In:
Canadian Journal of Forest Research, Canadian Science Publishing, Vol. 22, No. 2 ( 1992-02-01), p. 175-182
Abstract:
Variation patterns and selection efficiencies for the three growth traits height, diameter, and volume were studied in two selected interspecific hybrid populations of eastern cottonwood (Populusdeltoides Bartr.): P. deltoides × Populussimonii Carr. and P. deltoides × Populusnigra L. Growth variables differed quite significantly (P 〈 0.01) among clones in each of the two hybrid populations, and they were more dominantly controlled by genetic factors than by environmental regimes. There were higher broad-sense heritablity levels for growth traits in this study than in other related studies. Genetic variances and broad-sense heritabilities for all traits markedly increased with stand development in the two hybrid populations; but the increasing rates with age of these two genetic parameters for diameter and volume were more rapid for P. deltoides × P. simonii hybridization than for P. deltoides × P. nigra hybridization. Selection of the best 5% of the clones from P. deltoides × P. simonii and the best 10% from P. deltoides × P. nigra produced mean 6th-year volume growth increases of 51 and 37%, respectively. Relative to P. deltoides, their high parent, the ratio of clonal heterosis of these selected hybrid clones was 5–23% for 6th-year volume. With different selection intensities, early selection of juvenile growth traits for the two populations, P. deltoides × P. simonii and P. deltoides × P. nigra, can also produce substantial indirect genetic gains for short rotation harvest traits. Further studies of Populus yield breeding and selection models were suggested.
Type of Medium:
Online Resource
ISSN:
0045-5067
,
1208-6037
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1992
detail.hit.zdb_id:
1473096-0
SSG:
23
SSG:
12
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