DNA-informed breeding techniques allow breeders to examine individual plants before costly field trials. Previous studies with tree fruits such as apple (Malus ×domestica) and peach (Prunus persica) have identified cost-effective implementation of DNA-informed techniques. However, it is unclear whether breeding programs for herbaceous perennials with 1- to 2-year juvenile phases benefit economically from these techniques. In this study, a cost-benefit analysis examining marker-assisted selection (MAS) in a Pacific northwest U.S. strawberry (Fragaria ×ananassa) breeding program was conducted to elucidate the effectiveness of DNA-informed breeding in perennial crops and explore the capabilities of a decision support tool. Procedures and associated costs were identified to create simulations of the breeding program. Simulations compared a conventional breeding program to a breeding program using MAS with low (12.5%), medium (25%), and high (50%) removal rates, and examined different scenarios where MAS had diminishing power to remove individuals as selections reenter the breeding cycle as parent material. We found that MAS application under current costs was not cost-effective in the modeled strawberry program when applied at the greenhouse stage, but cost-effectiveness was observed when MAS was applied at the end of the seedling trials before clonal trials with a removal rate of 12.5%.
Seth D. Wannemuehler, Chengyan Yue, Wendy K. Hoashi-Erhardt, R. Karina Gallardo, and Vicki McCracken
R. Karina Gallardo, Parichat Klingthong, Qi Zhang, James Polashock, Amaya Atucha, Juan Zalapa, Cesar Rodriguez-Saona, Nicholi Vorsa, and Massimo Iorizzo
Informed assessment of priority genetic traits in plant breeding programs is important to improve the efficiency of developing cultivars suited to current climate and industry needs. The efficiency of genetic improvement is critical for perennial crops such as cranberries, as they usually involve more resources, time, and funding compared with other crops. This study investigated the relative importance of cranberry producers’ preferences for breeding traits related to fruit quality, productivity, plant physiology, and resistance to biotic and abiotic stresses. Industry responses revealed that fruit characteristics affecting fruit quality, including firmness, fruit size and anthocyanin content, and resistance to fruit rot, were the most desired traits in new cranberry cultivar release. These traits have the potential to increase the quality standards needed to process high-value sweetened dried cranberry products, positively affecting price premiums received by producers, which is critical for the economic viability of the cranberry industry. Our findings will be useful to breeders and allied scientists seeking to develop an advanced DNA-based selection strategy that would impact the global cranberry industry.
Seth D. Wannemuehler, James J. Luby, Chengyan Yue, David S. Bedford, R. Karina Gallardo, and Vicki A. McCracken
Incorporating DNA-informed breeding techniques can improve selection efficiency for desired traits as compared with conventional breeding methods that do not use DNA-informed techniques. Incorporation of DNA technologies requires additional costs associated with reagents, equipment, and labor. To elucidate the cost-effectiveness of DNA-informed breeding in perennial crops with multiple years per generation, we conducted a cost–benefit analysis examining incorporation of marker-assisted selection (MAS), a type of DNA-informed breeding, applied to an apple breeding program. Annual operational costs for a midwest apple breeding program were used to develop a simulation with inputs including itemized costs and per unit costs for procedures at each breeding program stage. Simulations compared costs of MAS breeding techniques to conventional breeding methods to identify the break-even point (BEP) where cost-savings associated with MAS equals the accrued additional costs. Additional sensitivity analyses were conducted to examine changes in laboratory costs, seedling maintenance costs, and seedling evaluation costs. We found the BEP for this program occurs when MAS results in a removal rate of 13.18%, and changes to other costs (i.e., maintenance costs) result in a smaller percent decrease to the overall program budget. Our findings are useful to perennial crop breeding programs in which managers are considering incorporating DNA-informed breeding techniques.
Chengyan Yue, R. Karina Gallardo, James J. Luby, Alicia L. Rihn, James R. McFerson, Vicki McCracken, Tom Gradziel, Ksenija Gasic, Gregory L. Reighard, John Clark, and Amy Iezzoni
We conducted audience surveys at three major peach producer meetings across the United States. We found that the relative importance assigned to fruit quality and tree traits by producers varied across producers’ end markets. Fresh peach producers indicated fruit flavor and size were the most important fruit quality traits, whereas processed peach producers viewed fruit size, fruit firmness, and absence of split pits as being the most important traits for a successful peach cultivar. These results have potential to ensure that peach breeding programs are consonant with fresh and processed peach producers’ needs for fruit and tree traits.
