Occurrence of Giant Antipodals in the Female Gametophytes of Australian Bossiaeeae, Indigofereae and Mirbelieae (Leguminosae)

Abstract

A survey of the female gametophyte development in 62 Australian species of subfamily Papilionoideae showed that giant antipodal cells were found in all species of Bossiaea, Goodia and Platylobium of the tribe Bossiaeeae; in all species of Burtonia, Daviesia, Gompholobium, Sphaerolobium and Viminaria of the tribe Mirbelieae; and in Indigofera australis of the tribe Indigofereae.

The giant antipodals were deeply staining, usually had large nuclei with prominent nucleoli and persisted well after fertilisation. The giant antipodals appeared to have a nutritive function in the female gametophyte as they develop at the expense of the nucellus.

The occurrence of giant antipodals is of taxonomic significance in the tribes Mirbelieae and Bossiaeeae. This evidence supports the separation of the 'Templetonia group' (Templetonia, Hovea, Lamprolobium) from the other genera in the Bossiaeeae (Bossiaea, Goodia and Platylobiurn or the 'Bossiaea group'). The suggestion is also made to reassess the relationships and composition of the tribes Mirbelieae and Bossiaeeae based on the presence of giant antipodal cells. This would result in the tribe Bossiaeeae consisting of the genera Burtonia, Daviesia, Gompholobium, Sphaerolobium and Viminaria and the members of the 'Bossiaea group', Bossiaea, Goodia and Platylobium.