| Autor: |
Kanaabi M; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Settumba MB; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda., Nuwamanya E; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Muhumuza N; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Iragaba P; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Ozimati A; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; College of Natural Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda., Namakula FB; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Kayondo IS; International Institute for Tropical Agriculture (IITA), Ibadan 200113, Nigeria., Baguma JK; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Nanyonjo AR; College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda.; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Esuma W; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda., Kawuki RS; National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda. |
| Abstrakt: |
Breeding for low-hydrogen-cyanide (HCN) varieties is a major objective of programs targeting boiled cassava food products. To enhance the breeding of low-HCN varieties, knowledge of genetic variation and trait heritability is essential. In this study, 64 cassava clones were established across four locations and evaluated for HCN using three HCN assessment methods: one with a 1 to 9 scale, on with a 0 ppm to 800 ppm scale, and a quantitative assay based on spectrophotometer readings (HCN_Spec). Data were also collected on the weather variables precipitation, relative humidity, and temperature. Highly significant differences were observed among clones ( p < 0.001) and locations ( p < 0.001). There was also significant clone-environment interactions, varying from p < 0.05 to p < 0.001. Locations Arua and Serere showed higher HCN scores among clones and were associated with significantly higher ( p < 0.001) mean daily temperatures (K) and lower relative humidity values (%) across 12 h and 18 h intervals. Within locations, HCN broad sense heritability estimates ranged from 0.22 to 0.64, while combined location heritability estimates ranged from 0.14 to 0.32. Relationships between the methods were positive and strong (r = 0.75-0.92). The 1 to 9 scale is more accurate and more reproducible than either the 0 to 800 ppm scale or spectrophotometric methods. It is expected that the information herein will accelerate efforts towards breeding for low-HCN cassava varieties. |
