GST Values Research Articles

Nephroprotective effects of silymarin and its fabricated nanoparticles against aluminum-induced oxidative stress, hyperlipidemia, and genotoxicity.

Aluminum (Al) is a ubiquitous element with proven nephrotoxicity. Silymarin (SM) is a mixture of polyphenolic components extracted from Silybum marianum and exhibited protective influences. However, SM bioactivity can be enhanced by its incorporation in chitosan (CS) through the use of nanotechnology. This work proposed to assess the protective influence of SM and its loaded chitosan nanoparticles (SM-CS-NPs) on aluminum chloride (AlCl3)-induced nephrotoxicity. Six groups were created randomly from 42 male Wistar rats and each one contains 7 rats (n = 7). Group I, acted as a control and received water. Group II received SM (15 mg/kg/day) and group III administered with SM-CS-NPs (15 mg/kg/day). Group IV received AlCl3 (34 mg/kg) and groups V and VI were treated with SM and SM-CS-NPs with AlCl3 respectively for 30 days. AlCl3 administration significantly elevated TBARS, H2O2, and kidney function levels besides LDH activity. Whereas GSH, CAT, SOD, GPx, GST, and GR values were all substantially reduced along with protein content, and ALP activity. Additionally, significant alterations in lipid profile, hematological parameters, and renal architecture were observed. Moreover, TNF-α, TGF-β, and MMP9 gene expression were upregulated in kidney tissues. The administration of SM or its nanoparticles followed by AlCl3 intoxication attenuated renal dysfunction replenished the antioxidant system, and downregulated TNF-α, TGF-β, and MMP9 gene expression in renal tissues compared to the AlCl3 group. SM-CS-NPs have more pronounced appreciated protective effects than SM and have the proficiency to balance oxidant/antioxidant systems in addition to their anti-inflammatory effect against AlCl3 toxicity.

Analysis of genetic relationships between broomrape populations from different countries using ISSR markers

Orobanche cumana, commonly known as sunflower broomrape, poses a significant risk to sunflower cultivation in areas located along the Black Sea and across Europe. A study was conducted to analyze the genetic diversity and differentiation among populations of this parasitic plant originating from Bulgaria, Turkey, Republic of Moldova, and Romania. A total of 269 individuals from 23 populations were genotyped using 13 ISSR markers. The frequency distribution of alleles in the broomrape populations from Romania, Turkey and Bulgaria is more homogeneous than that from Moldavian populations. However, according to genetic diversity parameters O. cumana populations from Moldova and Turkey were more variable (total gene diversity Ht=0.188; 0.214), than those from Bulgaria and Romania (Ht=0.112; 0.067). The highest values of gene diversity within populations (Hs = 0.138) were found in Turkish broomrape. The value of Gst ranged between 0.359-0.516, indicating a very high level of genetic differentiation among populations. These results are consistent with low Nm values (0.468-0.895). Pairwise differentiation index (PhiPT) and Nei’s unbiased measures of genetic distance (GD) showed similar patterns, indicating a maximum (PhiPT=0.500; GD=0.261) and, respectively, minimum (PhiPT=0.238; GD=0.079) values between broomrape from Turkey and Romania, respectively, Romania and Moldova. Dendrogram constructed using the UPMGA method based on Nei's genetic distances and Pearson's dissimilarity clustered together Moldavian and Romanian broomrape and grouped in two separate clusters populations belonging to Bulgaria and Turkey. The PCA analysis confirmed the results of UPGMA clusterization. Overall, both methods suggest that the groupings of broomrape are partly determined by its geographical origin, as well as by the genetic differences and similarities accumulated over time, and are not related to virulence.

Recurrent selection effects on the genetic structure of maize landrace assessed by SSR markers

Recurrent selection method was applied in one maize landrace (Zea mays L.) population, Macaco, for one cycle of selection. In the present study the changes in genetic structure were investigated at 18 microsatellite loci. A total of 81 alleles were observed in cycle 0 (C0) population which 79 were maintained in cycle 1 (C1) population. Thus, a reduction of 2.5% in the allele frequency was observed after one cycle of selection in C1 population. The heterozygozity reduction was also observed after one cycle of selection. In nearly 44% and 55% of the loci evaluated in C0 and C1 populations, respectivelly, the changes in allelic frequencies in populations were not due exclusively by genetic drift effects. Although few changes have been observed in allelic frequencies, the grain yield increase was observed after one cycle of recurrent selection. The genetic differentiation estimated by GST and RST values, for microsatellite data between C0 and C1 populations indicate that genetic variability degree was maintained in C1 population. This result suggest that C1 population can be used in a new recurrent selection cycles.

