Low Glycemic Potatoes, a value-added crop for Montana

Final Report for SW12-108

Project Type: Research and Education
Funds awarded in 2012: $154,000.00
Projected End Date: 12/31/2015
Region: Western
State: Montana
Principal Investigator:
Dr. David Sands
Montana State Univ
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Project Information


The overall goal of our lab is to develop value-added crops with highly desirable nutritional attributes that are suitable for production in the state of Montana. This nutritional focus includes high-protein, gluten-free, and low-glycemic index crop varieties. The objectives of this proposal were to identify and evaluate low glycemic lines of potato that would be more suitable for consumption by individuals with diabetes Type II and associated health problems and to deliver the varieties to commercial growers (seed potato producers and market potato producers). We screened the starch profiles of over 110 varieties of U.S. potato and evaluated the agronomic performance of the most promising 10 varieties. After several rounds of agronomic evaluation in the MSU greenhouse, the pool was reduced to six varieties with the most promising starch profiles. Confirmation that the selected varieties are agronomically adapted to the northern plains took place during the 2015 growing season.

There are two distinct industries for potato production in the U.S. First, there are the certified seed potato producers with a primary focus on production of disease-free seed. Montana has an enviable seed potato industry that supplies certified seed potatoes to commercial potato producers across the U.S. Only cultivars that have been certified virus- and bacterial-free by the MSU Seed Potato Lab can be planted in Montana. (One of the six selected cultivars has already been released by the potato lab and is in production by four Montana seed producers. Certification of the other five is currently in progress. As soon as the cultivars are released, they will be field evaluated by commercial seed producers in Montana.) The second industry is production of potatoes for the fresh market and for the processed markets (optimum production is dependent upon high-quality, disease-limited certified seed potato).

Each of the six lines was screened for the common viral pathogen PVY and then agronomically tested in experimental field plots in Williston, North Dakota and Parma, Idaho. The lines will be further increased this winter at California Polytechnic University (Pomona, CA) and test marketed. The primary marketing attribute of these potatoes is low glycemic index (starch profile) or glycemic load (total starch content) and will be the first option for market development. The marketing will focus on natural markets, farmers markets, and health markets. We are actively pursuing collaborations with diabetic support groups to command production and processing of lower GI crops (we have developed a similar collaboration with the American Celiac Society to strengthen introduction of Montana-produced gluten-free crops and products). The glycemic index of these potatoes will be lower than conventional potatoes, but the actual index has yet to be determined due to cost of human medical studies. The need for such testing is obvious and will increase production and demand. We continue to pursue funding for the human testing.

Project Objectives:

The overall goal of this project was to develop low glycemic potato as a value-added Montana crop. The specific objectives were to:

I. Identify low-Glycemic Index Potato cultivars that are adapted for production in Montana.

II. Evaluate selected cultivars in field studies in collaboration with Montana seed potato producers and select the most-promising cultivars for seed production scale-up.

III. Generate a feasibility analysis including economics of low GI seed and commercial potato production and estimated market demand.

IV. Evaluate selected lines in greenhouse studies for disease susceptibility (year 1) and impact of agronomics on starch profiles (year 2 and 3).

V. Evaluate selected cultivars in field studies in collaboration with Montana potato producers to determine the most-promising cultivars for low-GI potato production in eastern Montana. Work with producers to scale-up production to commercial levels. 

VI. Evaluate cultivars in local and university taste studies (MSU, Extension, and Producers).

Performance Targets.

In our proposal, we designed a project consisting of a number of cascading objectives. Most of the objectives were premised upon completion of the preceding objective. This research project was not completed prior to the Western SARE award, and a number of roadblocks were encountered that altered the proposed timeline (i.e. development of a laboratory analyses to accurately predict GI, necessity of actual human GI testing to market product) or precluded modification of the research plan (i.e. field testing of the lines was done in ND and ID. We definitely underestimated the time necessary to introduce a new variety of potato to seed potato producers and potato producers and to develop markets and demand. The Tri-State Potato Breeding Program estimates that it takes 8-10 years to develop and introduce a new potato variety. We are well within this timeframe.

