Advances and prospects in fungal disease resistance breeding of roses

Rosa species, as one of the most economically and ornamentally valuable flower groups worldwide, not only occupy a core position in the horticultural industry but also possess long-term substantial value for breeding applications. However, their production systems rely heavily on disease management. The persistent threats of fungal diseases, including black spot, powdery mildew, and gray mold, have severely impaired the ornamental quality and commercial value of rose plants, constituting a major constraint on the stable development of the rose industry. Compared with conventional hybrid breeding, molecular breeding allows targeted modification of specific heritable traits and plays a pivotal role in the development of disease-resistant rose cultivars. In recent years, with the rapid advancement of genomics, transcriptomics, and functional genomics, a growing number of gene resources and regulatory mechanisms associated with disease resistance in Rosa species have been progressively elucidated. This review systematically summarizes the pathogen characteristics, disease symptoms, and damage patterns of major fungal diseases affecting Rosa species, with a particular focus on research progress in disease-resistance-related transcription factors (e.g., WRKY, MYB, and bZIP), resistance genes (e.g., Rdr, MLO, and CPR), and key gene families identified from Rosa chinensis and Rosa hybrida materials. In addition, by integrating research evidence from model plants and major crops, this review comparatively analyzes the functional evolution of different regulatory factors and their underlying disease resistance mechanisms, thereby improving the understanding of the molecular regulatory network governing disease resistance in Rosa species. Furthermore, this review outlines the current applications and future potential of emerging molecular breeding technologies, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), in the functional dissection of resistance genes and precise genetic improvement of roses. By systematically synthesizing major research achievements in the disease resistance of Rosa species, this review summarizes the current progress and existing challenges in relevant research and proposes future research directions for resistance gene mining, molecular regulatory network elucidation, and molecular design breeding. This study aims to provide a theoretical basis for the improvement of disease resistance and the breeding of new highly resistant cultivars of Rosa species.