1. 1Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Seeland, Germany; email: nagel@ipk-gatersleben.de
2. 2Lindner Center for Conservation and Research of Endangered Wildlife (CREW), Cincinnati Zoo & Botanical Garden, Cincinnati, Ohio, USA
3. 3Department of Botany and Geology, Universitat de València, Burjassot, Spain
4. 7Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex, United Kingdom
5. 4Institute of BioEconomy (IBE), National Research Council (CNR), Florence, Italy
6. 5Department of Cell Biology and Biotechnology, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
7. 6The Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT), KU Leuven, Leuven, Belgium