However, we have identified low GI lines of potato. We will continue to work with farmers in the Northwest to scale-up production of the potatoes and seed potatoes. We will continue to work with the Montana Seed Potato industry to scale-up seed potato production in Montana and with Northwest potato producers to introduce production of the low GI potato (current demand for the low GI potato is in the garden industry and is not yet in the potato processing industry). Our collaboration with the health food industry and medical support communities will continue.


Potatoes are a dietary staple across the U.S and the world, providing valuable carbohydrate and vitamins with minimal fat. Most varieties of potato have high glycemic index (GI). Glycemic index is a measure of how rapidly a food is digested. There are two types of starch and they are digested at different rates. Branched starch or amylopectin is very rapidly digested, causing an immediate spike in blood glucose because it is simultaneously digested from each branch of the molecule. Straight starch or amylose is digested much slower because there is only a single point of digestion. Foods with a high glycemic index elicit a very rapid spike in blood glucose levels, which is undesirable in individuals who have diabetes or struggle with obesity. Thus, there is a need for more foods/crops with a higher ratio of amylose. Because glycemic index testing is a human study, it is very expensive ($5,000-25,000 per sample), thus limiting its use in germplasm screening. Fortunately, the GI is relative to the content of resistant starch (amylose) in a given food. As the ratio of resistant starch increases, the GI decreases. Foods with a low GI have a high content of amylose (resistant starch). Varieties of potato with low glycemic index have been identified and are commercially available in niche markets in Denmark and Australia, but are essentially non-available in the U.S. The overall goals of this project are to identify a low GI potato in the U.S and understanding the consumer demand and markets for this value-added potato.


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Materials and methods:

1.  Starch Assay. A primary goal of this project was to develop a laboratory assay to quantify the starch profile of a potato and predict the glycemic index. We compared three different assays for potato starch composition (granule structure, spectrometry, and enzymology) and ranked the varieties. The potato cultivars were obtained from several sources, including USDA Potato labs in Aberdeen, Idaho and Madison, Wisconsin, from commercial seed companies, and from a private breeder in Washington State. In 2015, we obtained germplasm from South America.

1.1  Microscopic Visualization of Granule Structure (Hogg et al. 2013). Potato tubers were cut with a sharp knife. The exudates from one of the cut sides of the tuber was smeared onto a microscope slide and visualized using a light microscope. High amylopectin (branched starch) are plump and very smooth (Fig. 1). Starch granules with a higher content of amylose (straight starch) are shrunken with cracks in the granule. This assay provided us with a simple method to rapidly screen hundreds of potato varieties and greenhouse/field samples.

1.2.  Biochemical Spectrophotometric Assays of Extracted Starch. Our second assay was a modified spectroscopic method from published standard biochemical methods and is based on the fact that amylose and amylopectin have slightly different absorption spectra. Purified starch was isolated from each tuber and stained. The ratio of the two types of starch was determined by comparing absorption ratios of light at several wavelengths (Fig 2).  This assay was conducted by both MSU and by an Idaho potato company. The results from these two assays differed. At this time we do not know if the starch profile differed due to the different environment or if there are site deviations in the protocol. We are more confident in our analysis utilizing 3-4 different analyses.

1.3.  Swelling Power. The starch ratio can also be estimated by the swelling power of the isolated starch. Branched starch will absorb more water than straight starch. Starch with a higher ratio of straight starch will swell less. The protocol is as described by Hogg et al. 2013.

1.4.  Enzymatic Glucose Release Assay. An enzymatic test was also used to evaluate the selected cultivars.

2.0  Field Potato Production.

Year 1: The most promising low GI lines were planted in the MSU plant growth center. The resulting tubers were used to confirm the starch findings. Ten of the lines were increased in a private garden that was geographically isolated from seed potato acreage. Seed potatoes were closely monitored for disease throughout this cycle. The planting and harvesting were done by hand by the cooperating producer with the assistance of MSU. Yield between varieties and within plants from a single variety were high variable. Tubers were screened for starch composition and plant disease at MSU.

