Quantitative trait loci controlling cyanogenic glucoside and dry matter content in cassava (Manihot esculenta Crantz) roots
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Date
2007
Journal Title
Journal ISSN
Volume Title
Publisher
Hereditas
Abstract
Cassava (Manihot esculenta Crantz) is a starchy root crop grown in the tropics mainly by small-scale farmers even though
agro-industrial processing is rapidly increasing. For this processing market improved varieties with high dry matter root
content (DMC) is required. Potentially toxic cyanogenic glucosides are synthesized in the leaves and translocated to the
roots. Selection for varieties with low cyanogenic glucoside potential (CNP) and high DMC is among the principal objectives
in cassava breeding programs. However, these traits are highly influenced by the environmental conditions and the genetic
control of these traits is not well understood. An S1 population derived from a cross between two bred cassava varieties
(MCOL 1684 and Rayong 1) that differ in CNP and DMC was used to study the heritability and genetic basis of these traits.
A broad-sense heritability of 0.43 and 0.42 was found for CNP and DMC, respectively. The moderate heritabilities for DMC
and CNP indicate that the phenotypic variation of these traits is explained by a genetic component. We found two
quantitative trait loci (QTL) on two different linkage groups controlling CNP and six QTL on four different linkage groups
controlling DMC. One QTL for CNP and one QTL for DMC mapped near each other, suggesting pleiotrophy and/or linkage
of QTL. The two QTL for CNP showed additive effects while the six QTL for DMC showed additive effect, dominance or
overdominance. This study is a first step towards developing molecular marker tools for efficient breeding of CNP and DMC
in cassava.
Description
Keywords
Cyanogenic glucoside, Cassava (Manihot esculenta Crantz) roots
Citation
Balyejusa Kizito, E., Rönnberg‐Wästljung, A. C., Egwang, T., Gullberg, U., Fregene, M., & Westerbergh, A. (2007). Quantitative trait loci controlling cyanogenic glucoside and dry matter content in cassava (Manihot esculenta Crantz) roots. Hereditas, 144(4), 129-136. DOI: 10.1111/j.2007.0018-0661.01975.x