Final Report for LNE09-281
Four 2 acre demonstration aronia orchards were maintained at farms in Fryeburg, ME, Preston, CT and Mansfield, CT. Demonstration orchards were used for farmer education and participation. Demonstration orchards had their first year of moderate production, yielding 1.5 lbs of fruit per plant (an impressive number since it was only the 3rd growing season). Field days were held in August in Connecticut and Maine. Growers have been identified who are interested in establishing aronia orchards and micropropagated Viking aronia plants are being supplied to some of these growers to help with orchard establishment. Contracted biochemical analysis of many of our wild aronia accessions has been completed. Findings showed that there is great variation in wild germplasm for antioxidant capacity, anthocyanins and polyphenolic content. This variation can be used to breed better aronia cultivars. Two new cultivars have been breed and identified as having characteristics that should make them successful new introductions. New cultivars are desperately needed since all aronia production results from a single genotype. The new cultivar has been multiplied using tissue culture and in 2013 it will be trialed with several growers to assess its performance and suitability. Key new collaborations were formed with a scientist who is an expert in fruit biochemical analysis and with a second scientist who is an expert in the area of fruit taste, particularly with bitter and astringent qualities. These new collaborations will facilitate development of information for farmers about how to produce aronia crops that are the most healthful and best tasting.
Aronia melanocarpa, the black chokeberry, is a cold hardy, pest free, adaptable fruiting shrub native to the northeastern U.S. that requires low inputs and thrives on marginal lands. Purple-black fruits produced by Aronia are around the size of blueberries and have the highest known levels (5 times higher than cranberry and blueberry) of antioxidants (anthocyanins and flavonoids) of any temperate fruit and also contain strong anticancer compounds. Aronia is grown extensively in Eastern Europe and Russia where the fruits are processed and used in beverages, wine, jelly and baked goods.
In the U.S., Aronia is largely unknown as a fruit crop, but there are no obvious limitations to prevent it from becoming popular here as well. Preliminary work in Iowa, Oregon, Wisconsin and Nebraska has demonstrated the viability of Aronia as a U.S. fruit crop. Iowa extension suggests Iowa will have a $21 million Aronia industry in the next 5 years. These indicators, plus the public’s growing interest in functional foods, points to Aronia as a viable new fruit crop for New England. Farmers are generally unaware of Aronia’s potential as a new crop and need assistance in developing business plans for Aronia production and information about how to grow, manage and market Aronia on their farms.
Aronia germplasm currently in cultivation is limited to essentially a single genotype that was developed in Russia about 100 years ago. New germplasm with expanded genetic diversity is needed so farmers can reduce their risk of using a genotype monoculture for their production and provide a better product to consumers. Great diversity exists in wild U. S. germplasm which can be used to produce varieties with cultural improvements, enhanced phytochemical composition and better flavor.
Performance Target. Twelve farmers will each have established an average of 2 acres of aronia by the conclusion of the 4-year grant period. Average production of 15,000 lbs. of fruit per acre will yield 360,000 lbs. of fruit annually. If aronia fruit sells at $1.45 per lb., then aronia production in the Northeast from work performed with funds from this grant will result in $522,000 gross sales annually for farmers.
Farmer establishment of aronia orchards was limited by an extreme shortage of liner plants that could be used to establish new orchards. The plant shortage resulted from very strong demand for small, inexpensive aronia liner plants, particularly from the rapidly expanding Midwest U. S. aronia industry and the inability of propagation suppliers to respond quickly enough due to the relatively long time it takes to produce salable liners. We were able to divert effort and resources to produce a limited number of aronia liner plants at the University of Connecticut for distribution, but not enough to meet the needs of the performance target. During the duration of the project, four 2-acre orchards were established, grew well and produced significant crops (2 tons per acre) during their third growing season. Maximum harvest yields occur once plants reach 5 years. Several other growers trialed smaller numbers of plants due to the limited availability of liners. Aronia information development and delivery was highly successful and many potential growers now have the knowledge to move forward with aronia production as plant material becomes available.
Evaluation of wild Aronia germplasm.
Wild aronia plants were obtained on multiple collection trips as seeds, cuttings or divisions at appropriate times of the year. Collections were made over a significant portion of the natural range of Aronia, with an emphasis on New England collections. Some accessions were sent to us by colleagues and by USDA. Plants were initially grown in containers to the 2 gal. size and were then spring planted in the ground. Plants were established in the field at the UCONN Plant Science Research and Education Facility located in Storrs, CT, USA 41º47’40.26”N 72º13’39.61”W, USDA plant hardiness zone 6a. Soil series for the planting plot is either Woodbridge fine sandy loam or Paxton and Montauk fine sand loams. Three replicates of each accession were laid out in a completely randomized design. Plants were placed in rows with 2m within row spacing and 3m between row spacing.
