The Evolution and Maintenance of Mixed Mating Systems
McCauley, David .
The effect of mitochondrial inheritance and self-fertilization on gender in a gynodioecious species.
Gynodioecious plants are those in which female and hermaphrodite individuals coexist within populations. Females are obligatorily outcrossing, whereas in some species hermaphrodites may also undergo self-fertilization. Often in these systems, sex determination is a consequence of a cyto-nuclear interaction between male sterility elements traced to the mitochondrial genome and nuclear restorer genes. Such a genetic system is prone to conflict. Two issues complicate the genetics of sex determination in the gynodioecious species Silene vulgaris. It is often assumed that mitochondrial genes are maternally inherited and uniform (homoplasmic) within individuals. Quantitative PCR based studies of S. vulgaris will be presented demonstrating that the inheritance of the mitochondrial genome is not strictly maternal, with heteroplasmy a common result. Further, crossing studies show that self-fertilization of hermaphrodite individuals produces a higher proportion of female offspring than does outcrossing, an issue not usually considered in the study of gynodioecy. Potential consequences of these observations will be discussed in the context of existing theory.
Log in to add this item to your schedule
1 - Vanderbilt University, Biological Sciences, Box 351634 B, Nashville, TN, 37235, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Stevens 5/Hilton
Date: Monday, July 9th, 2007
Time: 9:15 AM