Ref ID: 9555
Ref Type: Conference Proceeding
Authors: Apiolaza, L. A., Potts, B. M., and Gore, P. L.
Date: 2001
Volume:
Num Volumes:
Edition:
Start Page: 155
End Page:
ISBN/ISSN:
Editors:
Conference Date: 10-15 September, Valdivia, Chile
Conference Title: Developing the Eucalypt of the Future
Conference Location:
Publisher: Instituto Forestal
Pub Place: Chile
Series Title: IUFRI International Symposium
Series Editor:
Keywords: breeding/bud/clone/control/cross/density/deployment/effect/error/eucalypt/Eucalyptus/family/flower/function/future/generation/genetics/Eucalyptus globulus/heritability/impact/island/natural/open-pollination/seed orchard/pedigree/pollen/pollination/population/production/program/reproduction/seed/seedling/sense/site/symposium/temperate/temperature/time/tree/value/variation/genetic/flowering/flowering time
Abstract: Sexual reproduction is a key element for breeding programs. Seed production is commonly used for both breeding of advanced generations and deployment purposes. Although controlled pollination is a reliable procedure to produce individuals with known pedigree, open pollination is often used in breeding programs and it is the norm for natural populations. Estimation of breeding values and deployment of open pollinated seed rely on assumptions such as panmixis and large number of parents contributing pollen. In spite of this, there is evidence that these assumptions do not hold for temperate eucalypts. The aim of this project is to quantify the degree of variation and genetic control of peak flowering time for Eucalyptus globulus.
Trees were assessed for flowering in open pollinated seed orchards, seedling seed orchards and clonal seed orchards, covering most of the subraces of Eucalyptus globulus. Flowering was assessed either every two weeks or every four weeks, scoring the percentage of flower buds still to open. Thus, percentages changed from 100% to 0% during the scoring time. Peak flowering time was defined as the 50 percentile of a 2-parameter Weibull cumulative density function fitted to the scores.
There is a large difference for peak flowering time between subraces. Some of the subraces do not overlap at all, with the consequent lack of crossing ability. An extreme example are the Flinders Islands and King Island subraces, which show early and late flowering respectively. Another important effect is site. The temperature gradient between sites has an impact on the average peak flowering time at both the subrace and the family levels. Narrow sense heritabilities for peak flowering time range between 0.3 and 0.9; however, the standard errors are large, because of small sample sizes.
Notes:
Address: Luis.Apiolaza@utas.edu.au
Reprint: In File
Program: SPF Genetic Improvement
Project: A1; A2
Deliverable:
Confidentiality: Confidential to All Partners
Availability:
Report: Annual Report 2001/2
Type of Work: Poster