Genetic diversity of Lippia sidoides Cham. and L. gracilis Schauer germplasm.

The conservation of plants in germplasm banks ensures the characterization and availability of these resources for future generations. The present study used DNA markers to obtain genetic information about germplasm collections of Lippia sidoides and L. gracilis, which are maintained in an Active Germplasm Bank (AGB). Genetic variability of samples in the AGB was assessed using 12 combinations of amplified fragment length polymorphism (AFLP) primers (EcoRI/MseI). Twenty simple sequence repeat primers designed for L. alba were tested to determine their transferability in L. sidoides and L. gracilis. The AFLP markers generated 789 markers. The assessed loci exhibited a moderate Shannon diversity index (I = 0.42) in both species, suggesting that the conserved accessions possess an intermediate level of genetic diversity. Twelve microsatellite loci amplified satisfactorily, and nine loci were polymorphic in each species. A total of 23, 22, and 36 alleles, with an average of 2.5, 2.4, and 3.27 alleles per locus were identified for L. sidoides and L. gracilis accessions in the AGB, and Lippia sp sampled plants, respectively. Analyses of genetic structure permitted the identification of three different groups using both sets of markers, of which two were representative of L. sidoides. The information generated in this study may help to create, expand, and maintain collections of these species and may assist in genetic-breeding programs.

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.

Development of a novel set of microsatellite markers for Lippia alba (Verbenaceae).

Microsatellite primers were developed and optimized for Lippia alba to characterize the L. alba germplasm bank of Universidade de São Paulo. A genomic library enabled the design of 9 microsatellite primers. Six of the 9 primers yielded polymorphic products, which defined 2 groups in the bank. The data provide support to characterize germplasm banks, genetic breeding programs for L. alba, and other genetic diversity studies and classifications of species in the genus Lippia.

Isolation and characterization of microsatellite loci for Bixa orellana, an important source of natural dyes.

Annatto (Bixa orellana) is a plant native from the American continental tropical zone. The seeds are used to produce a carotenoid-based yellow to orange food coloring. Microsatellite markers were developed for the Brazilian native species Bixa orellana to describe its genetic diversity and structure as well as to support conservation studies. Twenty-five microsatellite loci were isolated and characterized using an enriched genomic library. Ten loci were polymorphic in the 50 accessions sampled in this study, while 15 were considered monomorphic. The mean number of alleles per locus was 3.8, ranging from 2 to 6 alleles per locus. Mean values for the observed and expected heterozygosities were 0.541 (ranging from 0 to 0.658) and 0.639 (ranging from 0.422 to 0.787), respectively. All markers described in this study will be useful in further studies evaluating the genetic diversity, population dynamics, and conservation genetics of Bixa orellana.

Isolation and characterization of microsatellite loci from the tick Amblyomma aureolatum (Acari: Ixodidae).

Amblyomma aureolatum (Pallas) is the main vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever. This disease is the most lethal human spotted fever rickettsiosis in the world. Microsatellite loci were isolated from a dinucleotide-enriched library produced from A. aureolatum sampled in Southeastern Brazil. Eight polymorphic microsatellites were further characterized among 38 individuals sampled from São Paulo metropolitan region. The number of observed alleles ranged from 2 to 9, observed heterozygosity was 0.184-0.647, and expected heterozygosity was 0.251-0.747. Cross-species amplifications suggested that these loci will be useful for other Amblyomma species.

Isolation and characterization of microsatellites for the yam Dioscorea cayenensis (Dioscoreaceae) and cross-amplification in D. rotundata.

Dioscorea cayenensis and Dioscorea rotundata are among the most important yam species for the humid and sub-humid tropics. We isolated nine polymorphic microsatellite markers using a microsatellite-enriched genomic library technique. The nine primer pairs were validated in 22 D. cayenensis accessions, and were tested for transferability in 26 D. rotundata accessions. The number of bands ranged from 2 to 4, with a mean of 3.11. D. cayenensis gave primer polymorphism information content values ranging from 0.37 to 0.62, while for D. rotundata the values ranged from 0.15 to 0.66. The D parameter in D. cayenensis ranged from 0.14 to 0.40, while in D. rotundata it ranged from 0.05 to 0.34. These SSR markers will be useful to characterize genetic diversity in D. cayenensis and D. rotundata accessions.

New loci of Lychnophora ericoides and transferability to Lychnophora pinaster, endangered medicinal species from Brazil.

