ADVANCING THE DEVELOPMENT OF SEED-PROPAGATED HYBRID VARIETIES IN STRAWBERRY FOR ORGANIC AGRICULTURE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1013061
• Grant No.: 2017-51300-27292
• Cumulative Award Amt.: $467,902.00
• Proposal No.: 2017-02424
• Project Start Date: Sep 1, 2017
• Project End Date: Aug 31, 2022
• Grant Year: 2017
• Program Code: [113.A]- Organic Agriculture Research & Extension Initiative

Recipient Organization
UNIVERSITY OF NEW HAMPSHIRE
51 COLLEGE RD SERVICE BLDG 107
DURHAM,NH 03824

Performing Department
Biological Sciences

Non Technical Summary
The project is titled "Advancing the development of seed-propagated hybrid varieties in strawberry for organic agriculture". The goal is to produce both day-neutral and short-day flowering strawberry varieties that can be propagated by seed rather than by the conventional runner plant approach.Strawberries are typically propagated vegetatively from runners and purchased by growers as bare-root plants. The major problems are as follows: 1) The process of generating the bare-root plants requires many chemical inputs to avoid transmission of diseases and these chemical inputs may be harmful to the workers and the environment; 2) The grower planting schedule is dictated by the bare-root supplier and therefore planting stock availability is seasonally limited according to the purchaser's climatic region; and 3) Strawberry varieties developed for organic agriculture do not exist, and only one company located in Europe, offers any strawberry seed-propagated varieties.We are employing a breeding method called marker-assisted breeding (MAB), in which traditional cross-hybridization and phenotypic (trait-based) selection is complemented and enhanced by DNA testing using a high throughput technology known as a SNP (single nucleotide polymorphism) array.As a starting point, hybrid strawberry plants are being subjected to multiple cycles of inbreeding and selection as a means of exposing and purging genes for undesirable traits and approaching a true breeding state.From the resulting inbred plants, superior individuals will then be selected for use as parents in crosses to produce F1 hybrid seed, which can then be used to establish acceptably uniform populations of F1 hybrid plants for use in commercial fruit production. The inbreds and F1 hybrid combinations will be selected for traits of interest, including: fruit quality and productivity, vigor and disease resistance.Inbreds and hybrids will be subjected to DNA testing using the IStraw35® strawberry SNP array, which the UNH investigators previously helped to develop as member of the RosBREED (USDA-SCRI) project, and which is marketed by Affymetrix Inc. The results of such DNA testing assist breeders in associating favorable traits with plant genetic makeup in order to guide further cycles of marker-assisted-breeding.Development and selection of the inbred parents and of the F1 hybrids will initially been made at the UNH Macfarlane Greenhouses and Woodman Farm and the best of F1 hybrid populations will be planted at interested grower sites for evaluation. New strawberry varieties that are regionally adapted and suitable for organic agriculture will be made available to New England growers. These locally developed seed propagated varieties are expected to be suitable for organic agriculture in New England and our climatic region. In addition, in contrast to constraints of bare-root plants limited window of availability the seeds can be planted according to the growers' preferred time table.

Animal Health Component

100%

Research Effort Categories

Basic

0%

Applied

100%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
202	1122	1081	30%
201	1122	1081	30%
204	1122	1081	20%
211	1122	1081	10%
212	1122	1081	10%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 204 - Plant Product Quality and Utility (Preharvest); 211 - Insects, Mites, and Other Arthropods Affecting Plants; 202 - Plant Genetic Resources; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1122 - Strawberry;

Field Of Science
1081 - Breeding;

Keywords

breeding

f1 seed hybrids

grower participation

organic agriculture

strawberry varieties

Goals / Objectives
The Major Goal of the project is to provide strawberry growers with regionally adapted, seed-propagated strawberry varieties that are suitable for organic agriculture and are pleasing to consumers. Organically-certifiable, seed-propagated varieties provide an attractive and environmentally friendly alternative to the vegetatively propagated varieties currently relied upon by the strawberry industry.The objectives of the project are as follows:1. Develop inbred selections to serve as parents for production of F1 hybrid seed.2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy.3. Evaluate combining abilities of inbreds as parental pairs for hybrid seed production.4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties.

