Effects of harvest period, storage, and genotype on postharvest physiological deterioration responses in cassava

Abstract

Abstract. Rahmawati RK, Khumaida N, Ardie SW, Sukma D, Sudarso. 2021. Effects of harvest period, storage, and genotype on postharvest physiological deterioration responses in cassava. Biodiversitas 23: 100-109. Postharvest physiological deterioration (PPD) is the major constraint in cassava root production. The breeding program to develop PPD tolerant cassava varieties requires a long period to complete. Although it is the first step in breeding for PPD tolerance, evaluating cassava germplasm responses for the PPD remains a major problem because it is a laborious process, and the evaluation often contains a high experimental error. This study aims to develop methods for evaluating PPD response, i.e., evaluating the effects of two harvest periods and storage on PPD responses of nine cassava genotypes. The developed scoring system based on cassava root discoloration could group the evaluated cassava genotypes into either PPD tolerant, medium tolerant, or sensitive. The tolerant varieties showed less than 10% root discoloration areas, while the medium tolerant was between 11-20%, and the sensitive was larger than 20%, respectively. ADR-24 and GJ-11 were identified as PPD tolerant, while ML-19 was sensitive using the developed scoring system. This study showed that PPD is a complex phenomenon associated with genetics and environmental factors. Root dry matter content and maximum root diameter traits may play an important role in PPD development in cassava. We have developed procedures for identifying genotype responses to PPD and showed that cassava roots harvested as early as eight months after planting and stored as late as five days under the control relative humidity were good conditions for studying PPD. Evaluating the percentages of root discoloration was a good measure for PPD response prediction. Moreover, we showed that less than 10%, 20%, and more than 20% of root discoloration might be used to group cassava into PPD tolerant, medium tolerant, and sensitive for Indonesian accessions. Therefore, the methods developed in this study may support the Indonesian cassava breeding program and provide biochemical and molecular analysis materials to elaborate the mechanisms of PPD in cassava roots.

Advances in Cassava Trait Improvement and Processing Technologies for Food and Feed

“…The PPD has been associated with both plant genetics as well as environment, particularly storage conditions. In Indonesia, different cassava genotypes were observed to have a range of 10 to more than 20% deterioration and were classified as having low, medium, and high susceptibility to PPD [51]. Similar variations have also been observed in cassava from Africa and South America [52][53][54].…”

“…Post-harvest physiological deterioration results in cassava roots turning blue, black, or brown in color one to five days post-harvest. The discoloration is accompanied by a bitter taste rendering the roots unusable [51]. The PPD has been associated with both plant genetics as well as environment, particularly storage conditions.…”

A method for rapid and homogenous initiation of post-harvest physiological deterioration in cassava storage roots identifies Indonesian cultivars with improved shelf-life performance

“…Measurement of selected root parameters revealed a significant correlation between root length and PPD scores at 2 dph. This observation highlights the importance of selecting cassava storage roots with homogenous sizes to assess PPD tolerance [ 22 , 29 , 38 ]. Indeed, the rapidity and extent of PPD onset could be linked to the level of oxygen entry into the storage roots as it is required to trigger the oxidative burst (reviewed in [ 33 ] and [ 49 ].…”

Influence of Harvest Periods on Cassava (<i>Manihot esculenta</i> Crantz) Agronomic Traits and Physiological Response to Post-Harvest Physiological Deterioration

“…A rapid increase in soluble sugars content coupled with a decrease in starch content and root dry weight were reported by [17]. PPD has been found to be associated with agronomic traits as reported by [18] and [19]. Factors such as cultivar, environmental conditions, and soil preparation and composition are of high importance in PPD sensitive and tolerance considerations [20] [21].…”