Genetic variation in cassava for postharvest physiological deterioration

Abstract

Cassava storage roots start deteriorating 1 to 3 days after harvest due to postharvest physiological deterioration (PPD) which reduces the potential of cassava as a commercial crop. The objective of this study was to examine the extent of genetic variability in cassava for PPD. Genetic variability is important in selecting suitable genotypes for crop improvement. Twelve cassava genotypes were evaluated in a randomized complete block design at three different locations in Uganda for five different harvest times, and PPD assessment was done 7 days after each harvest time. Genotype, location, harvest time, genotype × harvest time and harvest time × location were highly significantly different for PPD. Estimates of phenotypic, genotypic and environmental variance components revealed that a large portion of the phenotypic variance was accounted for by the genotypic component which is an indication of substantial genetic variability among the test genotypes for PPD. This genetic variability is important in a breeding programme because it indicates that significant genetic gain through phenotypic selection is possible for PPD. The results give guidance to breeding efforts for improved shelf life of cassava storage roots.

Keywords:

• Manihot esculenta Crantz
• storage roots
• shelf life
• variance components
• breeding

Acknowledgement

The authors acknowledge the staff of the National Crops Resources Research Institute in Uganda for helping in storage of samples and data collection.

Additional information

Funding

The authors are grateful to the Alliance for a Green Revolution in Africa for the financial support coordinated by the African Centre for Crop Improvement under the directorship of Professor Mark Laing.