All types of living organisms have one thing in common: the
ability to reproduce—that is, to produce offspring that are similar to the parent
organism. We toss around phrases like "she has her father’s eyes" or
"her mother’s smile." But how is the feat of reproduction—and
inheritance—accomplished? Obviously, organisms
must have some mechanism to ensure that, for example, a maple tree’s characteristics
get passed down to its offspring. Maple trees always beget maple trees—that
is, trees with certain common characteristics.
During the rest of this week’s lecture, and some of
next week’s, we’re going to dive into the details of plant reproduction. This
week we’re going to look at different types of cell division, and discuss how plants
form eggs and sperm. Then we’ll look at how these reproductive cells unite to form a
new plant, and look at the development of seeds and fruit. Next week we’ll focus on
how genetic material is passed from parent to offspring, and survey the history of plant
breeding.
How is this information useful to gardeners? Well, did you
ever wonder exactly what an F1 hybrid is? Or why most gardeners don’t save seeds from
hybrid plants? Why is it that you can plant squash and pumpkins next to each other, and
not worry about cross-pollination affecting the crop—but you need to isolate
different types of corn? What is genetic engineering and why is it so controversial?
Before we can answer these and other common gardening questions we need to cover some
information about how plants reproduce and how traits are inherited.
These subjects can be challenging, so don’t worry if
you don’t fully understand all the material the first time through. As you become
more comfortable with the terminology, the concepts should become clearer to you.
Hopefully, by the end of next week you’ll have a general understanding of plant
reproduction and the principles of inheritance.
