Lerma SJ. Maldia
University of the Philippines Los Baños, Philippines
Title: Genetic diversity and structure of Gmelina arborea Roxb. and Falcataria moluccana (Miq.) Barneby & J.W.Grimes plantations in the Philippines based on microsatellites
Biography
Biography: Lerma SJ. Maldia
Abstract
Statement of the Problem: In the Philippines, industrial tree plantations have the largest share to the country’s current total log production. Gmelina arborea and Falcataria moluccana (Paraserianthes falcataria) are two commercially important plantation species in the northern and southern regions of the Philippines, respectively. But, often the quantity and quality of wood of the species are low and poor. Field testing of planting materials from various plantations has recently been established to determine significant variation in important traits, with aims to select the best possible source(s). However, the lack of information on the origins or seed sources of the introduced materials has posed major limitation that could assist with the selection of materials for economical and faster improved production.
Methodology & Theoretical Orientation: This study assessed the genetic diversity and ascertained the genetic structure of all currently available propagated materials of the two species. The usefulness of molecular markers to assess genetic variation especially in recurrently planted populations has been well demonstrated and in this study the microsatellite markers developed for each species were used.
Findings: Based on structure analysis, without prior information on the location of individuals, the optimum genetic clusters (K) of Gmelina arborea and Falcataria moluccana are four and two, respectively. However, the distribution of the genetic clusters in each species does not correspond to a specific or unique sampling location but was randomly distributed in generally all sampling locations. Compared to the natural populations of Gmelina arborea, there was notable (20-30%) decreased in genetic diversity in the materials available in the Philippines, although modest divergence was found among clusters. For Falcataria moluccana, high genetic variation within-but low differentiation between clusters was observed.
Conclusion & Significance: Genetic diversity and structure of forest tree plantations is a foremost crucial concern to consider in tree breeding and improvement as genetic gain increases with high genetic variation in a species. Therefore, the results of this study should be useful as baseline information for tree breeding and improvement of these species.