Year 2: The most promising varieties were planted in a private garden and at the MSU research farm. Plants were closely monitored for PVY development. Tubers were harvested by hand. A portion of the tubers from selected varieties were distributed to year 3 producers and a portion was used for the preliminary taste evaluation. The starch profile of the field tubers was confirmed as described.

Year 3: The potato varieties or lines with the highest amylose were planted at the Williston Research Extension Center in North Dakota and on a commercial research farm in Parma, Idaho. Commercial growing protocols for planting, growth, and harvest were used. Researchers at each of the institutes monitored the potatoes for agronomic traits. The starch composition of the tubers harvested in North Dakota are to be evaluated at MSU. The growth habit, starch profile, and content of the tubers harvested in Idaho were evaluated by the cooperator. We had proposed evaluating the lines in eastern Montana. We were not able to plant the tubers due to a change in management at the targeted research station. The trial was relocated to North Dakota.

3.0  Sensory panels. A number of preliminary taste tests have been completed confirming that the potatoes are acceptable to the average consumer. Unfortunately, with the delays early in this study, we were not able to grow enough tubers of our select lines to conduct taste studies. However, the study protocol has been designed by the MSU Sustainable Foods lab and potatoes are being grown in California for a spring 2016 sensory test at both MSU and Cal Poly.

4.0  Evaluation of the impact of fertility on starch profile. Specific varieties were produced in the MSU greenhouse under variable fertility conditions. Potatoes were screened for starch composition. The purpose of this study was to determine if we can modify the amylose content using agronomics. In the initial study, fertility did not affect starch profile and the data is not shown. This study will be repeated in the field.

5.0  Marketing. We know that there is significant demand for lower GI foods, especially in markets targeted towards individuals with diabetes II or metabolic disorders. We know that demand for garden seed for low glycemic potato varieties (Nicola and Rosamundo) greatly exceeds supply. Such low-GI potatoes sell rapidly at farmer’s markets. Unfortunately, the human GI ranking is the only meter recognized by the food industry and consumers to predict the effect of a food on blood sugar. Thus, before we can conduct an accurate feasibility study, we must demonstrate that our lab assay of starch profile reliably predicts GI and are seeking supplemental funding for the GI studies. However, there is uniform agreement that demand for low GI foods is increasing. The increased demand for low GI potatoes will be parallel for increased demand for low GI durum wheat and low GI pea. In January 2015, there was announcement in the popular press that the Australian Carisma “low Glycemic” potato will be introduced in the U.S. market.

Research results and discussion:

1.0  Starch Assay. The glycemic index of a food is determined by feeding the food to test subjects and measuring the effect on blood glucose. The cost of this human assay ($5,000-25,000/food preparation) precludes its use as a tool to screen crop populations and select low GI varieties. The starch profile is a significant determinant of the glycemic index (GI) (Fig 3). We proposed that controlled laboratory analysis of potato starch would provide more reliable, reproducible results and would be a powerful tool for variety selection. Thus, the first objective in this proposal was to develop quick and inexpensive laboratory analyses to estimate the starch profile of potatoes or seed. Our initial assumption was that a single test could rank all the varieties relative to their glycemic index. We compared four different assays of potato starch composition (granule structure, spectrometry, swelling power, and enzymology) and ranked the varieties. The potatoes were ranked differently depending upon the chosen assay. However, by combining the results of all three of the tests (granule structure, spectrometry, and swelling power) in a sequential manner, we were able to reliably rank cultivars and have narrowed our focus to six cultivars of potatoes. Development of this system and ranking of germplasm took longer than we projected, but we are very confident that this system gives a true analysis of starch profile and can be applied to a number of crop species.

