The evolution and prevalence of reproductive assurance in the genus Lachenalia

Since its proposal by Darwin (1876), the concept of reproductive assurance (RA) has been much discussed, modified and tested. It is hypothesized to occur under pollen- and/or mate-limitation, each of which can arise in a multitude of manners, and RA itself takes many forms. Here its evolution and prevalence in the genus Lachenalia (Asparagaceae) is investigated. The genus exhibits many of the characteristics suggested in the literature to be associated with reproductive assurance, including intraspecific polyploids, vegetative reproduction and self-compatibility. Of the 27 study species, 20 were found to be self-compatible and four were capable of autonomous self-pollination. Pollinator-dependent species were found to have more attractive floral display structures. The five species exhibiting intraspecific polyploidy were all self-compatible. Offset production, known to occur in many Lachenalia species, was thought to exhibit a negative association with self-compatibility. No significant association, however, was found. A deeper understanding of the patterns of reproductive assurance in the genus requires study of the mechanisms enforcing self-incompatibility, and of the ecological and physiological correlates of reproductive assurance, is needed.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2013

Author dc:creator

• Rink, Ariella

Advisors dc:contributor.advisor

• Verboom, Tony
• Rodger, James

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/14015

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/14015