Potato Association of America honors industry up-and-comers
For the past 20 years, the Potato Association of America (PAA) has honored graduate students with cash awards for outstanding student research presentations given during paper presentation sessions at its annual meeting.
In 2000, an endowment was established to honor the late Frank L. Haynes, longtime professor of potato breeding and genetics at North Carolina State University, to create this program.
PAA’s annual meeting took place July 26-28. This year, 23 students competed for five awards. Below is information on the winners and their research.
Bio: I am currently a graduate research assistant with the David Douches Potato Breeding and Genetics program and Michigan State University. I received my bachelor’s degree in plant science from Utah State University and my associate’s degree in Botany from Snow College in Utah.
Research: “The possibilities and limitations of implementing Solanum verrucosum bridge crosses in breeding programs.” The domesticated potato (Solanum tuberosum L.) is the fourth-most important food crop worldwide and critical food security crop in the developing world. The high significance of this crop coupled with high production losses place potato as a high priority for genetic improvement, especially in the face of climate change. Potato breeding is currently undergoing a seismic shift from a tetraploid outcrossing crop towards a F1 hybrid system using diploid inbred lines as parents. This transformation has changed how potato breeders access important traits from wild species and presented new challenges. Several barriers inhibit the use of the more valuable wild species in traditional breeding schemes and complicate their use in diploid breeding.
Of all the wild species available to potato breeders, wild diploid species from North and Central America are of special interest because of their high degree of disease resistance, pest resistance and tuber quality traits. These valuable species, such as S. bulbocastanum, S. pinnatisectum and S. jamesii, are difficult for plant breeders to access, as crosses between these species and cultivated potatoes aren’t typically possible.
Solanum verrucosum is a unique wild potato species originating from central Mexico. Primary traits of interest include self-compatibility, which would allow the development of inbreds, and the ability to act as a parent in crosses with cultivated potato. S. verrucosum is able to cross with both cultivated potatoes and the genetically distant and isolated wild species from North and Central America, thus acting as a bridge between cultivated potato and these important wild species. The use of S. verrucosum bridge crosses is a simple and valuable technique that offers direct access to valuable wild species traits; and bridge crosses using S. verrucosum require less time and resources compared to other methods used.
There is an acute and critical need to accelerate the genetic improvement of potato to answer the needs of an ever growing global population, climate change, and rapidly evolving cosmopolitan pests such as late blight and Colorado potato beetle. Currently, the most valuable traits known are from the sexually isolated species from North and Central America. At MSU, we have been able to incorporate genetics from these wild species into our breeding lines using S. verrucosum bridge crosses. We are implementing plans to make use of many of these valuable wild species to answer the needs of producers and provide realistic host plant resistance to late blight and Colorado potato beetle.
Bio: I completed my undergraduate degree in agronomy and sustainable production from EARTH University in Costa Rica. My passion for plant breeding brought me to North Dakota State for an internship with the potato breeding program and subsequently to pursue a master’s degree. I am very interested in the applications of new technologies in plant breeding and commercial production. I intend to strengthen my research expertise through a Ph.D. and continue working with potatoes.
Research: Weed control in potato production is an important concern to secure profitable production. Apart from reducing yield potential and reducing the tuber size profile, weeds can interfere with harvest practices and compete for nutrients, moisture and sunlight. Weeds may also harbor diseases, insects and nematodes. On most farms, effective weed control is achieved through herbicide application. The most widely used herbicide on potato acres across the U.S. to control broadleaf weeds and annual grasses is metribuzin, which may be applied pre-emergence and post-emergence. Nonetheless, metribuzin causes mild to severe foliar injury to sensitive genotypes, affecting yield and tuber quality in certified seed and commercial potato production. The knowledge of a potato genotype’s response to metribuzin is important to avoid significant yield and quality reduction.