Project Methods
Inbred parents and F1 hybrid seed will be developed:Five pedigrees involving six initial founding parents will be used in generating inbreds, with additional parents and pedigrees to be initiated in year 1. Strawberry fruit resulting from crosses will be harvested and the seeds will be cleaned, and stored. Seeds for planting will be surface sterilized and germinated. Upon initiation of flowering of plants to be inbred, unopened flowers will be protected with fine-mesh bags to enforce self-pollination. Wherever possible, at least 200 seeds will be sown from each unique cross in germination trays. At the end of the process, a subset of up to 50 vigorous seedlings will be transplanted to plug trays. Approximately 4-8 weeks later, up to 30 of the most vigorous plug plants from each cross will be selected and planted in the field. Based upon the outcome of self-pollination, a specified number of vigorous plants that have produced a sufficient abundance of selfed seed will be selected for advancement. These plants will be clonally reproduced and maintained in replicate at the UNH.F1 generation: For each initial cross, the aim will be to select up to 24 F1 plants, which will then be self-pollinated, culminating in the production of a sufficient amount of seed to establish S1 progeny families. Based upon the seed germination and reproductive success of the S1 families, the number of represented F1 founders will ultimately be reduced to six per cross. These six final F1 founder plants (per cross) will be maintained and clonally replicated to insure preservation. S1 and S2 generations: Seed germination and reproductive success will be assessed as described above. S1 and S2 families of up to 30 members each will be assessed. Within each family, up to 15 plants will be chosen for enforced selfing. Depending upon their reproductive success, up to six plants per family will be advanced to seed harvesting. On this basis, with up to six plants per S1 family, we will have up to 72 S1 plants per initial cross. Subsequently, on the basis of S2 family performance, one to three S1 plants will be retained per family. An initial excess of progeny numbers at every stage will be required to insure against loss through selection, particularly with reference to seed germination, seedling vigor, and plant reproductive success. S3 generation: The foregoing process will be used to generate 12 S3 families per cross, each descended from a different F1 founder. From each family, four inbreds will be selected on the basis of sufficient vigor and sexual fecundity for potential use in subsequent inbred × inbred crosses. Additional S generations: The process of selfing will be continued until the degree of uniformity to be found in the F1 hybrid seed progeny is satisfactory.Phenotypic data will be collected at multiple life cycle stages in each generation to include seed germination rates, seedling vigor, floral characteristics, and fruit characteristics. Attention will be paid to the possible occurrence of male sterile S3 individuals, which could be employed as females in subsequent hybrid seed production.Experimental plan and statistical approach: For the initial evaluation at the UNH farm, each of the F1 hybrid seed varieties and a one or two cultivars for comparison will be planted in four completely randomized replicated plots of thirty plants each, an approach similar to (Kaczmarska et al., 2016). The cultivar will be Jewel and/or Tribute depending on whether the F1 hybrid seed varieties are expected to be SD and/or DN respectively. The uniformity of each hybrid seed variety will be evaluated for flowering cycle (weeks in flower), plant vigor (plant diameter) and plant runner production (0 to 9). Fruit traits will include yield, and quality, and flavor. Uniformity per trait will be expressed as the plot coefficient of variation, providing a basis for comparisons of uniformity across hybrid populations. The hybrid seed varieties will be compared to each other and to the comparator cultivars. Hybrid performances will be compared using plot means subjected to ANOVA and methods used by other researchers for comparison inbreds (Shaw et al., 1997) and of strawberry germplasm and cultivars (Kennedy et al., 2013).Genetic determinants of inbreeding depression and assess combining ability of inbreds as parental pairs for F1 hybrid seed production:The marker allele constitutions of the six founding clones and of select progeny plants will be determined by genotyping on the IStraw35 Array. The resulting panel of F1 plants will be subjected to SNP genotyping to define their allele compositions. The six parental plants will be included in all genotyping assays as controls. The allele frequencies at each genotyped SNP locus in these S1, S2, and S3 panels will be determined and compared to the founders and to the F1 seed hybrids and analyzed to identify markers and marker blocks that are over and under-represented, or alleles and marker blocks that are absent in the selected inbreds which may result from population purging due to positive selection for favorable traits. Conversely, an unchanged level of heterozygosity may suggest enforcement of heterozygosity in some genomic regions as requisite for vigor and survival. Finally, phenotypic and marker-based selection will be used to select inbreds for inbred × inbred crosses to assess specific and general combining ability.Outreach Plan:Engage growers in the evaluation of seed-propagated F1 hybrid varieties: During project year 1, Co-PD Sideman (Extension Specialist) will assist in the selection of interested strawberry growers, the primary stakeholder, in Northern New England (New Hampshire, Maine, Vermont) and conduct outreach activities for coordinating grower trials. In year 2 and 3, PD Mahoney and Co-PD Sideman will visit participating growers to facilitate on-farm trials and evaluations with the aim of identifying one to two growers per state as continuing partners. In year 3, interested participatory growers will receive seed-derived hybrid plant populations of up to 100 plants, and will qualitatively evaluate them on their farms with respect to vigor, productivity, fruit quality, and uniformity. The PD and Sideman or other project representatives will conduct site visits with participating growers during the production season.In addition to engaging grower in the evaluation of seed-propagated hybrid populations, ongoing feedback will be solicited from growers throughout the project timeline via field days, where growers can view and help "select" F1 hybrid varieties at the UNH Woodman farm, and extension research reports on project findings, and presentations at meetings of the Northeast Organic Farming Association, New England Vegetable and Berry Growers, North American Strawberry Growers Association, International Society for Horticultural Science, RosBREED, and others. We will engage in numerous activities aimed at educating students at the University of New Hampshire, as well as strawberry growers and other stakeholders. Over the course of the project we anticipate that at least ten undergraduate students employed as field, greenhouse, and lab helpers will gain valuable knowledge and practical experience. In addition, students in the "Evolutionary Genetics of Plants" and "Plant Domestication: Past, Present, and Future" courses regularly taught by Dr. Davis with contributions by Dr. Mahoney will be exposed to related concepts in crop evolution, genetics, and plant improvement. We will educate growers and stakeholders via technical publications, presentations at grower meetings, publication in scientific journal, presentations at scientific conferences, and maintenance of a project website (now in development).

