Tomato gene researchers from Cold Spring Harbor Laboratory have determined a specific genetic mechanism for hybrid vigor, the property of plants resulting from cross-breeding of distinctly different inbred varieties in order to achieve a yield boost. Now that the underlying mechanism for this property has been uncovered, it will be possible to exploit this to significantly increase yield of processing tomatoes, according to a recent paper by Jiang et al., 2013.
Processing tomatoes, which are commonly used for making sauce and juice, are determinate, meaning that they are like a compact bush and stop growing earlier than garden and greenhouse varieties. As a result, they produce fewer fruits than indeterminate garden varieties.
In earlier research, Professor Zach Lippman and Israeli colleagues identified a rare genetic abnormality in the gene that makes florigen, a hormone that controls the process of flowering and flower production. This mutation caused a substantial increase in tomato yields in bush tomatoes.
Lippman and his team, led by postdoctoral researcher Ke Jiang, uncovered the reason for this increase: the mutation reduced the amount of florigen, the hormone that stops the plant from producing flowers.
“Tomato Yield Heterosis (hybrid vigor) is Triggered by a Dosage Sensitivity of the Florigen Pathway that Fine-Tunes Shoot Architecture,” according to the paper.
“This is because,” Lippman explains, “bushy tomato varieties are highly sensitive to the amount, or dosage, of the florigen hormone, which alters plant architecture – that is, how many flowers can form before growth ends. These discoveries lead to an exciting prediction: that it may be possible to tweak florigen levels to increase yields even further.”
Cold Spring Harbor Laboratory
