Traits and Genetics
By Treena Hein
Canadians love their potato chips. Agriculture and Agri-Food Canada (AAFC) reports that the potato chips industry in Canada is expected to increase to $1.7 billion by the end of 2016. That’s why those within the AAFC breeding program have been hard at work on two new chip varieties, released in February 2014 for the potato industry to evaluate.
These two newbies are among 15 other new potato selections, including varieties best suited for French fry production and fresh market. They have all been released through AAFC’s Accelerated Release Program, which offers potato industry entrepreneurs of any size the opportunity to evaluate front-runners coming out of early selection trials.
Agnes Murphy, AAFC research scientist at the Potato Research Centre in Fredericton, N.B., says, in terms of the need among growers for better chip selections, it’s always present and steady. “Growers and processors are always keen to try new chip selections, especially if they offer a competitive edge by reducing the cost of production through better yields and lessening the need for inputs,” Murphy says. “There are exacting requirements for manufacturing chips, and traits associated with that must be combined with improved agronomic traits and low rates of defects for any of the new selections to succeed.”
The two new chip selections (see sidebar for details) were all produced using classical breeding methods. Murphy explains that this entails choosing parents each year according to specific objectives and traits the plants may confer to their progeny. “Parents may be cultivars or breeding selections that have been well-characterized for numerous traits such as yielding potential, shape, tuber culinary qualities, skin and flesh colour, disease and pest resistance,” she says.
The parents are grown in greenhouses or growth chambers to produce flowers, which are used for the first step in breeding – the hybridizations. Pollen from the parents (those chosen to serve as male parents) is collected and applied the female stigma (flower part). If the fertilization is successful, small fruit (berries that look like miniature green tomatoes) will form that can contain several hundred botanical seeds. Murphy points out that not every cross combination is successful and that there are a number of barriers that may prevent fertilization. But in cases where it is successful, the next step involves extracting the botanical seeds (also called TPS for true botanical seed to differentiate them from the seed tubers) from the berries and adding them to the seed inventory.
“Then each year, TPS are sown in greenhouses as you would bedding plants,” Murphy says. “Each seed that grows will produce a potato plant that may form small tubers. One small tuber is collected from each separate plant and kept for planting to the field the following year in what is referred to as the first field generation.” From then on the plants are multiplied vegetatively and evaluated for adaptation and for the traits that are important for each end-use category (chip, French fry or fresh market).
Most of the 15 AAFC selections on offer have had five or six years of evaluation, which includes agronomic and culinary performance and disease and pest challenges. “Modern molecular technologies and tools are applied wherever feasible to assist with evaluation,” says Murphy.
“Each year, a series of adaptation trials are conducted nationally at sites across the country. There are usually 40 or more selections plus reference checks included in the trials. The data collected from the trial sites are analyzed and reviewed carefully to identify the selections that will advance to the Accelerated Release Program (ARP) process.”
Growers who wish to evaluate these ARP selections had to contact AAFC by the end of February. Samples of these selections from the AR2014 series are offered to growers or associations on a non-exclusive basis for up to two years of field evaluation. “So, there may be multiple evaluators in different regions participating in Phase 1 each year,” Murphy explains. “After that, in Phase 2, the selections are offered for exclusive field testing for up to three more years based on a competitive bidding process. At any point in Phase 2, if the performance is promising, the right’s holder may negotiate a license with AAFC and variety registration may proceed. All the assessments are performed by the grower or grower’s agent.”
Having the farmers on board means all the hard work of developing these chip varieties under the ARP will continue on schedule. “Potato breeding and cultivar development is absolutely a team effort with lots of people contributing along the way in greenhouse, fields and laboratories,” Murphy notes. “People directly involved include technicians, farm staff, trial collaborators at national trial sites and data managers. Behind-the-scenes administrative staff facilitate the day-to-day operations and provide communications support and more. Dr. Benoit Bizimungu and I are very fortunate to have such a dedicated and highly competent group working with us.”
Murphy says she loves participating in the quest for improved varieties. “There is a continuum in potato breeding that appeals to me,” she says. “The current offerings of selections build on years of contributions made by our predecessors while blending in exciting research advances being made by our colleagues.”
Agriculture and Agri-Food Canada’s new chip potato selections
AR2014-02 F09020 (Brodick x CS7232-4) chip variety is a round potato with flaky light yellow skin, cream coloured flesh, and good chip colour. It offers potato growers a higher-yielding chip potato, with fewer internal imperfections that can reduce chip quality.
AR2014-03 FV15559-79 (Andover x F87031) chip variety is also a round selection with slightly flaky buff skin, creamy flesh, very good chip colour and resistance to PVX. It does better than other chip varieties in cold storage, prolonging shelf life and reducing the need for chemical treatment to control disease that can occur in storage.
Both the new selections have a molecular marker associated with a gene that provides resistance to golden nematode pathotype, Ro1. Murphy says this pest is a quarantine pest and not all widespread, so resistance is useful basically only for areas where it occurs or for export seed markets. Some well-known chipping cultivars such as Atlantic are resistant to golden nematode while others are not, and having the marker is an add-on benefit. For more, see