Biomarkers of oxidative stress and inflammation in subjects with COVID-19: Characterization and prognosis of the disease

Coronavirus disease (COVID-19) is an acute respiratory disease caused by the new coronavirus (SARS-CoV-2) that has spread throughout the world causing millions of deaths. COVID-19 promotes excessive release of pro-inflammatory cytokines leading to acute lung injury and death. Reactive oxygen species (ROS) and oxidative stress (OS) may also play a role in the pathophysiology of COVID-19. The present study investigated levels of inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10, IL-12) and OS biomarkers (MPO, SOD, CAT, GST enzymes and contents of GSH, TBARS and PC) in patients with SARS-CoV-2 infection, which were correlated with disease severity. Patients with SARS significantly increased IL-1β levels, while IL-6 levels were elevated in both groups of SARS-CoV-2 positive patients. The most severe patients showed increased levels of IL-8 and IL-10, while subjects without SARS showed lower values. MPO activity were higher in both groups of SARS-CoV-2 positive patients, while SOD and CAT activity were decreased in both groups. Compared to controls, GGT was elevated only in the SARS patient group, while GST values were increased in the group of positive patients in SARS-CoV-2 without SARS and were decreased in patients with SARS. GSH and UA contents decreased in SARS-CoV-2 positive subjects, whereas TBARS and PC contents increased in both groups of SARS-CoV-2 positive patients, particularly in the SARS patient group. In addition, several important correlations were found between cytokines and the different OS parameters suggesting some inter-relationship in the complex antioxidant system of the patients. In general, patients with SARS-CoV-2 infection showed higher levels of OS biomarkers, and also elevated contents of IL-6 and IL-10, probably worsening the damage caused by SARS-CoV-2 infection. This damage may contribute to the severity of the disease and its complications, as well as a prognosis for SARS-CoV-2 patients.

Haplotype and phylogenetic diversity using mitochondrial 12S rRNA gene marker in Bali cattle

Bali cattle is one of Indonesia's original livestock genetic resources. The 12S rRNA can be used as a marker of genetic diversity, and until now, there has been no report on Bali cattle. The study was aimed to analyze the gene of mtDNA 12S rRNA to determine haplotype diversity and phylogenetics in Bali cattle populations of the eastern region of Indonesia. A total of 95 blood samples used consisted of three different populations which were Bali cattle, Ongole crossbred (PO) and Madura cattle as a comparison. This research was analyzed using PCR and sequencing methods. The data were analyzed using the cluster W method for estimating genetic distances, calculating diversity, and reconstructing phylogenetic trees using the MEGAX, DNAsP and Network. The genetic distance values ranged from 0.00200 to 0.01508, and the Haplotype diversity values ranged from 0.66000 to 0.91111. The nucleo-tide diversity values ranged from 0.00174 to 0.01673. There were 16 haplotypes found. The values of Gst, Nst and Fst were 0.00803, 0.07550, 0.07622; respectively. Based on the analysis, there were dif-ferences between Bali cattle from various populations, there were specific haplotypes. The 12S rRNA gene can be used as a genetic marker for diversity studies in Bali cattle and other cattle breeds although the diversity is low.

Genetic fingerprinting ofZiziphus jujubaby using SCoT and REMAP molecular markers

AbstractJujube is both consumed as a food source and medicinal plant in local markets. It is expected that different geographical populations ofZiziphus jujuba, differ in their genetic content as they grow in different ecological conditions. It is important to have detailed information on population genetic structure and the available genetic variability to make a proper germplasm collection of jujube. We have no data on jujube populations of Iran based on SCoT and REMAP molecular markers, and therefore we planned a population genetic study of these trees in 10 geographical areas. We used SCoT and REMAP molecular markers for our genetic investigation. We found the loci with a high value of Gst (1.00) in SCoT and REMAP markers that can be used in fingerprinting of jujube.

