RAPD-based evaluation of genetic diversity among populations of the Iranian endemic species Rhabdosciadium aucheri Boiss. (Apiaceae).

Rhabosciadium aucheri is an Iranian endemic herbaceous species that grows in the west, center, and south regions of Iran. In the present study, genetic variation of 70 individuals belonging to seven natural populations of four provinces was investigated using Random Amplified Polymorphic DNA (RAPD) markers. Ten out of twenty-two RAPD primers employed in this study, generated 110 highly amplified and reproducible loci and a mean of 11.1 bands per primer and 48.13% of polymorphism was obtained. According to our results, the primer OPA10 presented the highest effective number of alleles, Shannon's index, and genetic diversity. The highest value of genetic identity (0.916) was determined between Hamadan, Nahavand and Hamadan, Alvand Mts. populations and the highest genetic distance (0.277) was observed between Hamadan, Asadabad and Kurdistan, Qorveh populations. Therefore, there is an obvious correlation between genetic diversity and geographical distribution. PCA was obtained based on RAPD molecular data and Neighbor Joining (NJ) dendrogram was provided successively. Similar results were attained employing UPGMA and Neighbor Joining dendrograms, supported by PCA ordination plot. Overall, almost moderate level of polymorphism was obtained by RAPD molecular markers at the population level that shows a reasonable amount of intraspecific variability. The reason might be due to the low level of gene flow between populations that could give rise to high genetic differentiation.

Interspecific hybridization between cultivated morels Morchella importuna and Morchella sextelata by PEG-induced double inactivated protoplast fusion.

The commercial production of Morchella mushrooms calls for urgent breeding of excellent varieties or strains with appropriate tools, such as protoplast fusion. However, the protoplast fusion in morels has not been studied. In this paper, interspecific hybridization between cultivated morels of M. importuna and M. sextelata by PEG-induced protoplast fusion was conducted. Apart from functional complementation of double inactivated protoplasts, the fusants were characterized by cultural and cultivated characters and molecular markers of random amplified polymorphic DNA (RAPD). The results suggested that the hybrids and their parents showed significant difference in their inoculum recovery time, mycelial growth rate, yield of cultivation and total amino acid content of ascocarps. Moreover, positive barrage reactions were observed between parental strains as well as between each parent and a hybrid line. A dendrogram created on the basis of RAPD fingerprints exhibited three major clusters, in which morel hybrids showed intra-cluster variations, M. sextelata #6 formed an out group, while M. importuna #4 was phylogenetically closer to morel hybrids. All the results demonstrated that real fusants were obtained in our study. Protoplast fusion may provide an ideal alternative for new strain selection, and thus will promote the healthy development of morel industry.

Induction of powdery mildew resistance in gerbera (Gerbera jamesonii) through gamma irradiation.

In this study, the effect of gamma irradiation in inducing resistance/tolerance towards powdery mildew disease was investigated in Gerbera jamesonii cv. 'Harley'. In vitro shoot cultures were established through capitulum explants on Murashige and Skoog medium supplemented with 22.2 µM 6-benzyladenine (BA) and 2.53 µM indole acetic acid (IAA), followed by gamma irradiation of regenerated shoots (3-5 cm). Activity of four antioxidant enzymes i.e. superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase increased significantly as compared to the control and reached to highest level at the most stringent doses of mutagen. Ninety randomly selected irradiated plants (6 months old) and 100 control plants were inoculated with fungal conidial suspension, to screen for tolerance/resistance against powdery mildew. The severity of the disease was recorded on 0-4 scale with '0' indicating highly resistant; '1' indicating resistant; '2' indicating medium resistance; '3' indicating susceptible and '4' indicating highly susceptible. Three plants (3.33%) irradiated with 5 Gy were found to be tolerant to powdery mildew as these plants showed slight and delayed development of fungal colonies on the leaves. The random amplified polymorphic DNA characterization showed that the irradiated plants had DNA patterns that were different from the control and mother plants.

Genetic and phytochemical diversity analysis in Bunium persicum populations of north-western Himalaya.

