Genetic variability in Jatropha curcas L. from diallel crossing.

Physic nut (Jatropha curcas L.) presents high oilseed yield and low production cost. However, technical-scientific knowledge on this crop is still limited. This study aimed to evaluate and estimate the genetic variability of hybrids obtained from dialell crossing. Genetic variability was carried out using ISSR molecular markers. For genetic variability, nine primers were used, and six were selected with 80.7% polymorphism. Genetic similarity was obtained using the NTSYS pc. 2.1 software, and cluster analysis was obtained by the UPGMA method. Mean genetic similarity was 58.4% among hybrids; the most divergent pair was H1 and H10 and the most similar pair was H9 and H10. ISSR PCR markers provided a quick and highly informative system for DNA fingerprinting, and also allowed establishing genetic relationships of Jatropha hybrids.

Restoration over time and sustainability of Schinus terebinthifolius Raddi.

The success of recovery programs on degraded areas is dependent on the genetic material to be used, which should present heterozygosity and genetic diversity in native and recovered populations. This study was carried out to evaluate the model efficiency to enable the recovery of a degraded area of the Lower São Francisco, Sergipe, Brazil. The target species for this study was Schinus terebinthifolius Raddi. Three populations were analyzed, the recovered area, seed-tree source population, and native tree population border established to the recovered area. The random amplified polymorphic DNA (RAPD) markers were used for diversity analysis. Genetic structure was estimated to evaluate the level of genetic variability existent in each population. There was no correlation between the spatial distribution and the genetic distances for all trees of the recovered area. The heterozygosity present in the recovered population was higher than the native tree population. The seed-tree source population presents genetic bottlenecks. Three clusters were suggested (ΔK = 3) with non-genetic structure. High intra-population genetic variability and inter-population differentiation are present. However, gene flow may also introduce potentially adaptive alleles in the populations of the recovered area, and the native population is necessary to ensure the sustainability and maintenance of the populations by allelic exchange.

Structure and genetic diversity of natural Brazilian pepper populations (Schinus terebinthifolius Raddi).

In the face of a possible loss of genetic diversity in plants due the environmental changes, actions to ensure the genetic variability are an urgent necessity. The extraction of Brazilian pepper fruits is a cause of concern because it results in the lack of seeds in soil, hindering its distribution in space and time. It is important to address this concern and explore the species, used by riparian communities and agro-factories without considering the need for keeping the seeds for natural seed banks and for species sustainability. The objective of this study was to evaluate the structure and the genetic diversity in natural Brazilian pepper populations (Schinus terebinthifolius Raddi). Twenty-two alleles in 223 individuals were identified from eight forest remnants located in the states of Minas Gerais, Espírito Santo, and Sergipe. All populations presented loci in Hardy-Weinberg equilibrium deviation. Four populations presented six combinations of loci in linkage disequilibrium. Six exclusive alleles were detected in four populations. Analysis of molecular variance showed the absence of diversity between regions and that between the populations (GST) was 41%. Genetic diversity was structured in seven clusters (ΔK7). Brazilian pepper populations were not structured in a pattern of isolation by distance and present genetic bottleneck. The populations São Mateus, Canastra, Barbacena, and Ilha das Flores were identified as management units and may support conservation projects, ecological restoration and in implementation of management plans for Brazilian pepper in the State of Sergipe.

A comparative framework of the Erythrina velutina tree species in reforested land and native populations.