Estimation of genetic diversity and population genetic structure in Gymnema sylvestre (Retz.) R. Br. ex Schult. populations using DAMD and ISSR markers

BackgroundGymnema sylvestre (Retz.) R. Br. ex Schult. is a well-known medicinal plant against diabetes in India. There is as such no organized cultivation in India, and the plant is still being collected from the wild for their therapeutic uses. It is, therefore, important to estimate the genetic diversity and population genetic structure of G. sylvestre to ascertain the genetically diverse germplasm. The present study, therefore, was undertaken to analyze the genetic variability in 118 accessions belonging to 11 wild populations of G. sylvestre using directed amplification of minisatellite-region DNA (DAMD) and inter simple sequence repeats (ISSR). ResultsThe present genetic analyses of 11 populations with 25 markers (8 DAMD and 17 ISSR) revealed significant genetic diversity (H = 0.26, I = 0.40, PPL = 80.89%) at a species level, while the average genetic diversity at the population level was low. Among the 11 populations studied, PCH and UTK populations showed maximum genetic diversity, followed by KNR and AMB, while TEL population revealed the lowest genetic diversity. AMOVA and Gst values (0.18) revealed that most of the genetic variations are found within populations and very less among populations, and higher gene flow (Nm = 2.29) was found to be responsible for the genetic homogenization of the populations. The clustering pattern resulting from the UPGMA dendrogram was in congruence with STRUCTURE and PCoA, segregating all the 11 populations into two main genetic clusters: cluster I (populations of North and Central India) and cluster II (populations of South India). The clustering patterns obtained from all three statistical methods indicate that the genetic structure in G. sylvestre populations corresponds to the geographical diversity of the populations and represents a strong genetic structure. ConclusionThe genetically diverse populations identified during the present study could be a potential genetic resource for further prospecting and conserving this important plant resource.

Genetic diversity assessment of the indigenous goat population of Benin using microsatellite markers.

Improved knowledge of the diversity within and among local animal populations is increasingly necessary for their sustainable management. Accordingly, this study assessed the genetic diversity and structure of the indigenous goat population of Benin. Nine hundred and fifty-four goats were sampled across the three vegetation zones of Benin [i.e., Guineo-Congolese zone (GCZ), Guineo-Sudanian zone (GSZ), and Sudanian zone (SZ)] and genotyped with 12 multiplexed microsatellite markers. The genetic diversity and structure of the indigenous goat population of Benin were examined using the usual genetic indices (number of alleles Na, expected and observed heterozygosities He and Ho, Fixation index FST, coefficient of genetic differentiation GST), and three different methods of structure assessment [Bayesian admixture model in STRUCTURE, self-organizing map (SOM), and discriminant analysis of principal components (DAPC)]. The mean values of Na (11.25), He (0.69), Ho (0.66), FST (0.012), and GST (0.012) estimated in the indigenous Beninese goat population highlighted great genetic diversity. STRUCTURE and SOM results showed the existence of two distinct goat groups (Djallonké and Sahelian) with high crossbreeding effects. Furthermore, DAPC distinguished four clusters within the goat population descending from the two ancestry groups. Clusters 1 and 3 (most individuals from GCZ) respectively showed a mean Djallonké ancestry proportion of 73.79% and 71.18%, whereas cluster 4 (mainly of goats from SZ and some goats of GSZ) showed a mean Sahelian ancestry proportion of 78.65%. Cluster 2, which grouped almost all animals from the three zones, was also of Sahelian ancestry but with a high level of interbreeding, as shown by the mean membership proportion of only 62.73%. It is therefore urgent to develop community management programs and selection schemes for the main goat types to ensure the sustainability of goat production in Benin.