Ploidy Determination: Ploidy of all accessions was determined using flow cytometry. A modified version of the protocol in Arumuganathan and Earle (1991) summarized in Lehrer et al. (2008) was followed. Two to three newly emerged leaves were macerated using a fresh razor blade in nuclei suspending solution in a 55mm petri dish on a freeze pack. The methods were then modified in accordance with Meng and Finn (1999) by adding 2 g of PVP-10 per 50 ml of extraction buffer and fluorescently staining released nuclei after filtering with propidium iodine, instead of during maceration. Relative fluorescence of total DNA was measured using a Becton-Dickson FACS Calibur Dual Laser Flow Cytometer (Becton, Dickson and Co., Franklin Lakes, NJ) at the Flow Cytometry and Confocal Imaging Facility at the University of Connecticut in Storrs, CT. The cytometer was equipped with an Argon ion laser emitting radiation at 488 nm. For each sample, 10,000-20,000 particles were measured. Data were logged and displayed in histograms by BD Cellquest TM software (Becton, Dickson and Co., Franklin Lakes, NJ). Standard tetraploid and diploid sample histogram peaks were compared to samples of unknown ploidy.
Fruit phytochemical analysis: Fruits were harvested in July, August, and September of two consecutive years when pomes were assessed to be visually ripe. Berries were handpicked, placed in Ziploc® bags, and transported in a cooler with ice. In the lab fruits were placed in a -80 ºC freezer within 24 hours. Samples were shipped overnight on dry ice to the Analytical and Biological Chemistry Lab at the John F. Kennedy Space Center, Orlando, FL where they were stored at -80 °C and analyses were performed. Fruit fresh weight was determined and samples were lyophilized and weighed again to determine dry weight. Freeze dried berries were ground with a Wiley Mill under a stream of dry gaseous nitrogen to prevent the adsorption of moisture from the air. Powdered fruits of each sample were divided into two aliquots, one for anthocyanin determination and one for ORAC/phenolic analysis.
Total anthocyanins and anthocyanin profile were determined by spectrophotometry and by HPLC (High-performance liquid chromatography), respectively. Approximately 100 mg (the sample was accurately weighed and documented for subsequent calculation) of each dry Aronia sample powder was placed in an ASE350 cell of the Dionex Automated Solvent Extraction System (Dionex Corporation Sunnyvale, California) and extracted with a solvent mixture of methanol:water:acetic acid 85:14.5:0.5(V/V/V). Extraction was carried out under 160 PSI of nitrogen at 100°C oven temperature for 10 minutes with a total volume of 14 ml. Extracts were filtered through 0.45 µm nylon membrane filters and subjected to HPLC analysis as described in Wu et al. (2004a) with minor modification to optimize the separation of individual anthocyanin. The sample extract (10 µl) was injected onto the HPLC and its constituents were separated on an analytical column (Zorbax SB-C18, 250 mm x 4.6 mm with an Altima C18 5µm guard column) using a mobile phase mixture consisting of 10% acetic acid (Mobile Phase A) and 100% methanol (Mobile Phase B) with varying proportions over time at a flow rate of 0.8 ml/min and column oven temperature of 30 oC. Anthocyanins were detected by a diode array UV-Vis detector at 520 nm with a bandwidth of 10 nm. Anthocyanin standards purchased from Sigma Aldrich were analyzed in the same way as the sample extract, and used to identify the anthocyanin constituents in the sample extract based on the match of retention time, UV spectrum and mass spectrum. A calibration curve was established using the standard Kuromanin Chloride (cyanidin-3-O-glucoside), subsequently all other anthocyanin constituents were calculated as the equivalent amount of cyanidin-3-O-glucoside. The same sample extracts were subjected to spectrophotometric analysis at 530 nm for the quantification of total anthocyanin content as cyanidin-3-O-glucoside equivalence (Kleinhenz et al., 2003).
A separate extract was prepared for the determination of Oxygen Radical Adsorption Capacity (ORAC) and total phenolics in Aronia berries. Twenty five milligrams (25 mg) of the freeze dried Aronia powder was placed in an ASE350 cell and extracted with acetone:water:acetic acid at the ratio of 70%:29.5%:0.5%. The sample extract of 0.2 ml was subsequently reacted with Folin-Ciocalteu phenol reagent for the determination of total phenolics by the modified Folin-Ciocalteu assay (Prior et al., 2005). A series of known concentrations of gallic acid was prepared and reacted with the same reagent to create a calibration curve that was in turn used to determine the concentration in the sample extracts. Consequently, the total phenolics were expressed as gallic acid equivalent. Another sample of 0.2 ml of 1/50 diluted extract was subjected to ORAC assay on a 96 well plate format as described in (Wu et al., 2004b; Prior et al., 2005).
