GENE EDITING IN THE DEVELOPMENT OF SWEET PEPPER HYBRIDS FOR OPEN-FIELD CULTIVATION: THE SIGNIFICANCE AND PROSPECTS OF APPLYING CRISPR/CAS9 AND ITS NEW-GENERATION TOOLS

Abstract

Sweet pepper (Capsicum annuum L.) is a heat-loving, high-value vegetable crop whose yield and product quality are considerably limited by viral and fungal diseases, pests and abiotic stresses. Combining resistance and quality traits simultaneously in open-field hybrids by conventional breeding methods requires a long time and considerable labour. CRISPR/Cas9 and its new generations — Cas12a, base editing, prime editing and multiplex editing — allow precise, targeted modifications to be introduced into genes of interest and thus accelerate the breeding process. This review analyzes the main directions of gene editing in pepper — resistance to powdery mildew (CaMLO2), anthracnose (CaERF28, NAC72) and potyviruses (eIF4E/pvr2) — as well as the results achieved in improving fruit quality and agronomic traits. At present, the recalcitrance of pepper to in vitro regeneration remains the main technical obstacle; virus-induced gene editing (VIGE), DNA-free RNP methods and developmental regulators (GRF-GIF, BABY BOOM, WUSCHEL) are promising approaches to overcoming it. The article also discusses the regulatory status of transgene-free edited cultivars and the prospects for integrating gene editing into the breeding of open-field sweet pepper hybrids.