Did 'paleo-polyploidy' really occur in proteaceae?

Cytological data for 188 species in 65 genera of Proteaceae were collated f rom the literature. Excluding the occasional infrageneric polyploid, Protea ceae have seven confirmed character states for chromosome number (n = 14, 1 3, 12, 11, 10, 7, 5). Genera of subfamily Persoonioideae are x = 7, and, on a cytoevolutionary doctrine of 'paleo-polyploidy' in angiosperm families, these low chromosome number taxa were hypothesised to represent the ancestr al genome of Proteaceae. Chief supporting evidence for this hypothesis is t he ancient origin of Persoonioideae in Proteaceae phylogeny. However all cu rrent genomes in Proteaceae have features that suggest that they are derive d, including those of Persoonioideae with their 'genomic obesity', and by r eference to the chromosomes of Bellendenoideae (n = 5) and the outgroup Pla tanaceae (n = 21), quite probably their number is also a derived character state. Furthermore the high chromosome number genera of Proteaceae in subfa milies Proteoideae and Grevilleoideae (n = 14, 13, 12, 11, 10) have genomic lengths that are far smaller than would be expected from a doubling of the chromosomes of Persoonioideae, and, so far as any information is available , these genera are also genetic diploids, This paper questions 'paleo-polyp loidy' as a general cytogenetic mechanism for plant macroevolution at the l evels of genus, tribe and sub-family in Proteaceae. It is proposed that dip loid cytoevolutionary processes of chromosome number increase and decrease from a primitive genome of FN = 24, with specific examples of x = 12 and x = 21, can explain the cytological phenomena in the family.