Leicester scientists in discovery of new type of plant

Dr James Higgins from our Department of Genetics and Genome Biology has been involved in the discovery of a new type of plant growing in Shetland.

Scientists at the University of Stirling discovered the plant – with its evolution only having occurred in the last 200 years.

The new plant is a descendant of a non-native species, the yellow monkeyflower (Mimulus guttatus), which colonised the United Kingdom in Victorian times. It has evolved through the doubling of the number of chromosomes, known as genome duplication or polyploidy.

The plant, referred to as ‘Shetland’s monkeyflower’, produces yellow flowers with small red spots. It is larger than the typical monkeyflower and its flowers are more open.

Researchers say the finding is significant as it shows that a major evolutionary step can occur in non-native species over a short period of time, rather than over thousands of years.

Dr Higgins worked with scientists at Stirling, carrying out tests after a “chance encounter” with the plant while conducting fieldwork near Quarff, Shetland.

He said: “The Shetland yellow monkey flower is a beautiful example of rapid evolution taking place around us. It has recently experienced whole genome duplication which is the doubling of chromosome numbers in each cell. It is of scientific relevance as the majority of crop plants we rely on for energy and nutrients have also been through this process. By counting the number of chromosomes we were able to determine that the number of chromosomes had doubled in the new population compared to the plants originally introduced in Victorian times.”

The scientists measured the plant’s genome size and surveyed 30 populations of monkeyflowers from Shetland and across the United Kingdom.

The plants were then grown under controlled conditions and their floral and vegetative characteristics were measured to compare the effect of genome duplication in morphology and flowering time.

The team also conducted genetic analyses to investigate the relationship between the new polyploid plant and other populations in the Shetland Isles.

Genome duplication is common in the evolutionary history of flowering plants and many crops – such as potatoes, tobacco and coffee – are polyploids. However, it is rare to witness the phenomenon in recent history.

The paper, Recent autopolyploidisation in a wild population of Mimulus guttatus (Phrymaceae), has been published in the Botanical Journal of the Linnean Society.