Research Team Seeks to Boost Berry Quality
A recent survey of U.S. blueberry growers show they believe the berries are going to need firmer texture and better flavor, and those should be priorities for breeders, even more so than making them easier to grow.
“You would think growers would care more about production traits, such as saving on pesticides,” says Massimo Iorizzo, Assistant Professor of Plant Genetics and Genomics at North Carolina State University, who led the survey. “I like it that they’re placing a priority on fruit quality — it shows they care more about the end user, the consumer, more than themselves. Quality for blueberry and cranberry is key, the growers are emphasizing how important.”
The survey serves as the basis for a project Iorizzo is directing, “Vaccinium CAP: Leveraging genetic and genomic resources to enable development of improved blueberry and cranberry cultivars to growers and consumers,” which is under consideration for a USDA Specialty Crops Research Initiative (SCRI) grant. The overall objective of the project is to develop DNA-based tools to select and efficiently deliver cultivars with improved fruit texture, appearance (size), and metabolite composition and that can improve machine harvest efficiency and extend shelf life. This project represents a continuation of a planning grant funded by USDA National Institute of Food and Agriculture.
Chad Finn, USDA Research Geneticist in Corvallis, OR, and a project co-director, says the survey shows growers value the importance of texture, whether you call it firmness, crispness, or just plain “pop,” that they think consumers prize above all. Southern highbush blueberries are known for that crispness, while Northern highbush are known for flavor; breeders would like to combine them.
“I think what this project is doing is bringing the Northern and Southern varieties together,” he says, “pooling our resources to get the best of both worlds.”
Native Crops Targeted
While the survey focused on blueberries, the project would include cranberries, another of the very few fruit crops native to North America. Another project Co-director is Nicholi Vorsa, a Rutgers University Biology Professor who heads the Philip E. Marucci Center for Blueberry and Cranberry Research and Extension.
Vorsa, who has trials across the country and Canada, says they have identified five excellent cranberry candidates with resistance to fruit rot, which is a complicated disease complex that is caused by at least 15 fungi, each of which can be more difficult depending on the year. Unfortunately, none of the five showing resistance are attractive from a horticultural standpoint, so Vorsa hopes that as part of the project he can do more crosses with DNA markers, accelerating the process.
That’s the key to the project, says Iorizzo, which he likened to a similar project that also has fruit quality as its top objective, RosBREED. What RosBREED has done for crops in the Rosaceae families — such as apple, cherry, peach, pear, strawberry, and roses, as well as blackberry, peach, and cherry rootstocks — coordinating breeding and genomics-based approaches, Iorizzo would like to see applied to Vaccinium.
Firmness is certainly the tops for both crops, he says, especially blueberries.
“Firmness is so important in blueberry — besides consumer preference, it plays a role in shelf life, consumer preference, and reducing damage during mechanical harvest,” he says, noting that the 50% of the crop that is for fresh market is still mostly hand-picked. “Also, if you have a berry with improved texture, you may be able to store them longer so there is more flexibility in supply chain, and less waste.”
Iorizzo notes that North America is the world’s largest producer of cranberries and blueberries, and the U.S. leads production of both crops. Driven by recognition of the health benefits associated with cranberry and blueberry consumption, world production grew 40% and 35%, respectively from 2006 to 2014. He says stakeholders need more research support to sustain the increasing product demand of this dynamic industry, to expand into new production regions and adapt to changing consumer preferences.
Cranberry and blueberry growers have indicated that the development of new cultivars is among the most common priority, but resources have been are lacking to take these breeding efforts to the next level and establish a science-based approach, integrating the most advanced technology to address long-term critical needs.