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Molecular diversity and host specificity in ectomycorrhizal communities in the tropical forest of Yasuní National Park, Ecuador

Mafla Endara, Paola Micaela (2018) BIOM02 20172
Degree Projects in Biology
Popular Abstract
Cooperation in soils can make a huge difference

At a first glance, the coexistence of diverse plants in ecosystems seems to be completely harmonious. However, there is a high competence of these organisms for obtaining resources. In this scenario, most of the plants have decided to make a lifetime deal with fungi in order to ensure their development and survival. This symbiotic association is called mycorrhiza, in which plant roots give carbon to the fungi in exchange of water and nutrients.

There are different types of mycorrhizal fungi. The most abundant are arbuscular mycorrhizal fungi (AMF), which are present in more than 70% of vascular plants. They dominate most of the tropical forests, probably by their great ability to... (More)
Cooperation in soils can make a huge difference

At a first glance, the coexistence of diverse plants in ecosystems seems to be completely harmonious. However, there is a high competence of these organisms for obtaining resources. In this scenario, most of the plants have decided to make a lifetime deal with fungi in order to ensure their development and survival. This symbiotic association is called mycorrhiza, in which plant roots give carbon to the fungi in exchange of water and nutrients.

There are different types of mycorrhizal fungi. The most abundant are arbuscular mycorrhizal fungi (AMF), which are present in more than 70% of vascular plants. They dominate most of the tropical forests, probably by their great ability to acquire phosphorous, a limiting nutrient in these ecosystems. The second most important are ectomycorrhizal fungi (EcMF), which are present in only 2% of vascular plants. They dominate boreal and temperate forest, most likely for their efficiency to acquire nitrogen, a scarce nutrient at those latitudes. Surprisingly, EcMF are also found in the tropics, where their presence is usually rare and only relatively abundant in monodominant forests. The ecological factors involved in this phenomenon are still unknown.

Neotropics are ideal for these studies. Due to their high biodiversity, many potential host plants and EcMF are expected. However, despite the continuous effort to improve the knowledge of these associations, many species remain poorly described. Besides, there is still no certainty if most of the ectomycorrhizal plants are exclusive or also associated to AMF. Considering all these aspects, our aim was to use metabarcoding (DNA pool of different organisms from one single sample) in order to solve some of the main questions.

Plant roots were collected from different trees (Coccoloba, Gnetum, Guapira and Neea) in the lowland neotropical forest in Ecuadorian Amazonian. The DNA was extracted, amplified and sequenced. The pool of DNA received was edited for obtaining clusters of unique sequences. These sequences were assigned with a fungal name based on their similarity with others previously identified in a database. Only records of AMF and EcMF were kept. Statistical analyses included richness, diversity and composition of the mycorrhizal communities.

For the first time, molecular data revealed the coexistence of AMF and EcMF in the individuals of the four host plants. More studies are needed to understand the advantages or disadvantages to the plant for being associated with two types of mycorrhiza. Regarding only EcMF, species-richness and diversity were lower than expected, but more complex than reported some years ago. EcMF communities were very similar with no evidence of host specificity or forest type preference, but more studies are needed to confirm this.

Master’s Degree Project in Biology, 30 credits, 2018
Department of Biology, Lund University

Advisor: Pål Axel Olsson
Biodiversity Unity (Less)
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author
Mafla Endara, Paola Micaela
supervisor
organization
course
BIOM02 20172
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8947888
date added to LUP
2018-06-11 13:07:27
date last changed
2018-06-11 13:07:27
@misc{8947888,
  author       = {Mafla Endara, Paola Micaela},
  language     = {eng},
  note         = {Student Paper},
  title        = {Molecular diversity and host specificity in ectomycorrhizal communities in the tropical forest of Yasuní National Park, Ecuador},
  year         = {2018},
}