Progeny selection and inheritance of resistance to Colletotrichum siamense in Mangifera indica crosses

Abstract

Introduction Anthracnose is the main mango disease worldwide, affecting flowers, branches, leaves, and fruits in the field and post-harvest. The present study aimed to understand the inheritance of resistance to anthracnose caused by Colletotrichum siamense in the progenies Haden x Tommy Atkins (cross1) and Keitt x Tommy Atkins (cross2) to support the selection of resistant progenies. Materials and methods Artificial pathogen inoculation was performed on 15-year-old plants by manually spraying a 106 conidia mL-1 suspension on young branches and leaves, followed by covering with a humidity chamber for 48 hours. The plants were considered resistant when the absence of symptoms was >90% over three different evaluations. Estimates of genetic parameters were obtained by the REML/BLUP and chi-square tests and by the Burton method (BM). Results and discussion Keitt and Haden were resistant to the fungus, while Tommy Atkins was moderately susceptible. In both crosses, anthracnose resistance showed a 15:1 epistatic segregation conferred by recessive alleles, with 90% heritability for both crosses, according to the BM. The REML/BLUP broad-sense heritability was high, corresponding to 88% and 78% for cross1 and cross2, respectively, also indicating simple inheritance for anthracnose resistance. The average genetic gain of the selected progenies was 23.3%, and two of them showed resistance to anthracnose close to 100%. Conclusion Our results indicate high heritability and simple inheritance for anthracnose resistance in mango, making it possible to obtain resistant progenies in the first generation after a crossing with at least one resistant genotype followed by simple cloning to maintain the resistant plant.