Lychnophora pinaster in endangered campos rupestres: phenolic compounds and population ecogeography.

Lychnophora pinaster, known as arnica-mineira, is endemic to campos rupestres, at risk of extinction. The present study aimed to characterize the ecogeography and phenolic constituents of 11 L. pinaster populations collected in the mesoregions North, Jequitinhonha, Metropolitan of Belo Horizonte and Campos das Vertentes in the state of Minas Gerais, Brazil. Phenolic constituents were identified and quantified by Ultra-high performance liquid chromatography- mass spectrometry. Lychnophora pinaster occurs in sites at high altitude (700 and 1498 m), annual rainfall of up to 1455 m, soils with low fertility and predominantly loamy texture. Therefore, it can be considered tolerant to acidic soils, with low availability of nutrient. The most abundant substances in all populations were vitexin (18 - 1345 ng/g) and chlorogenic acid (60 - 767 ng/g). The 11 populations formed four groups in relation to the phenolic constituents, with group 1 consisting of the populations of the North Mesoregion (GM, OD) and Jetiquinhonha (DIMa), group 2, the Metropolitan of Belo Horizonte (SRM, NLSC, SM, RPS, CTRA), group 3, the North Mesoregion (ODMa and DI), and group 4, the Campos das Vertentes (CC). Among the populations, only those from the Metropolitan of Belo Horizonte showed correlation of soil properties with phenolic constituents.

Evidence of altitudinal gradient modifying genomic and chemical diversity in populations of Lychnophora pinaster Mart.

Lychnophora pinaster Mart. (Asteraceae) is endemic to the Brazilian Cerrado. It is distributed along the altitudinal gradient of the mountainous ranges of the state of Minas Gerais. This study aimed to evaluate the influence of altitude on the genetic diversity of L. pinaster populations and the effects of altitude and climatic factors on essential oil chemical composition. Essential oils from L. pinaster populations from the north (North 01, North 02, and North 03, 700-859 m) and the Metropolitan region of Belo Horizonte (MhBH 01 and MrBH 02, 1366-1498 m) were analyzed. SNP markers from L. pinaster in these regions and Campos das Vertentes (CV 01, CV 02, and CV 03, 1055-1292 m) were also analyzed. The main compounds in essential oils were 14-hydroxy-α-humulene (North 01 and North 03), cedr-8(15)-en-9-α-ol (North 02), 14-acetoxy-α-humulene (MrBH 01), and 4-oxo-15-nor-eudesman-11-ene (MrBH 02). Hierarchical cluster and heatmap analyses showed that the North and MrBH populations included five different groups, indicating the chemical composition of essential oils is distinct in each population. Furthermore, principal component analysis showed that higher altitudes (1366 m and 1498 m) in the MrBH influence the chemical composition of essential oils, and climatic factors determine the chemical composition in North region. The genetic diversity showed that most alleles are in Hardy-Weinberg equilibrium and imply high genetic variation and genetic polymorphisms between populations. Furthermore, the results of Mantel tests (R = 0.3861517; p = 0.04709529; R = 0.9423121; p = 0.02739726) also showed that higher altitude (>1360 m) shapes the genetic diversity at the MrBH. The genetic structure showed that higher altitudes (>1360 m) contribute to the structure of the MrBH populations, but not to North and CV populations. Therefore, the altitudinal ranges of Minas Gerais mountainous ranges determine the higher genetic and chemical diversity of L. pinaster populations.

Cytogenetics and characterization of microsatellite loci for a South American pioneer tree species, Croton floribundus.

Despite the recent advances in plant population genetic studies, the lack of information regarding pedigree, ploidy level, or mode of inheritance for many polyploids can compromise the analysis of the molecular data produced. The aim of this study was to examine both microsatellite and cytogenetic characteristics of the pioneer tree Croton floribundus Spreng. (Euphorbiaceae) to test for the occurrence of polyploidy in the species and to evaluate its implications for the appropriate use of SSR markers. Seven microsatellite markers were developed and screened for 62 individuals from a semi-deciduous tropical forest in Brazil. Chromosome number, meiotic behavior, and pollen viability were evaluated from male flower buds. All SSR loci were highly polymorphic. The number of bivalents observed in meiosis n = 56 (2n = 8× = 112) and the maximum number of alleles per individual (Ni = 8) demonstrated the occurrence of polyploidy in C. floribundus. The normal meiotic pairing and the high pollen viability suggested that C. floribundus is a regular and stable polyploid, most likely an allopolyploid. The combined SSR and cytogenetic data provided new evidence on the origin and evolution of the species as well as assured the accurate use of SSR loci for population genetic studies of the polyploid pioneer species.