Preliminary study on genetic differences between two species of finless porpoises, genus Neophocaena, with lack of genetic divergence between two subspecies of the narrow-ridged finless porpoise, N. asiaeorientalis: cytochrome b sequence analyses

Using samples from bycaught finless porpoises, cytochrome b sequences were analysed and phylogenetic trees were constructed. The aims were to: (1) determine genetic divergences within the genus Neophocaena; (2) examine interspecific divergences between N. asiaeorientalis and N. phocaenoides; and (3) examine intraspecific divergence between N.a. asiaeorientalis and N.a. sunameri. For this purpose, complete cytochrome b sequences for 12 N.a. sunameri specimens, collected from fishery markets at Pohang in southeastern Korea, were obtained, and these sequences were compared to the corresponding partial (402bp) and complete (1,140bp) sequences of Neophocaena, obtained from GenBank. From a maximum likelihood tree with the partial sequences of the two Neophocaena species, two clades were detected, corresponding to the two species, with average genetic distance of 1.64%, four fixed site differences (1.00%), and a Gst value of 0.64, although we did not examine the specimens from Southeast Asia and contiguous South China Sea. Furthermore, from the complete sequences, we recognised a lack of genetic divergence between the two subspecies of N. asiaeorientalis, with a Gst value of 0.06 and two pairs of identical sequences between them, indicating that our results do not support current subspecies classification. Thus, we newly found that our cytochrome b sequencing results are useful for the examination of interspecific and intraspecific divergences in Neohpocaena, although further genetic analyses with additional specimens of Neophocaena across its distributional range are necessary to confirm the findings in this study.

Polygynandry and high genetic diversity supported by kinship and population genetics from neotropical catfish ichthyoplankton

AbstractKnowledge about reproductive biology is critical for understanding species ecology and evolution, hence their conservation. However, such information remains elusive for many species due to the difficulty of observing mating in nature. Herein, we coupled population and sociogenetic analysis to assess the reproductive biology of an important South American catfish, the “painted catfish” Pimelodus maculatus. We analysed the genetic diversity and kinship patterns of three wild ichthyoplankton samples identified by DNA barcoding and screened with microsatellite loci. We found the same trend in the three samples analysed: a high number unrelated larvae (r < 0.25) and potential parents involved (Ca1, 24♀:24♂; Ca2, 21♀:23♂; Cin, 24♀:25♂), as well as a high number of familial clusters (ML: 19‐21; MCMC: 23‐26). The data indicate a parental sexual proportion close to 1:1 and a polygynandrous mating system. We found high levels of genetic diversity, low GST values (GST < 0.014), but moderate DEST values between the tributary and reservoir samples (DEST > 0.25; Cin x Ca1 or Cin x Ca2), a similar pattern to the observed in adult populations. These results indicate that the mating system of P. maculatus has played an important role in minimising the loss of genetic diversity, a condition that may have favoured the species in a highly fragmented landscape.

Genetic diversity of three major spider mites damaging rubber trees

Three spider mite species, Eotetranychus sexmaculatus, Eutetranychus orientalis and Oligonychus biharensis, are widely distributed in China, infesting rubber trees. They cause various damages in different areas with different landforms, climates and rubber-growing varieties. The difference in habitat of the spider mites may result in genetic differentiation. It supposed be one of the main reasons for their various damage levels in different geographic regions. To examine whether the population genetic differentiation exist between E. sexmaculatus, E. orientalis and O. biharensis, we collected samples of three mite species from ten locations in China and one in Vietnam. Mitochondrial COI sequences of collected samples were analyzed. The results showed that the value of genetic differentiation among populations of the three mites was: E. orientalis > O. biharensis > E. sexmaculatus. There were 16 haplotypes in eight populations of E. orientalis and relatively large genetic distances between haplotypes. E. orientalis had the maximum Fst and Gst values, 0.792 and 0.434, respectively. There was no significant differentiation of E. sexmaculatus among different geographic regions after excluding the Ruili population. Both O. biharensis and E. orientalis were clustered into three large branches in the phylogenetic tree. A single peak appeared in the total population mismatch distribution curve and a star-like haplotype network of E. sexmaculatus suggests a history of population expansion. Three rubber tree spider mites collected in Yunnan had the greatest genetic diversity with the maximum number of haplotypes. In contrast, the genetic diversity of these three spider mites collected in Hainan and Guangdong was relatively small, with few haplotypes. These results implied that genetic differentiation existed in these three spider mites. Specific property and geographic isolation might be the major factor triggering genetic differentiation of E. orientalis, E. sexmaculatus and O. biharensis.