Morphological evaluations:In two consecutive years, morphological and phenological characteristics were recorded from late April until November. Phenological characters, e.g. peak flowering date and fruit ripe date, were observed weekly or bi-weekly. Height, width, and base stem diameter was measured for each replicated plant of each accession. The following leaf characteristics were recorded: leaf pubescence, new stem growth pubescence, phyllotaxy. Leaf pubescence and new growth pubescence was rated on a scale of 0-6. Phyllotaxy was scored as distichous for two- ranked foliar arrangement or polystichous for spirally displayed leaves. Leaf perimeter, leaf width, leaf factor (ratio of leaf area to the perimeter), leaf ratio (ratio of leaf length to width), and leaf length were measured for 5 leaves, at least 3 nodes from the branch tip, per replicated plant with a CI-203 Laser Area Meter (manufactured by CID, Inc. Vancouver, Washington State, USA).The following fruit and flowering characteristics were measured or recorded: inflorescence number per 30 cm of branch; flower diameter; peak flowering date;, ripe fruit color; fruit ripe date; ripe fruit length and width; the weight of 25 ripe fruits.
During the fall 2013 we initiated an online survey of consumers in all northeastern states. A total of 807 respondents completed the survey (91% completion rate).Questions within the survey included demographic and purchasing behaviors for various berries. Berries were chosen as berry sales exceed $5.3 billion dollars annually and are the leader in fresh produce sales while also seeing increasing popularity of new berry varieties (i.e. aronia). Within the survey, we also included a choice based conjoint experiment in order to answer the questions of interest. The choice based conjoint design consisted of four berry attributes each made up different levels. Given price has widely been found to be a major factor in the purchasing decision, we included price as an attribute with price levels being $1.99, $2.89, $3.99, $4.59, $5.29, and $5.99 for a 6 ounce container of berries. The package size was standardized across all choice sets at 6 ounces as this is a common container size and all berries utilized in the experiment can be found in this package size. We also included five types of berries (blueberry, blackberry, raspberry, black currant, and aronia berry) in order to see how new and emerging (aronia and black currant) compared to more common berries. Organic was also included as an attribute. The final attribute incorporated both location and retail outlet. The attribute levels were farm stand grown in [state], farmer’s market grown in [state], grocery store grown in [state], grocery store grown in U.S., grocery store grown in northeast, and grocery store grown outside U.S, where [state] was replaced by the state of residence for the respondent taking the survey. Using the above attributes and levels, a choice set description might be “Grocery store raspberries for $5.29 produced in the Northeastern U.S.,” or “Farm stand aronia berries for $3.99 produced in Connecticut.” Using this format, we can calculate the difference in the retail effects by examining the differences between WTP for berries at the farm stand, farmer’s market, and grocery store. We can calculate premium differences by states by adding interactions to the model to capture state differences. In order to minimize respondent fatigue, a fractional factorial design was used where we maximized the design efficiency (99.5%) with a design error of (0.52). This design resulted in 15 choice sets with 4 products plus a “none of the above” option. Within the survey, the appearance of the choice sets and products within the set were randomized to minimize fatigue or ordering effects. After collecting the data, we utilized a mixed effects logit model to analyze the data whereby the attribute levels were used as explanatory variables. As has been done in other papers, we interacted locally labeled with demographics (i.e. gender, income, age, and primary shopper) in order to capture any demographic effects on WTP for local. In order to better understand state differences we interacted locally labeled with state of residence.
In spring of 2010, 2011, and 2012, 700 hybridization attempts were made between Aronia, various Sorbus, various xSorbaronias, various ×Sorbopyrus and xSorbocotoneaster. One hundred fifteen crosses between various accessions of A. melanocarpa were also made, as well as the interspecific crosses of arbutifolia x melanocarpa and melanocarpa x mitschurinii. Fifty Aronia × Pyrus hybridization attempts were made. Aronia × Sorbus crosses were attempted 42 times using diploid A. melanocarpa as the maternal parent. S. aucuparia, S. ×arnoldiana × alnifolia,and S. domestica were used as pollen parents. Aronia diploids were pollinated by intergeneric hybrids 185 times. The intergenerics used as pollinators were ×S. sorbifolia, ×S. fallax ‘Ivan’s Beauty’, ×Sorbocotoneaster pozdnjakovii, ×S. fallax, and ×Sorbopyrus. Two hundred and eight intergeneric × intergeneric crosses were made using ×S. fallax as the female parent. The intergeneric pollen parent for these crosses came from ×S. dippelii, ×S. sorbifolia, ×S. alpina, and ×Sorbopyrus. Fifty ×S. fallax flowers were pollinated using Pyrus pollen. ×S. fallax was backcrossed 36 times to S. aucuparia. Fifteen hybridization attempts were made between Sorbus alnifolia and A. arbutifolia var. purpurea and an A. mitschurinii.
