<S1-4> Combining field and molecular approaches to understand the regeneration processes of tropical tree species

Abstract

Reproductive and regeneration processes comprising flowering, pollination, seed development, seed dispersal, and seedling establishment are crucial in determining the abundance and spatial distribution pattern of species in a community. Investigators have tried to assess the ecological and genetic consequences of these processes in tropical tree species, particularly focusing on dipterocarps and using combined field and molecular approaches such as ecological genetics. Here we review the findings obtained using ecological genetics in the Lambir Hills National Park, Sarawak, Malaysia. Through field surveys during several general flowering (GF) events, the demography of flower to seedling, the pollination process, and patterns of seed/seedling survival have been investigated. Gene flow and mating systems of dipterocarp trees have been investigated using DNA markers such as microsatellites. These studies have revealed the reproductive process of dipterocarp trees and attempted to identify the ultimate cause of GF. In addition, recent advances in knowledge and techniques of molecular biology enable us to characterize the detailed genetic background of GF. We review applied studies pertaining to the physiological and developmental pathways underlying flowering, which have been elucidated in model plants. A large amount of genomic information was obtained from a flowering dipterocarp tree by high-throughput and cost-effective next-generation sequencing, and flowering genes were identified. The information obtained supported the hypothesis that the trigger of flowering is drought. Finally, we discuss the perspectives for future research using an ecological genetics approach in tropical forests.