Progress 12/01/13 to 11/30/16
Outputs
Target Audience:There are two stakeholder audiences for this project. The first audience were the Maine wild blueberry growers. There are approximately 550 growers in Maine. The second audience are highbush blueberry breeders. There are approximately 15-20 breeders that specialize or tangentially have an interest in highbush blueberry breeding in the U.S. This audience is significant because introgression of wild blueberry genes into highbush varieties has already occurred in order to enhance colde tolerance. Changes/Problems:A major problem did occur during the conduct of this project. Out co-PI, Dr. Alan Brown at North Carolina State University, did not conduct research to complete his objectives (identify molecular markers for the cabdidate genes for the genetic association analysis of cold and frost tolerance AND develop estimates of linkage disequilibrium by sequencing multiple genomic scaffolds containing candidate genes). We received the subcontract funds from North Carolina State University and we were able to complete the objectives that were originally assigned to Dr. Brown. However, this issue did delay our research progress by about one and a half years. We are confident now that we will finish all of the research and publish the results within the next 6 months. What opportunities for training and professional development has the project provided?This project provided training for my garduate student and technicians to conduct a linkage dis-equilibrium analysis of wild lowbush blueberry and to then begin to conduct genetic association analysis. In addition, several undergraduates working on this project gained valuable training in assessing and scoring cold damage to flower buds and frost damage to flowers. They also were trained in extraction of DNA and assessing genetic diversity using EST markers, SNPs, and microsatellites. How have the results been disseminated to communities of interest?Some of the results have been desseminated to Maine wild blueberry growers, blueberry breeders, and the USDA Fruit Genetics Laboratory (Director: Dr. Lisa J. Rowland) in Beltsville, MD. Four oral presentations were made to Maine blueberry growers during their blueberry extension meetings in 2012-2014 ( 1) Beers, L.A., Drummond, F.A., Rowland, L.J., and Bell, D.J. 2012. Comparing genetic diversity between managed and non-managed populations of lowbush blueberry. Annual Blueberry Hill Summer Blueberry Field Day. Jonesboro, ME. July 18, 2012; 2) Beers, L. and F. Drummond. 2013; 3)Beers, L. and F.A. Drummond. 2013. Deciphering the cold hardiness of lowbush blueberry using an association genetics approach. WBANA/WBREW Annual Meeting, Bangor, ME. Cold tolerance in wild blueberry. January 8, 2013, Maine Agricultural Trade Show, Augusta, ME.; 4)Beers, L. and F.A. Drummond. 2014. Cold Tolerance of Wild Blueberry. New Brunswick Blueberry Growers Annual Meeting, Moncton, N.B., Canada.). Presentations on the genetic diversity of wild blueberry in its native range and wild blueberry patterns of cold tolerance were also made to horticulturalists and blueberry breeders in 2013, 2014, and 2015 (see conference publications). Scientific journal manuscripts are expected to be written and submitted for publication. Currently, one manuscript is completed and two additional manuscripts await the completion of data analysis. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The first two years of this project resulted in two completed objectives. The first documented the genetic diversity of wild blueberry (V. angustifolium) across its geographic range. Expressed sequenced tagged-polymerase chain reaction (EST-PCR) molecular markers were used to evaluate the genetic diversity of lowbush blueberry across its geographic range and to compare genetic diversity among four paired managed/non-managed populations. Seventeen lowbush blueberry populations were sampled in a general north south transect throughout eastern United States with distances between 27km to 1600km separating populations. Results show that a majority of genetic variation is found within populations (75%) versus among populations (25%), and that each population sampled was genetically unique (P ≤ 0.0001), with the exception of the Jonesboro, ME and Lubec, ME populations which were found not to be significantly different (P = 0.228). Spatial autocorrelation analysis suggests that statistically significant differential genetic structure occurs between populations at 50m and then 1000m geographic distance. However, genetic structure did not appear to be explained by latitude (P =0.1026) nor cold hardiness zone (P = 0.4941). The effects of management for commercial fruit harvesting on genetic diversity were investigated in four locations in Maine with paired managed and non-managed populations. Significant differences were found between these populations (P = 0.0002) indicating that commercial production practices are influencing the genetic diversity of lowbush blueberries