Genetic Diversity of Cassava (Manihot esculenta Crantz) in Ecuador by Using SSR Markers

Abstract

Cassava (Manihot esculenta Crantz), domesticated in the Amazonian region of South America, presents an important diversity in Ecuador, where it is a main staple food; however, only few Ecuadorian cassava accessions have been included in international molecular assessments. The purpose of this study was to apply suitable cassava mi-crosatellites to characterize the genetic variability of the Ecuadorian cassava collection composed mainly of local landraces from the Coast, Andes and Amazonia regions. The use of microsatellite markers allowed the determination of the genetic diversity of the collection. Seven selected SSR primers, permitted to identify homozygous and hetero-zygous materials within the cassava collection of 133 accessions. The loci presented an average genetic diversity value of 0.7 and an average PIC value of 0.67, which is con-sidered high. Low number of duplicates (8.8%) were identified in the Ecuadorian col-lection which is not fully duplicated at CIAT. Currently, a wide range of cassava diver-sity is still cultivated in multi-crop agro-ecosystem, mainly in the Coast and Amazo-nian regions. Especially in the Amazonian region, due to important cultural uses of cassava by local ethnic communities, more in depth studies in the region could unveil the genetic diversity present in situ today.