Abstract: A T1 (sugarcane population originating from true seeds) and T2 (first
sugarcane clonal stage) population were used to estimate genetic parameters
and compare selection strategies for Diatraea saccharalis (Lepidoptera: Crambidae)
resistance in sugarcane. In the T1 stage, heritability at the family mean
level (h²=0.77) was higher than individual genotype heritability (h²=0.16), and
the additive genetic effect was more important for sugarcane borer resistance
than non-additive effects. In addition, there was high genotypic variance among
and within full-sib families. In the T2 population, genotypic variance was high,
and heritability at the clone mean level was moderate (h²=0.61). We can conclude
that family experiments enable selection of more promising families and
parents for borer resistance. However, due to high genotypic variance within
families, family selection at the T1 stage must be followed by clone selection
at the T2 stage.
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