Genetic diversity study of Pinus merkusii Jungh. & de Vriese in the Philippines

• Main Author: Abanador, Louise C.
• Format: text
• Language: English
• Published: Animo Repository 2015
• Subjects: Pinus merkusii; Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/5034
• Institution: De La Salle University

Evaluating the population status, morphological differences and degree of genetic variation of the remaining populations of Pinus merkusii is crucial for planning effective conservation methods. Samples from Guisguis (Sta. Cruz, Zambales), Mt. Tapulao (Palauig, Zambales) and Sablayan (Occidental Mindoro) were assessed using quadrat method, vegetation analysis, needle morphological analysis and microsatellite analysis. Pinus merkusii is suggested to be listed as Endangered at the national level with less than 5000 km² extent of occurrence and due to the continuing decline in habitat quality caused by mining and forest fires. It is the dominant species in its habitat, along with shrubs from Rubiaceae, Lamiaceae and Lauraceae and an understory of grass (Poaceae). Species diversity was highest in Mt. Tapulao followed by Guisguis and Pagasa. Needle morphological variation and genetic diversity were highest in Guisguis within and among populations which was largely attributed to its low elevation. The lowest genetic diversity observed in Mindoro was attributed to its isolation from mainland Luzon. However, its heterozygosity and inbreeding coefficient was closely equivalent to Mt. Tapulao, suggesting that its isolation as an island did not cause significant genetic variation. Gene flow in P. merkusii populations implies that the three populations studied though geographically isolated, were not reproductively isolated. In situ conservation methods are recommended in Guisguis to maintain or enhance its genetic diversity. Implementation of botanical gardens and seed orchards with representatives from all populations is also suggested, as well as the evaluation of genetic diversity of P. merkusii using other informative genes.