Location: Vegetable Crops Research
2022 Annual Report
Objectives
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 5: Develop alternative cranberry production practices that improve water conservation and decrease plant disease. [NP301 C1 PS1B C2 PS2A] Expected benefits include a systems approach to cranberry production that includes genetic improvement, genomics, disease and pest mitigation, and water conservation.
Approach
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.
Progress Report
The progress reported relates to Objectives 1-4. We are investigating the variability of cranberry cultivars at both phenotypic and genetic levels to comprehend cranberry plasticity and develop cultivars with superior traits. Image- based phenomics is an effective tool for nondestructively evaluating plant traits and acquiring a thorough understanding of their diversity with low error rates. We are building version 1 of an image-based system for cranberries to capture all growth stages in the field with a high-resolution autofocus focal depth lens. We are enhancing the system's capability by adding temperature and humidity sensors that can measure environmental conditions at the canopy level. This approach should enable us to integrate high throughput phenomics into cranberry research initiatives, measuring trait response to environment and management as a cost-effective and realistic alternative. We are also developing machine algorithms to analyze the images and identify the developmental stages. The data will be utilized to acquire insight into cranberry growth and development and
detect phenological variations across different cultivars. This study will assist in characterizing the cultivar's responses to multiple environments/locations (Wisconsin, Massachusetts, and New Jersey) and management strategies to improve productivity. We are studying yield and quality traits in cranberry using traditional data collection methods. We are also developing high-throughput fruit quality data collection and visualization software to massively collect and understand these data. Molecular tools are being applied to study and identify cranberry genes by mapping those genes found to control important traits. We have developed several high-density molecular maps and a composite map which we are using to map traits of economic importance. These efforts will help breed cranberry cultivars more efficiently by allowing marker-assisted breeding. The Wisconsin cranberry research station is completely operational and over 3750 total field plots were developed. This work has been a collaboration with cranberry growers to establish a cranberry research station in Wisconsin. The various plots include cultivars, natural diversity, breeding crosses, and experiments established to test the horticultural needs, performance, and selection of important cranberry cultivars. Mating disruption involves the use of sex pheromones to prevent male insects finding females and mating. The U.S. cranberry mating disruption program has incorporated a new pheromone carrier type (micro-encapsulated carriers) and has tested higher loading levels. A bio-insecticide comprised of native Wisconsin nematodes has recently been shown to be highly effective when applied at large scales, and can be sprayed via standard grower spray equipment. Bee-microbe interactions continue to be investigated and appear to be vital for larval bee development. We are developing methodologies for evaluating different cranberry cultivars for their photosynthesis, water use efficiency, and nutrient uptake. We are also implementing low-cost, effective phenotyping tools to track cranberry varieties' growth and development in the field. This imaging platform should allow us to integrate high throughput phenomics into cranberry research programs ranging from quantifying diversity to nutrient management as a feasible low-cost solution. In addition, the digital phenotyping tool and information derived will help breeders in genotype selection based on desired traits and breed new cultivars that interest cranberry growers. We are also studying the expression stability of reference genes in different tissues and experimental conditions for accurate normalization of cranberry gene expression studies.
Accomplishments
1. Genetic testing of cranberry beds identified contamination with unwanted cranberry plants. Unwanted cranberry clones are found in commercial cranberry beds that are intended to be a single uniform clone. Identification of contamination and the impacts of contamination remain crucial issues to the cranberry industry to maintain long-term high productivity. To address this issue, tissue samples were taken by ARS researchers in Madison, Wisconsin, from the former commercial beds of the new Wisconsin Cranberry Research Station (WCRS) in 2017 for genetic fingerprinting analysis. A total of 288 DNA samples were collected in ten cranberry beds, and the ‘Stevens’ cultivar represented 180 samples, or 69% of the 261 samples expected to be ‘Stevens’. The results also indicated that visual differentiation was accurate in distinguishing between genotypes and detecting large areas of contamination. A yield analysis was conducted along with genotypic uniformity assessments and found significant correlations between historical yield of the beds and their level of genetic contamination. Overall, this study demonstrates the usefulness of genetic uniformity testing and mapping for cranberry bed management and renovation decision-making. Genetic testing of cranberry beds will allow growers to decide when to renovate their plantings to maintain productivity while using resources wisely since management and renovation of cranberry beds is expensive and time consuming.