The microscopic analysis of the starch granule correlated with the spectrophotometric analysis of starch profile and can be used to rapidly eliminate potato varieties with a high content of branched starch (Fig. 2). Using these two assays we developed a ranking of available lines of potatoes with the highest amylose lines listed at the top in descending order (Table 1, Fig 4). All of the top ten selected varieties have a more desirable starch profile than variety Nicola, the U.S. standard for low glycemic index. The top six cultivars include two commercially available lines, a positive finding in that their agronomic and table traits have been proven to be market acceptable in the table potato category. One of the lines is already produced by the Montana seed potato industry. Information regarding its beneficial starch profile has not yet been released as a value-added attribute. Additionally, one of the lines is a variety from Peru that is recognized as safe for diabetics as part of their cultural tradition and ancient wisdom.

1.1  Relationship between yield and glycemic index. Amylopectin (branched starch) takes up more room than amylose and granules with a high content of branched starch tend to be plump (Fig. 2). Subsequently, the seed or the tuber tends to be plump. Amylose takes up less room and the granules tend to be cracked and shrunken. Accordingly, the seed is smaller and wrinkled. Because yield is profitable, breeders and farmers will pick the plumpest tuber/seed every time even though the wrinkled tuber/seed could have vast nutritional advantages.  

2.0  Production. Disease-free microtubers from the selected varieties were planted in plots in Williston, North Dakota and Parma, Idaho. The tubers were hand planted at each location. The tubers were planted at the same density routinely used in the commercial fields at the given location. The plants were irrigated, fertilized, or treated on the same schedule as commercial production. Plants were harvested and evaluated for adaptation, tuber quality and yield. Pesticide application was responsive to local conditions and forecasts. The harvested North Dakota plants were transported to MSU to screen for starch profile and estimate glycemic index. Lines with undesirable starch profiles were eliminated from the study. The Total Starch content of tubers from the Idaho data is presented in Fig. 4. The starch content of a common Russet variety contained over 15% starch. The starch content of the low glycemic lines ranged from 8.5 to 12.8%. This result might indicate that the selected varieties not only have a lower GI but also a lower glycemic load. Variation in amylose content was not significant in the Idaho studies. They used a different analysis than we use at MSU and we suggest that our technique using multiple bench analysis is more accurate/sensitive. Variety Bobcat 5 had approximately twice the yield of the other low GI selections. This study was a blind study done without the actual variety names. Bzuna did not yield under the Idaho field conditions.

2.1  Selection of disease-free germplasm for planting in Montana (Seed potato). Each of the selected potato lines is currently being process in the MSU potato line. This process includes tissue culturing of plant material to obtain disease free tissue. The tissue is evaluated using ELISA, PCR, and Electron microscopy. Microtubers are produced from disease-free plants. The microtubers are grown in the MSU greenhouse. The resultant mini-tubers are distributed to potato nurseries and growers in Montana. This process is estimated to take an addition 5-6 months.

2.2  Greenhouse evaluation of disease susceptibility. A few tubers from each selected line were planted in the MSU greenhouse and monitored for development of PVY, the most problematic viral disease for potato production using standard phytopathological protocols with adequate replications to ensure statistical significance. Once we established baseline disease reactions, we evaluated the effectiveness of existing disease control strategies (agronomic, chemical, and biological). Highly susceptible lines were eliminated from the study. In 2015, we had an outbreak of Late Blight, a serious fungal disease of potato. The lines are currently being screened for susceptibility to this pathogen.

3.0.  Sensory Evaluation. We have done preliminary consumer acceptance and demand research. Unfortunately, the GI result is the only measure of starch that is commonly accepted in the food and health industries and they are hesitant to accept our biochemical findings. We have to prove that our system is better to gain acceptance. In our market research, we found that the Carisma potato in Australia, which has been successfully marketed for its low glycemic properties, was marketed after glycemic testing was done at the University of Sydney.

