Fourteen primers generated 161 polymorphic RAPD-PCR bands. A substantial degree of genetic diversity was found among the wild cranberry collections. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) separated the wild clones and three cultivars into five main clusters, and identified the two remaining cultivars as outliers. Furthermore, within four clusters, the genotypes tended to form sub-clusters that were in agreement with the principal coordinate (PCO) analysis. Geographical distribution explained 10% of total variation as revealed by analysis of molecular variance (AMOVA). The RAPD markers detected a sufficient degree of polymorphism to differentiate among cranberry clones and cultivars, making this technology valuable for germplasm management and the more efficient choice of parents in current cranberry breeding programs.     

Worldwide genotyping of castor bean germplasm (<Emphasis Type="Italic">Ricinus communis</Emphasis> L.) using AFLPs and SSRs

Worldwide genetic diversity in 200 individuals comprising 41 castor bean accessions was assessed using amplified fragment polymorphisms (AFLPs) and simple sequence repeats (SSRs). We found that, despite surveying five continents and 35 countries, genetic diversity in castor bean germplasm is relatively low (overall H _e = 0.126 for AFLPs and 0.188 for SSRs) compared to estimates of genetic diversity in other plant species. Our data also show no geographic structuring of genotypes across continents or countries within continents. An assessment of the congruence between AFLP and SSRs indicates a low correlation (R ² = 0.19) between the two data sets, but each marker class nonetheless shows similar patterns of low-genetic diversity and a lack of geographic structure. Our data do suggest that SSRs yield a higher percentage of polymorphic loci, higher heterozyosity and a greater range of genetic distances, and are therefore more informative than are AFLPs on a locus-by-locus basis. Based on comparisons with numerous other plant species, we suggest that the lower genetic variation in this worldwide collection may be due to one or more factors including: sampling strategies that have not captured the full extent of genetic variation in the species; artifactual variation due to long-term germplasm storage and seed regeneration; or intense selection followed by domestic cultivation of a limited number of castor bean genotypes, which are widely propagated for their horticultural and agro-economic value.     

Population Genetics of <Emphasis Type="Italic">Escontria chiotilla</Emphasis> in Wild and Silvicultural Managed Populations in the Tehuacán Valley,Central Mexico

Escontria chiotilla is a columnar cactus that grows in the arid and semiarid lands of Central Mexico and produces edible fruit with economic. In the wild, this plant species is distributed as part of thorn-scrub and tropical deciduous forests, but in the Tehuacán Valley also occurs in silvicultural managed in situ populations, in which people practise artificial selection enhancing phenotypes with larger fruits. The population genetics of wild and managed populations was studied to analyse the effects of management on genetic structure of E. chiotilla. A total of 150 individuals from six populations were studied, analysing 13 loci for eight enzymes by starch gel electrophoresis. The genetic variation in wild populations was significantly higher than in managed populations (H_o = 0.079, H_e = 0.134, H_T = 0.370, and H_o = 0.052, H_e = 0.110, H_T = 0.298, respectively), indicating that silvicultural management has caused a reduction of the genetic variation in populations. Most of the genetic variation in both wild and managed populations occurs within populations (D_ST = 0.027 in the wild and 0.018 in managed populations). The genetic distance coefficients were slightly different for silvicultural managed populations than in wild ones, illustrating an incipient effect of management on the genetic structure of populations. However, values of Nm_GST = 3.845 and Nm_FST = 3.848 indicate that a high gene flow counteracts the effects of human selection on the differentiation of populations.     

Genetic diversity of Pakistan wheat germplasm as revealed by RAPD markers

Wheat breeding in Pakistan started in 1930s before partition in the United India and so far has released more than 68 cultivars, but no systematic analyses of the genetic diversity of Pakistan wheat have been made. Twenty Pakistan wheat cultivars released from 1933 to 2002 were examined for genetic diversity and relationships using random amplified polymorphic DNA (RAPD) markers. Forty-two RAPD primers were applied and 184 polymorphic bands were generated for each cultivar. Most of the cultivars were genetically interrelated, although six of them displayed some genetic distinctness. The RAPD variation observed among these cultivars was low. Only 40.7% of the total scorable bands were polymorphic, and 26.1% of the polymorphic bands were observed most frequently (f = 0.95) among the 20 cultivars. The proportions of polymorphic bands for each cultivar ranged from 0.67 in ‘Yecora’ to 0.84 in ‘C-250’ with an average of 0.76. About 1.4% of the RAPD variation might have been fixed over the 69 years of wheat breeding, but such fixation was not statistically significant. These results are significant for future improvement and conservation of Pakistan wheat.     