Erythrina velutina Willd. (Fabaceae: Papillionoideae) is a pioneer species found in tropical and subtropical regions of the world that has medicinal properties and that is used in reforestation projects. This species is rare in some areas of northeastern Brazil. This study aimed to characterize and compare genetic structures of natural and restored populations of E. velutina, with a focus on the selection of tree seeds. A total of 108 individuals from five natural populations and one restored population were analyzed using ISSR markers, resulting in 407 polymorphic fragments. A high rate of polymorphism was observed in the restored population. The highest genetic variability was identified within populations (82%). Genetic bottleneck tests were significant for the Carmópolis/Rosário do Catete and Laranjeiras natural populations along with the Laranjeiras restored population. Genetic distances significantly correlated with spatial distance. Only the restored population retained unique alleles. Similarly, increased genetic distance was observed in individuals of the restored populations compared to the other populations. Observed genetic variation in both natural and restored populations of E. velutina was moderate, thus enabling selection of divergent trees from those trees supplying seeds. Environmental protection and management of these areas is necessary for the maintenance of these individuals and subsequent reproduction. We recommend suggestions for E. velutina conservation, since the restoration model adopted in this study did not promote the development of the specimens until the reproductive stage in a fashion that aims to augment the soil seed bank supply, as is suggested for pioneer species.

Analysis of genetic diversity of Laeliinae (Orchidaceae) in the State of Sergipe using ISSR markers.

The Orchidaceae represent one of the largest and most diverse families on the planet. However, this family is constantly threatened by predators and by the advancement of urban centers over its natural habitats. The objective of this study was to use inter-simple sequence repeat markers to evaluate the genetic diversity between orchid accessions of the Laeliinae subtribe, which comprise part of the Orchidaceae study collection at the Department of Agronomic Engineering of the Federal University of Sergipe. DNA was extracted from each specimen by using an adapted 2% cetyltrimethyl ammonium bromide protocol. Similarity between individuals was calculated using the Jaccard method. Clustering was carried out by the unweighted pair group method with arithmetic mean method, with resampling and 10,000 bootstraps. Eighty-seven fragments were obtained, all of which were polymorphic, revealing high variability between accessions. The mean similarity was 35.77% between Encyclia sp individuals, and 35.90% between specimens of Cattleya tigrina. For Epidendrum secundum, a relationship between geographic and genetic distances was observed, and the accession collected in the southern part of the State of Sergipe (Serra de Itabaiana National Park) was more divergent than that of the other parts of the state. The data generated in this study will guide further research aimed at the ex situ conservation of these materials.

Molecular characterization of patchouli (Pogostemon spp) germplasm.

Patchouli [Pogostemon cablin (Blanco) Benth.] is an aromatic, herbaceous plant belonging to the Lamiaceae family native to Southeast Asia. Its leaves produce an essential oil regularly used by the perfume and cosmetics industries. However, since patchouli from the Philippines and India were described and named Pogostemon patchouli, there has been a divergence in the identity of these species. The objective of the current study was to study the genetic diversity of patchouli accessions in the Active Germplasm Bank of Universidade Federal de Sergipe using microsatellite and inter simple sequence repeat markers. The results of both types of molecular markers showed that there are two well-defined clusters of accessions that harbor exclusive alleles. It was observed that these two clusters are genetically distant, suggesting that they belong to two different species. Based on the results, two accessions were classified as Pogostemon heyneanus and the remaining accessions were classified as P. cablin.

Populations of Erythrina velutina Willd. at risk of extinction.

The goal of this study was to characterize the structure of two natural populations of the coral tree using RAPD and ISSR markers. The study evaluated all individuals in two different areas in the northeastern region of Brazil: the first was in the riparian area, 10 km x 100 m along the edge of the lower São Francisco River, and the second was in the municipality of Pinhão, in a semiarid region between the municipalities of Neópolis and Santana do São Francisco. We used all the coral trees present in those two areas (37 individuals). The results of the RAPD and ISSR markers were highly congruent, supporting the reliability of the techniques used. Similarity was estimated using the Jaccard arithmetic complement index. A dendrogram was constructed using the unweighted pair group method with arithmetic mean cluster algorithm, and the robustness of the data was bootstrapped with 5000 replicates. A principal coordinate analysis was performed on the basis of Jaccard coefficients. The total genetic variation observed was 21%, corresponding to the variation between the populations, and 79% of the variation was observed within the populations.

Cross-species transferability of microsatellite markers in the genus Lippia.

