Heritability of the main agronomic traits of taro

The increase of production of an important root crop such as taro [Colocasia esculenta (L.) Schott, Araceae] implies the development of new varieties through an efficient breeding scheme. The breeding of new taro cultivars is a complex process which requires experience, ad-equate genetic resources, and reliable data about inheritance of crucial agronomic traits. To obtain these data, 2-yr heritability taro trials were conducted in Vanuatu with 42 full-sib families of variable sizes. In the first clonal generation (C1), a fully randomized complete block design was planted with plots of 16 datum plants. During the second clonal generation (C2), parents were included with their offspring in two alpha incomplete block designs with elementary plots of 12 and 4 datum plants, respectively. Both family and narrow-sense heritabilities were higher for the number of suckers and dry matter content than for corm weight or its components (corm length and width). A high percentage of valuable hybrids were observed among a small number of families. These results, combined with the moderately high family heritability values for several traits, recommend the creation of a small number of large full-sib families when working with a narrow genetic base and the creation of numerous small full-sib families when dealing with a broad genetic base. (Résumé d'auteur