The present study explores morphological, genetic and phytochemical composition of Bunium persicum populations belonging to high altitudinal areas of Indian Himalayan region. In total, 23 morphological traits (13 quantitative and 10 qualitative traits) and 32 Random Amplified Polymorphic DNA primers were employed to infer the population structure of the species. Of the fourteen populations, five genetically diverse populations were analyzed for phytochemical diversity. Among morphological traits, inflorescence, seed and branch traits were most significant in detecting variation. At molecular level, primers TIBMBA-06 and OPR-16 were found most polymorphic with respect to Polymorphism Information Content and Marker Index values. Dendrogram grouped all populations into two major clusters while population from Shong region out grouped separately showing its distantness from all other populations. STRUCTURE analysis was done by using Bayesian model, which characterised all populations into four clusters and some degree of admixture was also observed within individuals. Shong population showed distinct genetic makeup as also suggested by dendrogram. Phytochemical analysis showed the presence of 55 components, of which, 2-methyl-3-phenyl propanal, benzeneacetic acid, 1-phellandrene, γ-terpene, α-terpinolene, Δ0.3-carene and sabinene were major components in its essential oils. The present study revealed high genetic and phytochemical diversity in B. persicum accessions from north-western Himalayan regions. Specifically, accessions from Saptal regions were having higher quantity of essential oils and can be selected for cultivation to meet the commercial demand to some extent. Further, the diversity information provided herein can be useful in management and improvement of this species through future breeding programmes.

Next-Generation Sequencing (NGS) Identified Species-Specific SSR and SNP Markers, Allow the Unequivocal Identification of Strawberry Tree (Arbutus unedo L.) Germplasm Accessions and Contribute to Assess Their Genetic Relationships.

The strawberry tree (Arbutus unedo L.), an evergreen bush to small tree of the Ericaceae family, is a main component of the natural flora of the Mediterranean basin that also grows profusely through the Iberian Peninsula, southwestern France, and Ireland. The small edible red fruits are usually used to produce preserves, jams, and liquors, as the Portuguese "aguardente de medronho". The leaves and fruits have been used for a long time in traditional medicine, and their bioactive compounds are presently the subject of intense research. A strawberry tree germplasm collection was recently established by the company Corte Velada (Odiáxere, Portugal). A set of 50 germplasm accessions was selected for a breeding program. A next-generation sequencing project was performed, resulting in the establishment of the first strawberry tree genome assembly and further identification of 500 SSR and 500 SNP loci. Individual molecular fingerprints for the unequivocal identification of the selected 50 accessions were established based on 71 markers alleles amplified by 4 SSR and 9 SNP markers. The same species-specific markers alleles combined with 61 random amplified markers amplified by 5 RAPD and 5 ISSR primers were used to assess the genetic variability and genetic relationships among the selected accessions.

Genetic variation of wild and hatchery populations of the catla Indian major carp (Catla catla Hamilton 1822: Cypriniformes, Cyprinidae) revealed by RAPD markers.

Genetic variation is a key component for improving a stock through selective breeding programs. Randomly amplified polymorphic DNA (RAPD) markers were used to assess genetic variation in three wild population of the catla carp (Catla catla Hamilton 1822) in the Halda, Jamuna and Padma rivers and one hatchery population in Bangladesh. Five decamer random primers were used to amplify RAPD markers from 30 fish from each population. Thirty of the 55 scorable bands were polymorphic, indicating some degree of genetic variation in all the populations. The proportion of polymorphic loci and gene diversity values reflected a relatively higher level of genetic variation in the Halda population. Sixteen of the 30 polymorphic loci showed a significant (p < 0.05, p < 0.01, p < 0.001) departure from homogeneity and the F(ST) values in the different populations indicated some degree of genetic differentiation in the population pairs. Estimated genetic distances between populations were directly correlated with geographical distances. The unweighted pair group method with averages (UPGMA) dendrogram showed two clusters, the Halda population forming one cluster and the other populations the second cluster. Genetic variation of C. catla is a useful trait for developing a good management strategy for maintaining genetic quality of the species.

Molecular diversity in the genus Nicotiana as revealed by randomly amplified polymorphic DNA.

