Yams (Dioscorea species) are among the primary agricultural commodities and major staple crop in Africa, India, South East Asia, South America and the Caribbean. However, the crop is laden with serious production problems arising from factors such as anthracnose disease, pests, and declines in soil fertility. This project seeks to revolutionize yam production in developing countries through the development and field-testing of low-cost genotyping/phenotyping biosensors that contain an integrated paper-based biobattery. These proof-of-concept devices will provide self-sustainable, field-tested sensing systems that can be used to detect the presence of disease causing pathogens by smallholder farmers in the developing world. The project will provide international interdisciplinary research training for students and postdoctoral researchers. All project outcomes will be available for use by the scientific community. DNA sequences will be available through GenBank. Information about biosensors will be provided through multiple mechanisms that include peer-reviewed publications as well as organized field-testing by smallholder farmers using standard protocols and handouts. <br/><br/>This project will address some of the fundamental research and constraint issues associated with decreased yam production in developing countries. This project aims to develop and characterize the next generation of low-cost biosensors that can be used to assess differences in virulence and inter- and/or intraspecific genetic diversity in fungal isolates that cause anthracnose diseases in Dioscorea alata and Dioscorea cayanensis, two species of yams. Specific objectives are to (i) conduct molecular and biochemical characterization of healthy and fungal-infected yam varieties to identify DNA markers associated with up to 150-180 field-collected fungal isolates; ii) use markers as the basis for designing a multiplex SNP paper-based bioassay to detect the presence of fungal pathogens; iii) attach biosensor that is powered by a novel microbial-based bio-battery to the back of a smartphone; sensor signals could be read visually or via custom-based applications (apps) to be developed for smartphones; and, iv) develop standardized protocols for screening yams for anthracnose resistance using the new biosensing tools as a first step to deploying the technology in the field. It is anticipated that the proposed devices can serve as a model for transforming low-cost tools into precision agriculture to promote increased food production in developing countries in developing countries. In addition, the project can potentially shift the paradigm for flexible and stackable paper-based batteries by enabling, through their architecture and design, exceptional electrical characteristics and functionalities.