MOLECULAR ANALYSIS OF INTERSPECIFIC AND INTERGENERIC RELATIONSHIPS OFBANKSIA USING RAPDS AND NONCODING CHLOROPLAST DNA-SEQUENCES

Random amplified polymorphic DNA (RAPD) and chloroplast DNA (cpDNA) ma rkers were used to study interspecific and intergeneric relationships of Banksia (Proteaceae) to aid breeding of the genus for cut flower pr oduction. The accepted morphological phylogeny of Banksia, with two su bgenera, two sections and 13 series, is unclear regarding the relation ships of the commercial cut flower species B. coccinea. Fifteen RAPD p rimers and a non-coding cpDNA sequence between the trnL (UAA) and trnF (GAA) gene were applied to species of Banksia, the related genus Drya ndra, and to Musgravea heterophylla as the outgroup, with cluster anal ysis applied to the results. The two methods were in broad agreement w ith each other, and with the accepted taxonomy, with closely related s pecies pairs and groups clustering together, but RAPDs were not inform ative between distantly related species or species pairs. Banksia cocc inea clustered with Dryandra and formed a polytomy with 2 Dryandra spe cies and the two sections of subgenus Banksia. Subgenus Isostylis form ed a polytomy with D. formosa, basal to subgenus Banksia, but with B. cuneata and B. illicifolia (both in subgenus Isostylis) polyphyletic. Dryandra did not separate as a clade and fell within Banksia, raising questions about the currently accepted view of the two as sister gener a with parallel morphological development. The results indicate that i nterspecific and intergeneric hybridisation with genus Dryandra and su bgenus Banksia may be possible routes for improvement of the commercia l species B. coccinea.