The genus Nicotiana consists of 64 recognized species of which, only two species, tabacum and rustica are cultivated extensively. Wild Nicotiana species are storehouses of genes for several diseases and pests, besides genes for several important phytochemicals and quality traits, which are not present in cultivated varieties. Randomly amplified polymorphic DNA (RAPD) analysis was used to determine the degree of genetic variation in the genus Nicotiana and to develop species specific markers. Twenty two species and two interspecific hybrids were analyzed by using 18 random decamer primers. Genetic polymorphism abounds among the wild species of genus Nicotiana (99.5 %) as evidenced by the high degree of polymorphism in RAPD profiles. The pairwise similarity measures in the species of subgenus Rustica was 0.252 whereas in the subgenus Tabacum was 0.189, suggesting that there was significant diversity among the species of these subgenera. In the species of subgenus Petunioides, the range of pairwise similarity measures was 0.128 to 0.941. The clustering pattern coincided with the traditional classification of Nicotiana species. All the primers generated specific bands in the various species. Thirty six species-specific markers identified in the present study will be useful in interspecific breeding programs.

Genetic variation in wild and hatchery populations of giant freshwater prawn (Macrobrachium rosenbergii) revealed by randomly amplified polymorphic DNA markers.

Sustainable improvement and conservation of any genetic resource depend on the assessment of its intra- and inter-population genetic variation. In order to estimate genetic variation in both wild and hatchery populations of Macrobrachium rosenbergii, randomly amplified polymorphic DNA (RAPD) analysis was performed. Analyses of 51 polymorphic loci amplified from genomic DNA by three decamer random primers revealed different degrees of genetic variation in two wild (Bhairab and Rupsha rivers) and hatchery-derived gher (Gher-1 and Gher-2) populations. The proportion of polymorphic loci was found to be higher in wild populations (0.90 and 0.65 for the Bhairab and Rupsha populations, respectively) than the hatchery-derived gher populations (0.29 and 0.16 for Gher-1 and Gher-2, respectively). Likewise, the river populations contained higher levels of gene diversity (0.221 and 0.179 for Bhairab and Rupsha populations, respectively) than the gher populations (0.114 and 0.045 for Gher-1 and Gher-2, respectively). These results suggest reduction of genetic variation and heterozygosity in the hatchery-derived gher populations. Inter-population similarity indices and pairwise genetic distance values showed that variation between the wild or between the gher populations were lower than those between the wild and hatchery populations. On average, 14 loci exhibited significant deviation from homogeneity in wild vs hatchery population pairs, whereas 2 and 3 loci showed heterogeneity in Gher-1 vs Gher-2 and Bhairab vs Rupsha population pairs, respectively. A genetic distance-based UPGMA dendrogram segregated river populations from the gher populations. Our study, therefore, revealed substantial levels of genetic variation between wild and hatchery populations of M. rosenbergii.

Genetic Analysis of Aedes aegypti Using Random Amplified Polymorphic DNA (RAPD) Markers from Dengue Outbreaks in Pakistan.

BACKGROUND: Keeping in view the havoc situation of dengue fever in Pakistan, the current study was designed to demonstrate the genetic variations, gene flow and rate of migration from Lahore and Faisalabad. METHODS: The larvae were collected from both natural and artificial breeding places from each collection site. The adult mosquitoes were collected by means of sweep net and battery-operated aspirator. DNA extraction was performed using TNE buffer method. Ten GeneLink-A series RAPD primers were used for PCR amplification and the data was analyzed through POPGENE. RESULTS: The number of amplification products produced per primer varied from 8-12, ranging from 200 to 2000 bp with an average of 10.0 bands per primer. The percentage of polymorphic loci amplified by each primer varied from 22.5 to 51%. The UPGMA dendrogram demonstrates two distinct groups from Faisalabad and Lahore populations. The genetic diversity ranged from 0.260 in Faisalabad to 0.294 in Lahore with a total heterozygosity of 0.379. The GST value for nine populations within Lahore was 0.131 (Nm= 3.317), whereas for nine populations in Faisalabad GST value was 0.117 (Nm= 3.773). The overall genetic variation among eighteen populations showed GST= 0.341 and Nm= 1.966. CONCLUSION: The genetic relatedness and Nm value show that Ae. aegypti populations exhibit intra-population gene flow both in Faisalabad and Lahore. Although, both cities show a distinct pattern of genetic structure; however, few areas from both the cities show genetic similarity. The gene flow and the genetic relatedness in few populations of Lahore and Faisalabad cities need further investigation.

