Breeding and Genetics – Past performance
Background
Research in radiata pine tree breeding started in the early 1950s, and it has remained a major ingredient in the growth and development of commercial plantation forestry in New Zealand.
Radiata pine is now entering its third generation of breeding and still has considerable improvement ahead.
Achievements
Over the last 50 years of breeding, stem acceptability rose from 45% to over 80%, and volume growth increased some 35%.
In 1997, the GF Plus scheme followed to include other traits of interest such as wood density and corewood stiffness.
Over the last 10 years, one of the most significant achievements of tree breeding has been re-capture of density lost from much of the forest estate as a result of decisions to pursue rapid growth and the production of clearwood. Losses have now effectively been reversed. Increased density will contribute to strength, stiffness, and stability.
Costs
In 2001, the Radiata Pine Breeding Company was established and shareholders then contributed some $900,000 p.a. by way of cash and royalty income to match similar contribution from FRST.
FOA member contributions, including share of royalty income, are approximately $650,000 p.a. The total RPBC Research and Operations annual budget, including all overheads, is $1.8 million.
Financial Benefits
Analyses of the financial benefits arising principally from the improvements in growth and form made over the period to 2000 show that genetics was responsible for most gain up to the 1990s, but since then improvements have resulted from an equal contribution of genetics and management practices.
In 2010, improvements were estimated to have a capitalised value of $4.294 billion across the entire estate (equivalent to an annual value of $344 million). Stands planted after 2000 will be some 31% more productive than unimproved stock. Conventional genetics can add a further 15% gain by 2050, which will double to 30% if genomic selection becomes integrated into the radiata pine breeding programme.
Genomics to speed the process
Issue
- Tree breeding is slow and it may take up to 25-30 years before the new genetics enters commercial production.
- If the length of this breeding and deployment cycle can be halved, the impact would be to double genetic gain available over time and increase the rate of improvement in key traits of economic importance.
Genomic selection
Genomic selection represents a step-change in animal and plant breeding. Together with the introduction of forward selection, it will allow the early selection of genotypes for deployment without the need for progeny testing. Multiple traits can be assessed simultaneously.
The technology would shorten the breeding and deployment cycle by some 15 years, and deliver twice the gain per unit time.
Outline of Science Programme
Partial genetic sequencing of radiata pine (not expensive) and the identification and selection of SNPs (like small “snippets” of DNA) to act as molecular markers for expressed genes. (Full sequence and mapping in associated research at Scion).
SNPS are then distributed in very small quantities on a SNP chip. This is technology that has been commercialised and will be purchased internationally. Initially, 50,000 SNPs will be placed on a chip, with each chip costing some $500 and requiring a minimum production of 1200.
The next stage involves “training” where genotypes with known phenotypic data for traits of interest have their DNA extracted and tested against the SNP chip. Matches between the two relate patterns on the SNP chip with presence of genes associated with traits. SNPs of no function are discarded. A chip can only be used once against one tree.
The target commercial chip will be smaller (3-5,000 SNPs) and cheaper. It will be used to screen parents of the production and elite populations and for the development of genetic breeding values (GeBVs). This information will be used for breeding and particularly deployment decisions. Testing and validation procedures will be included.
Regional clonal testing of selected genotypes will provide the early multiplication phase for delivery of planting stock by 2022.
Costs
The cost of the upcoming 5-year R&D programme, commencing F14, is estimated at $1 million a year (total $5 million). An application for funding will be made to MBIE to establish a research partnership.
This will require industry to supply 50% of the required funding, namely $500k a year for 5 years.
Potential Benefits
The Genomic Selection programme will deliver improved planting stock for commercial deployment in 2022.
Current genetic improvement will deliver some additional 15% gain over the period to 2050. The first impact of genomic selection will deliver an additional 15% gain by 2050.
Total gain achievable by 2050, expressed as gain in volume, will therefore be in the order of 30%.
This equates to an increase of 135m³/ha, and an increase in value of some $12,000/ha at the end of rotation calculated on a current production of 450m³/ha. Additional pulses of some 10% gain (ca. 40-50m³ volume equivalent) will follow at 8-10 year intervals.
Genetic approaches – Finding the plus gene(s)
Opportunity
There are many technologies that can be used to deliver improved planting stock, most of them based around finding and deploying the best genetic material.
Process
The process outlined below can be used to select for genes for growth, wood quality, disease resistance and other traits.
- The end point is to deliver, in this case, disease resistant planting stock to either seed orchards or clonal material.
- The traditional approach is for single trait selection – a slow method involving field testing or trial surveys.
- Molecular technologies, including metabolomics, SNP markers, and genomic selection can greatly speed the process of selecting for multiple traits, Genomic selection will also shorten the time for production of planting stock
- The genetic engineering (GE) approach can involve single or multiple gene transfer - both within and across species.
- All approaches require field testing, and in the case of GE, the application of somatic embryogenesis technology to achieve transformation and delivery.
Benefits
The benefits of the different pathways are outlined.
Endophytes for increased productivity
Opportunity
Endophytes are micro-organisms (including fungi) located within healthy functional plant tissue.
Some root endophytes promote plant growth, for example via improved nutrition, increased photosynthetic efficiency, increased tolerance to abiotic stress.
The opportunity is to identify outstanding root endophytes that give long-term growth promotion in Pinus radiata.
Research
Screen root endophytic fungi from the Lincoln University Bio-Protection Research Centre culture collection for growth promotion of P. radiata.
Select best performing isolates for long-term evaluation: nursery, - plantation - life of crop.
Inoculation of best isolates in cost-effective practical manner for industry (e.g. seed coating).
Mass production of pure cultured inoculum of best root endophytes (e.g. Trichoderma – sporulate freely, stable, rapid growth, easy to produce).
Research Costs
The major cost will be one full-time research technician for screening and testing to select the best isolates.
The cost for this project including supervision and materials would be approximately $150K/year (2–5 years depending on progress).
Potential Benefits
We have identified several promising isolates in preliminary growth-promotion assays with P. radiata.
High probability of successful outcome.
A similar approach with plantation forestry in SE Asia has resulted in increased growth of 3-15% for trees up to 4 years old (10-45% increase in wood volume).
Assuming a 5% growth promotion in P. radiata, wood volume would increase by 16%.
Possible reduction in rotation time.
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