Progress 09/01/17 to 08/31/22

Outputs
Target Audience:Updates on our breeding results to-date have been presented and stakeholder inputs have been obtained at the International Society for Horticultural Science VIII, International Strawberry Symposium, NH Farm and Forest conference, RosBREED meetings, the NOFA-NH Winter Conference, the UNH Spring Macfarlane Open Houses, NASGA conference, ASHS, and UNH NHAES MacFarlane and Woodman Farm tours. Interactions at these and other venues have confirmed that the concept of seed-propagated varieties is viewed as an attractive option by strawberry growers. LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk). TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk). LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview). LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk). LL Mahoney, Breeding Strawberry Varieties, NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). LL Mahoney, Breeding Strawberry Varieties, NHAES Food and Agriculture Extension Staff Quarterly Meeting, UNH NHAES Woodman Farm, July 25, 2019 (tour of fields and discussion on planned seed varieties). LL Mahoney, Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, UNH NHAES Woodman Farm, August 17, 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). New England Vegetable and Fruit Conference and Trade Show, Manchester NH, December 10-12, 2019 (LL Mahoney attended and networked on breeding strawberries and planned seed varieties). LL Mahoney, NHAES Virtual Twilight Meeting, June 24, 2020 (presentation on update on strawberry breeding for fruit quality and seed varieties). LL Mahoney, Durham Farm Field Day, August 21, 2021. Featured selections of F1 hybrid are being made for future evaluation by interested growers. LL Mahoney, Breeding Strawberry Varieties at UNH Posters: Breeding Fresh Market Strawberry Varieties, Breeding Ornamental Strawberry Varieties, and Making a strawberry cross, NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 2, 2022 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). LL Mahoney, Strawberry F1 Seed Hybrids, UNH Cooperative Extension Vegetable and Farm Team Tour, UNH NHAES Woodman Farm August 19, 2022 (tour of F1 seed hybrid replicated plots). Changes/Problems:Progress on each of the project objectives was delayed 2020-2021 due to the Covid-19 pandemic. On-site research was limited and on-site visits by the public were prohibited until August 2021. The Covid-19 pandemic required scaling down of research at UNH. Fewer seeds from fewer families were sown as limited access was granted to complete the work. Given that a key output of this OREI project was the engagement of growers in the evaluation of F1 seed hybrids generated from inbreds, the seeds were generated and stored rather than sown. A request was made to extend the project by an additional year, during which time additional inbreeding and F1 hybrid seed could be generated with the anticipation that the summer of 2022 would be post-Covid-19 and permit in-person grower evaluations.Project extension to August 31, 2022, permitted an additional summer of data collection. What opportunities for training and professional development has the project provided?Eight undergraduate students and one graduate student have gained valuable work experience and training in the following: strawberry propagation both seed and vegetative via runners and crown divisions. strawberry inbreeding, fruit collection for seed harvesting and cleanup. phenotyping in the field for plant vigor, heath as well as fruit production and quality fruit quality assays for Brix and acidity plant field and greenhouse maintenance Mentored undergraduate students who presented at the UNH Undergraduate research Conference. A Benner, A Perkins LL Mahoney (2019) Fertilizer Regime for Organic Strawberry Production. UNH COLSA 28th Annual Undergraduate Research Conference, April 27, Durham, NH. T Fischer, M Alix, A Benner, A Perkins, LL Mahoney (2019) Strawberry Breeding. UNH COLSA 28th Annual Undergraduate Research Conference, April 27, Durham, NH. LL Mahoney served on Graduate Master's Thesis committee: Quantifying nutrient and light requirements for day-neutral strawberries in controlled environment agriculture (2019) Anna Elizabeth Devitto Master's Thesis Pl Mahoney and Co-Pl Davis served as co-advisors on Graduate Master's Thesis committee: The development of knowledge and resources relevant to the genetic manipulation of day neutral flowering habit in strawberry (2020) Samikshya Rijal Master's Thesis How have the results been disseminated to communities of interest?Results and insights gained from this research have been disseminated in multiple venues, including conferences of the North American Strawberry Growers Association, American Society of Horticultural Science, RosBREED, NOFA-NH, the VIII International Strawberry Symposium, and local growers' workshops. Updates on results have been presented at the following public events and meetings. In addition to Zoom and phone conservations with potential parties of interest are on-going and letters of support were provided as part of an OREI grant proposal submitted in January 2021. LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk). TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk). LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview). LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk). LL Mahoney, RG Sideman, TM Davis (2019) Breeding Strawberry Seed Varieties in Northern New England for Organic Agriculture. IX North American Strawberry Symposium, 2019 North American Strawberry Growers Association Annual Meeting, February 3-6, Orlando, Florida. LL Mahoney participated and shared results informally during RosBREED2 hosted Partner's Meeting San Diego, California January 11, 2019 and RosBREED2 Participants Meeting, March 25-28, Lansing, Michigan. LL Mahoney participated and shared results informally and with posters during the NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019. LL Mahoney (2019) Breeding Strawberry Fruit and Ornamental varieties, UNH Extension Food & Agriculture Program Staff Summer Meeting, July 25 UNH NHAES Woodman Horticultural Farm, Durham NH, July 25 (Talk). LL Mahoney (2019) Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, August 17 UNH NHAES Woodman Horticultural Farm, Durham NH (Talk). LL Mahoney, New England Vegetable and Fruit Conference and Trade Show attended and networked, Manchester NH, December 10-12, 2019. LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight Meeting, June 24, 2020. LL Mahoney, Durham Farm Field Day, August 21, 2021. Featured selections of F1 hybrid are being made for future evaluation by interested growers. LL Mahoney, Breeding Strawberry Varieties at UNH Posters: Breeding Fresh Market Strawberry Varieties, Breeding Ornamental Strawberry Varieties, and Making a strawberry cross, NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 2, 2022 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). LL Mahoney, Strawberry F1 Seed Hybrids, UNH Cooperative Extension Vegetable and Farm Team Tour, UNH NHAES Woodman Farm August 19, 2022 (tour of F1 seed hybrid replicated plots). LL Mahoney, Breeding Edible and Ornamental Strawberries for New England, Inspired, 2022 Horticultural Report, Research from the New Hampshire Agricultural Experiment Station, Summer 2022. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. Develop inbred selections to serve as parents for production of F1 hybrid seed. As background, field phenotyping is conducted at the UNH Woodman Farm in certified organic fields and inbreeding is completed at the UNH Macfarlane Greenhouse Facility in a certified organic greenhouse. Seeds anticipated to generate repeat flowering plants are sown in February for field planting in May. The repeat flowering plants begin to bear fruit in the same year in which the seeds are sown and so phenotyping and selections are begun in that first year and completed the second year. Seeds anticipated to generate short-day plants requiring flower initiation, are sometimes later sown in May, and planted in the field in August, and phenotyping is completed the following year. In general, within each inbreeding generation, more seeds are generated than can be sown and therefore the seeds selected for sowing are based on the qualities of the parents with the most desirable fruit quality and productivity, as well as plant health and flowering cycles. Select genotypes are maintained in a greenhouse and some are also planted in the field to reserve as potential parents pending results of progeny tests. Beginning with a set of six cultivars, subsequently expanded to thirteen, we generated a diversity of foundational hybrids, from which twenty-one inbred lineages have been derived, and carried through repeated cycles of inbreeding through self-pollination. We have produced over 160,000 seeds including 16,000 S4 (fourth generation inbred) and 19,000 S5 seeds, and have field evaluated over 7,800 inbred plants. Advances to the sixth generation of inbreeding (S6) were made in two families in 2021. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The data analysis on the IStraw SNP genotyping indicates progress on inbreeding is as expected as evidenced by the reduction in heterozygosity and corresponding increase in homogeneity with each selfing generation. Genetic heterozygosity was reduced from a mean of 45% in the founding hybrids to 5% in fourth generation inbred plants, and that hybrid vigor and good fruit quality could be restored in progeny of crosses between fourth generation inbreds. The data analysis on the IStraw SNP genotyping guided the choice of parents for the F1 seed hybrids crosses and choice of seed families sown in February 2021. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Initial inter-crossings were completed between potentially promising inbred parents for seedling generation. We have produced F1 seed hybrids via combinatorial crossing of selected inbreds and have thus far evaluated twenty-two F1 seed hybrid populations.Phenotyping revealed high level of heterosis between the distantly related inbred parents and the expected corresponding limited restoration of hybrid vigor between closely related inbred parents and a high level of homogeneity.In addition, two of the progeny families were evaluated for suitability under low tunnel plasticulture for season extension until early November.During the last year of the project, the most fruitful or productive F1 seeds from six families were evaluated in replicated plots for evaluation of flowering habit, heterosis and homogeneity. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We have generated interest for the upcoming varieties of initial F1 seeds planned for evaluation summer of 2020 during the following presentation and events. As initial F1 seeds were evaluated on-site summer of 2020, as UNH was not allowed to permit the public to visit UNH facilities and field sites from mid-March: we generated interest in the evaluation of upcoming varieties with a virtual meeting. LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk). TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk). LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview). LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk). NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties. LL Mahoney, Breeding Strawberry Varieties, NHAES Food and Agriculture Extension Staff Quarterly Meeting, UNH NHAES Woodman Farm, July 25, 2019. LL Mahoney, Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, UNH NHAES Woodman Farm, August 17, 2019. New England Vegetable and Fruit Conference and Trade Show attended and networked, Manchester NH, December 10-12, 2019. LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight meeting, June 24, 2020. LL Mahoney, Durham Farm Field Day, August 21, 2021. Featured selections of F1 hybrid are being made for future evaluation by interested growers. LL Mahoney, Breeding Strawberry Varieties at UNH Posters: Breeding Fresh Market Strawberry Varieties, Breeding Ornamental Strawberry Varieties, and Making a strawberry cross, NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 2, 2022 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). LL Mahoney, Strawberry F1 Seed Hybrids, UNH Cooperative Extension Vegetable and Farm Team Tour, UNH NHAES Woodman Farm August 19, 2022 (tour of F1 seed hybrid replicated plots). LL Mahoney, Breeding Edible and Ornamental Strawberries for New England, Inspired, 2022 Horticultural Report, Research from the New Hampshire Agricultural Experiment Station, Summer 2022.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight meeting, June 24, 2020
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: TM Davis, Y Yang, D Frailey, LL Mahoney (2020) A Pentaploid-Based Linkage Map of an Octoploid Strawberry Hybrid Reveals Unusual Patterns of Recombination, Plant and Animal Genome Conference, January 11-16, San Diego, California
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Davis, TM, Y Yang, LL Mahoney, and DC Frailey (2020) A pentaploid-based linkage map of the ancestral octoploid strawberry Fragaria virginiana reveals instances of sporadic hyper-recombination. Horticulture Research 7:77, 15
• Type: Other Status: Published Year Published: 2019 Citation: LL Mahoney, RG Sideman, TM Davis (2019) Breeding Strawberry Seed Varieties in Northern New England for Organic Agriculture. IX North American Strawberry Symposium, 2019 North American Strawberry Growers Association Annual Meeting, February 3-6, Orlando, Florida. (poster)
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Iezzoni, AF, J McFerson, J Luby, K Gasic, V Whitaker, N Bassil, C Yue, K Gallardo, V McCracken, M Coe, C Hardner, JD Zurn, S Hokanson, Evd Weg, S Jung, D Main, CdS Linge, S Vanderzande, TM Davis, LL Mahoney, C Finn, and C Peace (2020) RosBREED: bridging the chasm between discovery and application to enable DNA-informed breeding in rosaceous crops. Horticulture Research 7:177, 23.
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: PI Mahoney and Co-PI Davis served as co-advisors on Graduate Master's Thesis committee: Samikshya Rijal (2020) The development of knowledge and resources relevant to the genetic manipulation of day neutral flowering habit in strawberry, UNH Agriculture, Nutrition and Food Systems Master's Thesis

