Genetic and molecular mechanisms regulating parthenocarpy: Paradigms from cucumber and initial exploration in other Cucurbitaceae crops

Abstract Parthenocarpy, the ability to set fruit without pollination and fertilisation, is an important crop trait that helps stabilise yield in Cucurbits under unfavourable environmental or indoor farming conditions. While cucumber ( Cucumis sativus L.) is widely recognised as the primary model for parthenocarpy research in Cucurbitaceae owing to its abundant natural varieties, emerging studies are now deciphering the molecular pathways underlying this trait in zucchini ( Cucurbita pepo L.). Conversely, other cucurbit species continue to suffer from substantial research gaps. Primarily, the review provides a systematic summary of the parthenocarpy basis and discovered parthenocarpic varieties in Cucurbits. Subsequently, by delving into the genetic and molecular mechanisms, this review highlights the central roles of auxin, gibberellin, and cytokinin in activating parthenocarpy, whereas ethylene and abscisic acid (ABA) function as negative regulators of this trait. Conventional genetic, next‐generation gene mapping and sequencing studies have identified numerous important quantitative trait loci and candidate genes, most of which are involved in auxin biosynthesis, signalling transduction, and polar transport. In addition, the synergistic interactions between auxin and gibberellins, cytokinins, and the inhibition of ABA/ethylene were thoroughly analysed to clarify this complex regulatory network. In addition to discussing the latest advances in the genetic and molecular biology mechanisms of parthenocarpy, this review also aims to highlight the potential of gene editing technology and molecular markers in shortening parthenogenetic breeding processes. This is a key direction for developing next‐generation cucurbit varieties that meet the needs of indoor cultivation and adapt to global climate change.