Reproductive biology and genetic marker diversity in Grevillea infecunda (Proteaceae), a rare plant with no known seed production

Abstract

Grevillea infecunda D.J.McGillivray is a narrow endemic that reproduces vegetatively via root suckering. The reproductive biology of five Grevillea infecunda populations was investigated by scanning electron microscopy and light microscopy. Stigma maturation follows normal Grevillea development. However, a large number of pollen grains with aberrant forms were documented. A fluorochromatic reaction (FCR) test revealed 0.04% pollen viability. All pollen samples collected from two populations were completely sterile. All viable grains were >100 µm in diameter and included aberrant forms. Amplified fragment length polymorphism (AFLP) technique was used to investigate genotypic diversity in G. infecunda. Three primer pairs revealed sufficient variation in 109 loci to assign a unique phenotype to every individual (N = 40) sampled. This suggests that the populations were established from founder seedlings. The species has apparently lost the ability to reproduce sexually but genotypic variation is maintained through asexual reproduction via root suckers.