Progress 09/01/20 to 08/31/21

Outputs
Target Audience:We continued to generate interest in the evaluation for the upcoming varieties as initial F1 seed hybrids during on-site tours at the Durham Farm Field Day held August 21, 2021. Selections of F1 hybrid are being made for future evaluation by interested growers. The August 2021 Field day was the first permitted on-site Field Day open to the public tour since the summer of 2019, before Covid-19. Changes/Problems:Progress on each of the project objectives was delayed 2020-2021 due to the Covid-19 pandemic. On-site research was limited and on-site visits by the public were prohibited until August 2021. The Covid-19 pandemic required scaling down of research at UNH. Fewer seeds from fewer families were sown as limited access was granted to complete the work. Given that a key output of this OREI project was the engagement of growers in the evaluation of F1 seed hybrids generated from inbreds, the seeds were generated and stored rather than sown. A request was made to extend the project by an additional year, during which time additional inbreeding and F1 hybrid seed could be generated with the anticipation that the summer of 2022 would be post-Covid-19 and permit in-person grower evaluations. What opportunities for training and professional development has the project provided?Undergraduate students have been trained in the following: strawberry propagation both seed and vegetative via runners and crown divisions. strawberry inbreeding, fruit collection for seed harvesting and cleanup. plant tissue collection and preservation for DNA genotyping phenotyping in the field for plant vigor, heath as well as fruit production and quality fruit quality assays for Brix and acidity plant field and greenhouse maintenance How have the results been disseminated to communities of interest?Zoom and phone conservations with potential parties of interest are on-going and letters of support were provided as part of an OREI grant proposal submitted in January 2021. What do you plan to do during the next reporting period to accomplish the goals?1. Develop the inbred selections to serve as parents for production of F1 hybrid seed. During the fall/winter of 2021-2022, limited inbreeding will be completed in the greenhouse on 30 selections from the summer of 2021. Phenotyping and selections of genotypes field planted started during summer of 2021 will be completed during the 2022 season. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The data analysis will be completed. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Evaluation of F1 hybrid seeds field planted during the 2021 season will be completed summer of 2022. The F1 hybrids will be evaluated for progeny vigor and homogeneity. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We are planning a special field day during the summer of 2022 to engage growers for future projects.

