Estimates for heritability and consumer-validation of a penetrometer method for phenotyping softness of cooked cassava roots

Abstract

Although breeders have made significant progress in the genetic improvement of cassava (Manihot esculenta Crantz) for agronomic traits, lack of information on heritability and limited testing of high-throughput phenotyping methods are major limitations to improving root quality traits, such as softness after cooking, which rank high among Ugandan consumers. The objectives of this study were to determine heritability for softness of cooked cassava roots, and quantify the relationship between penetrometer and consumer testing methods for phenotyping softness of cassava roots. Softness defined as the maximum force (N) needed to penetrate cooked root samples using a penetrometer, was evaluated at four cooking time intervals: 15, 30, 45, and 60 min on 268 cassava genotypes. Estimates of broad-sense heritability (repeatability) ranged from 0.17 to 0.37, with the highest value observed at 45 min of cooking time interval. In the second study involving 135 cassava consumers from Kibaale district in Uganda, penetrometer measurements of cooked roots from six cassava varieties were found to be in strong agreement (r2 = 0.91; P-value = 0.003) with ordinal scores of root softness from consumer testing. These results suggest that: (a) softness of cooked cassava roots is a trait amenable for evaluation and selection; and (b) a penetrometer can readily be used for assessment of cooked root softness. These findings form the basis for operationalising the routine assessment of root softness in cassava breeding trials, an output that will enhance ongoing efforts to breed for desired end-user root quality traits.Key words: Breeding, cooking, Manihot esculenta

Plant phenotyping relevance

調理済みキャッサバ根の軟らかさという植物器官形質を、ペネトロメーターで測定・評価し、消費者試験との一致性を検証した研究であり、表現型取得法が中心です。

Code and data availability

The article describes cassava root softness phenotyping (penetrometer measurements on 268 genotypes, consumer testing) and mentions a public deposit of the farmer-variety list on Cassavabase (ftp://ftp.cassavabase.org/manuscripts/Iragaba_et_al_2019_quality/Phenotype_infos/). However, this URL does not match any allowed

No evidence-backed public reproduction asset is currently recorded.