Mating System and Effective Population Size of the Overexploited Neotropical Tree (Myroxylon peruiferum L.f.) and Their Impact on Seedling Production.

The reproductive system of a tree species has substantial impact on genetic diversity and structure within and among natural populations. Such information, should be considered when planning tree planting for forest restoration. Here, we describe the mating system and genetic diversity of an overexploited Neotropical tree, Myroxylon peruiferum L.f. (Fabaceae) sampled from a forest remnant (10 seed trees and 200 seeds) and assess whether the effective population size of nursery-grown seedlings (148 seedlings) is sufficient to prevent inbreeding depression in reintroduced populations. Genetic analyses were performed based on 8 microsatellite loci. M. peruiferum presented a mixed mating system with evidence of biparental inbreeding (t^m-t/ = 0.118). We found low levels of genetic diversity for M. peruiferum species (allelic richness: 1.40 to 4.82; expected heterozygosity: 0.29 to 0.52). Based on Ne(v) within progeny, we suggest a sample size of 47 seed trees to achieve an effective population size of 100. The effective population sizes for the nursery-grown seedlings were much smaller Ne = 27.54-34.86) than that recommended for short term Ne ≥ 100) population conservation. Therefore, to obtain a reasonable genetic representation of native tree species and prevent problems associated with inbreeding depression, seedling production for restoration purposes may require a much larger sampling effort than is currently used, a problem that is further complicated by species with a mixed mating system. This study emphasizes the need to integrate species reproductive biology into seedling production programs and connect conservation genetics with ecological restoration.

Characterization of Genetic Variability and Population Structure of the Tick Amblyomma aureolatum (Acari: Ixodidae).

The hard tick Amblyomma aureolatum (Pallas) is a vector of the bacterium Rickettsia rickettsii, the etiologic agent of Brazilian spotted fever (BSF) in parts of Brazil. Despite its wide distribution in southeastern South America and its public health importance, there is no information about genetic variation of this species that might help to understand the epidemiology of BSF. Using data from eight microsatellite markers and ticks from six localities, we used a population genetics approach to test the hypothesis that tick populations from areas with the presence of R. rickettsii are genetically different from ticks from areas without R. rickettsii Contrary to expectations, we found low genetic structure between studied regions. Thus, the presence of R. rickettsii in the specific area is more likely correlated with ecological and the environmental conditions or due to unknown gene coding regions of A. aureolatum genome that would be related to R. rickettsii infection resistance.

Development and characterization of microsatellite markers for Piptadenia gonoacantha (Fabaceae).

UNLABELLED: • PREMISE OF THE STUDY: Microsatellite primers were designed for Piptadenia gonoacantha (Fabaceae) and characterized to estimate genetic diversity parameters. The species is a native tree from the Atlantic Forest biome commonly used in forest restoration; it has medicinal potential and the wood is economically useful. • METHODS AND RESULTS: Twenty-eight microsatellite loci were identified from an enriched genomic library. Fifteen loci resulted in successful amplifications and were characterized in a natural population of 94 individuals. Twelve loci were polymorphic, with allele numbers ranging from three to 15 per locus, and expected and observed heterozygosities ranging from 0.2142 to 0.8325 and 0.190 to 0.769, respectively. • CONCLUSIONS: The developed markers will be used in further studies of population genetics of P. gonoacantha, aimed at conservation and management of the species in natural populations and in forest restoration projects.

Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2011-30 November 2011.

This article documents the addition of 139 microsatellite marker loci and 90 pairs of single-nucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross-tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele-specific primers for Engraulis encrasicolus.