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Peas, the humble vegetable that helped scientists to discover hereditary traits

Photo of Pisum sativum peas

 

This important and well-loved food also played a crucial role in the scientific discovery of hybridisation, the process by which hybrid plants are created.

Where did peas originate?

The origins of peas are not very well known. Archaeological evidence found in the Fertile Crescent (the area surrounding modern day Israel and Jordan and the land in and around the Tigris and Euphrates rivers), indicates that people have been cultivating peas since 8,000 BC. Western Asia appears to be the area in which the pea was first cultivated and from there it was spread by humans to Europe, China and India. Today, peas are grown in all temperate countries and in most tropical highlands. 

How have peas been useful to science?

The father of modern genetics, Gregor Mendel, famously performed breeding experiments with the pea and discovered the mechanisms governing inheritance by crossing different types of pea plants and observing the offspring. The pea is an ideal plant for genetic study because of the presence of observable traits with contrasting forms, its short life-cycle and its production of many offspring from one cross.

Peas are still very useful to modern plant science, especially in understanding how this crop can adapt to climate change. The Millennium Seed Bank and the Global Crop Diversity Trust are engaged in a ten-year project, called 'Adapting Agriculture to Climate Change'. The project aims to protect, collect and prepare the wild relatives of 29 key food crops, including pea, so that they are available to pre-breeders for the development of new varieties that are more resilient to the effects of climate change.

What are the different uses for this crop?

Peas are a valuable food source for millions of people throughout the world. They belong to the plant family Leguminosae (also known as Fabaceae) and, like many legumes, have the ability to fix nitrogen from the air through a symbiotic relationship with bacteria housed in root nodules, making them very rich in protein.

There are three main types of pea. Field pea is grown for the dry seeds, garden pea is cultivated for the immature green seeds and sugar pea is grown for the immature pods. 

Peas are prepared in a number of different ways depending on the type or cultivar used: The dry seeds of field pea are consumed as a pulse dish and need to be soaked first to soften them before boiling. They can also be roasted or decorticated (having their thin seed coat removed) and split before boiling (known as split peas). The young seeds of garden pea and the young pods of sugar pea only need to be boiled for a few minutes before they are ready to be eaten.

As well as being an excellent food source for humans, the high protein content of peas means they are commonly used as animal feed in many Western countries. The plant is also used for forage, hay, silage and green manure. Its ability to fix nitrogen makes pea a good fertiliser and cover crop.

For a beauty treatment the seeds of pea can be crushed and used as a face-mask for acne and wrinkles.  

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