Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
Horticultural Science
Non Technical Summary
Cold-hardy, hybrid grape cultivar development can be advanced through both traditional and molecular genetic approaches. The University of Minnesota (UMN) grape breeding project aims to develop products that spans several distinct sectors including wine grape; table grape; food, beverage, and food products; as well as ornamental and landscape plants. Advancements within the project include the development and testing of DNA markers for early screening of seedlings prior to field planting for important traits, and the use of DNA tests to select top quality parents for performing elite crosses. To date, we have marker tests for several traits including: disease resistance (several powdery mildew genes), flower sex, and seedlessness. This proposal aims to implement routine marker assisted breeding (MAB) as a tool to predict seedling performance and accelerate areas within the breeding timeline, especially for developing disease resistant varieties. Research in wine making will complement variety development, but will also focus on best practices for commercial wine production using cold-hardy grape cultivars. Research driven knowledge on wine making and grape growing will be disseminated through education and extension programming.
Animal Health Component
90%
Research Effort Categories
Basic
10%
Applied
90%
Developmental
(N/A)
Goals / Objectives
1. Advance hybrid grape cultivar development for (a) cold-hardy wine grape production, (b) table grape markets, (c) food, beverage, and food product industry, and (d) ornamental landscape installations through traditional and high-throughput phenotyping methods.2. Implement routine marker assisted breeding (MAB) in grape cultivar development through (a) identifying marker-trait associations, (b) developing DNA tests for associated traits, (c) implementing DNA tests for screening potential parents and culling offspring.3. Develop protocols and best enology practices for commercial wine production using cold-hardy grape cultivars.4. Advance the understanding and practice of grape growing and wine making across the state through outreach and extension programming
Project Methods
Objective 1 Cultivar developmentTwo general approaches are used for hybrid grape cultivar development, traditional breeding methods and marker assisted breeding (covered below). Parents are selected for a cross pollination based on their complementary traits of interest the breeder would like to combine in an offspring. A family is created, and seedlings are evaluated in the first year in a nursery for growth habit and disease resistance, then planted and evaluated in 3-5 years when the offspring will flower and fruit for the first time. The breeder then evaluates the population as a whole, and each individual within the cross. The first culling decisions are based on visual performance of the vine and organoleptic properties of fruit quality by a single observer in the field. This is a labor-intensive process, inherently biased, prone to sampling fatigue, and time consuming.Superior wine grape selections, those fruit samples with fruit chemistry falling within the wine making standards, are processed for microvinification. Over the last 5 years we have increased sample wine volumes acceptable for our evaluations from 250 mL to 1000mL increasing the quality with fewer faults and flaws. We then conduct sensory analysis on those wines. The most elite selections are clonally propagated to increase the number of plants available in order to evaluate different vineyard sites, test within multi-state projects (NE1720), and to increase the fruit available for wine analysis.The key wine breeding targets include: total acidity 6-9 g/L; cold hardiness >80% primary bud survival; powdery mildew resistance (durable); phylloxera resistance; sugar content (~24°Brix); predictable, sustainable yields; reduced management inputs; tannic red wine. For table grapes, the key breeding targets include a long harvest window, good storability, maintenance of flavor in storage, and seedlessness. We have just concluded 2 years of a table grape evaluation project, which included post-harvest evaluation and sensory analysis. Additional considerations for table grapes include evaluation of fruit texture, flavor, berry size, seed trace size, and storability. Rootstock evaluations include resistance to insect pests, nematodes (collaboration with Dr. Zasada, USDA-ARS, Corvallis, OR), rooting capacity, and graft compatibility.An ongoing collaboration with Dr. Adrian Hegeman investigates the secondary metabolites contributing to grape flavor and aroma. In addition to using mass spectrometry, the project includes sensory analysis and genetic approaches to understand the genomic basis for different compounds. We are expanding this work for two years to study a fine mapping population that segregates for color, disease resistance, insect resistance, and flavors. This population is suitable for getting to the candidate