in the landscape. However, evidence for a difference in the number of unique polymorphic bands (a measure of genetic diversity) between managed and non-managed sites suggested significance at the 0.1 alpha level (P = 0.0770). While "housekeeping" genes (markers) did not show a difference in genetic diversity among managed and non-manged landscapes, stress genes did show significantly fewer diversity in managed compared to non-managed landscapes. The second year of this grant funded research saw the completion of the second round of cold and frost hardiness trials for 80 lowbush blueberry (Vaccinium angustifolium) plants. Four populations (20 plants each) were chosen based on geographic location throughout Maine representing the major blueberry producing regions of the state. Cold hardiness trials were conducted on closed, presumably dormant, flower buds in October, November, and December 2014. Severe weather and heavy snow made it impossible to conduct cold hardiness trials in January and February of 2015, and the next trial was not carried out until we were able to access the populations in March. Flower buds began to break dormancy in April and frost hardiness evaluations for the 80 plants on exposed floral tissue were conducted in April, May, and June 2015. This completed the cold and frost hardiness trial objectives outlined in the grant. Results for this second year of hardiness trials mirrored the results from 2014. Generally, a temporal pattern of hardiness emerged as plants increased their hardiness levels as the fall season progressed and entered winter. Plants reached their maximum hardiness in December of 2014 with most plants surviving to -35°C or below. Plants exited from the dormant state and began to lose their hardiness in late March and early April 2015. Frost hardiness evaluations also followed a temporal pattern with a decrease in hardiness with an increase of floral tissue emergence. Fifty molecular markers were used for genetic analysis of all 180 lowbush blueberry plants that were evaluated for cold hardiness. Combination of EST-PCR and SSR molecular markers were used that represent linkage groups in the closely related highbush blueberry (Vaccinium corymbosum). Association of cold and frost hardiness traits with specific regions of the genome is currently underway with an anticipated completion date of October 2015. Linkage disequilibrium analysis for a subset of lowbush blueberry clones was also completed in 2015. The third year and final year of this grant funded research was focused on analyzing the genetic diversity, cold hardiness, and frost hardiness data collected between November 2013 and June 2015 for 180 lowbush blueberry (Vaccinium angustifolium) plants. Plants represent nine populations (20 plants each) throughout Maine in the major blueberry producing regions of the state. Five populations were sampled during the winter of 2013/2014 while four populations were sampled during the winter of 2014/2015.mGenetic diversity of the 180 plants was evaluated using EST-PCR and SSR molecular markers that yielded 606 loci for analysis. Of the 50 molecular markers used, 45 yielded repeatable polymorphic bands suitable for analysis. Significant differences were found between 7 of the 9 populations (P ≤ 0.0001) with 92% of the variance found within the populations and the remaining 8% found among the populations. Positive spatial structure was found at within field distances (≤100m) but spatial structure was not evident at greater distances. Cold hardiness evaluations were conducted on closed, dormant flower buds in the winter of 2013/2014 and 2014/2015. Temporal patterns of cold hardiness were evident in both 2014 and 2015 datasets. Generally, plants began to increase hardiness with early winter collections (October-November), reaching maximum hardiness (≤-30°C) in mid-winter (January-February), and then gradually losing hardiness in spring (March-May). Patterns varied by plant throughout the season with some gaining hardiness earlier, with others retaining hardiness later into the spring. Cold hardiness levels at each time point were found to be significantly different for many of the plants. Frost hardiness evaluations were conducted on emerging/open flowers in the spring of 2014 and 2015. Although significant differences are found between individual plants for frost hardiness, there are fewer instances relative to the cold hardiness evaluations. There is a trend of decreasing frost hardiness as flowers develop, and 100% of the plants had significant damage to the flowers at -8°C when the corolla was fully developed. Generally, there is a much narrower range of temperatures (-6°C to -8°C) at which significant damage occurs with open flowers than closed dormant buds. Current efforts are focused on using TASSEL software to associate cold and frost hardiness data with the genetic data in an effort to identify loci that may be linked to cold/frost hardiness traits. Anticipated completion for this final step is March 2017.
