Descripción
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Pathogen infection may condition the population dynamics and genetics of their hosts. However, and at odds with animal hosts, there is limited evidence on the role of virus infection in the population dynamics and genetics of wild plants, and the potential impact of viruses is rarely considered in analyses of wild plant diversity or in plant conservation programmes. We have approached these subjects focussing on an endangered plant species, the chiltepin (Capsicum annuum var. aviculare), which is the wild ancestor of domesticated pepper. Chiltepín is indigenous of the dry tropical forests of Mexico, where its populations are threatened by human over-exploitation and habitat degradation. In this system we have analysed the impact of viral infection on the host population dynamics and its relationship with host ecology and host population genetics. To do so, we sampled during three years chiltepin populations over their distribution range in Mexico, both in its wild habitat and in habitats with different degrees of anthropisation. Plants were analyzed for the presence of viruses known to have either a broad host range, or previously reported infecting pepper in México. Demographic analyses showed that virus infection had a negative effect on host fecundity and survival, thus impacting on the population dynamics of chiltepin. Incidence was highest for begomoviruses, and symptomatic plants were most often infected by Pepper golden mosaic (PepHMV) or Pepper huasteco yellow vein (PHYVV) viruses. While chiletpin populations had a strong spatial structure, this was not so for either PepGMV and PHYVV, and their population structure suggested a recent epidemic expansion on the host population. The relationship between virus incidence and habitat degradation was analysed, incidence being highest and more variable over the years in the anthropic habitats as compared to the wild ones. The highest incidence in anthropic habitats was associated with a decreased biological diversity of the habitat and with an increased host density, according to theory, but not with a decreased genetic diversity of the host. Our results show that viral infections may have a role in the population dynamics of a wild plant and may be an additional risk factor for the survival of endangered species. | |
Internacional
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Si |
ISSN o ISBN
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00-0000-000-0 |
Entidad relacionada
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The Samuel Roberts Noble Foundation |
Nacionalidad Entidad
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E.E.U.U. DE AMERICA |
Lugar del congreso
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Aardmore (Oklahoma, EEUU) |