Abstract Detail

Systematics Section / ASPT

Bayer, Randall [2], Rich, Sarah [2], Morton, Cynthia [3], Mabberley, David [1], Sykes, Stephen [4].

Phylogenetic relationships of the Australasian Citrus (Rutaceae: Aurantioideae)..

The citrus fruits and their wild relatives belong to the Rutaceae, within the subfamily Aurantioideae. The subtribe Citrineae (tribe Aurantieae) is a group of these plants which are unique in bearing fruits containing pulp vesicles that fill all the space in the segments of the fruit not occupied by the seeds. They are almost exclusively native to China and the South Pacific region, including Australia. Their unique fruits are the basis for one of the most important fruit industries in warm countries of the world due to the great commercial importance of the juice extracted from species of the genus Citrus. Breeding programs are already investigating native members resistance to salt, boron and the cold, but the breeding of new, high quality Citrus cultivars is dependent on reliable information about the relationships of species in genera within the tribe Aurantieae. The tribe Aurantieae contains three subtribes the Citrinae, Triphasiinae and the Balsamocitrinae and the taxonomy of the Citrinae has been controversial, the genus Citrus itself being variously described as consisting of from 1 to 162 species. Closely related to the genus Citrus are several genera, which were recognized by W.T. Swingle, including the genera Clymenia, Eremocitrus, Fortunella, Microcitrus, and Poncirus. Recent work of Mabberley has questioned the distinctness of these genera and many botanists now include them within an enlarged concept of the genus Citrus. The aim of this study is to provide a molecular-based phylogeny of members within the tribe Aurantieae based on chloroplast DNA sequences. Three regions from the chloroplast genome; the trnL intron and trnL - trnF intergenic spacer; the rpsL16 intron and the atpB coding region have sequenced. The close relationship of Clymenia, Eremocitrus, Fortunella, Microcitrus, and Poncirus to Citrus has been confirmed.

1 - Royal Botanical Gardens, Sydney, New South Wales, 2000, Australia
2 - CSIRO, Division of Plant Industry, P.O. Box 1600, Canberra, Australian Capital Territory, 2602, Australia
3 - Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, Pennsylvania, 15213, U.S.A.
4 - CSIRO, Division of Plant Industry, Private Mail Bag, Merbein, Victoria, 3505, Australia

Keywords:
atpB
Citrus
rps16 intron
trnL/F
Rutaceae
phylogeny
Australia
Aurantioideae
Microcitrus
Eremocitrus
Poncirus
Fortunella.

Presentation Type: Paper
Session: 38-14
Location: Cottonwood A (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 5:30 PM
Abstract ID:288