Genetic resources are among the most important research inputs in breeding activity. In this study, we proposed a diversity indicator for registered wheat varieties of NIAS genebank, using coefficient of variation. Employing this indicator as the research input, our research production function reveals that greater diversity in wheat variety leads to higher efficiency in wheat breeding activity. However, given the importance of diversity as a research input, our questionnaire survey of wheat breeders reveals the increasing transaction cost of variety transfer from foreign researchers. Supporting breeders with improved research infrastructure, such as material transfer agreement, is important to meet the changing environment of consumers’demand.