Ref ID: 9783
Ref Type: Personal Communication
Presenters: Shepherd, M.
Date: 15-4-2002
Duration: 30 minutes
Event Name: WoodFest
Event Series: CRC-SPF Seminar Series
Event Dates: 15 April
Location: Gympie, Queensland
Recipients:
Recipient Organisations: QFRI, DPI-Forestry
Num Audience: 40
Organisers: Dieters, M.J.
Individual Organisers: Dieters, M. J.
Keywords: analysis/architecture/breeding/Caribbean pine/character/conventional/correlations/correspondence/CRC-SPF/cross/density/detection/diameter/distribution/dry/effect/environment/eucalypt/experiment/F1/family/forestry/gene/genes/genetic/genetic improvement/genetic map/genetics/genome/growth/height/hybrid/hybrids/importance/index/inheritance/interaction/interspecific/loci/map/marker/marker-aided selection/MAS/measurement/model/molecular/molecular breeding/molecular genetics/New South Wales/pine/Pinus caribaea var.hondurensis/Pinus elliottii var.elliottii/Pinus hybrid/population/production/program/property/QFRI/QTL/QTL detection/quality/quantitative/quantitative trait loci/Queensland/region/selection/selection strategy/seminar/series/site/sites/stem/strategy/study/trait/tree/wood/wood properties/wood quality/molecular genetic studies
Abstract: Quantitative trait loci (QTL) analysis is one of the most powerful molecular genetics approaches for understanding genetic architecture ie. the number of genes, their relative magnitude of effect, their intralocus gene action, their distribution in the genome and the importance of interactions amongst genes and with the environment. Knowledge of genetic architecture can be used directly in conventional tree breeding programs in the modelling of selection strategies but ultimately the most powerful use of this knowledge may be for molecular breeding including marker-aided selection (MAS). Under the auspices of the CRC for Sustainable Production Forestry, researchers at Southern Cross University and QFRI are conducting QTL detection experiments in the slash × Caribbean pine F1 hybrid. We have been developing restricted models of genetic architecture for physical wood properties, branching and stem traits. The models are restricted in the extent to which intralocus gene action can be evaluated and in the experimental power to detect QTL due to the limited experimental populations available for this work. The power, nonetheless, should be sufficient to detect large effect QTL but there was no evidence of large effect QTL in these traits. This observation is consistent with expectations from quantitative studies on these characters but not with previous QTL studies in interspecific eucalypt hybrids. This suggests there is less divergence amongst slash and Caribbean pine than those used in the eucalypt hybrids. The model emerging for the genetic architecture of wood quality traits is one of small additive effect genes. The inheritance of branching characters, when considered at a family level, tends to be stable across sites, however, this was not the case for most physical wood properties ie. ring, earlywood and latewood width and density, dry wood index, and whole core basic density. The unfavourable phenotypic correlations between gross growth measurements, stem height (HT) and diameter at breast height (DBH) were not evident in this family but a correspondence in genome regions influencing HT and ring, earlywood and latewood widths and densities may indicate the same genes are involved in controlling all of these characters. Greater resolution in genetic maps will be required to determine whether these genetic correlations are a consequence of pleiotrophy (same genes influencing several traits) or due to separate closely linked genes.
Notes: Entered by Mervyn Shepherd (6/5/2002)
Address: mshepher@scu.edu.au
Reprint: Not in File
Program: SPF Genetic Improvement
Project: A7
Deliverable: A7-3
Confidentiality: Confidential to All Partners
Availability: Authors;
Report: Annual Report 2001/2
Type: Presentation