P0078
Whole Chloroplast Genome Sequence of Coffee Species Reveals their Relationships
Hue T.M. Tranab, Tal Coopera, Agnelo Furtadoa, Darren Craync, Robert J Henrya* and Perla Hamond
a Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Australia
b Western Highlands Agriculture & Forestry Science Institute (WASI), Vietnam
c Australian Tropical Herbarium, James Cook University, Cairns, Australia 4870
d IRD / UMR DIADE, 911 av Agropolis, Montpellier 34394 cedex 5, France
* Corresponding author: Robert Henry, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St Lucia QLD 4072, Australia, Tel. +61 7 3346 0551; Email: robert.henry@uq.edu.au
Abstract
Coffee belongs to the Rubiaceae family and the Coffeeae tribe. The taxonomy and classification of coffee has been controversial. Previous studies divided the Coffeeae tribe into two genera Coffea L. and Psilanthus Hook.f. Whole chloroplast genome sequences of 16 samples representing 15 species have been assembled using Illumina sequence data (from the 13 genomes consortium) in order to investigate the relationships among species in the Coffeeae tribe. Coffee species were collected from eleven countries representing different regions of origin. Two approaches of reference-guided mapping assembly and de novo assembly were compared. Different methods of phylogeny construction were applied. Results showed the discrimination of coffee species into two clades with high bootstrap value and probability. Four Psilanthus from Oceana formed into one clade and the other two Psilanthus from Africa were included in a clade that grouped all Coffea. This suggested that the origin of Psilanthus is probably in Asia. Species grouped according to their biogeographic origin and almost all sub-groups are in agreement with previous studies. The position of C. Canehora is interesting and should be considered as more complex than previously thought. The maternal genomes of C. arabica (Arabica) and C. canephora (Robusta) are divergent. This result is in agreement with the fact that the chloroplast genome of Arabica should be that of the maternal parent i.e. C. eugenioides. This is the first phylogeny of Coffea constructed from whole chloroplast genome sequences. The understanding of relationships among coffee species has significant implications for the improvement of coffee.