Traditionally, metribuzin screening involves visual assessments of foliar injury, plant height reduction after application of herbicide and yield at harvest. This approach is not only tedious but is less effective in estimating crop performance due to human error and environmental conditions at the time of evaluation. This leads to the objective of my research, which is to establish a screening protocol for metribuzin sensitivity using high throughput phenotyping for application in the Northern Plains production region. High throughput phenotyping is a rapid and nondestructive tool that can identify some biotic and abiotic stresses in plants, prior to visible foliar symptoms. In 2020, 32 advanced NDSU breeding selections and commercial potato cultivars across all market classes were evaluated.
Plant height, foliar injury, canopy cover and drone images at seven, 14 and 21 days after post-emergence application of metribuzin were collected to identify parameters most correlated with yield and grade. Reflectance data from the drone images and canopy cover collected in 2020, had a higher correlation with total yield compared to foliar injury and plant height. Results from this research confirm the applicability of unmanned aerial vehicles (i.e drones) for high throughput phenotyping to evaluate metribuzin sensitivity in potato genotypes very early in the season. A second year of this study is currently being plant height, foliar injury, canopy cover and drone images at seven, 14 and 21 days after post-emergence application of metribuzin, were collected to identify parameters most correlated with yield and grade. Reflectance data from the drone images and canopy cover collected in 2020, had a higher correlation with total yield, compared to foliar injury and plant height. Results from this research confirm the applicability of unmanned drones for high throughput phenotyping to evaluate metribuzin sensitivity in potato genotypes very early in the season. A second year of this study is currently being conducted.
Bio: I am a Ph.D. student and senior research associate at the University of Idaho’s Department of Entomology, Plant Pathology & Nematology under Louise-Marie Dandurand, Ph.D. I have a bachelor’s degree in environmental science from Allegheny College and a master’s in horticulture from the University of Arkansas.
Research: My research focuses on eradication of Globodera pallida, the pale cyst nematode (PCN), a quarantined pest in Idaho. It is a major threat to the Idaho potato industry as it has potential to cause up to 80% yield loss if left uncontrolled. Growers with infested fields are losing profit because they cannot plant potatoes until PCN is deemed fully eradicated and their fields undergo the extensive deregulation process.
PCN eggs can survive dormant in cysts in the soil for 20 to 30 years and will only hatch in the presence of a hatching stimulus typically released by a host plant, which makes eradication challenging. Soil fumigation has been the primary method of control, but fumigants are becoming more and more restricted or banned altogether due to environmental concerns.
My goal is to investigate trap crops and crop rotation as alternative more sustainable control strategies for PCN. A trap crop for PCN must release a hatching stimulus that causes eggs to hatch but then prevents PCN from infecting and developing in the roots. Previous research has shown Solanum sisymbriifolium, litchi tomato to be an effective trap crop in reducing PCN, however, it does not produce a valuable yield and growers are concerned it may become a noxious weed. It is worthwhile to investigate trap crop potential of other crops, especially those that may have commercial value.
We are assessing trap crop potential of several other solanaceous species as well as quinoa, which has been shown to be a nonhost causing PCN hatch. Our objectives are also to evaluate the impact and feasibility of litchi tomato and quinoa on populations of PCN over time in both greenhouse and Idaho field conditions.
Three-year crop rotations with this trap crop and the partially resistant potato variety Innovato” are also being assessed. If litchi tomato and quinoa are successful in significantly reducing PCN populations in the field, they can be recommended to growers with PCN-infested acreage. Ideally, this project would establish more sustainable strategies for use in an integrated management approach to the eradication of the pale cyst nematode.
Bio: I am entering my fourth year of a Ph.D. in the Plant Breeding, Genetics and Biotechnology at Michigan State University under David Douches. I have a bachelor’s degree from Michigan State as an honors student majoring in plant biology with an additional major in genomics and molecular genetics and a minor in plant, animal and microbial biotechnology.
