Lerma S J Maldia
University of the Philippines Los Baños, Philippines
Title: Application of genetic diversity and structure data in forest restoration: The case of native white oaks (Quercus) in Japan
Biography
Biography: Lerma S J Maldia
Abstract
Statement of the Problem: Oaks are ecologically important components of broadleaved temperate forests of Japan. They are common planting species for forest restoration, greening programs and establishment of forest parks. However, genetic risk involved in planting without knowledge of the origins of plant materials has been a concern over these activities. Studies showed that introduction of foreign genotypes into new environment during restoration could result to loss of local adaptation, mortality due to maladaptation, genetic pollution or pose threats to regional biodiversity.
Methodology & Theoretical Orientation: To offset these risks, establishing transfer (or seed) zones or regions within which planting stocks can be moved with least or no negative effects on the average fitness of population must be carefully considered. Seed zoning have generally used edaphic and climatic data, ecophysiological data, and/or results of provenance tests. Recently, the utility of geographic patterns of genetic variations revealed by molecular markers for zoning in restoration has been recognized. In this study we determined the genetic variations at nuclear and chloroplast genomes of native white oaks species (Genus Quercus, Section Prinus; Q. aliena, Q. crispula, and Q. serrata), including some of their variants in Japan, in order to recommend genetic guidelines for transfer of planting materials for these oaks species for restoration.
Findings: The genetic structure and distribution of chloroplast haplotypes of the studied oaks species displayed generally distinct geographic genetic structures of northern and southern populations, following the north-south lineages of other deciduous broadleaved species in Japan, but with generally limited within-population diversity in northern populations. On one hand, the signals of genetic structure of nuclear genome seemed related to their range-wide distributions. The northsouth differentiation at nuclear genome was very weak for the widely distributed Q. serrata but very strong for the sparsely distributed Q. aliena and relatively fragmented in the south Q. crispula.
Conclusion & Significance: The sharp north-south difference in genetic backgrounds at two genomes suggests completely differentiated gene pools for these two large genetic populations, and thus, can be considered genetically distinct transferrable zones for planting stocks of Q. aliena and Q. crispula. Plant materials for restoration, therefore, should be restrictively sourced from and transplanted within each transfer zone and inter-planting between zones must be avoided.