Location: Vegetable Crops Research2018 Annual Report
Objective 1: Map and identify genes that underlie cranberry yield and quality traits, and explain the phenotypic differences between selected genotypes using genetic, genomic, and molecular approaches. Objective 2: Develop new enhanced cranberry germplasm and cultivars by integrating genetic and genomic breeding approaches with conventional cranberry breeding. Objective 3: Develop tools for the early detection and prevention of new, emerging cranberry pests (insects and mites). Sub-objective 3. Develop bio-insecticides using newly discovered, native nematode species. Objective 4: Develop new integrated pest management technologies for pest management and sustainable production of cranberry. Sub-objective 4.A. Develop a multi-species mating disruption program for the major moth pests of U.S. cranberries. Sub-objective 4.B. Investigate the biology and ecology of native pollinators to ensure the sustainable production of cranberries.
Objective 1: A multi-pedigree QTL mapping approach will be used to map cranberry yield and fruit quality traits. Phenotypic trait data collection will include traditional and newly developed high-throughput methodologies to measure yield and fruit quality related traits and other horticultural measurements, including total fruit weight, percent rotten fruit, average berry weight, and other fruit quality parameters such as TAcy and firmness. A composite SSR/SNP high-resolution cranberry genetic map developed based on three half-sibling populations will be used for QTL analysis. Objective 2: This research will collaborate with cranberry growers to establish a cranberry research station in Wisconsin and to establish various sized research plots to test the horticultural needs and performance of a selection of important cranberry cultivars. Phenotypic information that will be collected will be determined based on previous research to include the best traits to measure yield and quality. Additionally, a classic inbred-hybrid system will be used based on the best performing cranberry cultivars in the industry to develop improved cranberry lines and varieties in terms of yield and quality. Prior to creating cranberry inbreds and hybrids, horticultural, genetic, and genomic information will be carefully considered to ensure that strategic crosses are accomplished. Objective 3: A novel, effective bio-insecticide will be developed for arthropod pest suppression in commercial cranberry marshes. Two highly virulent nematode species, both native to Wisconsin, will comprise the bio-insecticide, and the nematode blend will ultimately be developed such that it can be applied at large-scales using standard spray equipment. Arthropod population suppression will be assessed among pest species and non-target species alike. Objective 4: A multi-species mating disruption system will be developed to control the top three insect pests of Wisconsin cranberries. The sex pheromones of these insect species will be loaded into carriers that can be applied efficiently via standard fertilizer-application equipment. We will also examine the capacity of the cranberry plant to prime its chemical defenses after 'eavesdropping' on the pheromones of its major pests. Bee-microbe symbioses will be investigated as a means to better understand and protect the native pollinators of cranberries.
This progress report relates to Objectives 1 and 2. ARS scientists in Madison, Wisconsin have been working to provide growers and breeders phenotypic and molecular data to increase cranberry breeding efficiency. We are currently collecting yield and quality trait data for genetic mapping. We are using imaging techniques based on custom designed software to maximize data collection efficiency to characterize the most valuable traits in cranberry plants belonging to three mapping populations. The data from the three mapping populations will be used to molecularly and positionally map and study the action genes involved in cranberry fruit quality and yield. All of the data will be merged in a composite genetic map that will be the basis of a future molecular breeding program in cranberry. This progress relates to Objectives 3 and 4. ARS scientists in Madison, Wisconsin continue to advance the practice of integrated pest management (IPM) in United States cranberries by investigating explicitly the intersection between crop production technology, arthropod biology, and agroecology. Based on recent findings, new nematode bio-insecticide formulations are being manufactured by ARS researchers in Madison, Wisconsin and tested at large scales (15 acres) on commercial cranberry acreage in central Wisconsin. The pests targeted are cranberry fruitworm and flea beetles. The loading of pheromones into new carriers has been completed successfully, and the next step is to examine their longevity in the field. Field deliveries will be conducted soon, and growers will deploy the carriers using their fertilizer spreading equipment. Monitoring of moth populations will commence soon thereafter.