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ARS Home » Pacific West Area » Davis, California » Nat'l Clonal Germplasm Rep - Tree Fruit & Nut Crops & Grapes » Research » Publications at this Location » Publication #231296
Title: Lack of association between allozyme heterozygosity and juvenile traits in Eucalyptus

Author
item Aradhya, Mallikarjuna
item PHILLIPS, V. - UNIV OF HAWAII-TROPIC AG

Submitted to: New Forests
Publication Type: Popular Publication
Publication Acceptance Date: 5/16/1994
Publication Date: N/A
Citation: Aradhya, M.K., Phillips, V.D. 1995. Lack of association between allozyme heterozygosity and juvenile traits in Eucalyptus. New Forests 9: 97-110

Interpretive Summary: Genetic variability for juvenile waits, which included basal diameter, height, biomass accumulation, and growth increment, was studied in eight provenances involving four species, Eucalyptus grandis, E. saligna, E. camaldulensis and E. urophylla, under uniform greenhouse conditions. The species differed significantly for all juvenile waits including individual mean allozyme heterozygosity, and high levels of variability were observed within and among species, which indicated that scope for selection exists for these waits. There was considerable reduction in genetic variability for all waits at 6 months of age when compared to that observed at 4 months. Eucalyptus saligna recorded the highest mean for basal diameter and biomass accumulation, while E. camaldulensis exhibited the highest mean for height. The two E. camaldulensis provenances exhibited the highest individual mean heterozygosities (0.425 and 0.417), followed by E. saligna (0.296 and 0.258), E. urophylla (0.254 and 0.233), and E, grandis (0.300 and 0.163). The juvenile traits were correlated with individual mean allozyme heterozygosity to examine the possibility of developing a genotypic basis for early selection of potentially superior individuals in a tree improvement program.

Technical Abstract: Genetic variability for juvenile waits, which included basal diameter, height, biomass accumulation, and growth increment, was studied in eight provenances involving four species, Eucalyptus grandis, E. saligna, E. camaldulensis and E. urophylla, under uniform greenhouse conditions. The species differed significantly for all juvenile waits including individual mean allozyme heterozygosity, and high levels of variability were observed within and among species, which indicated that scope for selection exists for these waits. There was considerable reduction in genetic variability for all waits at 6 months of age when compared to that observed at 4 months. Eucalyptus saligna recorded the highest mean for basal diameter and biomass accumulation, while E. camaldulensis exhibited the highest mean for height. The two E. camaldulensis provenances exhibited the highest individual mean heterozygosities (0.425 and 0.417), followed by E. saligna (0.296 and 0.258), E. urophylla (0.254 and 0.233), and E, grandis (0.300 and 0.163). The juvenile traits were correlated with individual mean allozyme heterozygosity to examine the possibility of developing a genotypic basis for early selection of potentially superior individuals in a tree improvement program.