Research: Advancements in breeding of cultivated tetraploid potato have been limited by its complex genome and reproductive barriers. Due to these limitations, there is still an abundance of economically important associated genes in potatoes whose functions have yet to be understood. To address these limitations, breeding and genetic engineering approaches are being used in potato to create diploid self-compatible inbred lines that are more accommodating for studying gene function. At the diploid level we can also more readily employ new biotechnology techniques, like genome editing, which is a molecular tool that can create specific changes to a targeted sequence in an organism’s genetic material. This can be used to both introduce advanced traits into breeding material as well as being a powerful tool to study gene function. However, this requires germplasm that is amenable to plant transformation and regeneration, which are the methods we use in the lab to introduce our genome editing tools into the plant’s cells and then recover plants that have these targeted changes, respectively.
Regeneration is a tissue culture method that uses plant hormones to stimulate certain plant tissues, like leaves or stems, to produce shoots. This method is necessary for most applications of genome editing and genetic engineering because it allows us to recover a plant that carries the same targeted change throughout all its cells. Regeneration is a complex process and it is time consuming and resource intensive to study. Each plant within a species responds uniquely to the hormones used to regenerate, and identifying the ideal conditions needed to regenerate a given plant is challenging. Media and culture conditions have been optimized for several tetraploid potatoes, but there is still a need for diploid germplasm that can respond to these conditions as well.
To address these limitations, I wanted to identify diploid potatoes that could overcome these barriers. I assessed and ranked selected diploid potatoes for the traits valuable to applications of genome editing. A set of seven lines were evaluated for their regeneration ability, tuber yield and self-fertility. Based on their performance for the above traits, I identified several lines that can be used for applications of genome editing in potato, as well as ruling out ones that are not ideal.
This research serves as a foundation in our pursuit of understanding what makes the traits in potato that we know and love.
Bio: I earned a Ph.D. in potato agronomy from Washington State University in July 2021. I work as a postdoctoral researcher at WSU in Pullman. I also have a bachelor’s in agricultural and food systems from WSU and an associate’s in agribusiness from Columbia Basin College in Pasco, Washington.
Research: Aiming to improve tuber processing qualities by improving irrigation recommendations across multiple cultivars, Francisco’s Ph.D. dissertation focused on assessing potato crop water consumption, modeled evapotranspiration crop coefficients (Kc), and the effects of reduced late-season irrigation on Alturas, Clearwater Russet, Ranger Russet, Russet Burbank and Umatilla Russet.
Francisco evaluated water consumption of each cultivar by monitoring soil water content throughout the season. His findings indicated Alturas, Clearwater, and Ranger consumed more water late in the season than Russet Burbank and Umatilla. The water consumption trends were highly correlated with vine health; however, differences in cultivar growth patterns and water consumption were prevalent. Using this data, Francisco developed Kc values for the five potato cultivars, considering growing characteristics, soil characteristics, cultural management practices and the region’s climate. For ease of grower management, Francisco established two sets of Kc values: one for vigorous canopies and late-maturing characteristics, such as Alturas and Clearwater R., and the other for cultivars with mid-maturing canopies and lower late-season soil-water consumption, such as Burbank and Umatilla. The use of the new coefficients in modeled ET will aid growers in more accurate irrigation leading to higher profits and water conservation.
To refine late-season irrigation across the same cultivars as mentioned above, Francisco examined five irrigation levels beginning at mid-season, the peak of canopy development (95-110 days after planting). The treatments were 40%, 60%, 80%, 100% and 120% of evapotranspiration (ET) replacement and continued until vine-kill. Across the five potato cultivars, reducing irrigation late in the season reduced tuber yield. The economic return of russet varieties Clearwater, Ranger, and Burbank was maximized by irrigating with 100% ET late in the season. Alturas and Umatilla’s economic return was maximized by irrigating with 80-90% ET (10-20% less irrigation) during the last half of the season. In addition to reducing total yield, a reduction in late-season irrigation led to an increase in tuber specific gravity, improved tuber grade, and decreased tuber growth crack incidence in Alturas. Tuber fry color generally improved when late-season irrigation was reduced on all cultivars except for Ranger Russet, potentially enabling tubers to be stored at colder temperatures, which is highly desired by the frozen-processing industry. The research will provide potato growers with management options and guidelines to improve tuber quality — and thus economic return — and incentives to save water while also maintaining high yields.