RESUMEN
Panax vietnamensis Ha et Grushv. is a precious medicinal species native to the tropical forests of Vietnam. Due to habitat loss and over-harvesting, this species is endangered in Vietnam. To conserve the species, we investigated genetic variability and population structure using nine microsatellites for 148 individuals from seven populations across the current distribution range of P. vietnamensis in Vietnam. We determined a moderate genetic diversity within populations (HO = 0.367, HE = 0.437) and relatively low population differentiation (the Weir and Cockerham index of 0.172 and the Hedrick index of 0.254) and showed significant differentiation (P < 0.05), which suggested fragmented habitats, over-utilization and over-harvesting of P. vietnamensis. Different clustering methods revealed that individuals were grouped into two major clusters, which were associated with gene flow across the geographical range of P. vietnamensis. This study also detected that ginseng populations can have undergone a recent bottleneck. We recommend measures in future P. vietnamensis conservation and breeding programs.
Panax vietnamensis Ha et Grushv. é uma espécie medicinal preciosa nativa das florestas tropicais do Vietnã. Por causa da perda de hábitat e da colheita excessiva, essa espécie está ameaçada de extinção no Vietnã. Para conservá-la, investigamos a variabilidade genética e a estrutura populacional usando nove microssatélites para 148 indivíduos de sete populações em toda a distribuição atual de P. vietnamensis no Vietnã. Determinamos uma diversidade genética moderada dentro das populações (HO = 0,367 e HE = 0,437) e diferenciação populacional relativamente baixa (índice de Weir e Cockerham de 0,172 e índice de Hedrick de 0,254), com diferenciação significativa (P < 0,05), o que sugeriu fragmentação de hábitats, sobreutilização e sobre-exploração de P. vietnamensis. Diferentes métodos de agrupamento revelaram que os indivíduos foram agrupados em dois agrupamentos principais, que foram associados ao fluxo gênico em toda a área geográfica de P. vietnamensis. Este estudo também detectou que as populações de ginseng podem ter sofrido um gargalo recente. Recomendamos medidas em futuros programas de conservação e melhoramento de P. vietnamensis.
Asunto(s)
Plantas Modificadas Genéticamente , Panax , VietnamRESUMEN
Panax vietnamensis Ha et Grushv. is a precious medicinal species native to the tropical forests of Vietnam. Due to habitat loss and over-harvesting, this species is endangered in Vietnam. To conserve the species, we investigated genetic variability and population structure using nine microsatellites for 148 individuals from seven populations across the current distribution range of P. vietnamensis in Vietnam. We determined a moderate genetic diversity within populations (HO = 0.367, HE = 0.437) and relatively low population differentiation (the Weir and Cockerham index of 0.172 and the Hedrick index of 0.254) and showed significant differentiation (P < 0.05), which suggested fragmented habitats, over-utilization and over-harvesting of P. vietnamensis. Different clustering methods revealed that individuals were grouped into two major clusters, which were associated with gene flow across the geographical range of P. vietnamensis. This study also detected that ginseng populations can have undergone a recent bottleneck. We recommend measures in future P. vietnamensis conservation and breeding programs.
Asunto(s)
Panax , Humanos , Panax/genética , Panax/química , Vietnam , Fitomejoramiento , Repeticiones de Microsatélite/genética , Pueblo Asiatico , Variación Genética/genéticaRESUMEN
Understanding the fundamental mechanisms involved in the induction of biological damage by ionizing radiation remains a major challenge of today's radiobiology research. The Monte Carlo simulation of physical, physicochemical and chemical processes involved may provide a powerful tool for the simulation of early damage induction. The Geant4-DNA extension of the general purpose Monte Carlo Geant4 simulation toolkit aims to provide the scientific community with an open source access platform for the mechanistic simulation of such early damage. This paper presents the most recent review of the Geant4-DNA extension, as available to Geant4 users since June 2015 (release 10.2 Beta). In particular, the review includes the description of new physical models for the description of electron elastic and inelastic interactions in liquid water, as well as new examples dedicated to the simulation of physicochemical and chemical stages of water radiolysis. Several implementations of geometrical models of biological targets are presented as well, and the list of Geant4-DNA examples is described.