Mating system in Myracrodruon urundeuva (Anarcadiaceae): implications for conservation genetics

Abstract

-Mating system in Myracrodruon urundeuva (Anarcadiaceae): implications for conservation genetics. The aims of this study were to investigate the mating system of a fragmented population of the dioecious tropical tree Myracrodruon urundeuva Allemão, using five microsatellite loci and the mixed mating and correlated mating models. The study was conducted in the Estação Ecológica de Paulo de Farias (436 ha), where the population occupies about 142 ha. The mating system was estimated using 514 open-pollinated offspring, collected from 30 seed-trees. Estimates of the multilocus outcrossing rate confirm that the species is dioecious (t m = 1.0). Low levels of mating among relatives were detected in the population (1 -t s = 0.020). The estimate of paternity correlation (r p(m) ) indicated that offsprings were composed of mixtures of half-sibs and full-sibs, with the latter occurring at a low frequency (average of 0.148). The estimated coancestry coefficient within families (Θ = 0.147) was larger and the effective population size (N e(v) ) was lower (N e(v) = 2.98) than expected in progenies from panmictic populations (Θ = 0.125, N e(v) = 4, respectively). In terms of conservation, the results indicate that to retain an effective population size of 150, is necessary to collect seeds from at least 50 seed-trees.Key words -correlated matings, fragmentation, microsatellite, variance effective population size RESUMO -Sistema de reprodução em Myracrodruon urundeuva (Anarcadiaceae): implicações para a conservação genética. O objetivo deste estudo foi investigar o sistema de reprodução de uma população fragmentada da espécie arbórea dióica, Myracrodruon urundeuva Allemão, utilizando cinco locos microssatélites e os modelos mistos de reprodução e de cruzamentos correlacionados. O estudo foi conduzido na Estação Ecológica de Paulo de Faria (436 ha), onde a população ocupa uma área aproximada de 142 ha. Foram amostradas 514 progênies de polinização aberta coletadas de 30 árvores matrizes da população. A estimativa da taxa de cruzamento multilocus confirma que a espécie é dióica (t m = 1,0). Baixos níveis de cruzamentos entre parentes foram detectados na população (1 -t s = 0,020). A estimativa da correlação de paternidade (r p(m) ) indicou que as progênies são compostas por misturas de meios-irmãos e irmãos-completos, embora este último ocorra em menor proporção (média de 0,148). O coeficiente de coancestria dentro das progênies (Θ = 0,147) foi maior e o tamanho efetivo de variância (N e(v) = 2,98) foi menor do que o esperado em progênies de populações panmíticas (Θ = 0,125, N e(v) = 4, respectivamente). Em termos de conservação genética, os resultados indicam que para se obterem lotes de sementes com tamanho efetivo de referência de 150, é necessário coletar sementes de pelo menos 50 árvores matrizes.Palavras-chave -cruzamentos correlacionados, fragmentação, microssatélites, tamanho efetivo populacional 1.Parte da tese de doutorado da primeira autora,

Fungal endophyte diversity in the leaves of the medicinal plant Myracrodruon urundeuva in a Brazilian dry tropical forest and their capacity to produce L-asparaginase

“…The medicinal plant M. urundeuva has an important ecological role in the caatinga and brejo de altitude ecosystems, where this species contribute with native pollinators (Gaino et al 2011); however, the diversity of endophytic fungi from this species has not been studied in these two ecosystems, to the best of our knowledge, this study is the first report of endophytes and their biotechnological potential to produce L-asparaginase. Although some surveys (e.g.…”

Development of microsatellite markers for Myracrodruon urundeuva (F.F. & M.F. Allemão), a highly endangered species from tropical forest based on next-generation sequencing

“…& M.F. Allemão), or "aroeira" (Anarcadiaceae), is a dioecious species [2,3] with high wood quality and medicinal properties [4], but threatened of extinction [5] due to strong forest fragmentation of their biomes of occurrence. Native of South America, it occurs in Brazil, Bolivia, Paraguay and Argentina [6].…”

“…The use of molecular markers in population genetic studies of tree species has been shown to be effective. In M. urundeuva, previous studies were performed using isoenzyme markers [7,8], RAPD and cpDNA [9,10], AFLP [11,12] and more recently by microsatellite markers [1,3,[13][14][15]. In these last studies, nine microsatellite loci developed by Caetano et al [13] were used in the analysis of populations of M. urundeuva only from Paraguay and Argentina.…”

Genetic diversity of potential mother trees of Myracrodruon urundeuva by ISSR markers

“…Through these results, it is possible to plan that seed collection be performed in the most genetically distant mother trees, resulting in seeds with greater genetic variability, since the more divergent the parents, the greater the diversity of their progenies (Manfio et al 2012). In addition to this information, it is also necessary to distinguish individuals by sex for seed collection, taking into account the species M. urundeuva is predominantly dioecious (Gaino et al 2011). Collecting seeds taking into account the genetic diversity of species is essential to avoid future problems such as associated anomalies (anatomical deformities), dwarfism, physiological disorders, albinism or even mortality due to low weather resistance or pest attacks and other pathological agents, besides ensuring the preservation of the different alleles present in the species.…”