关键词: 黑荆树, 种源, 家系, 生长性状, 遗传变异, 早期选择

Abstract:

Black Wattle (Acacia mearnsii) is an important species in Australia for short rotation, with many uses. The species has been widely planted and utilized in southern China at present. This study was carried out in an open-pollinated 15-year-old provenance/progeny trial in Lufeng County, Yunnan Province. Total 158 open-pollinated progenies derived from 19 provenances in Australia and 8 open-pollinated progenies from China were tested in the trial. The phenotypic and genetic variations in growht traits of provenances/progenies were analyzed. The analysis results showed that height, DBH, bark thickness at breast height and the volume of individual tree were significantly different at 3, 5, 9 and 15-year-old trees among the provenances and progenies, which suggested that there was great potential either for provenance selection or family selection, and the variation was the major sources for the species improvement. Heritability and genetic correlation for growth traits were estimated for the open-pollinated families of A. mearnsii. The growth traits (height, DBH, bark thickness at breast height) of family heritability were over 0.7 and individual heritability was over 0.5, which meant these traits were strongly controlled by genetics. There were high phenotypic and genetic correlations for height, DBH and bark thickness at breast height between 3,5,9-year-old and 15-year-old progenies. The genetic correlation coefficients of 5 and 15 years old trees were over 0.8, which indicated that these relationships were mainly controlled by genetic factors. The stage from 5 to 9 years old was the best period for early selection in the open-pollinated provenance/progeny test of A. mearnsii, and the DBH was a better indicator than other traits due to its genetic stability.

Key words: Black Wattle(Acacia mearnsii), provenance, family, growth traits, genetic variations, early selection