New developments in fiber hemp (Cannabis sativa L.) breeding

Fiber hemp (Cannabis sativa L.) is a sustainable and high yielding industrial crop that can help to meet the high global demand for fibers. Hemp can be grown for fiber, seeds, and/or for dual purpose in a wide range of geographic zones and climates. Currently the main hemp producing regions in the world are China, Europe, and Canada. The number of new cultivars developed for each of these regions has gradually increased, with each region producing its own typical hemp cultivars for different purposes. In this article, the state of the art of fiber hemp breeding programs in Europe, China, and Canada are reviewed. The breeding strategies and tools used in the breeding of hemp cultivars are discussed. We also provide an overview of genetic diversity in hemp for different traits. In addition, the current knowledge of the main breeding goals for fiber hemp, which are an improvement of fiber quality and fiber yield, breeding for specific cannabinoid profiles, control of flowering behavior, male flowering control, and breeding of cultivars for specific environments are evaluated. Lastly, we discuss the inestimable value of next generation technologies to breed new hemp cultivars that are suitable for a biobased economy.