Life strategy traits of the liana Sericostachys scandens spreading in the montane forests in the Kahuzi-Biega national park (DR Congo)

Sericostachys scandens is a monocarpic and heliophilous liana, native in tropical African forests. In the montane forests of the Kahuzi-Biega National Park (KBNP) (East of DR Congo), it has been expanding very strongly for a decade, and is currently considered as having negative impacts on biodiversity conservation. In this paper, we test if S. scandens differs from three co-occurring, native, non spreading lianas (Gouania longispicata, Tacazzea apiculata and Adenia bequaertii) for functional traits which might influence plant expansion. For leaf traits (SLA, dry matter content, nitrogen concentration), S. scandens did not show extreme values compared to those of the three other lianas. In contrast, S. scandens had much higher biomass allocation to sexual reproduction. It also differs from the three other lianas for its reproductive strategy that combines both vegetative propagation and sexual reproduction, and propagule dispersal by wind. Moreover, S. scandens has larger leaves and a greater number of lateral branches per unit stem length. It is argued that the particular combination of functional traits exhibited by S. scandens may in part explain its propensity to behave as an opportunistic weed in the disturbed areas in the montane forests of Kahuzi-Biega. © 2012 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Genome Studies for Effective Management and Utilization of Coconut Genetic Resources

Coconut belongs to a typically South American subtribe (Attalinae), yet at the dawn of agriculture, it was in both the Indian and Pacific Oceans. How it reached this pre-historic distribution remains unclear. During the last 20 years, molecular markers have been developed to study coconut genetic diversity, assess gene flows and identify markers of agronomic traits. They have proven useful to identify coconut cultivars and to track genetic exchange between populations and human migrations. Two well-differentiated gene pools, originating from the Indian and the Pacific Oceans, were identified. Self-pollinating Dwarf coconuts resulted from a single domestication event in Southeast Asia. Markers for various agronomic traits were identified through linkage mapping and association studies. More recently, genome expression was studied in various organs, providing a representation of the coconut proteome and of its regulation, allowing to identify key genes involved in the metabolism of the endosperm and in somatic embryogenesis. Several research teams undertook its sequencing, and two draft sequences have been published. This large genome was recently assembled into 16 pseudomolecules by anchoring it on a linkage map. The biology of the coconut makes genetic improvement difficult. Genomic selection and marker-assisted selection can speed up the first stages of varietal development based on advanced generations of crosses between genetically distant populations. This will require profound changes in the methods used in field observation, aiming to acquire more phenotypic data at the individual level as well as the open availability of genomic resources