Analysis of intrinsic and extrinsic factors in the reproductive success of Myrcianthes coquimbensis, a threatened species of the Atacama desert, Chile.
Seed production in plants depends on the joint action of intrinsic and extrinsic factors. Knowledge of these factors may, eventually, be key to understanding the causes of species extinction. A failure in seed production can be caused by an insufficient pollination service; although, an intrinsic fa...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Chile |
| OAI Identifier: | oai:repositorio.anid.cl:10533/249811 |
| Acceso en línea: | https://hdl.handle.net/10533/249811 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Naturales Ciencias de la Tierra y del Medio Ambiente Botánica |
| Sumario: | Seed production in plants depends on the joint action of intrinsic and extrinsic factors. Knowledge of these factors may, eventually, be key to understanding the causes of species extinction. A failure in seed production can be caused by an insufficient pollination service; although, an intrinsic factor such as the mixed reproductive system, can ensure seed production in conditions when pollination service fails. This reproductive assurance, however, may disappear if seeds produce by selfing presents inbreeding depression, which can be enhanced by an insufficient allocation of resources by mother plants. In this thesis, different reproductive processes were analyzed in Myrcianthes coquimbensis, by examining the role of its reproductive system, the pollination environment, and the availability of resources. First, although seed production occurs mainly by outcrossing, it can also occur by selfing and agamospermia; however, autonomous selfing interferes with outcrossing in the flowers. Second, seed production was pollen limited in two populations; the degree of pollen limitation was negatively and positively associated with different components of the pollination environment. Third, the seeds produced presented inbreeding depression and its magnitude was greater in mother plants subject to greater water availability. Inbreeding depression negatively affected seedling performance, but indirectly through the initial seed size. Seed production in M. coquimbensis may be compromised pollen limitation and selfing cannot ensure it, due to interference (intra-flower) and inbreeding depression. The latter could be even more harmful in situations with high water availability, such as in years of extreme precipitation. Future studies should focus on the maintenance and conservation of environmental conditions that do not promote the incidence and magnitude of selfing in plants. |
|---|