Impacts
What was accomplished under these goals? 1. Develop inbred selections to serve as parents for production of F1 hybrid seed. Phenotyping and selection on seedlings set in field rows in June 2020 was completed summer of 2021. During the fall/winter of 2020-2021, an additional cycle of inbreeding was completed in the greenhouse on the 100 selections from the summer of 2020. Seeds from best performing inbred genotypes were sown and field planted spring of 2021. Advances in sixth generation of inbreeding (S6) were made in two families. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The data analysis on the IStraw SNP genotyping guided the choice of parents for the F1 seed hybrids crosses and choice of seed families sown in February 2021. The data analysis will be completed on the genotyping and on the phenotyping. The data analysis will be used in a manuscript preparation and a future project proposal. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Based on initial field evaluations of new founder families made during the summer of 2020, additional seeds from a selection of this families were sown in February 2021 and field planted in May 2021 and initial evaluations were made during summer of 2021. Additional crosses between two families of advanced S4 and S5 generation inbreds were completed to generate additional F1 hybrid seeds. The most fruitful or productive F1 seeds were sown in February 2021 and field planted in May 2021 in replicated plots for evaluation of flowering habit, progeny vigor and homogeneity . Phenotyping and evaluations of these new F1 seed hybrid plants during the summer will be completed summer of 2022. In addition, two of the progeny families are being evaluated for suitability under low tunnel plasticulture for season extension until late October/early November 2021. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We continue to generate interest in the evaluation for the upcoming varieties as initial F1 seed hybrids via site tours at the Durham Farm Field Day held August 21, 2021. Selections of F1 hybrid seeds will be made for future evaluation by interested growers. The August 2021 Field day was the first permitted on-site Field Day open to the public tour since the summer of 2019, before the Covid-19 pandemic.

Publications

Progress 09/01/19 to 08/31/20

Outputs
Target Audience:We generated interest in the project and our progress on inbreeding and upcoming varieties as initial F1 seeds will become available for evaluation in the near future. NHAES Virtual Twilight Meeting, June 24, 2019 (presentation an update on strawberry breeding for fruit quality and seed varieties). New England Vegetable and Fruit Conference and Trade Show, Manchester NH, December 10-12, 2019 (attended and networked breeding strawberries and planned seed varieties). Changes/Problems:The Covid-19 pandemic required scaling down of research at UNH. Fewer seeds from fewer families were sown as limited access was granted to complete the work. Given that a key output of this OREI project was the engagement of growers in the evaluation of F1 seed hybrids generated from inbreds, the seeds were generated and stored rather than sown. A request was made to extend the project by one year, during which time additional inbreeding and F1 hybrid seed could be generated with the anticipation that the summer of 2021 would be post-Covid-19 and permit in-person grower evaluations. Alternatively, we will plan on virtual options for grower engagement as the time approaches if necessary. What opportunities for training and professional development has the project provided?Undergraduate students have been trained in the following: strawberry propagation both seed and vegetative via runners and crown divisions. strawberry inbreeding, fruit collection for seed harvesting and cleanup. phenotyping in the field for plant vigor, heath as well as fruit production and quality fruit quality assays for Brix and acidity plant field and greenhouse maintenance PI Mahoney and Co-PI Davis served as co-advisors on Graduate Master's Thesis committee: The development of knowledge and resources relevant to the genetic manipulation of day neutral flowering habit in strawberry (2020) Samikshya Rijal Master's Thesis How have the results been disseminated to communities of interest?Results have been shared at meetings and local events: LL Mahoney, New England Vegetable and Fruit Conference and Trade Show attended and networked, Manchester NH, December 10-12, 2019. LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight Meeting, June 24, 2020 What do you plan to do during the next reporting period to accomplish the goals?1. Develop the inbred selections to serve as parents for production of F1 hybrid seed. During the fall/winter of 2020-2021, further inbreeding will be completed in the greenhouse on the 100 selections from the summer of 2020. Seeds from best performing inbred genotypes will be sown for field planting spring of 2021. Phenotyping and selections of genotypes field planted during spring 2020 will be completed during the 2021 season. Selections will be propagated for further inbreeding and crossing in the greenhouse during the fall winter of 2021/2022. Phenotyping and selections will be initiated for seedlings planted summer of 2021. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The data analysis will be completed on the genotyping and phenotyping completed to date. The analysis will be used to help guide additional genotyping. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Evaluation of the new founder F1 hybrids from more distantly related parents which began evaluations during the summer of 2020 will be completed. Additional crosses between two families of advanced S4 and S5 generation inbreds will be completed to generate additional F1 hybrid seeds. The most fruitful or productive F1 seeds from seeds generated 2019-2020 and 2020-2021 will be sown and field planted during the during the 2021 season. The parental selections used to generate the initial F1 hybrids were from one lineage and therefore very closely related and as expected did not generate the hybrid requisite vigor. New inbred generated F1 hybrid seed plants will be phenotyped and evaluated in the field during the summer of 2021. The F1 hybrids will be evaluated for progeny vigor and homogeneity. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We will continue to generate interest in the evaluation for the upcoming varieties as initial F1 seeds during on-site evaluations during the summer of 2021 via site tours and communications and are planning a special field day during the summer of 2021 to engage growers on farm evaluations. Selections of F1 hybrid seeds will be made for future evaluation by interested growers.