To test if Sorbus aucuparia could be used as a maternal parent, open pollinated fruits of S. aucuparia known to be in the vicinity of either cultivated or wild Aronia spp. were collected from three maternal plants. Seeds were extracted and stratified. One hundred open pollinated seeds from each of the three trees were planted and examined for ×Sorbaronia progeny. Additionally, ×S. fallax ‘Ivan’s Beauty’, ×Sorbocrataegus ‘Ivan’s Belle’, and ×S. fallax were allowed to be open pollinated in proximity to each other and to A. melanocarpa, A. arbutifolia, and A. prunifolia. Seeds of these intergenerics were planted to test for apogamy, fertility, and hybridization by counting and examining their progeny.
All seeds were provided 90 days of cold, moist stratification and then germinated in a greenhouse.
Effects of fruit harvest time on biochemical composition and sensory rating.
Viking aronia fruits were harvested from the UConn demonstration orchard weekly for 9 consecutive weeks beginning with the first development of fruit color until fruits became overripe. At each weekly harvest, all fruits were harvested from 50 plants in randomized in 5 blocks of 10 plants each. Fruits were destemmed, washed, kept separated by block and frozen at -20 F. Subsamples from each block were thawed and juiced using an apple cider press and the collected juice was collected for analysis. Phytochemical analysis (similar to that previously described) of the juice was conducted by Brad Bolling (Dept. of Nutritional Sciences, Univ. of Conn.) and HPLC determination of sugar and sugar alcohol composition was done by Covance, Inc., Princeton, NJ.
Valerie Duffy (Allied Health Sciences, Univ. of Conn.) used juice samples representing the 7 ripest collections dates to determine if flavor changed over the course of fruit ripening. A sensory panel of 50 adults was tested to determine their associations between chemical and sensory analysis of juice from berries harvested at the 7 time points. A hedonic ratings system was used. Next, we tested change in liking and oral sensation in prototypical sour (citric acid) and astringent (tannic acid) stimuli with added sucrose (.15, .3 M) and/or single ethyl butyrate (EB) stimuli. Finally, we tested the additive protocol in aronia juice that was similar in sourness/astringency to the prototypical stimuli.
Milestone 1. Maple Lane Farms, Preston, CT and Western Maine Nurseries will establish 1 acre Aronia orchards to serve as demonstration locations for education of additional farmers. On farm trials will verify successful cultural conditions for production in New England. Installation will be complete by June 2009, and verification of success will continue throughout project.
Demonstration orchards of 2 acres each were established at Maple Lane Farms, Preston, CT, Western Maine Nurseries, Fryeburg, ME and the University of Connecticut Research and Outreach Field Facility, Storrs, CT. Orchards were established one growing season behind schedule due to severe shortages of liner plant material. The demonstration orchard of Viking Aronia at Western Maine Nursery in Fryeburg, ME had been expected to produce a moderate fruit crop in 2012, but fruit production throughout the orchard was inconsistent, primarily due to excessive competition from weeds that were not properly managed by the farmer cooperator. Unfortunately, in 2013, the farmer sold the orchard land and the new landowner removed the aronia plants.
In 2012, at Maple Lane Farms in Preston, CT fruit production was also inconsistent, but in this case the cause was deer predation. Some parts of the orchard fruited well, while areas close to deer cover were damaged significantly by heavy deer browsing. Steps were being taken by the grower to control the deer problem. In 2013, yield was good and mechanical harvesting was conducted and fruits were used to produce juice which was blended with currant juice.
At the University of Connecticut Research and Outreach Field Facility plants produced a consistent, moderate fruit crop (about 1.5 lbs. per plant) in 2012. Significantly heavier fruiting occurred in 2013, where plants yielded over 5 lbs. per plant.
The crop at the University of Connecticut Research and Outreach Field Facility was used in a study where fruits were harvested weekly during a 9 week ripening period from first color to fruit shrivel. The important questions we were trying to answer with this study were how do fruit biochemicals and fruit flavor/sweetness change over the course of fruit ripening. Also, how long of a window do growers have to harvest aronia fruits when their biochemistry and flavor are at peak? These are questions we have repeatedly heard from aronia growers. For the nutraceutical biochemical work we collaborated with Dr. Brad Bolling (Nutritional Sciences, UConn) and for the flavor sensory testing we collaborated with Dr. Valerie Duffy (Allied Health, UConn). Biochemical analysis included ORAC, anthocyanins, proanthocyanins, phenolics, sugars and sugar alcohols. Flavor sensory analysis looked at how sugar and phenolic content of aronia juice affected consumer preference and how added sugars and olfactory flavorings improved juice preference.
