How Peas Self-Pollinate

Reproduction Basics

• Pea plants undergo sexual reproduction. Similar to flowers, they require a piece of pollen -- the "male" portion of the plant -- to reach the stigma, which acts as the "female" part. The main difference between pea plants and flowers is that flowers require an outside medium -- such as an insect -- to transfer the pollen; whereas peas are set up so that only their own stamen (the part that produces the pollen) reaches their stigma.

Self-Pollination Development

• After the pea plant develops pollen, it creates a tube-like projection that grows through the plant and into the ovary, connecting the two locations. This creates the pathway to fertilization, as the tube allows subsequent connection to the same plant's ovules, allowing fertilization between the two sexual parts to take place. After a successful fertilization attempt, seeds develop.

Problems With Self-Pollination

• Self-pollination sounds like a foolproof scheme and it does make plants very self-dependent, allowing sexual reproduction to take place within one environment. The downside is that self-pollination does not ensure fertilization. As farmers know, lots of plants will undergo self-pollination, but won't become fertilized as a result, even after several attempts. Weather that is extremely cold or hot can also cause issues with the reproductive organs, limiting fertilization occurrences.

Cross-Breeding

• As peas can self-pollinate, this fertilization technique can also be manipulated. What occurs is a technique known as "cross-breeding." The pea plant' was used at the center of Mendelian genetics. Punnett squares are used to show the results of cross-breeding. An example includes breeding a tall plant with a short plant (first performed by Gregor Mendel), in which the subsequent generations will all contain one dominant tall allele and one recessive short allele; however, future generations will have a variety of expressions when bred together due to the potential heredity probability differences.