Spatial Scale Patterns of Genetic Diversity and Gene Flow in Populations of Sweet Detar (Detarium microcarpum Guill. & Perr.; Fabaceae)

The main objective of this study is to investigate the patterns of genetic diversity and phylogenetic relationships within populations of Detarium microcarpum (Fabaceae) relative to different spatial conditions. Seventy-eight (78) accessions of D. microcarpum belonging to six populations (Phytogeographic districts) were sampled. In order to have very good quality DNA for molecular analysis, an optimization of the DNA isolation protocol was made. The molecular analysis of the accessions was carried out using 7 chloroplast microsatellite markers. The polymorphism rate (P) is 85.71% and the Polymorphism Information Content (PIC) was in the range of 0.43 (Ntcp_9) to 0.73 (Ccmp_2) with an average of 0.59. Allelic richness (A) ranged from 1.41 to 2.85 with an average of 2.04. The observed heterozygosity (Ho) ranged from 0.23 to 0.60 with an average of 0.39. The expected heterozygosity (He) ranged from 0.43 to 0.60 with a mean of 0.50. Wright's fixation index (FIS) ranged from -0.17 to 0.47. The effective allele (Ae) is between 1.77 and 2.53 with an average of 2.02. Wright differentiation index (FST) was 0.024. Phylogenetic analysis revealed that the NST value was significantly higher than the GST value (NST = 0.452; GST = 0.190; p <0.05). A relatively low hd haplotype diversity is obtained (Hd = 0.320). AMOVA analysis showed that 17.35% of the variation existed within populations but 45.80% among populations within the species. Neighbor-Joining phylogenetic tree of D. microcarpum revealed three non-distinct clusters haplotypes showing the existence of gene flow between populations of the species. Our findings of genetic structure and gene flow of D. microcarpum populations based on different spatial conditions is caused by evolutionary forces such as scattering and pollination.

Biosystematics, fingerprinting and DNA barcoding study of the genus Lallemantia based on SCoT and REMAP markers

Lallemantia is a medicinally important plant in the world. Due to interspecific hybridization and horizontal gene transfer, spices relationship and delimitation on the genus Lallemantia is difficult based on different molecular markers. Therefore, selecting the appropriate marker can be important. Fingerprinting techniques continue to be used for genomic profiling for the characterization of germplasm and the establishment of the identity of varieties/hybrids/parental sources of aromatic and medicinal plants. For this, we need to produce detailed information on genetic diversity available in Lallemantia as well as investigate spices relationship and delimitation. Therefore, the present study was performed on Lallemantia species in Iran. We used the start codon targeted and retrotransposon-microsatellite amplified polymorphism molecular marker for our genetic investigation with the following aims: 1- To reveal the species delimitation and species relationship in Lallemantia, and 2- To investigate discriminating power of the start codon targeted and retrotransposon-microsatellite amplified polymorphism markers by Gst and NM analysis. The results obtained revealed that the start codon targeted marker is the best to show the relationships between species while the retrotransposon-microsatellite amplified polymorphism marker is the best for species delimitation. we found the loci with the high value of Gst (1.00) in start codon targeted and retrotransposon-microsatellite amplified polymorphism markers that can be used in barcoding and fingerprinting of L. royleana.

Genetic (SSRs) versus morphological differentiation of date palm cultivars: Fst versus Pst estimates

Date Palm (Phoenix dactylifera L.) is one of the oldest domesticated fruit trees. For future breeding program, knowledge on genetic structure of cultivars is necessary. Therefore, the present study was performed with the following aims: 1- To provide data on genetic diversity and genetic structure of 36 date palm cultivars, 2- To provide data on the association between fruit characteristics and the genetic features of the cultivars. We used nine SSRs and EST-SSR loci for our genetic investigation. The most of SSR loci obtained have a high Gst value (0.70), and therefore have a good discrimination power for date palm cultivar differentiation task. K-Means clustering grouped date palm cultivars either in two broad clusters, or in 16 smaller genetic groups. This was supported by delta K = 2 of the STRUCTURE analysis. AMOVA produced significant genetic difference among date palm cultivars (PhiPT = 0.70, P = 0.001). New genetic differentiation parameters estimated also produced significant difference among date palm cultivars (G’st (Nei) = 0.673, P = 0.001; G’st (Hed) = 0.738, P = 0.001). Test of assignment revealed that some of the cultivars have 33-66% misassignment, probably due to genetic admixture. Heatmaps of genetic versus morphological and agronomical characters in date palm cultivars differed from each other showing the cultivars morphological changes is not merely related to their genetic content. It points toward the potential role played either by environmental conditions or local selection practice. The new findings can be utilized in future conservation and breeding of date palms in the country.