Impacts
What was accomplished under these goals? 1. Develop inbred selections to serve as parents for production of F1 hybrid seed. As background, field phenotyping is conducted at the UNH Woodman Farm in certified organic fields and inbreeding is completed at the UNH Macfarlane Greenhouse Facility in a certified organic greenhouse. Seeds anticipated to generate repeat flowering plants are sown in February for field planting in May. The repeat flowering plants begin to bear fruit in the same year in which the seeds are sown and so phenotyping and selections are begun in that first year and completed the second year. Seeds anticipated to generate short-day plants requiring flower initiation, are sometimes later sown in May and planted in the field in August, and phenotyping is completed the following year. In general, within each inbreeding generation, more seeds are generated than can be sown and therefore the seeds selected for sowing are based on the qualities of the parents with the most desirable fruit quality and productivity, as well as plant health and flowering cycles. An additional cycle of inbreeding was completed during the fall/winter of 2019-2020 on the 250 inbred plants phenotyped and selected during the summer of 2019. Seeds sown in February 2020 were chosen from among three lineages of families not yet well-advanced in the number of generations of inbreeding. The seeds sown will advance additional lineages of inbred families to expand the diversity of inbreds for use as parents. All 142 seedlings were transplanted and set in field rows in June 2020 and initial phenotyping was begun during the summer of 2020. Select genotypes are maintained in another greenhouse and some were also planted in the field to reserve as potential parents pending results of progeny tests. The field phenotyping was completed during the summer of 2020 on the 1,300 seedlings planted in 2019, and a selection of 100 genotypes were propagated for an additional cycle of inbreeding during the fall/winter of 2020-2021. Advances in fifth generation of inbreeding (S5) were made in two families. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The data analysis on the IStraw SNP genotyping indicates progress on inbreeding is as expected as evidenced by the reduction in heterozygosity and corresponding increase in homogeneity with each selfing generation. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Phenotypic evaluations were completed during the summer of 2020 on the initial F1 seed hybrid plants field planted during the 2019 growing season. These initial F1 seed hybrids were derived from 16 crossing families between advanced S3 and S4 generation inbreds. Phenotyping revealed a high level of homogeneity but also a limited restoration of hybrid vigor with the exception of one family generated from the two more distantly related inbred S3 and S4 parents. The limited restoration of hybrid vigor was anticipated due to the limited diversity of inbreds available to select as parents at the time. New founder F1 hybrids were generated from inter-crossings between commercial cultivars during the fall/winter of 2019-2020 to expand the diversity of inbreeding lines in order to further expand the pool of inbred lines for use as F1 seed parents in the future. In February 2020, 24 seeds of each of 10 new founder families were sown, and the seedling transplants were set in the field rows in June and initial field evaluation began during the summer of 2020. AdditionalF1 seed hybrids were generated from 27 crossings between the two more distantly related S4 inbreds families during the fall/winter of 2019-2020. Because of the Covid-19 pandemic and the associated high degree of uncertainty surrounding the ability to properly evaluate these progeny and whether growers would be permitted on-site to provide input, it was decided to postpone the sowing of these seeds. These F1 hybrid seeds were stored at 35-38F for future use. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We have generated interest in the evaluation of upcoming varieties as initial F1 seeds were evaluated on-site summer of 2020 with a virtual meeting, as UNH was not allowed to permit the public to visit UNH facilities and field sites from mid-March todate. New England Vegetable and Fruit Conference and Trade Show attended and networked, Manchester NH, December 10-12, 2019. LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight meeting, June 24, 2020

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: LL Mahoney, Update on strawberry breeding: flowers, fruit, and seed, NHAES Virtual Twilight meeting, June 24, 2020
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: TM Davis, Y Yang, D Frailey, LL Mahoney (2020) A Pentaploid-Based Linkage Map of an Octoploid Strawberry Hybrid Reveals Unusual Patterns of Recombination, Plant and Animal Genome Conference, January 11-16, San Diego, California
• Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Davis, TM, Y Yang, LL Mahoney, and DC Frailey (2020) A pentaploid-based linkage map of the ancestral octoploid strawberry Fragaria virginiana reveals instances of sporadic hyper-recombination. Horticulture Research 7:77, 15
• Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Iezzoni, AF, J McFerson, J Luby, K Gasic, V Whitaker, N Bassil, C Yue, K Gallardo, V McCracken, M Coe, C Hardner, JD Zurn, S Hokanson, Evd Weg, S Jung, D Main, CdS Linge, S Vanderzande, TM Davis, LL Mahoney, C Finn, and C Peace (2020) RosBREED: bridging the chasm between discovery and application to enable DNA-informed breeding in rosaceous crops. Horticulture Research 7:177, 23.
• Type: Theses/Dissertations Status: Submitted Year Published: 2020 Citation: PI Mahoney and Co-PI Davis served as co-advisors on Graduate Master's Thesis committee: Samikshya Rijal (2020) The development of knowledge and resources relevant to the genetic manipulation of day neutral flowering habit in strawberry, UNH Agriculture, Nutrition and Food Systems Master's Thesis