5.0 Marketing.

5.1. Existing Low GI Potatoes. The market feasibility study is incomplete at this time. This study is ongoing. Our model for this project is a low GI variety produced and marketed in Australia. Carisma is sold exclusively by one chain of grocery stores in Australia and sells for double the price of traditional potatoes. This variety is stringently protected and we have not been able to obtain a research sample. It is interesting that the researchers that developed Carisma have made numerous attempts to obtain our germplasm. In the United States and Europe, a waxy low glycemic potato called Nicola is primarily produced in home gardens or on truck farms. Nicola seed potato is available from a limited number of small seed potato producers and is carried over from one season to the next there is no significant production of Nicola seed potato. Demand for Nicola greatly exceeds supply. The five varieties that we have selected performed better in laboratory tests than varieties touted for their “low glycemic” scores. For example, variety Nicola has a relatively low GI index (58) and falls in the top quarter of our ranking but not in the top 10.

Much of the available Nicola seed is infected with the virus PVY. This niche potato is more available in Europe than in the United States. Rural economic development centers have not been accessed for a feasibility study because the product has not yet been run through human glycemic index testing.

5.2. Marketing Plan. Throughout the duration of this project, we have accumulated data on potential markets for a US low GI potato. We have combined this information with data collected on the starch profile and agronomic evaluations of the selected potato lines. We have also determined that our timeline for introduction of the low GI potato to producers and consumers was greatly underestimated. The initial marketing plan will focus on gardeners as opposed to commercial producers. Commercial potato production is tied to processing. Processors are slow to accept new varieties. In contrast, gardeners seek new varieties with desirable attributes (color, size, shape, and in this case, starch profile). Most consumers realize that it is difficult to purchase specialty potato varieties in large groceries or in processed foods. They are more available at truck farms and farmers markets. Specialty potato seed is sold across the U.S. including Ebay and Amazon.

The risk of producing a specialty potato is real. The risk of production of low GI potatoes in a garden is minimal because the preliminary production costs are low and the anticipated demand is higher. Acreage and producer expansion will be dependent upon demand. Second, potato gardeners tend to grow a variety of potatoes and do not have to rely on a single variety or a single market. The risk is much higher for commercial seed potato producers and commercial potato producers. First the input costs and acreage are much higher. Farmers will not produce a specialty potato unless they have a market. Demand for the specialty potato will be minimal until consumers and processors accept the variety.

The economic analysis of low-GI seed and commercial potato production is fairly straight forward and can be broken down into 5 questions. 1. Does the biochemical analysis of starch profile predict the glycemic index of the potato? 2. Are the selected potatoes genetically modified? (NO!). 3. Will the low-GI spuds garner a higher return than traditional varieties? 4. Is it economic to produce these potatoes and does the farmer make a reasonable profit? 5. How will the consumer become aware of low glycemic potatoes? and 6. Will consumers purchase the potatoes at the established price?

Overproduction of a specialty crop is a concern. Producers anticipating a high value market are forced into lower value commodity markets. Accordingly, we will work directly with the established potato seed grower association because they already regulate production and they already have a successful marketing program.

The table potato growers are less organized than the seed potato growers. Fresh production will be dependent up the availability of specific potato seed and demand for the variety in fresh and processed markets. Overproduction is simply diverted into less valuable common fresh markets.

Outside completion will emerge. Our objective is to get there first. Once we have market share, we intend to keep it by continued production of quality production and assertive advertising and marketing.

Research conclusions:

Diabetes is rampant in populations across the world. Incidence is tightly correlated with diet. Most agronomists focus on yield not on nutrition. Resultantly, we are increasingly creating crops and foods with high content of undesirable components and creating even more health problems. We suggest that production of low GI crops and consumptions of lower GI foods will be beneficial to consumers across the world. Better nutrition could ease the incidence and the severity of a number of diseases plaguing the human population. This product is not only beneficial to consumers; it will be beneficial to producers. Low-GI crops are value-added and will enable producers to develop and control a high value market.

Our goal is to successfully establish industries in Montana to produce low-GI seed potato and low GI commercial potatoes. The real measures of success are 1) Are farmers producing the low-GI potato lines, and 2) Are consumers buying the products?

The degree of success may also be relative to the magnitude or consumption and demand. If we have 1000 acres of production, are we successful? If we have 100,000 acres of production, are we successful?

