Establishment of gene pools for systematic heterosis exploitation in sugarcane breeding

Abstract

In sugarcane (Saccharum spp) breeding, despite the potential use of reciprocal recurrent selection (RRS) to explore both nonadditive and additive effects for economic value traits, to date, no publications have targeted obtaining heterotic groups to support this selection strategy. The aim of this study was to (a) to identify sugarcane gene pools to effectively explore nonadditive and additive genetic effects via reciprocal recurrent selection, (b) estimate genetic parameters, and (c) select parents and cross combinations. Seventy-nine sugarcane families were obtained from crossing 38 parents in a crossing scheme known as disconnected factorial design. The families were evaluated in randomized complete block design with five replicates. The statistical genetic analysis was performed with linear mixed models through restricted maximum likelihood/best linear unbiased predictor. The results revealed that nonadditive effects were predominant in explaining genetic variation for cane yield (t ha −1), pol yield (t ha −1), and fiber yield (t ha −1). For brix, fiber and corrected Pol (PCC) traits, additive effects were predominant. Estimates of specific combining ability and pedigree information allowed the establishment of gene pools for systematic heterosis exploitation through RRS breeding efforts. The prediction of the additive genetic values of parents for selection based on the progeny's behavior obtained via disconnected factorial design is an alternative that should be used in sugarcane breeding programs.

Applications of Quantitative Genetics and Statistical Analyses in Sugarcane Breeding

“…In commercial sugarcane breeding programs, estimates of h 2 ns for cane yield (CY) are generally low (i.e., \ 0.20) (Gravois et al 1991;Neto et al 2013;Pisaroglo de Carvalho et al 2014;Jackson 2018b). This is reflective of the importance or predominance of non-additive gene action relative to additive genetic effects (Hogarth et al 1981;Neto et al 2013;Pisaroglo de Carvalho et al 2014;Zhou 2019;Mendes de Paula et al 2020). Hence, performance of clones for cane yield tends to have a low predictive value of their general breeding value (BV).…”

Genomic Selection in Sugarcane: Current Status and Future Prospects

“…The varietal development programme in sugarcane breeding is a kind of recurrent selection. The parental lines for hybridizations are selected based on breeding values estimated from the performance of families or progenies of proven crosses (Chang and Milligan, 1992 ; Jackson, 2005 ; Burnquist et al, 2010 ; Lingle et al, 2010 ; Stringer et al, 2010 ; Mendes de Paula et al, 2020 ). Sugarcane is a clonally propagated crop, amenable for the exploitation of both additive and non-additive gene action.…”

“…This is helpful in the selection of an elite parental pool and prediction of parental cross combinations. The proportion of non-additive genetic variance is suitable for the selection of elite plant types from the ground nursery (Jackson, 2005 ; Mendes de Paula et al, 2020 ). A very high significant Specific Combining Ability (SCA) variance is observed for cane yield in an unselected population of 35 families indicating the predominance of non-additive genetic variance (Zhou, 2020 ).…”

“…A very high significant Specific Combining Ability (SCA) variance is observed for cane yield in an unselected population of 35 families indicating the predominance of non-additive genetic variance (Zhou, 2020 ). The evaluation of 79 families derived from 38 parental lines revealed the predominance of non-additive genetic variance for cane yield and additive genetic variance for brix and sucrose (Mendes de Paula et al, 2020 ). Sugarcane has a long history of low narrow-sense heritability and a higher proportion of non-additive genetic variance for cane yield as compared with CCS (Wei and Jackson, 2017 ; Mendes de Paula et al, 2020 ; Zhou, 2020 ; Yadav et al, 2021 ).…”

“…The evaluation of 79 families derived from 38 parental lines revealed the predominance of non-additive genetic variance for cane yield and additive genetic variance for brix and sucrose (Mendes de Paula et al, 2020 ). Sugarcane has a long history of low narrow-sense heritability and a higher proportion of non-additive genetic variance for cane yield as compared with CCS (Wei and Jackson, 2017 ; Mendes de Paula et al, 2020 ; Zhou, 2020 ; Yadav et al, 2021 ). Hence, the selection of parental lines based on breeding value does result in a low genetic gain and require due consideration for non-additive genetic variance in the choice of a parental pool for hybridization programmes.…”