Lychnophora ericoides and Lychnophora pinaster are species used in popular medicine as analgesic or anti-inflammatory agents to treat contusions, rheumatism, and insect bites. In this study, 21 simple sequence repeat loci of L. ericoides were developed and transferred to L. pinaster. Three populations of L. ericoides and 2 populations of L. pinaster were evaluated; they were collected in the State of Minas Gerais. Population parameters were estimated, and the mean values of observed and expected heterozygosity were 0.297 and 0.408 (L. ericoides) and 0.228 and 0.310 (L. pinaster), respectively. Greater genetic variability was observed within populations than between populations of L. ericoides (62 and 37%) and L. pinaster (97 and 2.8%). These results provide information for genetic conservation and taxonomic studies of these endangered species.

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.

Microsatellite markers for the Cabreúva tree, Myroxylon peruiferum (Fabaceae), an endangered medicinal species from the Brazilian Atlantic Forest.

The Cabreúva tree, Myroxylon peruiferum, is an endangered tropical species from Brazil used in forest restoration projects. It is known for its medicinal properties. Eleven microsatellite markers were developed for this species, from a microsatellite-enriched library. Nine of these markers, characterized in 30 individuals from a semideciduous forest remnant population in southeast Brazil, were polymorphic, with allele numbers ranging from 2 to 8 per locus; expected and observed heterozygosities ranged from 0.103 to 0.757 and 0.107 to 0.704, respectively. One locus (Mpe-C04) showed significant deviation from Hardy-Weinberg equilibrium, probably due to null alleles. Two other loci (Mpe-E09 and Mpe-H07) were monomorphic in this population. These microsatellite loci should be useful for future population genetic studies of this species.

The genetic diversity of Plasmodium malariae and Plasmodium brasilianum from human, simian and mosquito hosts in Brazil.

Plasmodium malariae is a protozoan parasite that causes malaria in humans and is genetically indistinguishable from Plasmodium brasilianum, a parasite infecting New World monkeys in Central and South America. P. malariae has a wide and patchy global distribution in tropical and subtropical regions, being found in South America, Asia, and Africa. However, little is known regarding the genetics of these parasites and the similarity between them could be because until now there are only a very few genomic sequences available from simian Plasmodium species. This study presents the first molecular epidemiological data for P. malariae and P. brasilianum from Brazil obtained from different hosts and uses them to explore the genetic diversity in relation to geographical origin and hosts. By using microsatellite genotyping, we discovered that of the 14 human samples obtained from areas of the Atlantic forest, 5 different multilocus genotypes were recorded, while in a sample from an infected mosquito from the same region a different haplotype was found. We also analyzed the longitudinal change of circulating plasmodial genetic profile in two untreated non-symptomatic patients during a 12-months interval. The circulating genotypes in the two samples from the same patient presented nearly identical multilocus haplotypes (differing by a single locus). The more frequent haplotype persisted for almost 3 years in the human population. The allele Pm09-299 described previously as a genetic marker for South American P. malariae was not found in our samples. Of the 3 non-human primate samples from the Amazon Region, 3 different multilocus genotypes were recorded indicating a greater diversity among isolates of P. brasilianum compared to P. malariae and thus, P. malariae might in fact derive from P. brasilianum as has been proposed in recent studies. Taken together, our data show that based on the microsatellite data there is a relatively restricted polymorphism of P. malariae parasites as opposed to other geographic locations.

Permanent genetic resources added to Molecular Ecology Resources Database 1 August 2010-30 September 2010.

This article documents the addition of 229 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acacia auriculiformis × Acacia mangium hybrid, Alabama argillacea, Anoplopoma fimbria, Aplochiton zebra, Brevicoryne brassicae, Bruguiera gymnorhiza, Bucorvus leadbeateri, Delphacodes detecta, Tumidagena minuta, Dictyostelium giganteum, Echinogammarus berilloni, Epimedium sagittatum, Fraxinus excelsior, Labeo chrysophekadion, Oncorhynchus clarki lewisi, Paratrechina longicornis, Phaeocystis antarctica, Pinus roxburghii and Potamilus capax. These loci were cross-tested on the following species: Acacia peregrinalis, Acacia crassicarpa, Bruguiera cylindrica, Delphacodes detecta, Tumidagena minuta, Dictyostelium macrocephalum, Dictyostelium discoideum, Dictyostelium purpureum, Dictyostelium mucoroides, Dictyostelium rosarium, Polysphondylium pallidum, Epimedium brevicornum, Epimedium koreanum, Epimedium pubescens, Epimedium wushanese and Fraxinus angustifolia.