Publications
- Type:
Other
Status:
Other
Year Published:
2017
Citation:
Beers,L., F. Drummond, and J. Rowland. In Prep. The geographic genetic diversity of wild blueberry. HortScience.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Beers, L. and F.A. Drummond. 2013. Deciphering the cold hardiness of lowbush blueberry using an association genetics approach. Wild Blueberry Research and Extension Workers Annual Meeting, Bangor, ME.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Beers, L. and F. Drummond. 2014. Genetic diversity of wild blueberry in its native range. NABREW Annual Meeting, Atlantic City, NJ, July 2014.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Beers, L., Rowland, LJ., Drummond, F.��2015. Genetic diversity of lowbush�blueberry (Vaccinium angustifolium) in managed and�non-managed populations throughout its native�range. Poster session for annual Botany Conference. Edmonton, Alberta.
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Progress 12/01/14 to 11/30/15
Outputs
Target Audience:The target audience are researchers and growers in Maine's wild blueberry production system. In addition, wild blueberry is a very important crop in the Canadian maritimes and Quebec. Therefore, our results are relevant to more than 1000 growers (about 500 growers are in Maine) and 13 research and outreach specialists. Changes/Problems:A significant development occurred during the final year of this project. My colleague and Co-PI did not conduct the genetic linkage dis-equilibrium modeling that was his objective. He had spent the funds, but did not deliver on this objective. Through discussions with North Carolina State University, the funds will be reimbursed to the University of Maine and the objective will be completed within this coming year. What opportunities for training and professional development has the project provided?This project resulted in training in molecular genetics for many of the graduate students in my lab. Mr. Lee Beers, one of the Co-PIs and PhD student on this project developed and conducted a workshop in the School of Biology and Ecology. How have the results been disseminated to communities of interest?Results from the second year of this research project were presented at several meetings in 2015. In March, a poster presentation titled "Cold hardiness of lowbush blueberry in Maine" was given at the University of Maine's first Wild Blueberry School in Bangor, ME. This presentation was also given during the University of Maine's annual Blueberry Field Day in Jonesboro, ME. Also in July, results and techniques were discussed at the Botanical Society of America's annual meeting in Edmonton, Alberta Canada. What do you plan to do during the next reporting period to accomplish the goals?The plan for the last "extended" year of this project is to finish the genetic statistical analysis of cold tolerance and write three manuscripts for submission to scientific journals.
Impacts
What was accomplished under these goals?
The second year of this grant funded research saw the completion of the second round of cold and frost hardiness trials for 80 lowbush blueberry (Vaccinium angustifolium) plants. Four populations (20 plants each) were chosen based on geographic location throughout Maine representing the major blueberry producing regions of the state. Cold hardiness trials were conducted on closed, presumably dormant, flower buds in October, November, and December 2014. Severe weather and heavy snow made it impossible to conduct cold hardiness trials in January and February of 2015, and the next trial was not carried out until we were able to access the populations in March. Flower buds began to break dormancy in April and frost hardiness evaluations for the 80 plants on exposed floral tissue were conducted in April, May, and June 2015. This completed the cold and frost hardiness trial objectives outlined in the grant. Results for this second year of hardiness trials mirrored the results from 2014. Generally, a temporal pattern of hardiness emerged as plants increased their hardiness levels as the fall season progressed and entered winter. Plants reached their maximum hardiness in December of 2014 with most plants surviving to -35°C or below. Plants exited from the dormant state and began to lose their hardiness in late March and early April 2015. Frost hardiness evaluations also followed a temporal pattern with a decrease in hardiness with an increase of floral tissue emergence. Fifty molecular markers were used for genetic analysis of all 180 lowbush blueberry plants that were evaluated for cold hardiness. Combination of EST-PCR and SSR molecular markers were used that represent linkage groups in the closely related highbush blueberry (Vaccinium corymbosum). Association of cold and frost hardiness traits with specific regions of the genome is currently underway with an anticipated completion date of October 2015. Linkage disequilibrium analysis for a subset of lowbush blueberry clones was also completed in 2015.