Progress 09/01/18 to 08/31/19

Outputs
Target Audience:We generated interest in the upcoming varieties as initial F1 seeds become available in the near future at the following events. NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). LL Mahoney, Breeding Strawberry Varieties, NHAES Food and Agriculture Extension Staff Quarterly Meeting, UNH NHAES Woodman Farm, July 25, 2019 (tour of fields and discussion on planned seed varieties). LL Mahoney, Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, UNH NHAES Woodman Farm, August 17, 2019 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Additional Three undergraduate students have been trained in the following strawberry propagation both seed and vegetative via runners and crown divisions. strawberry inbreeding, fruit collection for seed harvesting and cleanup. phenotyping in the field for plant vigor, heath as well as fruit production and quality fruit quality assays for Brix and acidity plant field and greenhouse maintenance Mentored undergraduate students who presented at the UNH Undergraduate research Conference. A Benner, A Perkins LL Mahoney (2019) Fertilizer Regime for Organic Strawberry Production. UNH COLSA 28th Annual Undergraduate Research Conference, April 27, Durham, NH. T Fischer, M Alix, A Benner, A Perkins, LL Mahoney (2019) Strawberry Breeding. UNH COLSA 28th Annual Undergraduate Research Conference, April 27, Durham, NH. Served on Graduate Master's Thesis committee: Quantifying nutrient and light requirements for day-neutral strawberries in controlled environment agriculture (2019) Anna Elizabeth Devitto Master's Thesis How have the results been disseminated to communities of interest?Results have shared at meetings and local events LL Mahoney, RG Sideman, TM Davis (2019) Breeding Strawberry Seed Varieties in Northern New England for Organic Agriculture. IX North American Strawberry Symposium, 2019 North American Strawberry Growers Association Annual Meeting, February 3-6, Orlando, Florida. LL Mahoney participated and shared results informally during RosBREED2 hosted Partner's Meeting San Diego, California January 11, 2019 and RosBREED2 Participants Meeting, March 25-28, Lansing, Michigan. LL Mahoney participated and shared results informally and with posters during the NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019. LL Mahoney (2019) Breeding Strawberry Fruit and Ornamental varieties, UNH Extension Food & Agriculture Program Staff Summer Meeting, July 25 UNH NHAES Woodman Horticultural Farm, Durham NH, July 25 (Talk). LL Mahoney (2019) Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, August 17 UNH NHAES Woodman Horticultural Farm, Durham NH (Talk). What do you plan to do during the next reporting period to accomplish the goals?1. Develop additional more distantly related inbred selections to serve as parents for production of F1 hybrid seed. During the fall/winter of 2019-2020, further inbreeding in the greenhouse will be completed on the 250 selections from the summer of 2019. Seeds from best performing inbred parents will be sown for field planting spring of 2020. Phenotyping and selections of genotypes field planted during spring 2019 will be completed during the 2020 season. Selections will be propagated for further inbreeding and crossing in the greenhouse during the fall winter of 2020/2021. Phenotyping and selections will be initiated for seedlings planted summer of 2020. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The results of SNP genotyping on the IStraw90 Axiom array of 106 inbreeding pedigree related genotypes demonstrates evidence of inbreeding and the results are being used to guide and complete additional SNP genotyping and to guide selection of parents. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Initial crosses between advanced S3 and S4 generation inbreds were completed to generate F1 hybrid seeds, and the most fruitful or productive F1 seeds were sown and field planted during the during the 2019 season. Initial evaluations indicate that the parental selections used to generate the F1 hybrids are too closely related to generate the hybrid vigor expected. The evaluation of these will be F1 hybrids will be completed during the summer of 2020. Additional inter-crossings are planned for fall/winter of 2019-2020 to generate F1 hybrids from more distantly related parents to begin evaluations during the summer of 2020. F1 hybrid plants will be phenotyped and evaluated in the field. The F1 hybrids are being evaluated for progeny vigor and homogeneity. Selections will be made, and seed generated for evaluation by interested growers. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We will continue to generate interest in the evaluation for the upcoming varieties as initial F1 seeds during on-site evaluations during the summer of 2020 via site tours and communications and are planning a special field day during the summer of 2020 to engage growers on farm evaluations.

Impacts
What was accomplished under these goals? 1. Develop inbred selections to serve as parents for production of F1 hybrid seed. Field phenotyping is conducted at the UNH Woodman Farm in certified organic fields and inbreeding is controlled and completed at the UNH Macfarlane Greenhouses in a certified organic greenhouse. Seeds anticipated to generate repeat flowering plants are sown in February for field planting in early May. The repeat flowering plants began to fruit in the same year in which the seeds are sown and so phenotyping and selections are begun in that first year. Seeds anticipated to generate short-day requiring flower initiation, are later sown in May and planted in the field in August, and phenotyping is begun the following year. In general, within each inbreeding generation, more seeds are generated than can be sown and therefore the seeds selected for sowing were selected based on the qualities of the parents with the most desirable fruit quality and productivity, and plant health and flowering cycles. Seeds were sown in February and May, and so during the growing season of 2018, 2,200 seedlings were transplanted to the field and the genotypes inbred during the winter were maintained in another greenhouse and some were also planted in the field to reserve as potential parents pending results of progeny tests. Selection of 206 genotypes were propagated for further inbreeding in the greenhouse during the fall/winter of 2018-2019. From amongst, the seeds generated, seeds of 56 families were selected and sown in February 2019. From each family, up to 50 of the best seedlings were transplanted and of these 1,300 individual genotypes were set in field rows in May 2019. The phenotyping was completed on the 2,200 seedlings planted during the during 2018, and a selection of 250 genotypes were propagated for further inbreeding during the fall/winter of 2019-2020. Advances in fifth generation of inbreeding (S5) were made in two families. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. IStraw SNP genotyping was completed on 192 individuals and initial data analysis indicates progress on inbreeding is as expected as demonstrated by the reduction in heterozygosity and corresponding increase in homogeneity. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Inter-crossings were completed between potentially promising inbred parents for seedling generation. Development of F1 hybrids for evaluation of homogeneity were made from intercrossing members of S4 families. The F1 hybrids seeds from 16 crossings were sown, and transplants of 350 were set in fields in May 2019 for evaluation. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We have generated interest in the evaluation for the upcoming varieties as initial F1 seeds become available evaluation summer of 2020 via the following. NHAES Greenhouse Open House and Macfarlane Research Event, Durham NH, April 5-6, 2019 (public discourse, tours, and posters on breeding strawberries and planned seed varieties. LL Mahoney, Breeding Strawberry Varieties, NHAES Food and Agriculture Extension Staff Quarterly Meeting, UNH NHAES Woodman Farm, July 25, 2019. LL Mahoney, Breeding Strawberries Varieties for the Region's Organic Growers, 7th Annual Durham Farm Day, UNH NHAES Woodman Farm, August 17, 2019.