2. Cranberry nematodes are voracious consumers of bacteria within insects. Nematodes kill insect pests via the deployment of bacteria that live within the nematodes. ARS researchers in Madison, Wisconsin, in collaboration with university researchers, have shown that nematodes that kill cranberry insects not only deploy these bacteria to overwhelm the insect immune system, but also consume these bacteria as their primary nutrition source. This explains a fundamental aspect of nematode biology, and also explains why certain nematodes are virulent bio- control agents of cranberry insect pests. Cranberry nematodes will be useful as alternatives to insecticide use in cranberry beds, and the knowledge of the mode of action of insect killing by nematodes will help in the deployment during cranberry integrated pest management programs.
3. The source of microbes and pollen is key for bee larval development. Native bee species are a critical component of cranberry production since they pollinate cranberry flowers. Bee larvae require microbes to complete their development and ARS researchers in Madison, Wisconsin, have recently shown that the particular microbes supplied by conspecific (mother bees are critically important. Specifically, the mother bee supplies a blend of microbes and pollen species that are partially derived from her own brood cell and partly from the flowers she visit, all of which tend to be conducive to the growth of her larvae. To demonstrate the critical importance of this particular microbial ‘seeding,’ microbes from a different species were substituted as the source of microbes (and pollen). Despite having ample pollen and microbes, the bee larvae that had the ’wrong kind’ of pollen and microbes substituted for their diet actually suffered significantly. This is the first evidence that bees require a particular microbial community and pollen community in their diet, underscoring the importance of microbes for supporting pollinator health.
4. Microbial ‘fingerprints’ evident in most animal proteins. Whether bees or beetles or condors, the roles of microbes in animal development have increasingly been recognized. ARS researchers in Madison, Wisconsin, have shown that the molecular ‘fingerprints’ of microbes have been found within the proteins of many different insect species in agricultural systems; thus, it was hypothesized that such dynamics would also affect macro-fauna in unmanaged ecosystems. It was important to examine the relative contributions of microbes in the development of such animals, largely as a means of testing the universality of the ‘microbe effect’ in any given ecosystem. Here, ARS researchers in Madison, Wisconsin, collaborated with university scientists to demonstrate the ‘microbe effect’ using condors, pumas, and vertebrate herbivores in the Andean plateaus of South America. This model ecosystem was an ideal demonstration of how microbes shape the trophic identities of animals, which helps to illuminate the universality of microbial roles in the ‘upward’ flow of biomass in natural food-webs.
Review Publications
Dharampal, P., Danforth, B., Steffan, S.A. 2022. Exosymbiotic microbes within fermented pollen provisions are as important for the development of solitary bees as the pollen itself. Journal of Experimental Biology. 12:e8788. https://doi.org/10.1002/ece3.8788.
Barcelo, G., Perrig, P., Dharampal, P., Donadio, E., Steffan, S.A., Pauli, J. 2022. More than just meat: Carcass decomposition shapes trophic identities in a terrestrial vertebrate. Proceedings of the Royal Society B. 36:1473–1482. https://doi.org/10.1111/1365-2435.14041.
Mucci, N., Jones, K., Cao, M., Wyatt, M., Foye, S., Kauffman, S., Taufer, M., Takizawa, Y., Chikaraishi, Y., Steffan, S.A., Campagna, S., Goodrich-Blair, H., Richards, G.R. 2022. Chemical ecology of a tripartite symbiosis. American Society for Microbiology. 00312-22. https://doi.org/10.1128/msystems.00312-22.
Matusinec, D., Maule, A., Wiesman, E.C., Atucha, A., Mura, J.D., Zalapa, J.E. 2022. The New Cranberry Wisconsin Research Station: Renovation priorities of a ‘Stevens’ cranberry marsh based on visual mapping, genetic testing, and yield data. International Journal of Fruit Science. 22:1, 121-132. https://doi.org/10.1080/15538362.2021.2014016.
