Albany, NY – In today's Academic Minute, Dr. Chris Martine of the State University of New York - Plattsburgh discusses the pros and cons of the different reproductive strategies that exist in the plant kingdom.
Chris Martine is an associate professor of biology at SUNY Plattsburgh where he conducts research into various aspects of plant reproduction. He has published numerous articles on the subject, and in 2011 received the SUNY Chancellor's Award for Excellence in Teaching. He holds a Ph.D. in botany from the University of Connecticut.
Dr. Chris Martine - How Plants Reproduce
Look around the room at most social gatherings. and you are likely to notice something about sex. I am speaking, of course, about the fact that human beings come in two genders: male and female. In fact, this is how things are for most of the species in the animal kingdom.
In the plant kingdom, however, things are quite different. More often than not, plants are cosexual: each individual plant has both male and female organs, with each of these producing either male sex cells (sperm) or female sex cells (eggs) - all on a single plant.
The rare condition in plants is when they appear as we do, with some individuals in a population having just male, or staminate, organs and others bearing only female, or pistillate, organs. This system is known as "dioecy," which literally means "two houses" - and it results in the fact that in a dioecious species (where males and females live apart) there is no way for a single individual plant to reproduce by itself. The male plant is dependent on the secure delivery of its sperm cells (in the pollen grain) to a female plant of the same species.
Something like 5 to 10 percent of the flowering plant species on Earth reproduce in this manner, with the rest enjoying the reproductive assurance of being able to make more of themselves even when another mate is nowhere to be found. So if the ability to self-produce works for so many plants, why would dioecy and the obligation to "find" another mate have evolved and be so widespread, occurring in dozens of unrelated plant lineages - from hollies to willows to Cannabis?
It turns out that one potential downfall to being able to fertilize yourself is ... well, that you can fertilize yourself. Dioecy might just be a way to avoid the pitfalls of becoming inbred. And in the plant world - where you can't get up and go and find a mate - this is one of the few ways to take reproductive matters into your own leaves.