gene level due to the high resolution of markers and population size (n=1000). High-throughput phenotyping is a target here in order to extract multiple data points from image analysis and for metabolomics approaches that identify thousands of features per sample that could be mapped individually or in network analyses.Objective 2 Marker assisted breeding (MAB)Grape breeders have been using MAB, utilizing DNA tests, to screen both parents and seedlings for desirable traits for the last 6 years. MAB is a tool for accelerating the rate of cultivar development by enriching germplasm for the trait of interest and targeting which plants are grown to maturity for evaluation. DNA is extracted from leaf tissue in the greenhouse from a seedling population(s) and extracted using available kits or protocols. Our genome-wide, rhAmpSeq protocol is suitable for routine MAB. We intend to continue using this approach or transferring the technology to more targeted techniques if and when they become economically suitable. MAB is driven by gene mapping experiments that aim to link a trait of interest with a region of a genome. This requires quality phenotyping across a population in appropriate experimental conditions. We have been successful in these experiments for the following traits: leaf variegation, cluster compactness, berry color, insect resistance, powdery mildew resistance, and leaf trichome density. We have even fine-mapped several of these loci using a large mapping population. This is the only known grape population of this magnitude and provides an exceptional resource for future studies.We will investigate berry color over the next 5 years using image analysis, gene expression, and mass spectrometry approaches. Our target populations are GE1205 and our fine mapping population due to the high levels of variation observed in those samples.The Ren10 powdery mildew resistance locus identified by Teh (2017) requires additional investigation in order to confirm the QTL and estimate the effect in a background where the gene is functionally independently of Ren3 resistance. We developed and established a gene mapping family in our vineyard in 2019 that segregates for Ren10 resistance allele. This population will be phenotyped locally for disease resistance and has already been genotyped.Objective 3 Enology best practiceNearly all grape cultivars grown in Minnesota are interspecific hybrids developed by plant breeders over the last century. Therefore, unlike varietals from long established winemaking traditions, the best enological practices are still in development. Research will be conducted in order to optimize protocols for cold-hardy cultivars developed (or in development). Modified processing parameter trials will be conducted to develop optimal procedures for individual cultivars. In red wines the effects of skin contact time, fermentation temperature, yeast strains, and tannin/oak on wine quality will be evaluated. In white wines, varying yeast strains, residual sugar, malolactic fermentation, and harvest date will be investigated.We have been investigating harvest time at weekly intervals for three years to evaluate the subsequent wines and make recommendations to growers. Most current recommendations for wine making focuses on a late harvest that allows the vines to mature the crop as long as possible before harvest. However, our research on 'Brianna' and other hybrid grapes have indicated that advanced maturity may increase the sugar concentration and reduce acidity, but can come with the cost of off-flavors and aromas (Rice et al. 2019).Objective 4 Education and extension--Technical information (such as updates on winter injury or disease monitoring) will be provided through electronic media (www.enology.umn.edu). The Minnesota Grape Growers Association (MGGA) and Minnesota Farm Winery Association (MnFWA) newsletter(s) as well as other trade publications will be used to disseminate technical information to grape and wine producers. Direct communication with producers is also important, and continued extension services will create a line of communication among stakeholders for activities conducted at UMN. The project hosts field days and research presentations each year which include workshops on techniques, samples of products (grapes or wine), dissemination of research activities, and promotes communication among industry stakeholders. The project also supports the educational efforts of MGGA through presentations and workshops at symposia (Cold Climate Conference), organizing events, and regular workshops.Our enology specialist Drew Horton has offered winemaker roundtables (6-8 per year) which has been an excellent way to build community within the industry. The format is supportive of winemakers at all levels and experience and focuses on using appropriate terminology and techniques. The producers share their best practices. Although not implemented in 2020 due to Covid-19, we intent to reinstate these outreach activities, as they have been deemed successful by the participants.