Molecular Mapping of Complex Traits - Genetics, Genomics and Breeding of Crop Plants - page 153

population from the cross GH×PAC2. In F 3 progeny, the authors identified
two QTLs for seed weight on LGs A and C, which explained 28.5% of the
total phenotypic variance. Favorable alleles for these QTLs were derived
from the GH parent. For oil content, two, three and two QTLs were detected
in F 2 , F 3 and F 4 generations, respectively. These QTLs accounted for 19.4%,
53.8% and 26.1% of phenotypic variance of oil content in F 2 , F 3 and F 4
generations, respectively. For three QTLs, the PAC2 alleles increased the
trait, and for four QTLs GH alleles increased oil concentration. Two QTLs
were detected in all of the three generations (LGs A and Q) and one QTL (LG
C) was specific to the F 3 generation.
Mokrani et al. (2002) detected two QTLs for grain yield per plant (LG 9),
one QTL for 1,000-grain weight (LG 16) and seven QTLs for oil percentage
in grain (LGs 9, 11, 12 and 13), with total phenotypic variation of 50.7%,
22.7% and 90.4%, respectively ( Table 5-1 ) . Grain yield per plant and oil
percentage in grain shared two QTLs on LG 9.
Bert et al. (2003) identified five QTLs for oil content in each of the F 2 and
F 3 progeny from the cross XRQ×PSC8. The total genotypic variation
explained by these QTLs was 68.1% in F 2 generation and 70.1% in F 3
generation. Four QTLs for oil content were detected in both the generations
and one QTL were specific to each of the generations. XRQ contributed
positive alleles for seven loci, but PSC8 contributed for only three QTLs.
Rachid Al-Chaarani et al. (2004) identified QTLs for grain weight per
plant, 1,000-grain weight and oil percentage in an RIL population. Four
QTLs for grain weight per plant (LGs 4, 6, 9 and 21), three QTLs for 1,000-
grain weight (LGs 4, 6 and 9) and four QTLs for oil percentage (LG 8, 11, 13
and 21) were identified. The phenotypic variation explained by these QTLs
were 43% for grain weight per plant, 53% for 1,000-grain weight and 39%
for oil percentage, respectively. LOD scores ranged from 4.04 to 13.51 and a
major QTL was detected for 1,000-grain weight (LG 9), which controlled
37% of the phenotypic variance for this trait. This QTL was also detected for
grain weight per plant. Three QTLs were common between grain weight per
plant and 1,000-grain weight (LGs 4, 6, and 9), but only one QTL appeared
to be common between 1,000-grain weight and oil percentage on pseudo-
linkage group 21. These results complement the pioneer works that described
molecular markers linked to oil characteristics and quantitative genetics
analysis (Leon et al. 1995, 2003).
QTLs involved in seed oil concentration and 100-seed weight were
detected in another study using 173 F 7 RILs from a cross between RHA280
(an unbranched, confectionary, fertility restorer line) and RHA801 (a
branched, oilseed, fertility restorer line) (Tang et al. 2006). Two hundred and
three SSR and insertion-deletion (INDEL) markers and three phenotypic
loci were used for map construction. Six QTLs were identified on LG 1, 4, 9,
10, 16, and 17 for seed oil concentration. These QTLs explained 55.7% of the