Chengyan Yue, R. Karina Gallardo, James J. Luby, Alicia L. Rihn, James R. McFerson, Vicki McCracken, Nnadozie Oraguzie, Cholani Weebadde, Audrey Sebolt, and Amy Iezzoni
Developing new cherry cultivars requires breeders to be aware of existing and emerging needs throughout the supply chain, from producer to consumer. Because breeding programs in perennial crop plants like sweet and tart cherries require both extended time and extensive resources, understanding and targeting priority traits is critical to improve the efficiency of breeding programs. This study investigated the relative importance of fruit and tree traits to sweet and tart cherry producers using ordered probit models. Tart cherry producers considered productivity and fruit firmness to be the most important traits, whereas sweet cherry producers regarded fruit size, fruit flavor, fruit firmness, freedom from pitting, and powdery mildew resistance as important traits. The location of producers’ orchards and their demographic backgrounds influenced their perceptions of the importance of traits. Our findings provide a quantitative basis to reinforce existing priorities of breeding programs or suggest new targets.
Chengyan Yue, R. Karina Gallardo, James Luby, Alicia Rihn, James R. McFerson, Vicki McCracken, David Bedford, Susan Brown, Kate Evans, Cholani Weebadde, Audrey Sebolt, and Amy F. Iezzoni
Systematic studies of the relative importance of apple traits for U.S. apple producers to inform U.S. apple breeding programs have been lacking. To fill this gap, a series of audience surveys with instant feedback at five apple producer meetings across the United States was conducted. The traits included in this study were fruit crispness, juiciness, firmness, flavor, soluble solids concentration, sugar–acid balance, shelf life at retail, freedom from storage disorders, host plant disease resistance, and other fruit and tree traits provided by the producer. Producers rated fruit flavor and crispness as the most important traits for a successful apple cultivar. The relative importance assigned to traits was associated with growing location and producers’ years of experience in the decision-making process of managing apple orchards. This study contributes directly to a larger effort that provides breeding programs with systematic knowledge of trait preferences of supply chain members, including producers, and should result in a more targeted approach to developing and commercializing new apple cultivars.
Zongyu Li, R. Karina Gallardo, Vicki A. McCracken, Chengyan Yue, Ksenija Gasic, Gregory Reighard, and James R. McFerson
U.S. peach (Prunus persica) growers are challenged by the need to protect their orchards from economically damaging diseases and deliver fruit with the quality expectations of the supply chain. This study focuses on the U.S. southeastern peach sector, including North Carolina, South Carolina, Alabama, Virginia, and Georgia. This region offers a useful case to analyze growers’ preferences for both fruit quality and disease resistance. We collected primary data from peach operations in 2016 and 2018. In both surveys, a discrete choice experiment was used to advance the understanding of how peach growers in the southeastern United States value fruit quality (i.e., fruit size and external color) vs. disease resistance [i.e., brown rot (Monilinia fructicola)]. The sample of growers surveyed in 2016 growers placed a greater importance on the fruit quality attribute that would imply higher returns, that is, fruit size (expressed as fruit diameter) compared with improvements in brown rot resistance and external fruit color. Meanwhile, the sample of growers surveyed in 2018 placed a higher importance to brown rot resistance and external fruit color compared with fruit size. Findings consistent for the 2 years are that growers are willing to pay for larger rather than smaller improvements in brown rot resistance, and that a large improvement in brown rot resistance is more important than external fruit color.