Inbreeding, outbreeding and RAPD markers studies of faba bean (Vicia faba L.) crop.

Five faba bean genotypes (Vicia faba L.) were selfed for two cycles to produce S1 and S2 generations. A half-diallel cross was carried out among them in each level of inbreeding (S0, S1 and S2) to obtain 10 F1 hybrids. Parental materials as well as their respective F1s were evaluated during the winter season of 2012. All studied traits except total dry seed yield showed significant inbreeding depression after the first generation of selfing (S1). No further decrease was noticed at the S2 generation. In the S1 generation the degree of inbreeding depression was highest for No. of branches/plant (-14.0%) and the least for weight of 100-seeds (-2.7). Some parents showed inbreeding vigor i.e. positive difference between S2 and S1 for some traits in S2 generation. Most studied traits showed significant positive heterosis values over mid-parent. The highest value of heterosis over the mid-parent was detected for total dry seed yield (128.8) and the lowest value of hybrid vigor was shown by weight of 100-seeds (1.2%). Specific combination among the 5 parental genotypes showed the highest value for heterosis for example cross Misr 2 × Giza 429 was the best cross for total dry seed yield, cross Giza 429 × Misr 1 for No. of branches/plant. Giza 429 is the best general combiner for most traits. Some crosses showed heterosis depression i.e. negative heterosis value in some traits. Hybridization among parental genotypes is recommended to be at the S1 or S2 generation. Twelve arbitrary primers produced different degrees of genetic polymorphism among the parental genotypes. A total of 65 amplification products were scored polymorphic. The percentage of polymorphic bands detected ranged from 33% to 100% with an average of 66.47%. The average of amplified bands was 5.42 polymorphic bands per primer. A positive, but non-significant, correlation (r = 0.085) between Euclidean distance and RAPD distance was observed.

Genetic Diversity of Pyrenophera tritici-repentis Isolates, the Causal Agent of Wheat Tan Spot Disease from Northern Iran.

BACKGROUND: The tan spot disease of wheat caused by Pyrenophera tritici-repentis has become a major disease in most wheat growing areas worldwide. OBJECTIVES: Here we used ISSR and RAPD markers to study the genetic diversity of 34 P. tritici-repentis isolates collected from North of Iran. MATERIALS AND METHODS: The leaves having the typical symptoms of tan spot disease were collected and after fungal isolation, purification and identification, DNAs were extracted. After PCR amplification using each primer, PCR products were run in agarose gels, and the resulting bands were scored. Cluster analysis was performed using Un-Wighted Nighbor Joining method. RESULTS: A total of 178 reproducible bands were scored. Out of which 115 (65%) were polymorphic corresponding to an average of 8 polymorphic bands per primer. The average PIC values for ISSR and RAPD markers were 0.38 and 0.43, respectively. A high degree of genetic variability among Iranian P. tritici-repentis isolates was identified. Cluster analysis based on un-weighted neighbor-joining method using the combined molecular data revealed five distinct clusters. The results from the cluster analysis indicated that the genetic similarity among the Iranian P. tritici-repentis isolates could be partly explained by geographic origins where the isolates were collected. CONCLUSIONS: Genetic variability of P. tritici-repentis along with relatively high level of geographic diversity observed in this study may suggest longer evolutionary period for the isolates from the Middle East, wheat center of origin, as opposed to other places.

Genetic differentiation over a spatial environmental gradient in wild Rubus ideaus populations.