Plants and guidance were provided to students at the University of Connecticut Spring Valley Farm student run organic farming learning community to help them set up an aronia permaculture planting.
Milestone 2. At least 120 farmers and 10 extension educators will increase their knowledge about Aronia as an alternative nutraceutical fruit crop through presentations and tours at workshops held at the two demonstration farms.
Two successful field days were held in summer 2012, to educate potential aronia growers and provide them with enough information make a decision about aronia production. These field days were held in Storrs CT (August 9) and Monmouth ME (August 16), both during the early part of the aronia harvest season. Field day speakers addressed the culture and marketing of aronia. Speakers at the CT workshop were Andrew Ristvey (University of Maryland Cooperative Extension: Growing aronia and growing an Industry), Allyn Brown (Maple Lane Farms, Preston, CT: Selling aronia: connecting with processors) and Mark Brand (University of Connecticut: Aronia germplasm: can we build a better aronia plant?). Speakers at the ME workshop were David Handley (University of Maine Cooperative Extension: How to grow aronia and other “bush fruits”), Lois Stack (Universtiy of Maine Cooperative Extension: Is aronia the right crop for you?) and Mark Brand (University of Connecticut: Aronia germplasm: can we build a better aronia plant?).
Highlights of these field days included: 1-At the UConn field day, participants were able to see Dr. Mark Brand’s two-acres of aronia, and also his extensive aronia collection. This brought to life several topics covered in the presentations. In particular, participants were able to taste fruits of more than 40 selections in the germplasm collection, an activity that made clear the potential of breeding for improved flavor, larger size, and early and consistent ripening. 2-At both field days, participants sampled aronia products such as juice, gummy bears and jelly. This enabled them to consider the importance of developing value-added products for small-scale and locally sold aronia. 3-At the UConn field day, a presentation by grower-cooperator Allyn Brown provided insight into the juice processing business, and the importance for large-scale growers to connect with a processor in advance of production. 4-At the Maine field day, participants were able to learn about small fruit production in general, and to view many other small fruits at UMaine's Highmoor Farm; this is important, as many growers who assess aronia as a crop also consider growing other small fruits. 5-At both field days, participants learned about the genetics of aronia, the potential of plant breeding for improving available cultivars, and other aspects of the research components of this and related projects.
Some other educational activities we conducted to improve awareness about aronia are as follows. We worked with UConn students in EcoHouse Residence Hall to teach them about aronia as a nutraceutical crop. The students helped pick fruit in fall 2013 and the fruits were used by UConn Dining Services to serve aronia-based products in on campus dining facilities. Primarily baked goods (muffins, biscuits) were served to the undergraduate student body in dormitory dining halls and desserts (panna cotta) were served to faculty and staff in on campus restaurants.
The UConn Dairy Bar will be making 200 gallons of aronia ice cream from fruits picked by students from the demonstration orchard. Ice cream will be marketed to the public during late winter- spring of 2014.
Milestone 3. At least 150 small fruit and vegetable farmers will increase their knowledge about Aronia as an alternative nutraceutical fruit crop through presentations at a half-day symposium on Aronia production at the New England Vegetable and Small Fruit Conference. December 2011.
Our desire had been to sponsor a half-day symposium just on Aronia at the New England Vegetable and Small Fruit Conference in December 2011. The organizers of the conference had reservations about devoting a half day to just the topic of Aronia, so they instead had a half day symposium on specialty fruit and Aronia was included in that group. We sponsored a speaker on Aronia, Dr. Eldon Everhart. He is one of national experts on Aronia and his presentation was titled “Aronia: a new/old berry crop for the Northeast”. Dr. Everhart’s presentation was published as: Everhart, E. 2011. Aronia: a new/old berry crop for the Northeast. New England Vegetable and Fruit Conference Proceedings. Pp. 225-226. Also, in the conference proceedings was Brand, M. and L.B. Stack. 2011. Aronia berry production: a promising crop for Northeast growers. New England Vegetable and Fruit Conference Proceedings. P. 227.
Milestone 4. At least 35 of the farmers who attend the field days or symposium will express an interest in establishing Aronia orchards.
Forty two potential aronia producers from four states attended the two field days. Of the 29 participants who returned evaluations of the event, 27 received enough information from the event to make a decision about planting aronia; and 27 plan to plant aronia. Mark Brand produced 500 micropropagated Viking aronia to give to interested growers wanting to establish an orchard. 300 plants were provided to a grower in VT in early spring 2013 to develop an aronia orchard. The remaining 200 plants were distributed to several other growers who wished to trial a smaller number of plants prior to investing in sizable acreage.
Milestone 5. Of those farmers attending workshops and the symposium, 12 will develop business plans and establish Aronia orchards.
