Early selection for resistance to cacao witches’ broom in new parental combinations

Abstract

Progenies from 69 crosses between parents obtained by recurrent selection for resistance and yield were inoculated with Moniliophthora perniciosa basidiospores. The symptoms were evaluated and compared with those in the equally inoculated progenies of Catongo, SIC 23 and SCA 6. Forty-three of the new progenies did not differ statistically from SCA 6, while 10 new progenies were statistically better than this control. The female parents that can be highlighted are (P4B x SCA 6), (MA 16 x SCA 6), (CEPEC 86 x SCA 6), and the EET 75 clone. The best male parents were (CAB 214), (CAB 208) and (P4B x OC 67), which did not differ from each other. This study proved the existence of gene combinations between fathers and mothers, the occurrence of additive effects and the dominant inheritance of these factors, which should allow the selection of clones with higher resistance levels and durability.

Resistance of cacao tree to witches’ broom disease – A study of inheritance

“…The present experiment produced new progenitors, several of them confirmed to have good resistance performance (10,12), for a second generation of recurrent selection and subsequently a third one. In regional trials, the clones selected from the first and second generations of recurrent selection have been evaluated to define new varieties for commercial planting.…”

Cacao parents help their offsprings to fight witches’ broom and black pod rot infections

“…For the structured base population, the effects of year, block, paternal, and maternal as individual parents and the paternal × maternal interaction were found significant for all field variables related to WB and BPR, except for the paternal × maternal interaction for BPR-diseased pods (F-test at 1% probability) (Supplementary file, Table S1-S4). These elements indicate the existence of additive effects (significant paternal and maternal effect) and dominance (significant paternalmaternal interaction) during the inheritance of these characteristics (Pires et al 2021). All sources were significant for all variables in the model with variation sources of year, block, and progeny (Supplementary file*, Tables S1-S4).…”