Location: Genetic Improvement for Fruits & Vegetables Laboratory
2023 Annual Report
Objectives
Objective 1: Breed improved strawberry plants that perform well for commercial growers, with emphasis on high yield, tolerance to abiotic stress, resistance to diseases, and fruit with excellent fruit quality and long shelf life.
Objective 2. Characterize important strawberry traits, their inheritance and genetic control, developmental and biochemical pathways, and metabolic processes, including the regulation of plant architecture, and fruit and flower development.
Approach
Standard plant breeding methods will be used to generate superior strawberry cultivars for traditional production practices and fruiting for the traditional short spring season. Novel evaluation practices for fruit quality and flavor will be developed and incorporated into the annual breeding cycle. A seedling screen for resistance to anthracnose crown rot, an emerging disease of worldwide importance, will be used to identify resistant strawberry plants and increase the breeding population’s average resistance to the disease. New cultivars resulting from selection based on increased disease resistance, fruit quality, yield, and shelf life will be released. To help satisfy demand for year-round availability, similar methods will be used to generate improved strawberry plants that fruit for an extended season from April through December. Because the longer-fruiting plants will face weather and pest challenges that are not problems during the traditional fruiting season, new comparison methods will be developed to facilitate identification of plants that produce fruit within the traditional season, and produce equally well outside the traditional strawberry season. Physiological, genomic, and transcriptomic analyses of novel mutant diploid strawberry lines will lead to identifying genes involved in growth and development required to meet predicted challenges, such as the trend toward completely contained growing environments for urban and off-season production. These insights into basic strawberry biology also will improve the tools breeders have to develop the necessary new cultivars. The results will help strawberry nurseries provide high-quality cultivars to growers, helping them produce strawberries more sustainably to satisfy increasing consumer demand for fresh, flavorful fruit year-round.
Progress Report
This is a newly established project approved thru OSQR review. Please see final annual report 8042-21220-257-000D.
In support of Objective 1, breeding improved strawberry plants, 84 seedlings likely resistant to anthracnose crown rot were selected for further evaluation. A higher number than planned selections were made for two reasons. First, 70% of the total seedling population died in the field the previous fall from anthracnose crown rot, possibly limiting the genetic diversity of the breeding population. Second, unusually cool and dry conditions prevented expression of anthracnose fruit rot.
In support of Objective 1, for the first year since the start of the repeat-fruiting strawberry breeding effort, repeat-fruiting selections were planted in replicated evaluations that included comparisons of selections under low tunnels and in open beds. This experiment will help determine if sufficient breeding progress has been made to allow future comparisons of repeat-fruiting selections in open beds only, saving research costs.
In support of Objective 2, molecular markers were developed to genotype a population of 400 plants resulting from a cross of the non-runnering EMS mutant with a plant that is homozygous for the DELLA ‘suppressor of non-runnering’ mutation and homozygous for a mutation in a gibberellin oxidase gene that results in the ‘non-runnering’ phenotype. DNA was extracted from each plant for genotyping, and seeds are being collected from each plant.
Accomplishments