A production budget was developed by Dr. Ben Campbell (University of Connecticut, Dept. of Agricultural and Resource Economics) in collaboration with a resource economics PhD student (Omer Hoke). The production budget is available to farmers as an Excel spreadsheet on our Aronia website (http://umaine.edu/agriculture/home/aronia/). Without a berry harvester the average time to recoup costs would be 5-6 years after planting, with a harvester it would take 4-5 years to recoup costs with the savings being on labor.
An online marketing survey focused on aronia in comparison to other berry crops was conducted in 2013 in which 806 consumers participated from the northeastern U. S. Results indicated that consumers were willing to pay $0.67 less for a 1/2 pint (8 ounce) container of aronia berries when told aronia berries had a bitter flavor compared with no information. However, consumers were willing to pay $0.53 more per 1/2 pint container when given health information about aronia berries compared with no information. When given both taste and health information, consumers were willing to pay $0.20 more per 1/2 pint container. From these results it is clear that giving health information will increase consumer preference for aronia berries. Other findings indicate that aronia berries can be most easily marketed to younger, active, health conscious consumers.
Milestone 6. Using findings from evaluations of Aronia germplasm, including USDA’s material, at least 150 farmers will understand which Aronia genotypes will perform best in New England, provide the greatest health benefits to consumers and have the highest market value.
The largest aronia germplasm collection in the world was assembled and contains 115 wild accessionsof A. arbutifolia, A. melanocarpa and A. x prunifolia. Accessions have been collected from the following states: AL, CT, DE, FL, IN, MA, MD, ME, MI, NY, NC, NH, OH, PA, TN, TX, VA, VT, WI, and WV. Additional accessions were from Finland, Japan, Ontario Canada, Russian Federation and former Soviet Union. 44 new Aronia accessions were contributed to the National Plant Germplasm System which has tripled the USDA holdings of this genus.
Morphological analysis and performance of the wild germplasm was completed and the following information was collected for all accessions: plant height, plant width, overall habit, leaf size and shape measurements, internode length, degree of stem and leaf pubescence, amount of flowering, ripe fruit color, fruit size and fruit ripening date. Melanocarpa has the earliest fruit ripening dates (early July through mid-August), x prunifolia is mid-season (mid-August to mid-September) and arbutifolia is late (early October through late November). Some particularly interesting melanocarpa genotypes were identified that have prostrate growth habits, which were previously unknown. These plants are useful for developing lower growing forms of aronia for growers.
Ploidy was also determined for all accessions using flow cytometry and we found that all arbutifolia are tetraploid, all mitschurinii are tetraploid, x prunifolia are either tetraploid or triploid and melanocarpa are either diploid (New England) or tetraploid (Southeast and Midwest). We also determined that polyploidy forms of aronia produce apomictic (asexual seed) and this is critical information to have in hand for breeding.
Biochemical analysis of a significant portion of the wild germplasm was conducted in collaboration with Dr. Lanfang Levine. Plant material was evaluated over two years for ORAC, total phenolics and anthocyanins. Considerable genetic variation exists in the wild material for these three important phytochemical measures. Superior individuals have been identified that have very high levels of ORAC, total phenolics and anthocyanins for use in breeding and possibly also for direct use by farmers.
Using AFLP fingerprinting we ascertained the genetic background of the single form of aronia that is currently used for fruit production. We found that the ‘Viking’ variety grown commercially is not Aronia melanocarpa, as previously thought, but actually an intergeneric hybrid between mountain ash (Sorbus aucuparia) and A. melanocarpa. So it is 75% aronia and 25% mountain ash. Knowing this genetic composition, breeders can work to develop additional superior aronia varieties by reproducing this hybrid, but starting with different parental genotypes.
We have been conducting a high volume of hybridizations to develop additional commercial aronia varieties for growers so they can move away from use of a single variety for all production. Primarily we have been making interspecific hybrids between unique aronia genotypes and also many intergeneric hybrids to use as prebreeding lines. We have also been making progress toward creating hybrids between pear and aronia with the expectation of developing sweeter aronia varieties or purple pears with high antioxidant levels.
Currently we have selected two new aronia hybrids that we have micropropagated and distributed to two production nurseries for evaluation. Both of these new hybrids are smaller growing forms. Several other hybrids are in the final stages of evaluation and should be released for trialing in 2015, once we have sufficient stock built up for distribution.
Milestone 7. 500 people interested in learning more about Aronia berry production will download chapters of the Aronia production manual from the internet and increase their knowledge of Aronia as a sustainable fruit crop.
A website (http://umaine.edu/agriculture/home/aronia/) was developed as part of this project. It presents information about aronia plant description and taxonomy; a literature review of culture and harvest of aronia; a literature review of the food and nutraceutical uses of aronia; a bibliography of aronia literature; a list of sources of aronia plants; and hotlinks to many web-based aronia resources.
