Cold Spring Harbor, N.Y. Giving tomato breeders and ketchup fans something to cheer about, a Cold Spring Harbor Laboratory (CSHL) scientist and his colleagues at the Hebrew University in Israel have identified a gene that pushes hybrid tomato plants to spectacularly increase yield. The yield-boosting power of this gene, which controls when plants make flowers, works in different varieties of tomato, and crucially, across a range of environmental conditions.
"This discovery has potential to have a significant impact on both the billion-dollar tomato industry, as well as agricultural practices designed to get the most yield from other flowering crops," says CSHL's Zach Lippman, Ph.D., one of the three authors on the study, which appears in the journal Nature Genetics online on March 28th. The study is co-authored by Israeli scientists Uri Krieger and Professor Dani Zamir.
The team made the discovery while hunting for genes that boost hybrid vigor, a revolutionary breeding principle that spurred the production of blockbuster hybrid crops like corn and rice a century ago. Hybrid vigor, also known as heterosis, is the miraculous phenomenon by which intercrossing two varieties of plants produces more vigorous hybrid offspring with higher yields. First observed by Charles Darwin in 1876, heterosis was rediscovered by CSHL corn geneticist George Shull 30 years later, but how heterosis works has remained a mystery.
Shull's studies suggested that harmful, vigor-killing gene mutations that accumulate naturally in every generation are exposed by inbreeding, but hidden by crossbreeding. "But there is still no consensus as to what causes heterosis," says Lippman. "Another theory for heterosis, supported by our discovery, postulates that improved vigor stems from only a single gene an effect called "superdominance" or "overdominance."
To find overdominant genes, the team developed a novel approach by turning to a vast tomato "mutant lib
|Contact: Hema Bashyam|
Cold Spring Harbor Laboratory