In the Southern Hemisphere spring officially begins on the 1st of September, but technically it is around the 22nd of September (called the vernal equinox) when the days are of equal length to the nights. Unlike humans, plants and animals don’t go by dates – they respond mainly to the length of days and the temperature.
Many plants flower after going through a period of extended cooling during winter, called vernalisation. This is well known amongst horticulturists, who promote early flowering by subjecting plants and bulbs to low temperatures. Some annuals and perennials treated in this way flower earlier in the season, while some biennials are made to flower in their first rather than second year of growth. Home gardeners also practise vernalisation by putting their bulbs in the fridge before planting.
Recently two Australian scientists at the CSIRO discovered a gene which is central to understanding how the process of vernalisation works. The Flowering Switch Gene, as they called it, is critical in flowering control. Most of the time this gene represses flowering, but it switches off after an extended period of cold. The discovery of the Flowering Switch Gene could boost the productivity of the world’s crops by billions of dollars each year.
Further information
Visit CSIROOnline at:
http://www.csiro.au/index.asp?type=mediaRelease&id=Prprize
or see the Department of Industry, Science and Resources website at:
http://www.isr.gov.au/science/pmprize/prizepmscience.html