• The distribution is examined of molecular (random amplified polymorphic DNA) markers within and between 12 wild raspberry (Rubus ideaus) populations ranging over 600 m altitude and 40 km distance from a lowland area of extensive raspberry cultivation to remote upland sites. • Most individuals are distinct, suggesting that seedling recruitment is the main means of propagation, but mean genetic similarities within sites (> 80%) are much greater than between sites (> 50%), suggesting a hindrance to gene movement between sites. • Sites of genetically distinct populations can be grouped in lowland, valley and upland clusters; genetic similarity between sites decreased at slightly > 4% per 100 m difference in altitude from c. 80% between adjacent sites to 50% at 600 m altitude difference. • Together with physiological data collected previously, the molecular evidence confirms that wild populations are more diverse than cultivars and suggests little gene flow from cultivated to wild, a result perhaps of reproductive asynchrony and little opportunity for seedling recruitment in established populations. The cause of the genetic differentiation between sites is not known and requires further study.

Molecular identification of sex in Simarouba glauca by RAPD markers for crop improvement strategies.

Due to lack of morphological methods to identify sex at early stage in the plants with long juvenile period the application of molecular markers is expected to facilitate breeding program. The objective of this study is to identify molecular markers linked to sex determination of the plant Simarouba glauca which assists in crop improvement program. Random amplified polymorphic DNA primers were tested on dioeceious and hermaphrodite plant Simarouba glauca. A set of eighty five RAPD primers were screened out of which only five primers were found to be associated with sex. The primer OPU-10 is male specific and OPD-19 primer is female specific. Another primer OPU-19 produced a unique amplification in only hermaphrodite individuals. Female and hermaphrodite specific primer OPS-05 amplified an amplicon in female and hermaphrodite and was absent in male plant. Primer OPW-03 produced amplicon specific to male and hermaphrodite plants and was absent in female plants.

Morpho-molecular analysis as a prognostic model for repulsive feedback of the medicinal plant "Andrographis paniculata" to allogamy.

Andrographis paniculata Nees. (AP) is a self-pollinated medicinal herb with a wide range of pharmaceutical properties, facing a low diversity in Malaysia. Cross-pollination of AP accessions leads to considerable rates of heterosis in the agro-morphological characteristics and anticancer phytochemicals of this eminent medicinal herb. However, the poor crossability of the plant at the interpopulation or intraspecific levels is an obstacle from the evolutionary and breeding points of view as an average of 4.56% crossability was recorded for AP in this study. Hence, this research aimed to elicit the impact of parental genetic distances (GDs) on the rate of crossability of AP using seven accessions in 21 possible cross combinations. To this end, a set of 55 randomly amplified polymorphic DNA (RAPD) primers and a total of 13 agro-morphological markers were employed to test the hypothesis. Twenty-two out of the 55 RAPD primers amplified a total of 257 bands of which 107 bands were found to be polymorphic. The principal component analysis (PCA) based on the RAPD markers revealed that the studied AP accessions were distributed to three distinct groups. Furthermore, it was noticed that even a minor increase in GD between two parents can cause a decline in their crossability. Unlike, the morphological-based GDs acted neutrally to crossability. This finding suggests that, despite the low genetic diversity among the Malaysian APs, a population prescreening using RAPD markers would be useful to enhance the rate of fruit set through selecting the genetically adjacent parents.

Micropropagation of Ficus religiosa L. via leaf explants and comparative evaluation of acetylcholinesterase inhibitory activity in the micropropagated and conventionally grown plants.

A high-frequency, season-independent, in vitro regeneration of Ficusreligiosa was developed, followed by comparative acetylcholinesterase inhibitory (AChEI) activity assay of the in vitro raised and conventionally grown plants. The use of AChEI activity is the most accepted strategy for the treatment of Alzheimer disease. Fully expanded, mature leaves were cut into different segments to initiate the cultures. The middle section of the leaf in vertical orientation with cut portion inserted inside the medium was found most suitable for direct shoot regeneration. Leaf explants responded with nearly consistent frequency (60-66.67 %) throughout the year. To obtain high frequency response with enhanced shoot multiplication rate, 32 plant growth regulator regimes were screened amongst which benzylaminopurine at 5.0 mg/l was found most suitable, yielding 100 % response and maximum number of shoots per explant (7.93); same concentration was also most supportive for repeated multiplication (6.53 shoots). The quality of the shoots and multiplication rate could be significantly enhanced (24.35 shoots) when adenine sulphate, glutamine and phloroglucinol, in an optimised concentration, were additionally supplemented. The clonal nature of the micropropagated plants was confirmed by random amplified polymorphic DNA analysis. A comparative analysis of AChEI activity was carried out amongst the methanolic extracts of stem segments of the mother plant, randomly selected seedlings of different age (4 and 6 months old) of the same mother plant and randomly selected micropropagated plants of different age (3 and 6 months age). The mother plant sample showed effective AChEI activity, with IC50 of 66.46 µg/ml while seedlings, of different age groups, performed poorly (6-month-old seedlings, Se-16M, yielded IC50 of 20,538.46 µg/ml, while two randomly selected 4 months' aged seedlings, Se-24M and Se-34M exhibited IC50 of 19,341.03 and 24,281.70 µg/ml). On the other hand, various micropropagated plants, 2 of 3 months (MiP-13M, MiP-23M) and 2 of 6 months (MiP-36M and MiP-46M) age behaved like the mother plant, exhibiting IC50 values of 71.87, 72.91, 67.65 and 69.65 µg/ml, respectively.

