Features Agronomy Traits and Genetics
New selections offer higher yields

Researchers at Agriculture and Agri-Food Canada (AAFC) who have been hard at work using science to help farmers achieve this goal shared their most recent successes with the industry during the annual release of new selections, held in February at the Potato Research Centre in Fredericton and at the Lethbridge Research Centre.

This year researchers released 16 varieties, all offering high yields. These include eight varieties for the fresh market, four for the French fry market, three for potato chip production and two specialty, pigmented varieties – one with red skin and pink flesh and the other with blue skin and dark purple flesh. All the varieties were developed in response to demands from growers, consumers and processors.

“Everyone is looking to better performing varieties that are easy to grow and have a good market potential. That combines good agronomics, but also good market traits,” says Benoit Bizimungu, the potato breeder who led a team of AAFC researchers at the Potato Research Centre. “Every year we try to put forward any selections that have any improvement over the existing ones in terms of either potential for further yield, reduced tuber defects, improved resistance or niche market potential. Any new selection has at least one additional beneficial trait compared to what’s on the market.”

Several of the varieties introduced through AAFC’s accelerated release program this year offer resistance to a major disease of concern for the industry: late blight.

Released for the French fry market, AR2015-04 (Defender x F00102) showed moderate resistance to foliar late blight in two years of controlled tests. “It’s not immune, but it shows some reduced susceptibility to existing strains, which is quite an improvement over some mainstream French fry varieties,” Bizimungu says. “We’re hoping to bring more improved varieties out in the coming years as the breeding progresses.”

Researchers also made some progress on breeding scab resistance into this year’s new releases. Eleven of this year’s new releases demonstrate at least moderate scab resistance during trials, and two varieties – AR2015-01 (A88093-1 x CO95007-1RU) for the French fry and fresh markets and AR2015-06 (Vigor x CV96105-2) for the chip and fresh markets – both demonstrated resistance to scab, scoring two and three, respectively, on the composite scab index.

This year’s accelerated releases also include two varieties that have demonstrated resistance to potato virus Y (PVY) in trials. Researchers report AR2015-11 (NO634-7 x AC Chaleur), developed for the fresh market, is resistant to PVY, although this variety does appear to be susceptible to potato virus X (PVX) by mechanical inoculation. The fresh market variety AR2015-16 (FV12486-2 x Cara) demonstrates “extreme resistance” to PVY, showing negative reactions to both mechanical and graft inoculation. However, this variety also seems to be susceptible to PVX by mechanical inoculation.

When it comes to pests, Bizimungu says researchers have been making some good progress on breeding varieties with resistance to cyst nematode by using marker-assisted selection. Four of this year’s releases have copies of Ro1; a marker associated with resistance to golden nematode. AR2015-07 (Exploits x Tenace) and AR2015-09 (N0634-7 x Rochdale Gold-Dorée) both have one copy of the marker, while AR2015-05 (F95024 x 12939-58) and AR2015-08 (F87070 x N0634-7) have two copies each of the RO1 marker.

The researchers have Colorado potato beetle in their sights as well. “There’s no resistance existing in varieties right now, so it takes a lot of spraying,” Bizimungu says. “We’re making some progress by introducing some natural resistance genes from wild species using conventional breeding. This shows some promising results and we’re hoping to bring that to the industry in the coming years.”

This year’s selections have been bred for specific traits to improve the marketability of various potato varieties. For example, AR2015-12 (Huckleberry x F02041) – a variety with red skin and pink flesh developed for the fresh market – has been bred to retain its colouration in storage. “Colours of some of the varieties eventually fade over time, which reduces the consumer appeal,” Bizimungu says. AR2015-12 and AR2015-15 (CV89023-2 x V0498-1) answer the industry’s need for a red skin variety that maintains its colour while also delivering good yield.

Bizimungu says AR2015-01 (A88093-1 x CO95007-1RU), developed for the French fry and fresh markets, also has strong potential, offering good yield in addition to good storage capacity and reduced bruising potential.

So far, industry response to this year’s releases has been very positive. “The varieties that we have released have all been requested by at least one company to try in the field,” Bizimungu says. “We see companies requesting a whole bunch of selections, but we see more and more people having a focus, which means that maybe the industry is looking more specifically into segments of the market in specific varieties.”

Looking ahead, Bizimungu expects the industry – and, by extension, the AAFC’s accelerated release program – will remain focused on varieties that add profitability to the field. “We need to have varieties that are easier to grow, have improved resistance to environmental stresses, and that require less input in terms of protection chemicals or fertilizer. We’d like to have very promising varieties that are easier to grow and that are adapted to growing conditions, in addition to meeting the industry and the consumer demands.”

Nutrition will be an important area of focus for future releases as well. “We’ve been working on improving antioxidant levels in pigmented-flesh selections, but also improving the carbohydrate profile in all selections so that potatoes look attractive to more segments of consumers in terms of digestibility and dietary fibre components,” Bizimungu says. “We’re looking at improving the nutrition attributes as well as looking at productivity traits.”

Search accelerated release potato varieties on Agriculture and Agri-Food’s website for more information.