Genetic control of resistance on Mangifera indica to Ceratocystis wilt

- We studied the inheritance of the resistance to Ceratocystis wilt in six full-sib families of Mangifera indica (mango).
- The inheritance is polygenic with greater magnitude of dominance effects and epistatic interactions.
- There is low frequency of alleles favorable to disease resistance in the material studied.
- The genetic gain obtained with selection of the 10 most resistant plants was 46% (46 % of reduction in disease severity).
- Other species of Mangifera should be tested to encourage the development of new cultivars resistant to Ceratocystis wilt.

Ceratocystis wilt, caused by Ceratocystis fimbriata is one of the most serious limiting factors for mango production in Brazil. Despite efforts in the selection and the identification of mango cultivars resistant to Ceratocystis wilt, the genetic basis of the resistance remains unknown. Therefore, the objective of this study was to understand the inheritance of resistance to C. fimbriata by artificial inoculations of the pathogen in progenies of six commercial varieties of mango using “Tommy Atkins” as the male parent. The cultivars “Keitt”, “Palmer”, “Tommy Atkins” and “Van Dyke” were confirmed as moderately resistant, whereas “Coquinho”, “Espada” and “Haden” were susceptible. The results of the inoculation on the progenies of these cultivars revealed that the resistance in mango is polygenic with a prevalence of genes expressing the effects of dominance and epistasis. The genetic gain with the selection of the 10 more resistant plants was 46%, which indicated a 46% reduction in disease severity. In general, a low frequency of the alleles favorable to disease resistance was observed in the population studied, which suggests the need for the introduction of new sources of genetic materials carrying the genes responsible for resistance.