The cross-species transferability of 20 microsatellite markers was tested in the genus Lippia. Eleven markers were polymorphic after screening 19 accessions of Lippia sidoides and Lippia gracilis maintained in the Active Germplasm Bank (AGB) from Universidade Federal de Sergipe. Additionally, 40 accessions of Lippia spp were collected in Sergipe to increase the germplasm bank. A total of 23, 22, and 36 alleles were identified, with an average of 2.3, 2.2, and 3.27 alleles per locus, respectively, for each group. The markers that were used were efficient tools to access genetic diversity in the germplasm bank and will be useful for further research aiming at the conservation and management of these important aromatic species.

Molecular characterization of bromeliads from northeast Brazil.

Bromeliaceae is an important botany family that includes many species with economic value; demand for members of this family is increasing. However, illegal collection frequently occurs, drastically reducing the species populations; thus, it is necessary to collect and store Bromeliaceae genetic material. In this study, we identified and quantified genetic variability of the Bromeliad family using dominant markers to create the first Germplasm Bank in the northeast region of Brazil. Molecular tools were used to characterize the collected accessions. The combination of 11 inter-simple sequence repeats and 13 random amplified polymorphic DNA markers were used to detect the genetic variability of wild bromeliad accessions.

Insights into Leptocybe invasa resistance in Eucalyptus: phenotyping, genotyping and in silico approaches.

The gall wasp, Leptocybe invasa, poses a significant global threat to Eucalyptus cultivation, by causing substantial economic losses. The objective of this study was to differentiate between resistant and susceptible genotypes by morphological characteristics using image analysis based on the damage caused by the gall wasp. In addition, consensus sequences derived from transposable elements (TEs) and the genome of Eucalyptus spp. Were identified by in silico analysis. Furthermore, another objective was to discriminate Eucalyptus genotypes in response to Leptocybe invasa by conducting molecular analyses involving transposable elements and inter simple sequence markers. For image analysis, the GroundEye ® system was used to collect images of 60 leaves from six genotypes, three of which were resistant and three susceptible. Eucalyptus spp. sequences were obtained from the GenBank database by in silico analysis and pairwise alignments with TE sequences were conducted using BLASTN. Multiple sequence alignment was performed with Clustal Omega, followed by the identification of conserved regions in Jalview. A motif signature was generated using Weblogo. For molecular characterization using ISSR markers and TEs, samples of young leaves were obtained from a total of 80 Eucalyptus seedlings, of which 50 were classified as resistant and 30 as susceptible to L. invasa. It was possible to distinguish gall wasp susceptible and resistant genotypes by image analysis. In silico analysis enabled the identification of conserved regions in the Eucalyptus spp. genome, which were associated with proteins involved in secondary metabolite production, e.g., terpenes, which play a role in the response to L. invasa. The discrimination capacity of TEs and ISSR primers was demonstrated and bands were generated that could be used to identify resistant genotypes. However, increasing the number of markers required to discriminate genotypes in both cases is suggested.

Morphological, agronomical and pharmacological characterization of Hyptis pectinata (L.) Poit germplasm

Several species of the genus Hyptis have presented medicinal characteristics and are frequently indicated to treat gastro intestinal infections, gramps and pain, as well as for skin infections. Three harvests were carried out using six H. pectinata accessions, and the following characteristics were evaluated: plant height, canopy diameter, leave length (L) and width (W), L/W relation and dry weight of leaves and stem. The accession SAM006 have presented highest leave dry matter yield when the three harvests were summed. The aqueous leaf extracts of the same six H. pectinata accessions were tested for anti-edematogenic effect using the carrageenin-induced rat paw edema at doses of 200, 400 and 600 mg/kg. The extracts administered orally had a significant anti-edematogenic effect. The dose of 200 mg/kg of accessions SAM004 and SAM005 had a stronger effect reducing the edema by 19.6 percent and 15.4 percent, respectively. Similar results were obtained using higher dosages of the aqueous extract of the accessions SAM002, SAM003 and SAM006. It can be concluded that the accessions SAM004, SAM005 and SAM006 are promising genotypes for a plant breeding program that aims the development of a cultivar with highest leave yielding and anti-edematogenic effect.