Accelerating eucalypt clone selection pipeline via cloned progeny trials and molecular data

Area of Science:

• Forestry
• Plant Breeding
• Genetics

Background:

• Eucalyptus plantations achieve high productivity through advanced silviculture and genetics.
• Long breeding cycles and poor seedling-to-clone performance correlation hinder genetic progress in traditional tree breeding.
• Cloned progeny trials (CPT) integrate progeny and clonal testing to accelerate clone selection.

Purpose of the Study:

• To assess the potential of CPT to speed up eucalypt clone selection.
• To estimate genetic parameters and analyze selection responses in CPT.
• To determine the optimal number of ramets per progeny for CPT in Eucalyptus urophylla x Eucalyptus grandis.

Main Methods:

• Estimation of genetic parameters (broad-sense heritability, accuracy).
• Analysis of selection responses.
• Prediction of the optimal number of ramets per progeny for CPT.
• Integration of CPT with SNP markers for enhanced genetic analysis.

Main Results:

• Decreasing ramets per progeny from five to one reduced heritability and accuracy estimates.
• Three ramets per progeny can be used in CPT without significant loss of accuracy.
• CPT effectively combines progeny and clonal evaluation, improving the correlation between early and final performance.

Conclusions:

• CPT accelerates the eucalypt clone selection pipeline by enabling simultaneous evaluation of progeny and clones.
• The use of three ramets per progeny in CPT is recommended for efficient selection.
• Integrating CPT with molecular markers can further enhance genetic gain and shorten breeding cycles for vegetatively propagated species like Eucalyptus.