Genetic diversity analysis of rice cultivars (Oryza sativa L. ) differing in salinity tolerance based on RAPD and SSR markers

Thirty rice cultivars were evaluated for salinity tolerance during the seedling stage and were divided into five tolerance groups including tolerant (T), moderately tolerant (MT), moderately susceptible (MS), susceptible (S) and highly susceptible (HS) which comprised 5, 10, 9, 4 and 2 cultivars respectively. Genetic diversity of all rice cultivars was evaluated using random amplified polymorphic DNA (RAPD) and simple sequence repeats (SSR) markers. The cultivars were evaluated for polymorphisms after amplification with 20 random decamer primers and 20 SSR primer pairs. A total of 161 RAPD markers and 190 SSR alleles were produced which revealed 68.94 percent and 89.47 percent polymorphism respectively. Mean genetic similarity coefficient was 0.82 for RAPD and 0.70 for SSR. Cluster analysis based on RAPD markers was effective in grouping cultivars based on their salt tolerance ability. Group IA1, IB and IV contained three T, three S and two HS rice cultivars respectively. The MT and MS cultivars which showed similar physiological responses to salinity were resolved into two groups: Group IA2 and Group II comprising ten and eight MT/MS cultivars respectively. Cluster analysis based on SSR markers separated rice cultivars into groups based on genetic relatedness which did not correspond to salinity tolerance level. The results from this study provided some useful implications for salt tolerance breeding programs. The evaluation of genetic similarity and cluster analysis together with salt tolerance ability provides some useful guides for assisting plant breeders in selecting suitable genetically diverse parents for the crossing program.

Genetic variation of wild and hatchery populations of the catla Indian major carp (Catla catla Hamilton 1822: Cypriniformes, Cyprinidae) revealed by RAPD markers

Genetic variation is a key component for improving a stock through selective breeding programs. Randomly amplified polymorphic DNA (RAPD) markers were used to assess genetic variation in three wild population of the catla carp (Catla catla Hamilton 1822) in the Halda, Jamuna and Padma rivers and one hatchery population in Bangladesh. Five decamer random primers were used to amplify RAPD markers from 30 fish from each population. Thirty of the 55 scorable bands were polymorphic, indicating some degree of genetic variation in all the populations. The proportion of polymorphic loci and gene diversity values reflected a relatively higher level of genetic variation in the Halda population. Sixteen of the 30 polymorphic loci showed a significant (p < 0.05, p < 0.01, p < 0.001) departure from homogeneity and the F ST values in the different populations indicated some degree of genetic differentiation in the population pairs. Estimated genetic distances between populations were directly correlated with geographical distances. The unweighted pair group method with averages (UPGMA) dendrogram showed two clusters, the Halda population forming one cluster and the other populations the second cluster. Genetic variation of C. catla is a useful trait for developing a good management strategy for maintaining genetic quality of the species.

