A Matter Of Selection

 

The Brassica oleracea all seem to have vastly different leaves as they all vary in color, shape, and size. Some of the plants have huge curled leaves, while the leaves of our plant are still small and simple. Our plant, kohlrabi, has leaves that measure 12 cm from stem to tip. However, most of the plants are bigger than this. The collard’s leaf measures 23 cm from stem to tip and the kale plant’s leaves measure 21 cm from stem to tip.

The Brassica oleracea has lots of variability in its different plants which is most likely an effect of selective breeding. It is also a good example of descent with modification as a variety of plans in this family all are descents of a single plant that has been affected by a variety of modifications over time, resulting a various separate plans ranging from cabbage to broccoli. For instance, in a location that is cold, a farmer might selectively breed out plants that cannot handle frost and cold weather. On the other hand, these geographic variables can also be the result of natural variations, such as plants that cannot handle frost, can’t survive in an area with a cold climate and a lot of frost or snow. In addition, farmers can have certain traits in their plants that provide more of an appeal to their customers such as flavor or color.Sometimes these variations are not necessarily intended, but are mutations to the plant. These genes are important to creating the specific plants that a farmer wants, ensuring the desired traits or attributes.  So through selective breeding and artificial selection theses plants have certain traits that become more prominent.

 

The one characteristic seen in the Brassica oleracea that appears to be consistent is the stems of the plants. The plant’s stems seem to have very close measurements. The kohlrabi, for example, stem is about 1 cm in width. Similarly, the collard’s stems is 1 cm in width. I think that this has stayed the same because this has proven to be the most helpful size for the plant stems to be.  

To get the characteristic they want, plant breeders have to get plants with the characteristics that they want to see in the offspring. Over time the plants will continue to have the characteristics selected and those characteristics not selected, will disappear.