DIVERSITY AND EVOLUTION OF THE CULTIVATION OF LATE YAMS KOKORO, DIOSCOREA ROTUNDATA POIR (DIOSCOREACEAE) IN YAM PRODUCTION AREAS IN BENIN

Yam is an important food crop in maintaining food and nutrition security in Benin. For this reason, the late Kokoro yams remain less documented in terms of their specific diversity, their geographical distribution and their evolutionary trajectories. The study assessed the diversity, uses and evolutionary dynamics of late Kokoro yams in the main production areas of Benin. It was conducted in 43 villages in the departments of Borgou, Atacora, Donga and Collines. Data were collected through individual interviews and group discussions and included 376 respondents. A total of 166 cultivars were recorded, including 71 in Donga, 59 in Borgou, 21 in Atacora and 15 in Collines. The average Shannon diversity index was 3.4 bits, with a maximum value in the Borgou (3.8 bits). Kokoro made up 37.62% of the yams produced and more than 80% of the crops were intended for self-consumption, especially during the lean season. Seeds were mainly from intra-Community trade and inheritance. Between 2012 and 2025, 61% of cultivars disappeared, with Borgou being the most affected with 72.32% of losses. This erosion is mainly due to sensitivity to poor soils, unavailability of seeds, low yield, diseases, pests and poor culinary or technological quality. Sixty-six elite cultivars were identified according to agronomic, technological and culinary criteria. Their classification revealed groups combining productivity, post-harvest conservation, drought tolerance and poor soil suitability. These results highlight the urgent need for integrated conservation, characterization and participatory improvement strategies to sustainably preserve this national plant genetic diversity.