Variation in Yellow Root Cassava (Manihot esculentus Crantz) Genotypes and Phenotypic Relationship for Selected Postharvest and Morphological Traits

Abstract

This study evaluated the variation in yellow root cassava (Manihot esculentus Crantz) genotypes and phenotypic relationship for selected postharvest and morphological traits. The trial was established at the Njala Agricultural Research Centre experimental site, Njala, during 2017/2018 cropping season in a randomized complete block design with three replications. Findings showed that the higher the total carotene content (TCC) in yellow flesh cassava genotypes, the longer the rate of postharvest physiological deterioration (PPD). Genotypes TR-0051-TCC/17 and TR-0012-TCC/17 recorded higher TCC (18.9 µg/g and 13.6 µg/g) and longer rate of PPD (4.29 and 3.14), respectively. Genotypes TR-0051-TCC/17, TR-0016-TCC/17, TR-0028-TCC/17, TR-0012-TCC/17 and TR-0020-TCC/17 had the highest TCC values of 18.9 µg/g, 16.09 µg/g, 14.72 µg/g, 13.6 µg/g and 11.23 µg/g with corresponding higher color chart values of 6, 6, 6, 5, and 6, respectively. This suggests the direct dependence of TCC on the root parenchyma color intensity in yellow flesh cassava genotypes. Findings also show a direct relationship between morphological and postharvest traits in yellow flesh cassava genotypes that could be exploited for the genetic improvement of cassava for increased shelf life, nutrition and related quality traits, as well as conservation and utilization of the crop.