R. Karina Gallardo, Eric T. Stafne, Lisa Wasko DeVetter, Qi Zhang, Charlie Li, Fumiomi Takeda, Jeffrey Williamson, Wei Qiang Yang, William O. Cline, Randy Beaudry, and Renee Allen
The availability and cost of agricultural labor is constraining the specialty crop industry throughout the United States. Most soft fruits destined for the fresh market are fragile and are usually hand harvested to maintain optimal quality and postharvest longevity. However, because of labor shortages, machine harvest options are being explored out of necessity. A survey on machine harvest of blueberries (Vaccinium sp.) for fresh market was conducted in 2015 and 2016 in seven U.S. states and one Canadian province. Survey respondents totaled 223 blueberry producers of various production sizes and scope. A majority (61%) indicated that their berries were destined for fresh markets with 33% machine harvested for this purpose. Eighty percent said that they thought fruit quality was the limiting factor for machine-harvested blueberries destined for fresh markets. Many producers had used mechanized harvesters, but their experience varied greatly. Just less than half (47%) used mechanical harvesters for fewer than 5 years. Most respondents indicated that labor was a primary concern, as well as competing markets and weather. New technologies that reduce harvesting constraints, such as improvements to harvest machinery and packing lines, were of interest to most respondents. Forty-five percent stated they would be interested in using a modified harvest-aid platform with handheld shaking devices if it is viable (i.e., fruit quality and picking efficiency is maintained and the practice is cost effective). Overall, the survey showed that blueberry producers have great concerns with labor costs and availability and are open to exploring mechanization as a way to mitigate the need for hand-harvest labor.
R. Karina Gallardo, Qi Zhang, Michael Dossett, James J. Polashock, Cesar Rodriguez-Saona, Nicholi Vorsa, Patrick P. Edger, Hamid Ashrafi, Ebrahiem Babiker, Chad E. Finn, and Massimo Iorizzo
Developing new blueberry cultivars requires plant breeders to be aware of current and emerging needs throughout the supply chain, from producer to consumer. Because breeding perennial crop plants (such as blueberry) is time- and resource-intensive, understanding and targeting priority traits is critical to enhancing the efficiency of breeding programs. This study assesses blueberry industry breeding priorities for fruit and plant quality traits based on a survey conducted at commodity group meetings across nine U.S. states and in British Columbia (Canada) between Nov. 2016 and Mar. 2017. In general, industry responses signaled that the most important trait cluster was fruit quality including the firmness, flavor, and shelf life. Fruit quality traits affect price premiums received by producers; influence consumer’s preferences; and have the potential to increase the feasibility of mechanical harvesting, all critical to the economic viability of the industry. There were differences across regions in the relative importance assigned to traits for disease resistance, arthropod resistance, and tolerance to abiotic stresses. Our findings will be useful to researchers seeking solutions for challenges to the North American blueberry industry including development of new cultivars with improved traits using accelerated DNA-based selection strategies.
Zongyu Li, R. Karina Gallardo, Wendy Hoashi-Erhardt, Vicki A. McCracken, Chengyan Yue, and Lisa Wasko DeVetter
Pacific Northwest North America (PNW) strawberry (Fragaria ×ananassa) growers are transitioning away from the processing to fresh-market sector in response to changes in local and regional markets. However, many of the regional cultivars bred for the PNW were not developed for the fresh market. There is a need to gain a better understanding of growers’ priority traits and their relative importance to enable breeders, researchers, and extension specialists to better serve this growing industry. The objective of this study was to provide such information on strawberry genetic traits of importance for the changing strawberry industry in the PNW with an emphasis on fresh-market production. Six surveys were administered to 32 growers representing ≈53%, 23%, and 15% of the total strawberry acreage in Oregon, Washington, and British Columbia, Canada, respectively. Growers ranked the relative importance of five plant and fruit traits, including fruit quality, disease resistance/tolerance, insect pest resistance/tolerance, plant stress tolerance, and other plant factors. Information about target markets, marketing channels, and general grower characteristics were also obtained. Whereas overall responses differed among the surveyed locations, fruit quality was considered the most important trait across all locations, with disease resistance/tolerance as the second most important. Specific fruit quality traits of importance were external appearance free of defects, skin color, size, sweetness, firmness, and flavor, whereas phytonutrients, seed color, and low drip loss after freezing and thawing were less important. Plant stress tolerance was identified as less important for strawberry growers in all locations. Results also showed many growers have already or are in the process of transitioning to the fresh market. Information obtained from this survey can be leveraged to target important breeding traits for fresh-market strawberry breeders within the PNW. Results also suggest priority areas of synergistic research and outreach activities to help growers achieve high fruit quality while managing diseases for fresh-market producers.