Ref ID: 11010
Ref Type: Journal
Authors: Shepherd, M., Mellick, R., Toon, P. G., Dale, G., and Dieters, M. J.
Pub Date: 2005
Journal Name: Annals of Forest Science
Volume: 62
Issue:
Start Page: 403
End Page: 412
ISBN/ISSN:
Keywords: adventitious rooting/adventitious rooting,broad sense heritability,clonal propagation,clonal repeatability,rooted cutting,rooting percentage,biomass/biomass/clonal/clonal repeatability/clone/commercial/control/correlations/cutting/cuttings/deployment/development/effect/environment/F1/F2/family/field/gain/gene/generation/genetic/genetic control/genetic correlation/growth/high/hybrid/inbreeding/influence/initiation/N/nursery/ortet/P/pattern/performance/Pinus/Pinus caribaea var.hondurensis/Pinus elliotii var.elliotii/Pinus elliottii/Pinus hybrids/plantation/plantations/pollination/quality/Queensland/rate/root/root system/rooted cutting/rooted cuttings/selection/stem/stem cuttings/structure/system/vigour
Abstract: Genetic control of adventitious rooting was characterised in two unrelated Pinus elliottii x P. caribaea families, an outbred F1 (n = 287) and a 2nd generation family derived from the self pollination of an F1 hybrid (inbred F2; n = 357). For both families, the percentage of rooted cuttings per ortet (rooting percentage) was assessed in three settings conducted over three sequential years beginning in 1998. In the third setting, root biomass was also measured on a sub-set of clones (n=50) from each family. On average, clones in the outbred F1 had a higher rooting percentage (mean ± SE; 59 ± 1.9 %) and biomass (mean ± SD; 0.41 ± 0.24 g), than clones in the inbred F2 family (mean ± SE; 48 ± 1.8 % and mean ± SD; 0.19 ± 0.13 g). A lower root initiation and development rate in the inbred family was consistent with the reduced vigour expected for a taxon that exhibits growth depression upon inbreeding. Despite the differences in genetic structure, genetic determination for rooting percentage was strong, in both families, as indicated by high individual setting clonal repeatabilities (e.g. Setting 3; outbred F1 0.62 ± 0.03 and inbred F2 0.68 ± 0.02 (H2 ± SE)), and the moderate - high genetic correlations amongst the three settings (within family genetic correlations between settings all exceeded 0.61). For root biomass, clonal repeatabilities for both families were lower (outbred F1 0.35 ± 0.09 and inbred F2 0.44 ± 0.10 (H2 ± SE)) indicative of a greater influence of nursery environment on root system quality. Weak positive genetic correlations between rooting percentage and root biomass in both families suggested a concomitant gain in root biomass would be insignificant, when selecting solely on the more easily assessable rooting percentage. Segregations patterns of rooting percentage in the outbred F1 and inbred F2 families suggested relatively simple genetic control (possibly a single gene of major effect). These results indicate that selection for rooting performance will provide an effective means of increasing the average nursery performance of clones field tested for commercial deployment in plantations
Notes: Entered by Mervyn Shepherd (24/02/2005)
Reprint: In File
Program: SPF Genetic Improvement
Project: A7
Deliverable: A7-3
Confidentiality: Confidential to All Partners
Availability: Online
Report: Annual Report 2004/5
Type: Article
Address: mshepher@scu.edu.au