High genetic diversity within and low differentiation among Juniperusexcelsa M. Bieb. populations: Molecular markers reveal their genetic structure patterns

J. excelsa M. Bieb forms about 82% of the total juniper forests in Turkey. A total of 456 plant samples belonging to 19 J. excelsa populations were collected to determine the genetic variation of J. excelsa and compare their genetic diversity among populations via simple-sequence repeat (SSR) and intron targeted amplified polymorphism (ITAP) markers. Seven SSR and 132 ITAP loci were polymorphic. The percentage of polymorphism for ITAP loci at the population level ranged from 31.34 to 55.97. Average values of expected heterozygosity, observed heterozygosity, Shannon's information index, Fis, Fst and Nm for SSR loci were 0.616, 0.512, 1.54, 0.124, 0.043, and 5.513, respectively. Genetic diversity values of ITAP loci were lower than those of SSR loci. Gst and Nm values for ITAP loci were 0.225 and 1.728, respectively. Pair-wise genetic distances varied between 0.023 and 0.292 for SSR loci, 0.010 and 0.110 for ITAP loci. The majority of the genetic variations originated from intra-population level (98% for SSRs, 80% for ITAPs). Mantel test results showed that there was no statistically significant correlation between pair-wise geographical and genetic distances. It was indicated that the populations had similiar structure pattern. It was seen that J. excelsa populations maintained their high genetic diversity. Additionally, genetic differentiations among the populations were low. No indication of genetic adverse effect related to habitat fragmentation was determined in the populations. In conclusion, it can be said that this situation is an advantage in terms of implementing conservation strategies for this species. The authorities in the Turkish Ministry of Forestry should plan some conservation studies in order to maintain

Genetic Uniformity of the MSXJ papaya hybrid (Carica papaya L.) during Micropropagation

Objective: To analyze the genetic uniformity of MSXJ hybrid papaya in vitro plants, obtained by direct organogenesis.Design/Methodology/Approach: The MSXJ papaya hybrid demonstrates quality characteristics for the national and exports market. In vitro culture of plant tissues represents a useful tool for their multiplication and conservation, but somaclonal variation can diminish their genetic and agronomic uniformity. In order to analyze the genetic uniformity of in vitro plants of this hybrid, ten ISSR primers were used for in vitro plants micropropagated during nine subcultures. DNA was extracted using the CTAB method. Data were analyzed using the program PopGene v 1.3.1.Results: Eighty-five loci of 200 to up to 2000 pb were generated, with 37 polymorphic loci. In the cluster analysis, three groups were observed which separate subculture one, subcultures two to eight, and subculture nine; the Gst value of 0.87 indicated genetic uniformity as far as subculture eight.Study Limitations/Implications: Papaya is one of the most important tropical fruits worldwide; however, these plants need to be healthy and genetically uniform to guarantee commercial success. In vitro propagation allows obtaining healthy and uniform plants, but it is necessary to study genetic uniformity during their micropropagation.Findings/Conclusions: The in vitro multiplication of the MSXJ papaya hybrid permitted the regeneration of vigorous plants in 30 d. Molecular profiles indicate that as far as subculture eight, there is genetic uniformity. As such, no more thaneight subcultures are recommended during micropropagation.