We can measure the results and outcomes of each component of the proposal. The most significant outcome of this proposal is that we have identified potato cultivars with low amylopectin content and therefore theoretical low glycemic indexes. The glycemic index of these lines is much lower than the glycemic index of more common cultivars such as Russets and Yukon Golds. We have evaluated the selected lines in field studies with confirmation that the lines have altered starch content. We need to repeat these studies to confirm if the cultivars have a higher content of straight starch and/or a decreased content of total starch. Either of these attributes is desirable. The market for a lower starch potato could be larger than the market for a low glycemic index potato. Five of six of the selected lines are adapted to the Northwest. We need larger field studies in order to accurately define yield. It is likely that the selected lines will have reduced yield. However, if the low-GI spuds are value-added, crop profit may still be increased. Our early results indicate that the selective lines are equally susceptible to potato virus. Studies to evaluate expression of PVY disease are ongoing. Symptomatic plants are rogued from a field as soon as possible. Asymptomatic plants are not removed and may actually create a large pathogen reservoir. Studies with Late Blight disease are in progress. We do have access to a late blight resistant line which could be crossed with the low glycemic index lines. Additionally, we need to confirm that the low-GI varieties are compatible with current methods of disease control (biocontrol, pesticides, rotation).The market analysis will not be completed until results of a human GI study are available. Product quality, price, and competition will affect market demand. If the final product is not economically beneficial to farmers, they will not produce it.

We will measure the success of the overall project by monitoring production and sales. Success will also be indicated by increasing acreage and increasing demand.

Participation Summary

Research Outcomes

No research outcomes

Education and Outreach

Participation Summary:

Education and outreach methods and analyses:

  1. Rocio Rivas has presented all of the described material in her Master’s thesis (ESTUDIO MORFOLÓGICO Y DE LA RELACIÓN ENTRE MILOSA/AMILOPECTINA CON ÍNDICE GLICÉMICO DE DIVERSAS VARIEDADES DE PAPAS. Estudio de tesis requerimiento para optar al título de Ingeniera en Alimentos). The thesis was presented to her research committee during the third week of December, 2015. Dr. Sands at MSU was her U.S. advisor. The Spanish version of the thesis will be available early in 2016. The English version will be available later in the year.
  2. Once we have the human GI data, we will publish the protocol for bench analysis of starch and correlation with human GI testing in a professional refereed journal. We have yet to decide if all of our information should be published or if it is in the interest of the grower to keep certain information proprietary.
  3. Once the field studies are completed and a low-GI variety is released, we will complete an MSU Extension publication (Montguide) on agronomics of low GI potato production. This publication will be written in collaboration with the MSU potato lab. Montguides are electronic and are updated yearly.
  4. The benefit of the low-GI potato will be presented to gardeners through the MSU master gardener program.
  5. The benefits of low-GI potato will be presented to local diabetes support groups.
  6. Popular press including local papers, newscasts, and the Prairie Star. The local press in Montana is more than willing to publish and broadcast stories on ongoing MSU research. We will work with the press to publish our efforts to develop value-added nutritious crops and foods. We anticipate ongoing communication with regional publications such as the Prairie Star newspaper and Rural Montana magazine. MSU research has previously featured in publications such as Delta Sky Magazine.
  7. In 2015, Dr. Sands has presented our research to USAID BIFAD and USDA NIFA Panels. https://www.usaid.gov/sites/default/files/documents/1867/2015.April%20BIFAD%20Public%20Meeting%20Bozeman%20Minutes.pdf
  8. The Creators and Disseminators of Ag Innovation has been actively involved in the promotion of this innovation. This small group includes a representative from FDPIR (Food Distribution Program on Indian Reservations) who is highly interested.  Additionally, a tribal college garden program grows potatoes and could be interested in demo plots. 
  9. The results will be presented on the local PBS program, “Montana Ag Live". The actual date of our participation has not yet been determined.

