Morphological Characterization of Yam Genotypes from Different Geographic Origins in Angola
Yam ( Dioscorea spp.) is a vegetable of great economic and social importance, cultivated in tropical and subtropical regions. It is a staple food for millions of people, especially in West Africa, valued for its tuberous roots rich in carbohydrates, proteins, vitamins and minerals. In addition to its nutritional value, yam has cultural and medicinal significance, used in ceremonies and therapies. In Angola, climatic and geographic diversity favors the cultivation of different yam genotypes, resulting in a genetic heritage that is crucial for crop resilience and food security. The morphological characterization of genotypes allows the identification of varieties with desirable attributes, such as disease resistance, productivity and nutritional quality, facilitating genetic improvement programs. This study aims to morphologically characterize yam genotypes from different geographic origins in Angola, contributing to the knowledge and conservation of genetic diversity and the development of sustainable agricultural strategies. Accessions were collected in the provinces of Cabinda, Cuanza Norte, Cuanza Sul, Malange, Uíge and Huambo, including Dioscoreaesculenta, Dioscoreaalata, Dioscoreacayenesisand Dioscoreabulbifera. After collection, the materials were documented with detailed information obtained from interviews with local producers. The accessions were planted at Fazenda Esperança, in the province of Huíla, from August 2022 to October 2023, in a completely randomized experimental design with 15 replications of each species, totaling 60 plants. Management practices included irrigation, staking and manual weeding. The morphological characterization was carried out after six months of planting, evaluating 22 descriptors of the aerial parts of the plants and, after 11 months, the tuber characterization was carried out in the Laboratory of the Institute of Agricultural Research in Huíla. Data analysis revealed significant variability in plant characteristics. All accessions had alternate leaves, with 50% having sagittate leaves, 25% lobed leaves and 25% chordate leaves. The majority of accessions (75%) did not have leaf lobes. Regarding petiole length, 65% had petioles between 5 and 10 cm, predominantly green (65%). The majority of accessions (61.67%) had a distance between the insertion of the petiole on the leaf and the upper end greater than 4 cm. Regarding tubers, 71.67% of accessions had underground tubers, with 31.67% elongated, 43.33% oval and 25% irregular. Statistical analysis showed significant differences between yam species in all morphometric characteristics evaluated, with Dioscoreabulbifera standing out with the highest average values for most of these characteristics.