Publications

• Type: Other Status: Other Year Published: 2019 Citation: LL Mahoney, RG Sideman, TM Davis (2019) Breeding Strawberry Seed Varieties in Northern New England for Organic Agriculture. IX North American Strawberry Symposium, 2019 North American Strawberry Growers Association Annual Meeting, February 3-6, Orlando, Florida. (poster)

Progress 09/01/17 to 08/31/18

Outputs
Target Audience:We have generated interest in the evaluation for the upcoming varieties as initial F1 seeds become available for evaluation early in 2020 for initial grower evaluation during the summer of 2020 at the following events. LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk) TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk) LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview) LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk) Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Undergraduate students have been trained in the following strawberry propagation both seed and vegetative via runners and crown divisions. strawberry inbreeding, fruit collection for seed harvesting and cleanup. phenotyping in the field for plant vigor, heath as well as fruit production and quality fruit quality assays for Brix and acidity plant field and greenhouse maintenance How have the results been disseminated to communities of interest?Initial results have been presented at the following public events: LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk) TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk) LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview) LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk) What do you plan to do during the next reporting period to accomplish the goals?1. Develop inbred selections to serve as parents for production of F1 hybrid seed. During the fall/winter of 2018-2019, further inbreeding in the greenhouse will be completed on the 206 selections from the summer of 2018.Seeds from best performing inbred parents will be sown for field planting spring of 2019 and summer of 2019. Phenotyping and selections of genotypes field planted during spring and summer of 2018 will be completed.Selections will be propagated for further inbreeding and crossing in the greenhouse during the fall winter of 2019/2020. Phenotyping and selections will be initiated for seedlings planted summer of 2018 and spring of 2019. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. The results of SNP genotyping on the IStraw90 Axiom array of 106 inbreeding pedigree related genotypes will be analyzed for evidence of inbreeding and the results will be used to guide and complete additional SNP genotyping. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Additional inter-crossings are planned for fall/winter of 2018-2019 and for the planned initial evaluation for F1 hybrid progeny vigor and homogeneity during the summer of 2019. Crosses between advanced S3 and S4 generation inbreds will be completed to generate F1 hybrid seeds, and the most fruitful or productive F1 seeds will be sown and field planted during the spring and summer of 2019. F1 hybrid plants will be phenotyped and evaluated in the field. Selections will be made and seed generated for evaluation by interested growers. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We will continue to generate interest in the evaluation for the upcoming varieties as initial F1 seeds during on-site evaluations during the summer of 2019 via site tours and communications and plan to engage growers on farm evaluations for summer of 2020.

Impacts
What was accomplished under these goals? The accomplishments completed for each of the objectives are as follows: 1. Develop inbred selections to serve as parents for production of F1 hybrid seed. Field phenotyping is conducted at the UNH Woodman Farm in certified organic fields and inbreeding is controlled and completed at the UNH Macfarlane Greenhouses in a certified organic greenhouse. Seeds anticipated to generate repeat flowering plants are sown in February for field planting in early May. The repeat flowering plants began to fruit in the same year in which the seeds are sown and so phenotyping and selections are begun in that first year. Seeds anticipated to generate short-day requiring flower initiation, are later sown in May and planted in the field in August, and phenotyping is begun the following year. In general, within each inbreeding generation, more seeds are generated than can be sown and therefore the seeds selected for sowing were selected based on the qualities of the parents with the most desirable fruit quality and productivity, and plant health and flowering cycles. In late summer of 2017, just prior to the project start date, 180 genotypes were selected based on field phenotyping and analysis. These genotypes were propagated for further inbreeding completed in the greenhouse during the fall and winter 2017-2018. Seeds were sown in February and May, and so during the growing season of 2018, 2,200 seedlings were transplanted to the field and the genotypes inbred during the winter of 2017-2018 were also planted in the field to reserve as potential parents pending results of progeny tests. During the summer of 2018, field phenotyping was completed on the previously field planted 1,770 seedlings and begun on the additional 2,200 seedlings. Selection of 206 genotypes were propagated for further inbreeding in the greenhouse during the fall/winter of 2018-2019. Advances to the fourth generation of inbreeding (S4) were made in two families. 2. Define genetic and phenotypic consequences of inbreeding as a guide to optimization of parent selection and breeding strategy. Plant tissue was collected on 106 inbreeding pedigree related genotypes for DNA isolation and Axiom IStraw90 SNP array genotyping and results are expected before the end of the calendar year. 3. Evaluate combining abilities of inbred genotypes as parental pairs for hybrid seed production. Inter-crossings were completed between potentially promising inbred parents for seedling generation. 4. Engage growers in the evaluation of seed-propagated hybrid strawberry varieties. We have generated interest for the upcoming varieties of initial F1 seeds planned for evaluation summer of 2020 during the following presentation and events: LL Mahoney, Breeding strawberries for the organic producers, NHAES Pollinator Appreciation Day and Research Field Day, UNH NHAES Woodman Farm, June 19, 2018 (Talk) TM Davis and LL Mahoney, Strawberry Social - Strawberries of New Hampshire: Past, Present, and Future, Temple NH, June 24, 2018 (Talk) LL Mahoney, Breeding strawberries for New Hampshire, interview - Manchester Union Leader, June 29, 2018 issue http://www.unionleader.com/article/20180730/NEWS02/180729564 (Interview) LL Mahoney, Breeding strawberries, Durham Farm Day, August 18, 2018 - (Talk)

Publications