1. Development of breeding lines using marker technologies: The approach used by the Genetics and Genomics Platform for Rice in Africa
FROM Maker-Assisted Selection (MAS) TO Marker-Assisted Recurrent Selection (MARS) TOWARD Genome-Wide Marker-Assisted Selection (GWMAS)
Selection of parental lines (P1 and P2) Inbred 1 x Inbred 2
Extraction of evaluation F2 derived-lines (BC, 3
NARS Crossing : P1 (recurrent parent) x P2 (donor parent) F2
for genotyped plants ways cross, double cross)
Breeding value : Estimation
F1 F3:4 of marker effect
X P1 Genotyping Plant selection based
on best GEBV*
BC1F1
QTL estimation
Cycle 1 Selection of Np plants (144)
, content and
Foreground selection
Identification of BC1F1 individuals that are
heterozygous for the closest marker and If large population size
F3:5 High density genotyping Selection of 4 plants
homozygous at the flanking markers
Genetics and (128-256 markers) and Inter-mating
effect
Backcross of the selected BC1F1 individuals
with P1 to produce BC2F1
BC2F1
Genomics Phenotyping Recombination
Platform for
Whole genome background selection
Choice of 24 seeds
Identification of BC2F1 individuals that are
heterozygous for the closest marker with the Rice in Africa
highest proportion of the recurrent parent genome Selection of lines based on genetic per cross
using higher molecular marker number.
Self the selected individuals to produce BC2F2 value, molecular score
Cycle 2 Selection of 144 plants
weight, intensity of selection…
BC3F1
Genotyping , selection of 4
Genotyping and genetic gain simulation in
crossing selected lines
plants and inter-mating
(Optimas: GCP IBP tool)
2x Recombination
Inter-mating of selected lines Choice of 24 seeds
BC3F3
per cross
Genotyping and genetic gain simulation in
crossing selected lines
(Optimas: GCP IBP tool) Selection of 144 plants
Inter-mating of selected lines
Improved
lines Repeat the procedure
Advanced for 2 cycles
Research
Extract fixed lines Institutes
Evaluation and advanced testing in conventional breeding
* Genomic Estimated Breeding Values