Development and characterization of microsatellite markers for the medicinal plant Smilax brasiliensis (Smilacaceae) and related species.

PREMISE OF THE STUDY: A new set of microsatellite or simple sequence repeat (SSR) markers were developed for Smilax brasiliensis, which is popularly known as sarsaparilla and used in folk medicine as a tonic, antirheumatic, and antisyphilitic. Smilax brasiliensis is sold in Brazilian pharmacies, and its origin and effectiveness are not subject to quality control. • METHODS AND RESULTS: Using a protocol for genomic library enrichment, primer pairs were developed for 26 microsatellite loci and validated in 17 accessions of S. brasiliensis. Thirteen loci were polymorphic and four were monomorphic. The primers successfully amplified alleles in the congeners S. campestris, S. cissoides, S. fluminensis, S. goyazana, S. polyantha, S. quinquenervia, S. rufescens, S. subsessiliflora, and S. syphilitica. • CONCLUSIONS: The new SSR markers described herein are informative tools for genetic diversity and gene flow studies in S. brasiliensis and several congeners.

New microsatellite markers for garlic, Allium sativum (Alliaceae).

PREMISE OF THE STUDY: A new set of microsatellite or simple sequence repeat (SSR) markers for garlic, an important medicinal spice, was developed to aid studies of genetic diversity and to define efficient strategies for germplasm conservation. METHODS AND RESULTS: Using a (CT)(8)- and (GT)(8)-enriched library, a total of 16 SSR loci were developed and optimized in garlic. Ten loci were found to be polymorphic after screening 75 accessions. The parameters used to characterize the loci were observed and expected heterozygosity, number of alleles, Shannon Index, and polymorphism information content (PIC). A total of 44 alleles were identified, with an average of 4.4 alleles per loci. The vast majority of loci were moderate to highly informative according to PIC and the Shannon Index. CONCLUSION: The new SSR markers have the potential to be informative tools for genetic diversity, allele mining, mapping and associative studies, and in the management and conservation of garlic collections.

Development and characterization of microsatellite markers for Hebanthe eriantha (Amaranthaceae).

PREMISE OF THE STUDY: Hebanthe eriantha (Amaranthaceae) is extensively collected and used in folk medicine. Microsatellite markers were developed and characterized to investigate the genetic structure and diversity of germplasm collections of this species. METHODS AND RESULTS: Eleven highly polymorphic microsatellite markers were developed. The number of alleles observed for each locus ranged from two to eight. The observed and expected heterozygosities ranged from 0.000 to 0.808 and 0.455 to 0.851, respectively. CONCLUSIONS: These results show the utility of microsatellite loci for studies of population genetics in H. eriantha, which are important for the future conservation and cultivation of this medicinal species.

A set of microsatellite markers for Arrabidaea chica (Bignoniaceae), a medicinal liana from the Neotropics.

PREMISE OF THE STUDY: Microsatellite markers were developed, optimized, and characterized for Arrabidaea chica (Humb. & Bonpl.) Verl. (Bignoniaceae), a Neotropical liana extensively used in folk medicine. The aim of this study was to develop molecular tools to investigate the genetic structure and diversity of natural populations and germplasm collections of this species. • METHODS AND RESULTS: Eight highly polymorphic microsatellite markers revealed a multibanded pattern, suggesting that the species is polyploid. The total number of bands per locus ranged from 9 to 17, revealing high levels of polymorphism. • CONCLUSIONS: The high level of polymorphism detected with these markers indicates their utility in devising conservation strategies and rational exploitation of A. chica.