Resistência genética de Musa spp. A Radopholus similis: fundamentos metodológicos, caracterização fenotípica e molecular

Abstract

Banana is one of the most important fruit crops worldwide and plays a fundamental role in global food security. Among the main constraints to banana production are plantparasitic nematodes, particularly Radopholus similis, one of the most destructive species associated with Musa spp. In this context, genetic resistance represents a sustainable and durable strategy for managing this pathogen. This study first conducted a systematic review of the literature published between 2011 and 2024 to identify sources of genetic resistance to nematodes in Musa spp. Following PRISMA guidelines, a standardized search strategy and predefined inclusion and exclusion criteria were applied across multiple academic databases, resulting in the selection of 69 studies. The review confirmed R. similis as the most extensively investigated nematode species worldwide and highlighted the existence of promising resistance sources within Musa germplasm. The resistance response of twenty banana genotypes from different regions of Brazil was also evaluated based on symptom severity and nematode reproduction factor. A wide variation in response was observed among genotypes of the Prata subgroup (AAB), whereas Cavendish subgroup (AAA) genotypes were predominantly susceptible. Additionally, the infection process of R. similis in roots of improved diploid banana genotypes, previously identified as contrasting in their response to the nematode, was investigated at histochemical and molecular levels. Gene expression analyses revealed hormonal and structural events associated with root resistance. Finally, a diagrammatic scale was developed and validated to improve the assessment of host response to R. similis infection, based on the extent of rhizome necrosis in banana seedlings. Rhizome area and symptom severity were quantified using ImageJ software, and scale validation involved ten inexperienced evaluators who estimated the severity of one hundred rhizomes with and without the use of the scale. The application of the scale significantly increased interrater agreement, improving R² and Lin’s concordance correlation coefficient (CCC) values and reducing systematic bias in severity estimates. Taken together, this study integrates systematic evidence, methodological advances, and experimental validation, providing novel contributions and practical tools to support Musa breeding programs focused on resistance to R. similis.