Assessment of genetic relationships among Pyrus species and cultivars using AFLP and RAPD markers

Twenty-five Pyrus communis L. cultivars including eight traditional Portuguese pears, and four commercial Pyrus pyrifolia (Burm.) Nak. (Japanese pear or `nashi') cultivars were analysed by RAPD and AFLP techniques focusing on their molecular discrimination and the assessment of their genetic relatedness. Twenty-five primers generated 324 RAPD markers, among which 271 (84%) were polymorphic. The AFLP technique, using seven primer combinations, revealed a similar level of molecular polymorphisms (87%), representing 418 polymorphic bands among a total of 478 scored in autoradiographs. The high reproducibility of RAPD and AFLP techniques was confirmed comparing DNA samples from different extractions and different digestions of DNA from the same plant. Three genetic similarity matrices and respective dendrograms were elaborated on using RAPD, AFLP or joint RAPD and AFLP data. Both molecular marker techniques proved their reliability to assess genetic relationships among pear cultivars. P. pyrifolia cultivars exhibit a closer genetic relatedness, clustering apart from P. communis cultivars. Within P. communis, `William's', as well as `Doyenne du Comice', cluster close to their hybrids. Most of the Portuguese cultivars tend to cluster together, indicating to constitute a relatively independent genetic pool, which can be of interest in pear breeding programs.     

RAPD and ISSR molecular markers in <Emphasis Type="Italic">Olea europaea</Emphasis> L.: Genetic variability and molecular cultivar identification

Thirty Portuguese and eight foreign olive (Olea europaea L.) cultivars were screened using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) markers. Twenty RAPD primers amplified 301 reproducible bands of which 262 were polymorphic; and 17 ISSR primers amplified 204 bands of which 180 were polymorphic. The percentage of polymorphic bands detected by ISSR and RAPD was similar (88 and 87%, respectively). The genetic variability observed was similar in the Portuguese and foreign olive cultivars. Seven ISSR and 12 RAPD primers were able to distinguish individually all 38 olive cultivars. Twenty specific molecular markers are now available to be converted into Sequence Characterised Amplified Region (SCAR) markers. Relationships among Portuguese and foreign cultivars is discussed.     

Abundant genetic diversity in cultivated <Emphasis Type="Italic">Codonopsis pilosula</Emphasis> populations revealed by RAPD polymorphisms

Genetic diversity of seven cultivated populations of Codonopsis pilosula Nannf. from Longxi County, Gansu Province of China was estimated using randomly amplified polymorphic DNA (RAPD) markers. The 17 selected RAPD primers amplified 205 polymorphic bands out of a total of 235 (87.2%). Nei’s gene-diversity statistics and population differentiation parameters based on AMOVA analysis indicated that the cultivated C. pilosula populations remained a high level of genetic diversity with Hs = 0.299 and I = 0.450. A greater proportion of genetic diversity was found within (77%) rather than among (23%) the populations. In addition, we also detected that populations from different altitudes had a considerable genetic differentiation after 40 years of cultivation at the same site. Populations from higher altitude had lower genetic diversity than those from lower altitude. Our results suggested that irregular and sparse cultivation practices, i.e., random collecting, preserving, and planting seeds of the medicinal species without deliberate selection, might be an efficient way to conserve genetic resources of medicinal plants, in addition to their effective uses.     

RAPD and ISSR fingerprinting in cultivated chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) and its wild progenitor <Emphasis Type="Italic">Cicer reticulatum</Emphasis> Ladizinsky

Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars, whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea.     

Genetic diversity of <Emphasis Type="Italic">Nelumbo</Emphasis> accessions revealed by RAPD

Total 65 lotus accessions in genus Nelumbo mainly collected from China, were subjected to random amplified polymorphic DNA (RAPD) markers to estimate the genetic diversity and to test the genetic basis of the relationships between morphotypes and molecular markers. Seventeen primers generated a total of 195 highly reproducible and discernible loci, among which 173 were polymorphic. Percent polymorphism varied from 66.7 to 100 with an average of 88.72, and five primers out of them, OPC05, OPG10, OPN20, OPP09 and OPS17, showed 100% polymorphism. A relatively high genetic diversity was detected among all the samples with the similarity coefficient values ranging from 0.45 to 0.85, and Nei’s gene diversity (h) 0.30, and Shannon index (I) 0.46. The UPGMA dendrogram clustered 65 accessions in four clusters and the clustering pattern showed two groups, N. nucifera ssp. nucifera and those accessions related to the American lotus, and some special cultivars, landraces, hybrids and the American lotus. Principal Coordinate Analysis (PCA) further indicated that the genetic diversity of Nelumbo accessions was not evenly distributed, instead, was presented by a clustered distribution pattern. Similar to the results revealed by the dendrogram, two main groups representing the two subspecies of N. nucifera, as well as some special landraces, cultivars of Chinese lotus, the Japanese lotus and hybrids out of the two groups were obtained. Neither the UPGMA dendrogram nor the PCA analysis exhibited strict relationship with geographic distribution and morphotypes among the accessions.