Genetic parameter estimates for growth traits and stem straightness in a breeding seedling orchard of Eucalyptus grandis


Citation

Gapare W. J., . and Gwaze D. P., . and Musokonyi C., . Genetic parameter estimates for growth traits and stem straightness in a breeding seedling orchard of Eucalyptus grandis. pp. 613-625. ISSN 0128-1283

Abstract

Genetic parameters for growth and stem straightness were determined for a fourth generation breeding seedling orchard (BSO) of Eucalyptus grandis in Zimbabwe. Data were from 30 half-sib open pollinated families assessed at two five and six years of age. Growth traits had low to moderate heritability estimates (0.04 to 0.20). Average genetic correlations were large and positive for all traits (rA 0.80). Both heritability estimates and genetic correlations were unaffected by systematic thinning. However selective thinning inflated heritability estimates at age of thinning and reduced them at subsequent ages after selective thinning. The latter was attributed to compensatory growth. Selective thinning reduced genetic correlations. Thus for unbiased estimates of genetic parameters from BSOs analysis should be done on data collected prior to thinning or from systematically thinned tests.


Download File

Full text available from:

Abstract

Genetic parameters for growth and stem straightness were determined for a fourth generation breeding seedling orchard (BSO) of Eucalyptus grandis in Zimbabwe. Data were from 30 half-sib open pollinated families assessed at two five and six years of age. Growth traits had low to moderate heritability estimates (0.04 to 0.20). Average genetic correlations were large and positive for all traits (rA 0.80). Both heritability estimates and genetic correlations were unaffected by systematic thinning. However selective thinning inflated heritability estimates at age of thinning and reduced them at subsequent ages after selective thinning. The latter was attributed to compensatory growth. Selective thinning reduced genetic correlations. Thus for unbiased estimates of genetic parameters from BSOs analysis should be done on data collected prior to thinning or from systematically thinned tests.

Additional Metadata

[error in script]
Item Type: Article
AGROVOC Term: Eucalyptus grandis
AGROVOC Term: Seedlings
AGROVOC Term: Genetic parameters
AGROVOC Term: Seed orchards
AGROVOC Term: Heritability
AGROVOC Term: Pollination
AGROVOC Term: Genetic correlation
AGROVOC Term: Thinning
AGROVOC Term: Breeding
AGROVOC Term: Afforestation
Depositing User: Ms. Suzila Mohamad Kasim
Last Modified: 24 Apr 2025 06:27
URI: http://webagris.upm.edu.my/id/eprint/22349

Actions (login required)

View Item View Item