Description and analysis of genetic diversity among squash accessions

In this work, the part of the squash core collection, maintained in the Greek Gene Bank, was assessed using the morphological and molecular data. Sixteen incompletely classified accessions of the squash were characterized along with an evaluation of their resistance against two isolates of Fusarium oxysporum. A molecular analysis using Random Amplified Polymorphic DNA (RAPD) markers was also performed, revealing high level of polymorphism. To study the genetic diversity among the squash accessions, a clustering procedure using Unweighed Pair Group Method and Arithmetic Average (UPGMA) algorithm was also adopted. Two independent dendrograms, one for the morphophysiological and one for molecular data were obtained, classifying the accessions into two and three main clusters, respectively. Despite the different number of the clusters there were many similarities between these two dendrograms, and a third dendrogram resulting from their combination was also produced, based on Gower's distance and UPGMA clustering algorithm. In order to determine the optimal number of clusters, the upper tail approach was applied. The more reliable clustering of the accessions was accomplished using RAPD markers as well as the combination of the two different data sets, classifying the accessions into three significantly different groups. These groups corresponded to the three different cultivated species of C. maxima Duch., C. moschata Duch., and C. pepo L. The same results were also obtained using Principal Component Analysis.

A abobrinha de inverno compõe um cultivo agrícola com valor econômico determinado exercendo, no entanto, um papel importante em zonas caracterizadas por um cultivo menos intensivo. Na Grécia, o cultivo da abobrinha se baseia, principalmente, em variedades locais conservadas a muitos anos por agricultores locais. Uma parte do cultivo nuclear da abobrinha, que é conservada pelo Banco Grego de Genes, foi melhorada utilizando-se dados morfológicos e moleculares, especialmente dezesseis cultivos de abobrinha classificados incompletamente, que foram diferenciados apenas com base em características morfológicas, em relação a uma avaliação à resistência contra o Fusarium Oxysporum, em dois isolamentos. Foi realizada uma análise molecular utilizando DNA Polimórficos Casual Amplificados índices (RAPDs), revelando um alto nível de polimorfismo. Para estudar a diversidade genética entre a coleção de abobrinhas, um procedimento de agrupamento foi realizado usando-se o algoritmo U.P.G.M.A. Dois dendrogramas independentes, um morfofisiológico e outro para dados moleculares, foram coletados, classificando as coleções em dois e três grupos básicos, respectivamente. Apesar do número diferente dos grupos, foram introduzidas muitas semelhanças entre os dois dendrogramas e um terceiro dendrograma foi produzido como resultado da combinação dos dois primeiros, baseado na distância de Gower e no algoritmo de agrupamento U.P.G.M.A. Para determinar o número ótimo dos grupos, a aproximação "upper tail" foi aplicada. O grupo mais aceitável das coleções foi conseguido usando-se índices RAPD, assim como a combinação dos dois grupos de dados diferentes, classificando as coleções em três grupos consideravelmente diferentes. Os grupos que correspondem às três espécies cultivadas diferentemente, que correspondem às três espécies cultivadas diferentemente por C.máxima Duch., C.moschata Duch. e C. pepo L. além disso, os mesmos resultados foram conseguidos usando-se a "Principal...

Population structure of Eupemphix nattereri (Amphibia, Anura, Leiuperidae) from Central Brazil

This study reports on 156 specimens of the amphibian Eupemphix nattereri, a widely distributed leiuperid, obtained from 11 municipalities of central Brazil. The extent of genetic variation was quantified by determining the mean number of alleles per locus and the proportion of polymorphic loci. An analysis of molecular variance (AMOVA) was performed on the random amplified polymorphic DNA (RAPD) haplotypes. The genetic distances obtained by calculating pairwise phist among local samples were used to determine population relationships using the unweighted pair-group method (UPGMA) and non-metric multidimensional scaling (NMDS). The cophenetic correlation was calculated to confirm agreement between the genetic matrix and the unweighted pair group method with averages (UPGMA) dendrogram. To determine if genetic distances were correlated to geographical distances we constructed pairwise genetic distance and geographical distance matrices and compared them using the Mantel test. The AMOVA results indicated significant genetic differences (p < 0.001) between E. nattereri populations, representing 69.5 percent of the within population genetic diversity. The Mantel test showed no significant correlation (r = 0.03; p = 0.45) between the genetic and geographical distance matrices. Our findings indicate that the genetic variation of E. nattereri populations was randomly distributed in geographic space and that gene flow for this species is probably structured at spatial scales smaller than those between our samples.