Welcome to the International Institute of Tropical Agriculture Research Repository
Regional Heritability Mapping provides insights into Dry matter (DM) Content in African white and yellow cassava populations
Abstract/Description
The HarvestPlus program for cassava (Manihot esculenta Crantz) fortifies cassava with beta-carotene by breeding for carotene-rich tubers (yellow cassava). However, a negative correlation between yellowness and dry matter (DM) content has been
identified. Here, we investigated the genetic control of DM in white and yellow cassava subpopulations. We used regional heritability mapping (RHM) to associate DM to genomic segments in both subpopulations. Significant segments were subjected to
candidate gene analysis and we attempted to validate candidates using prediction accuracies. The RHM procedure was validated using a simulation approach. The RHM revealed significant hits for white cassava on chromosomes 1, 4, 5, 10, 17 and 18 while
hits for the yellow were on chromosome 1. Candidate gene analysis revealed genes in the carbohydrate biosynthesis pathway including the plant serine-threonine protein kinases (SnRKs), UDP-glycosyltransferases, UDP-sugar transporters, invertases,
pectinases, and regulons. Validation using 1252 unique identifiers from the SnRK gene family genome-wide recovered 50% of the predictive accuracy of whole genome SNPs for DM while validation using 53 likely (extracted from literature) genes from significant segments recovered 32%. Genes including an acid invertase, a neutral/alkaline invertase and a glucose-6-phosphate isomerase were validated based on an a priori list for the cassava starch pathway and also a fructose-biphosphate aldolase from the calvin cycle pathway. The power of the RHM procedure was estimated at 47 percent when the causal QTL generated 10% of the phenotypic variance with sample size of 451. Cassava DM genetics is complex. RHM may be useful for complex traits.
Multi standard citation
Permanent link to this item
https://hdl.handle.net/20.500.12478/2404Digital Object Identifier (DOI)
http://dx.doi.org/10.3835/plantgenome2017.06.0050
IITA Subjects
Agrovoc Terms
Regions
Countries
Journals
Collections
Related items
Showing items related by title, author, creator and subject.
-
Cassava production and processing in the Democratic Republic of Congo: COSCA working paper, No 22
(2000)The importance of cassava relative to other crops in the cropping system was almost total; cassava was present in 70% of arable fields; maize and beans or peas were each present in 13% of arable fields and all other crops were present in 4%. Cassava was produced mostly for sale, yet it was not as important around market centers as in remote areas because imported rice and wheat products were easily accessible. Cassava land area was not expanding in many of the villages visited because of low-level ... -
Molecular biodiversity of cassava begomoviruses in Tanzania: evolution of cassava geminiviruses in Africa and evidence for East Africa being a center of diversity of cassava geminiviruses
(2005)Cassava is infected by numerous geminiviruses in Africa and India that cause devastating losses to poor farmers. We here describe the molecular diversity of seven representative cassava mosaic geminiviruses (CMGs) infecting cassava from multiple locations in Tanzania. We report for the first time the presence of two isolates in East Africa: (EACMCV-[TZ1] and EACMCV-[TZ7]) of the species East African cassava mosaic Cameroon virus, originally described in West Africa. The complete nucleotide sequence ...
