Genetic resources and domestication
of Acacia mangium
P.A. Butcher, G.F. Moran and H.D. Perkins,
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Abstract
Genetic diversity in the nuclear genome of Acacia mangium was assessed using 57 RFLP loci. Variation was determined for 10 individuals from each of 10 natural populations and compared with 100 individuals from the Subanjeriji seed production stand in Sumatra. This seed stand has provided much of the planting stock in Indonesian plantations. Estimates of genetic variation in natural populations were considerably higher than previously detected using allozymes.
Genetic differentiation between populations in New Guinea, Cape York, Daintree-Townsville, Sidei and Ceram was consistent with geographic discontinuities in the species distribution. The level of genetic diversity was highest in New Guinea and declined from north to south in the Australian populations. The lowest diversity was recorded in Ceram and Sidei. The ranking of populations based on growth performance in provenance trials corresponds with rankings based on levels of genetic diversity. |
Fifty-six percent of the variation detected in the natural populations was represented in the Subanjeriji seed orchard indicating a significant proportion of genetic diversity was not captured in the domestication process. The level of diversity in Subanjeriji reflects the low level of variation in the source populations in the Daintree-Townsville region and illustrates the limitations of establishing breeding populations from a restricted genetic base.
Key words: Acacia mangium, RFLPs, genetic variation, provenance variation, domestication
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