Intercrossing different varieties of plants frequently produces hybrid offspring with superior vigor and increased yields, in a poorly understood phenomenon known as heterosis1, 2. One classical unproven model for heterosis is overdominance, which posits in its simplest form that improved vigor can result from a single heterozygous gene3, 4, 5, 6, 7, 8. Here we report that heterozygosity for tomato loss-of-function alleles of SINGLE FLOWER TRUSS (SFT), which is the genetic originator of the flowering hormone florigen, increases yield by up to 60%. Yield overdominance from SFT heterozygosity is robust, occurring in distinct genetic backgrounds and environments. We show that several traits integrate pleiotropically to drive heterosis in a multiplicative manner9, and these effects derive from a suppression of growth termination mediated by SELF PRUNING (SP), an antagonist of SFT. Our findings provide the first example of a single overdominant gene for yield and suggest that single heterozygous mutations may improve productivity in other agricultural organisms.
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- Supplementary Text and Figures (3M)
Supplementary Figures 1–6 and Supplementary Tables 1–4