Parthenocarpy in the tomato (Solanum lycopersicum L.) cultivar ‘MPK-1’ is controlled by a novel parthenocarpic gene

Abstract

Parthenocarpy is a trait where fruit set and growth are triggered without pollination and fertilization. In the tomato (Solanum lycopersicum L.), this trait is considered attractive as it reduces the cost and labor requirements for fruit setting. In this study, we investigated the inheritance of parthenocarpy in ‘MPK-1’—a parthenocarpic tomato cultivar derived from a cross between a variant from a self-fertilization posterity of ‘Severianin’, which exhibited strong parthenocarpy and a non-parthenocarpic cultivar. It was reported that ‘MPK-1’ contains a pat-2 gene because ‘Severianin’ which has a pat-2 gene is its only parthenocarpic ancestor. However, we found that parthenocarpy in ‘MPK-1’ is controlled by a novel parthenocarpic gene, not pat-2. This novel gene, which was designated as Pat-k, is semi-dominant and located on chromosome 1. We also showed that the size of the parthenocarpic fruit of ‘MPK-1’ is similar to that of the pollinated fruit at maturity. Thus, ‘MPK-1’ may be used as a new parthenocarpic resource for breeding.