Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flowe...

that the pollen grains had germinated and that the pollen tubes had penetrated the stylar tissue. Demerec's third suggestion remains as a possibility and a fourth may be added which is likewise untested. The failure of gal pollen to fertilize Gals plants may be independent of stylar interaction altogether, and may involve some abnormal reaction within the ovule, such as inability of the pollen ...

Mammals of metatherian-eutherian grade are represented in a collection recovered from a Wise County, Texas, locality of Lower Cretaceous (Albian) age. The form, or forms, are distinctly primitive as evidenced by the very small low protocones, large stylar cusps, and wide stylar shelf. The presence of well-developed and separate metacones at such an early date would seem to place Deltatheridium ...

Gametophytic self-incompatibility (GSI) allows plants to block fertilization by haploid pollen whose S-allele constitution matches one of the two S-alleles in the diploid styles. GSI in Solanum chacoense requires a stylar S-RNase, first secreted from cells of the transmitting tract then imported into incompatible (self) pollen tubes. However, the molecular mechanisms allowing compatible pollen ...

Tobacco was transformed with a gene coding for an S-locus-specific glycoprotein of Brassica oleracea. The resulting transgenic plants showed tissue-specific and developmentally regulated expression of the introduced gene. lmmunolocaliration experiments showed that the Brassica gene was expressed in the stylar transmitting tissue of the transgenic plants. The pattern of expression of the introdu...

BACKGROUND AND AIMS Gesneriaceae is a pantropical plant family with over 3000 species. A great variety of pollination mechanisms have been reported for the neotropical members of the family, but the details of buzz-pollination and enantiostyly for the family have not been described. We investigated the floral biology and pollination ecology of Paraboea rufescens in Xishuangbanna, south-west Chi...