Truffles are the fruit of fungi that infect the roots of certain trees. They are of keen interest to pigs, particularly sows, because some secrete androstenol, a hormone produced by boars before mating. People who use sows to hunt for truffles often find it hard to prevent a sex-crazed animal from eating the truffle she has found and may lose fingers in the attempt.
It turns out the truffles, too, have sex lives, said Dr. Francis Martin, a plant biologist at the University of Nancy in France and leader of the research team. The precious fungi had long been thought to lead an asexual existence, but Dr. Martin and his colleagues have found that they have two sexes, or mating types.
The information is of great significance to truffle growers, whom Dr. Martin now advises to inject roots with both sexes of truffle spore. The truffle then benefits from the purpose of sex, which is of course to generate new combinations of genes and fresh diversity.