Publications
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2016
Citation:
Beers, L. in prep. Genetic Diversity and Genetic Association of Cold Tolerance in Wild Blueberry in Maine. in progress. University of Maine, Orono, ME
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Drummond, F.A. and D. Yarborough. 2015. Growing season effects on wild blueberry (Vaccinium angustifolium) in Maine and implications for management. Acta Horticulturae 1017: 101-108.
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Progress 12/01/13 to 11/30/14
Outputs
Target Audience: The target audience for the efforts reported here are the approximate 450 Maine wild blueberry growers. This group farms mostly in Washington County (ca. 70%). The median age is about 60 years old and about 30% are full-time growers. Most growers are conventionally based growers that practice IPM (80%) and almost 20% are organic. Eighty percent of the growers are male, but 40% farm with a spouse. Most of the growers are white, although the Passamaquoddy tribe owns and farms a substantial amount of land (ca. 2,000 acres). Rose et al. (2010) describes in much more detail the Maine wild blueberry grower target audience. My efforts for addressing the target audience have been directed at oral presentations and written Extension Factsheets. I made three oral presentations in the past year and I am currently working on rewriting a Factsheet on utilization of commercial bumble bees for pollination with my collaborator, Mr. Gaetan Chiasson, from New Brunswick, Canada, Provincial Blueberry Specialist. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project has provided the chance for undergraduate research assistants to receive training in molecular methods in plant genetics How have the results been disseminated to communities of interest? The results of this project have been disseminated at three meetings via oral preentations. The presentations are as follows: 1. Beers, L. and F. Drummond. 2014. Genetic diversity of wild blueberry in its native range. NABREW Annual Meeting, Atlantic City, NJ, July 2014. 2. Beers, L. and F.A. Drummond. 2013. Deciphering the cold hardiness of lowbush blueberry using an association genetics approach. Wild Blueberry Research and Extension Workers Annual Meeting, Bangor, ME. 3. Beers, L. and F. Drummond. 2014. Genetic diversity of wild blueberry in its native range. NABREW Annual Meeting, Atlantic City, NJ, July 2014. What do you plan to do during the next reporting period to accomplish the goals? We plan on conducting the seconf and final year of cold tolerance and measurements and then to model the association of genetic markers with cold tolerance.
Impacts
What was accomplished under these goals?
Over the course of the past year we have completed the first round of cold hardiness trials for 100 lowbush blueberry (Vaccinium angustifolium) plants sampled in four locations throughout Maine. Cold hardiness trials on dormant flower buds were carried out for these plants in November and December 2013 as well in February 2014. Frost hardiness trials for emerging flower buds were carried out in April and May 2014. Each sampled time point showed differences (some significant) between individual plants. Temporal cold hardiness profiles were created for each plant and many showed variation in not only level of cold hardiness, but also when the plants reached maximum cold hardiness and when the plants lost their hardiness. Several plants reached maximum hardiness at the first sampled point (November) while others did not reach maximum hardiness levels until February. This pattern was also seen when plants began to lose their hardiness in April. The second round of cold hardiness trials are under way (Nov 2014) for an additional 80-lowbush blueberry plants. Genetic analysis for all 180 plants is also currently under way to associate cold hardy traits to specific regions of the genome with the use of 60 molecular markers (SSR and EST-PCR). Results from the first year of this research project were presented at several meetings in 2014. In March, a presentation titled “Deciphering the cold hardiness of lowbush blueberry using an association approach” was given at the annual New Brunswick Blueberry General Meeting in Moncton, New Brunswick. Results were also discussed in June at the North American Blueberry Research and Extension Workers (NABREW) meeting in Atlantic City in a presentation titled “Genetic diversity of Vaccinium angustifolium in managed and non-managed populations throughout the geographic range”. A brief overview of the research and preliminary results were discussed at the University of Maine’s annual Blueberry Field Day in Jonesboro, ME in July.
Publications
- Type:
Other
Status:
Published
Year Published:
2014
Citation:
Drummond, F.A. and J.A. Collins. 2014. Blueberry biology experiments on wild blueberries in Maine, 2013. Maine Blueberry Commission, 137 pp.
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