- Recently installed Viking aronia pilot orchard at Maple Lane Farms, Preston, CT
- Wild aronia accessions growing in a common planting in Storrs, CT.
- Summary of impacts of field days and website.
- Collection of aronia juice flowing from a cider press.
- Spreadsheet of Aronia Production Costs.
- Aronia pilot orchard in Storrs, CT in August, 2012.
- New compact aronia cultivar UC165.
- New aronia cultivar UC166 in comparison to Viking.
- Aronia liners used to install pilot orchards
- Aronia panna cotta dessert made by University of Connecticut Dining Services and sold at on campus restaurants. Aronia berries used were grown in the Storrs, CT pilot orchard and picked by EcoHouse undergraduate students.
- Mark Brand, University of Connecticut, providing instruction at field day, Storrs, CT.
- Cleaned aronia fruit.
- Aronia pilot orchard in Fryeburg, ME in April 2012.
- Macerated, thawed aronia berries just prior to pressing in a cider press.
Abstracts and Presentations:
Leonard, P., M. H. Brand, B. A. Connolly. 2012. Identification of Intergeneric Hybridization in Aronia mitschurinii using Amplified Fragment Length Polymorphism Analysis. Annual Conference of the American Society for Horticultural Science. July 31-Aug 3, Miami, FL.
Brand, M. H. 2013. Chokeberry becomes an ornamental superfruit: Improving the genus Aronia. 57th Annual Iowa State University Shade Tree Short Course, February, 2013, Ames, IA.
Brand, M. H. 2013. Getting into the genetics of Aronia: Can we build better chokeberries? Midwest Aronia Association Conference, April 2013, Des Moines, IA.
Park J, Rawal S, Brand M, Durocher S, Sharafi M, Duffy VB. Aronia Berry Juice Sensory Analysis by Harvest Time and Oral Sensory Phenotype. Association for Chemoreception Sciences (AChemS) Meeting, April 2013, Huntington Beach, CA.
Martin, D., R. Taheri, M. Brand, A. Draghi, F. Sylvester, B. Bolling. 2013. Polyphenol-rich red and purple aronia berry extracts inhibit interleukin-6 from mouse splenocytes. Experimental Biology Meeting, Boston, MA. April 20-24, 2013.
Park, J., S. Rawal, M. Brand, S. Durocher, M. Sharafi, V. Duffy. 2013. Aronia berry juice sensory analysis by harvest time and oral sensory phenotype. Association for Chemoreception Sciences Meeting April 17, 2013 - April 20, 2013
Duffy, V., S. Rawal, B. Bolling, J. Park, M. Brand. 2014. Enhancing Sweetness and Palatability of Aronia Juice via Added Sugars and Olfactory Flavoring. Association for Chemoreception Science Meeting, Bonita Bay, Florida, April 9-13, 2014. International Mtg and the abstract will be published in the Journal Chemical Senses.
Hoke, O., B. L. Campbell, T. Hau, M. H. Brand. 2014. State and retail outlet impact on premiums for locally grown berries. 2014 Agricultural and Applied Economics Association Annual Meeting, Minneapolis, MN, July 27-29.
Refereed Journal Articles
Leonard, P.J., M.H. Brand, B.A. Connolly, and S.G. Obae. 2013. Investigation of the origin of Aronia mitschurinii using Amplified Fragment Length Polymorphism analysis. HortScience 48(5): 1-5.
Taheri, R., B. A. Connolly, M. H. Brand, B. W. Bolling. 2013. Underutilized chokeberry (Aronia melanocarpa, Aronia arbutifolia, Aronia prunifolia) accessions are rich sources of anthocyanins, flavonoids, hydroxycinnamic acids, and proanthocyanidins. J. Agric. Food Chem. 61: 8581-8588.
Martin, D. A., R. Taheri, M. H. Brand, A. Draghi, F. Sylvester, B. Bolling. 2014. Anti-inflammatory activity of aronia berry extracts in murine splenocytes. J. Functional Foods (in review).
Phytochemical content of wild Aronia germplasm. J. Amer. Soc. Hort. Sci. (in preparation).
Morpological analysis of speciation in wild Aronia taxa. Amer. J. Botany (in preparation).
DNA marker analysis of speciation in wild Aronia taxa. Amer. J. Botany (in preparation).
Interspecific and intergeneric hybridization as a pathway to improved Aronia cultivars. J. of Plant Breeding and Genetics (in preparation).
