Location: Vegetable Crops Research2012 Annual Report
1a. Objectives (from AD-416):
Objective 1. Initiate an integrated cranberry genetics and genetic improvement plan to develop enhanced germplasm and superior new cultivars of cranberry adapted for a short growing season climate with superior productivity, increased disease resistance, enhanced nutritional characteristics, improved environmental adaptation (especially cold tolerance), and more uniform ripening with excellent berry color. Evaluate field performance and quality under current commercial conditions as well as under enhanced production systems utilizing new IPM and water management technologies. Objective 2. Initiate an innovative and integrated research program to characterize current insect pest damage of the cranberry crops, develop efficacious and economical insect Integrated Pest Management (IPM) strategies for cranberry production systems, and respond to emerging insect pests. Evaluate field performance under current commercial conditions as well as under enhanced production systems utilizing new cranberry varieties and new water management technologies.
1b. Approach (from AD-416):
For Objective 1, novel phenotypic variation will be identified, genetically characterized, mapped on the cranberry genome, and key genes incorporated into breeding stocks that are well-adapted for commercial growers. DNA polymorphisms and molecular tools will be developed to improve the efficiency of cranberry breeding. Methods for accurately phenotyping traits of importance will be developed and promising genetic selections will be tracked in commercial production systems that include up-to-date IPM and water management technologies. For Objective 2, novel pest management strategies will be developed and evaluated including, but not limited to, biological controls, host pest resistances, reduced risk chemicals, and cultural practices. Pest biologies will be studied to develop models for making optimal control decisions directly applicable to commercial production systems. Environmental impact of climate change, emerging water management issues and their application to new cranberry cultivars will be incorporated into reduced-risk pest management strategies developed and evaluated in commercial production systems.
3. Progress Report:
Objective 1: The USDA-ARS Cranberry Genetics Laboratory (CGGL) is currently developing molecular tools useful for breeding and genetics studies in Vaccinium. Simple sequence repeats (SSR) and single nucleotide polymorphic (SNP) markers are being developed using next generation sequencing data. These markers will facilitate cultivar development through genetic mapping. Thousands of SSRs are being developed for the genetic mapping of important traits in cranberry. Additionally, sequencing efforts have yielded the complete plastid and mitochondria genomes of cranberry through bioinformatic approaches. Developed SSR markers are also being used for the genetic characterization of cultivated and natural plant germplasm and the discovery of best parental combinations in cranberry for controlled crosses prioritization. Cultivated and wild cranberry genotypes are continually being collected around the U.S. We are evaluating and comparing the genetic diversity of several cranberry collections, for example the USDA-ARS National Clonal Germplasm Repository (NCGR). Genetic information gained from examining cranberry collections together with information from a genetic survey of cultivated and wild cranberries conducted in Wisconsin allowed the designation and conservation of appropriate genotypes for several of the most important cranberry cultivars. Objective 2: Research has focused on elements of integrated pest management (IPM) and arthropod biology that facilitate reduced pesticide use in U.S. cranberries. Thousands of arthropod specimens collected in spring floods have been analyzed to reveal the diversity and abundance of pests physically removed from beds during flood events. The first ever 3-species mating disruption program was tested on four marshes in Wisconsin. The species targeted represent the top three pests of Wisconsin cranberries. Additionally, eight years of pheromone-baited trap-catch counts were analyzed to illuminate the historic flight patterns for these pests. The cranberry flea beetle has recently emerged as a major pest of Wisconsin cranberries, so an experiment was initiated to show that a single well-timed June soil-drench could replace three late-summer foliar sprays. Since soil-drench treatments would need to be applied where the beetle larvae are feeding underground, we conducted a study to determine isotopically where the beetles are overwintering. The temperature-specific growth rates of Sparganothis fruitworm, the most ubiquitous pest of U.S. cranberries, were empirically isolated. In the marshlands of Wisconsin, the 15N signatures of wild cranberry populations are being determined, forming the basis of in-depth investigations of cranberry trophic structure. A new invasive species, the spotted wing Drosophila, has been reported in Wisconsin. This Asian pest has caused major fruit crop losses on the East and West Coasts. In a collaborative study that focused on the susceptibility of ripe, under-ripe, over-ripe, and damaged cranberry fruit, the threat to cranberries has been characterized.
Zalapa, J.E., Simon, P.W., Hummer, K.E., Bassil, N.V., Senalik, D.A., Zhu, H., Mccown, B.H., Zeldin, E., Speers, J., Hyman, J. 2012. Mining and validation of pyrosequenced simple sequence repeats (SSRs) from American cranberry (Vaccinium macrocarpon Ait.). Theoretical and Applied Genetics. 124(1):87-96.