Genetic structure, differentiation, and slight evidence for no selective neutrality of some SSR markers in populations of Medicagociliaris (L.) Krock and Medicagointertexta (L.) Mill species

Medicago ciliaris (L.) Krock and Medicago intertexta (L.) Mill are most often found in saline regions and are considered as potential resources for genes related to salinity resistance. To explore the genetic diversity of these two species by mean of nrSSR (simplesequence repeats) markers, 11 accessions originated from different regions in north of Africa and Middle East were chosen. Ten among 14 markers turned out to be polymorphic and gave 72 alleles. Eight markers were very informative with PIC values > 0.5, and three of them were found to be nonneutral. Allelic richness was limited with an average number of alleles per locus of 2.7. All populations have a significant heterozygous deficit evidenced by both observed heterozygosity rates (null for most populations) and multilocus fixation index estimates. A strong differentiation between populations was highlighted by FST (0.805) and GST (0.919) values. Low values of gene flow (0.01-0.38) revealed a very weak gene exchange between populations regardless of the proximity of their sites of origin. The total variability breakdown by analysis of molecular variance (AMOVA test) showed a preponderance of interpopulation component (73%-72%) with respect to intrapopulation one (18%), mainly due to the mating system. Relationship analysis performed by NJ tree representation trends to place M. ciliaris as an ancestor and M. intertexta as a derivative. The two populations from the Sebkha site, characterized by the highest variability and more private alleles, constitute an ideal reservoir of genes for tolerance to salinity. Significant genetic diversity in the two aforementioned species is encouraging for their conservation

Genetic Diversity among Calamus brandisii Becc. (Arecaceae) Populations in Kerala Part of Western Ghats

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.

Genetic diversity and population structure of Croton urucurana Baill. (Euphorbiaceae) in Central Brazil by ISSR markers

Studies on the genetic diversity of species with pharmacological potential are essential for the conservation of genetic resources. The genetic characterization of a species can guide efforts to collect and conserve germplasm and, in the future, genetic improvement. Domestic cultivation of medicinal plants is an important strategy for protecting these species from over harvesting. Genetic studies of medicinal species by molecular markers could allow for assessment and management of these species. Croton urucurana Baill. is widely used in Brazilian traditional medicine, but there are practically no data about its genetic patterns. We used 12 ISSR markers to evaluate the genetic diversity levels of 30 trees distributed in three populations of C. urucurana, two of which were located in Brazilian savanna (Cerrado) and one on semi-deciduous tropical forest areas. From a total of 82 bands recorded, 89% were polymorphic and presented a Shannon’s diversity index of 0.26. The populations formed two distinct groups: Two populations were divided each into a different genetic group, while the Aquidauana population, which is in a transition area between the Cerrado and the Pantanal, presented a mixture of the two genetic groups. Croton urucurana has GST values (0.200) similar to those found in species with a mixed mating system, but the lack of detailed studies on the reproductive system of this species makes it difficult to correctly interpret the origin of the population structure observed. Moreover, even using a simpler marker we were able to identify regions that deserve further studies, especially from a chemical point of view, to see whether there are any differences between the populations that could help in defining future conservation strategies, management and genetic improvement plans of the species.

Genetic analysis of twenty two selected genotypes of Jatropha curcas L. (physic nut) from Africa, Asia and America, using SSR and AFLP markers

Twenty two genotypes of J. curcas L. from Africa (Senegal, Burkina Faso, Mali, Congo and Madagascar Island), Asia (Cambodia, China and India) and America (Ecuador, Dominican Republic and Brazil) selected for their vigor and their productivity were analyzed with ten SSR primer pairs and six AFLP primer combinations. The two marker approaches showed their ability to effectively reveal polymorphism among the selected genotypes: 94.02 and 56% of polymorphism for AFLPs and SSRs respectively. Among the three groups of selected genotypes, the Asian group was the least diverse while the genetic diversities found in African and American groups were slightly comparable. The Nei’s genetic diversity (He) of all twenty-two selected genotypes was 0.2029 based on combined SSR+AFLP data. The Gst value and the AMOVA analysis indicated that more than 80% of the genetic diversity resided within the groups. The analysis of the genetic relationships between the genotypes using the Nei’s standard dissimilarity matrix gave dissimilarity coefficients ranging from 0.14397 to 0.73943 with an average of 0.3540. The most distant genotypes were found between a genotype from Africa (Congo) and one from America (Ecuador). The clustering of genotypes obtained with the neighbor-joining dendrogram and the PCoA analysis revealed the existence of a certain level of diversity that can be used by breeders. Key words: Biodiesel, genetic diversity, jatropha, molecular markers, AFLP, SSR, plant breeding.