Identification of markers linked to post-harvest physiological deterioration (PPD) resistance in cassava lines

Abstract

Cassava (Manihot esculenta Crantz) undergoes deterioration within a short period after harvest due to the occurrence of post-harvest physiological deterioration (PPD). To extend the shelf life, it is important to understand the molecular aspect of PPD associated resistance. In this study, five PPD resistant and 23 PPD susceptible lines were used for identification of a marker linked to PPD resistance. The phenotypic assessment on PPD by visual scoring showed the extent of deterioration in roots at different intervals. The dry matter and starch content was significant over 3, 7 and 21 days and produced a gradual decline in the content as PPD progressed over time. In the present study, 20 gene specific primers and 17 SSR primers were used, all the 20 gene specific primers produced monomorphic bands among resistant and susceptible group. The 17 SSR markers were used to survey polymorphism in a bulk of ten genotypes (5-resistant and 5-susceptible lines) and a unique polymorphism was identified in SSRY 8 marker that differentiated resistant and susceptible group.