Optimising clonal performance in sugarcane: leveraging non-additive effects via mate-allocation strategies

Area of Science:

• Plant breeding
• Quantitative genetics
• Agricultural science

Background:

• Mate-allocation strategies can enhance progeny performance by utilizing non-additive genetic effects.
• These strategies are particularly beneficial for clonally propagated crops like sugarcane, prioritizing predicted progeny merit over parental breeding value.

Purpose of the Study:

• To compare mate-allocation strategies that utilize non-additive and heterozygosity effects against those focusing solely on additive effects for optimizing breeding value.
• To maximize clonal performance in sugarcane by exploring advanced mate-allocation approaches.

Main Methods:

• Utilized phenotypic and genotypic data from 2,909 sugarcane clones.
• Simulated families from 1,225 crosses, predicting progeny values using GBLUP (additive effects) and extended-GBLUP (additive, non-additive, heterozygosity effects).
• Employed integer linear programming for optimal mate-allocation and analyzed traits: tonnes of cane per hectare (TCH), commercial cane sugar (CCS), and Fibre.

Main Results:

• Mate-allocation strategies based on clonal performance significantly improved predicted progeny values: 57% for TCH, 12% for CCS, and 16% for Fibre compared to breeding value-based approaches.
• Exploiting non-additive and heterozygosity effects led to superior clonal performance but a decline in additive gain for TCH, attributed to epistasis.
• Selecting crosses based on clonal performance for TCH resulted in significantly lower progeny inbreeding coefficients than random mating.

Conclusions:

• Mate-allocation strategies leveraging non-additive and heterozygosity effects are highly effective for enhancing clonal performance in sugarcane.
• These advanced strategies successfully mitigate inbreeding depression, offering a significant advantage over traditional methods.
• The findings recommend implementing these sophisticated mate-allocation approaches in breeding programs for clonally propagated crops to improve overall crop yield and quality.