Additional Project Outcomes
Impacts of Results/Outcomes
We have established the largest aronia germplasm collection in the world. This collection is critical to producing substantial downstream impacts in the form of better aronia plants for farmers that require fewer inputs to produce high yields, are easier to harvest and process and contain the highest levels of nutraceutical compounds. The nucleus of information that can be derived from this extensive germplasm base has, at least in part, lead the USDA NPGS to elevate aronia to a top priority and featured genus. We have in fact added 44 aronia accessions to the NPGS and have at least tripled the genetic diversity contained within the national holdings.
Some key findings we have derived from our germplasm collection. 1. Habit and form can varying from creeping and prostrate, to low mounded, to tall and upright. 2. Black aronia can be either diploid or tetraploid, with the diploids only being found in New England. 3. Only diploids are useful for plant breeding, since tetraploids and triploids are apomictic. 4. Fruit size, fruit color and fruit ripening date for aronia are highly variable with some fruits ripening as early as the third week of July. 5. Significant differences exist in germplasm from southern, western and northeastern parts of the range. 6. The exact relationship and differentiators between purple and black aronia remain unclear.
Aronia growers are currently using only a single genotype for fruit production. Even though more than one named cultivar may be in use, the cultivars are all genetically nearly identical due to apomixis. Using AFLP marker analysis we have determined that the current commercial aronia variety is actually an intergeneric hybrid comprised of 75% Aronia melanocarpa and 25% Sorbus aucuparia. This information will help plant breeders create new aronia varieties that will perform at or above current genotypes. We have a number of pre-breeding lines developed that will facilitate breeding of more and varied cultivars of aronia for farmers to utilize. We also have developed two new cultivars (UC165 and UC166) that have entered production trials during the 2013 growing season.
The establishment of demonstration orchards has been very useful as a tool to educate farmers who are interested in aronia production. Furthermore, the orchards have been useful to the project personnel who have also learned a great deal from the orchards. The orchards have provided many additional opportunities for aronia education and research that were not initially envisioned.
Surveys of participants in our various aronia activities have worked well to document that information related to aronia was successfully delivered. We have also had a substantial amount of farmer interaction through emails, telephone calls and face to face visits. Server statistics have recorded that the online aronia resources have been useful to those seeking information about various aspects of aronia culture, genetics and production.
We have coordinated aronia food activities on campus which were tremendously useful in bringing awareness to aronia as a new, healthy fruit crop to students, staff and faculty. We have realized that the majority of the public is not at all familiar with aronia and more effort needs to go into this direction.
We have been able to develop some key, new collaborations that have been invaluable in advancing our understanding of aronia and its potential. While we have completed contracted biochemical analysis of a subset of our accessions, we have developed collaboration with a nutritional science biochemist at the University of Connecticut who is helping us do a more thorough evaluation of fruit biochemistry for our entire germplasm collection. Furthermore, he is helping us pinpoint the actual bioactive compounds. Information generated from this collaboration provides breeding direction as we create new genotypes for farmers to grow.
Similarly, we have a new collaboration with a food taste sensory expert who specializes in bitter and astringent food properties, two aspects of aronia fruit that make it less appealing for fresh consumption. This scientist, who is part of the Allied Health Sciences department at the University of Connecticut, has been helping us determine when farmers should harvest aronia fruits so they have the best flavor. She will also be helping us determine which of our new cultivars have the best flavor.
In general, farmers were very interested in learning about aronia as a nutraceutical crop. Most farmers we worked with had heard of aronia, were pretty certain they wanted to pursue production, but needed to learn more about the crop as they began their operations. One issue that slowed farmers’ ability to begin installation was a severe scarcity of inexpensive liner plants (small plants costing less than $1 each). The aronia industry in the Midwest has rapidly been gaining traction and propagators have been caught off guard. They did not anticipate the very high demand for the fruit genotypes of aronia. Larger plants, targeted to homeowners wishing to plant small numbers, were more available, but were too costly ($4-8 each) for commercial orchard installation. Less expensive appropriate liners are now becoming more available and growers are beginning to add aronia plants to their orchards.
Areas needing additional study
We have done a lot of work to understand the genetics of current aronia varieties used in production and document that they are intergeneric hybrids and all essentially the same, but much more work still needs to be done to disseminate this information. Many, many inquiries were from growers who wanted to know which cultivars they could/should be adding to their existing crop of Viking. All of the currently available cultivar options are genotypes that are genotypically very, very similar to Viking, and probably phenotypically identical.
Our interaction with growers in Iowa, Illinois, Nebraska, Wisconsin and Minnesota, where aronia production is fairly well established, suggests a need to study organic methods for aronia production, with specific information needed for fertility, weed control and pest control. Pruning techniques to manage aronia orchards to maximize yield have not been determined and we received many questions about this subject.
Public awareness of aronia needs to be increased; aronia marketing needs to be enhanced and aronia product development are topics that would frequently be discussed by growers.