Tulip Break Virus
Janna Beckerman, Associate Professor, Botany & Plant Pathology Department, Purdue University
Tulip break, described by Carolus Clusius in 1576, was one of the first identified virus-induced plant diseases. The symptoms of the tulip breaking virus results in color-breaking on the petals of affected flowers. ‘Breaking’ takes the form of conspicuous white or yellow streaks throughout the petals or streaking of a darker shade compared to the original color. Variegated tulips were referred to as Rembrandt tulips and became the subjects in many paintings by the Dutch Masters (even though Rembrandt never painted them!). This same virus that was responsible for the gorgeous color breaks in tulips was the cause behind the financial insanity that occurred during the Tulipmania period of 1636-1637. At the peak of tulip mania, in February 1637, lots of tulip bulbs sold for 90,000 guilders, the equivalent to more than $3.5 million in today's money (Pavord, 1999).
A virus is a disease-causing agent that is so small most can only be seen with an electron microscope. Viruses can infect any living organism, including people (e.g., The flu virus), animals (e.g., feline leukemia virus), and even other microbes, but were first identified infecting plants. Aphids spread tulip breaking virus as they feed on plants. These viruses depend on the help of aphids that also feed on stone fruit (cherries, plums, peaches, etc.) to get picked up from the stone fruit trees and then become transmitted to the tulip. The aphid inserts its stylet-like, sucking mouthparts directly into the infected plant and removes plant sap, with small amounts of the virus left in it mouth-parts. When the aphid moves to another host (either a tulip, or another stone fruit), the virus enters the plant’s vascular system when the aphid once again starts to feed.
Once inside the plant, viruses rapidly reproduce, with the infection spreading throughout the entire plant. Symptoms of tulip break vary but the patterns are often described as stripes, feathers, flames and streaks. It is not known if the virus-induced patterns reflect the actual distribution of the virus in the flower.
Today, "broken tulips," like 'Union Jack', ‘Princess Irene' (see photo), or 'Rembrandt Tulip Mix' are the result of breeding, not virus infection. Virus-infected bulbs are often stunted and weakened, reducing the vigor of the plant through each generation, making them increasingly difficult to propagate. Eventually the bulb has no strength left to flower, withering to nothing, resulting in the death of that variety. It's for this reason alone that some of the most famous examples of tulip break-infected bulbs like 'Semper August' and the 'Viceroy' are no longer in existence, and others, like ‘Absalon’ and ‘Beauty of Bath’ are exceedingly rare. Although virus infected tulips are difficult (but not impossible) to obtain commercially, keep in mind that the virus is lethal in lilies, one of the reasons commercial tulip producers work so hard to keep this virus out of tulip production!
Reference: Pavord, Anna. 1999. The Tulip. 388 pp.
For other images of broken tulips, see: http://oldtulips.org/index.php
Click image to enlarge
Princess Irene Tulip
Tulip Break Virus
Close-up Tulip Break Virus