Outreach to Ag Professionals and Producers

In Montana, producers, ag professionals and Extension personnel attend the same events as our producers. The producers are well connected to MSU/Extension and often drop by to interact with MSU researchers. We have specifically described the document to a number of producers and modified the research as to their suggestions. For example, Montana seed producers are very interested in the low-GI lines but encouraged us to evaluate them outside of MT. There is tremendous communication between growers via the Internet, telephone, and face-to-face. This section is purposely not specifically focused on ag professionals because we intend to work directly with producers and their associations/cooperatives. These associations/cooperatives will play the role of ag professionals in providing information about production and markets to potential producers. Both ag professionals and Extension personnel will promote production of low-GI table potatoes to their producers given desirable economics and markets. These potatoes can and will be marketed locally. Without interaction with the seed potato association, these producers may not have access to the specialty markets, specialty varieties, specific trademarks, or compositional data. MSU has increased effort to educate ag professionals and Extension on value-added crop production. Much of the conversation centers on the value of commodity crop production vs. the value of specialty crops and processed foods. As the low-GI crop industry develops, extension and ag professional training will increase to include proper production and processing of these specialty crops. When needed, this information will be transferred during yearly in service training sessions offered throughout the state. The Montana Department of Ag will be most involved in the marketing effort. We will work with the state employees to take advantage of existing programs and contacts.

Education and Outreach Outcomes

Recommendations for education and outreach:

Areas needing additional study

  1. Completion of a market study detailing entry into the garden sector, the seed potato sector, and commercial potato production sector. This study will focus on fresh potatoes. Analysis of the potatoes for processing will require a battery of further analysis. Low-GI potatoes could be exclusively marketed online, at natural food stores, a selected mainstream grocery store, or a combination of the above. These lines could be marketed as true seed as opposed to seed potato that would open a number of international markets. Our seed potato producers in Montana will each determine their strategy once they have virus-free material of the lines that are in the tissue culture pipeline
  2. Expanded field analysis of the selected lines and scale-up of planting materials.
  3. Completion of effort to isolate disease-free planting material suitable for production in Montana.
  4. Expanded distribution of the low-GI lines to gardeners and commercial producers.
  5. We need to further evaluate the effect of environment on starch composition and content. We have conflicting data on the amylose content of tubers produced in ND and produced in ID. We need to determine if the contradiction is the result of production differences or could be analysis differences. From a market standpoint, a variety that has increased amylose in one environment and decreased total starch in another environment could be valuable.
  6. One of the low-GI is Huckleberry Gold, a Tri-State Potato Commission Release. It is already certified and produced and marketed by four Montana Certified Seed Suppliers (Holbrook Seed Potatoes, Mangel’s Station, Mountain Spring Farms (Organic), and Spring Farms. This variety is shovel ready for increased production in 2016. It is the logical first line for a low starch marketing effort. Its stated characteristics are: "A beautiful nutritious variety that produces round to oval tubers with purple skin and yellow flesh. Huckleberry Gold is more resistant to growth cracks, secondary growth, and hollow heart than Yukon Gold. It has very high antioxidant concentrations and good resistance to common scab and Verticillium wilt." The other lines are within the Montana Seed potato certification system. This certification requires several generations and the lines will not be ready for release (G1 germplasm) to growers for at least two seasons.
  7. In contrast, the lines can and are being increased on a non-certified basis for market testing at California Polytechnic University in Pomona, California. Such increase will enable us to establish human testing and marketing approaches in California. Limited quantities of the tubers will be made available to gardeners throughout the Northwest (but not Montana).
  8. Development of significant demand and markets in the food industry will require completion of a human GI study. We have adequate tubers from the field experiments in CA and ID to complete these studies. We have submitted research proposals to several federal and state agencies.
  9. Completion of taste analysis. The MSU Department of Health and Human development has recently completed construction of a food laboratory. The low-GI potatoes will be evaluated in these labs. The tests will be administered by nutrition students to trained sensory panels. The protocol for this analysis has been developed.
  10. Once we have completed the trial, we will further evaluate the varieties in collaboration with the medical community and diabetes support groups.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.