TITLE:
Physicochemical Characteristics and QTL Mapping Associated with the Lipid Content of High-Lipid Rice
AUTHORS:
Na-Hye Kim, Jae-Keun Sohn, Kyung-Min Kim
KEYWORDS:
Lipid Content; Fatty Acid Content; Quantitative Trait Loci (QTLs); Rice (Oriza Sativa L.)
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.10,
October
9,
2013
ABSTRACT: This study was
conducted to examine the physicochemical characteristics and perform QTL
mapping of genetic factors associated with the lipid content of rice. A rice
strain with a high lipid content, “P31-2-2-2-B-B”, was developed from
mutants of “Dongjin” created by T-DNA insertion. The lipid
content of “P31-2-2-2-B-B” brown rice was 4.42% whereas that of
the donor cultivar “Dongjin” was 2.56%. The total fatty acid
content of the high-lipid mutant brown rice was 7.82% and that of “Dongjin” was 3.43%. The
unsaturated fatty acid composition of the mutant brown rice was 2.73% oleic acid,
2.74% linoleic acid, and 0.34% linolenic acid. In contrast, the fatty
acid composition of the donor cultivar “Dongjin” was 1.30%
oleic acid and 0.99% linoleic acid. The percentage of unsaturated fatty acid to
total fatty acid in the high-lipid mutant was higher (74.3%) than that of “Dongjin” (66.8%). Continuous
frequency distribution and transgressive segregation of the lipid
content were observed in the F3 family (seeds) derived from a
cross between the high-lipid mutant “P31-2-2-2-B-B” and a tongil-type cultivar “Samgang”. This result implied that
the lipid content was a quantitative trait controlled by a polygene.
Additionally, the broad sense heritability of lipid content was estimated to be
89.6% based on analysis of the F3 seeds. A significant QTL, qRLC5, was identified on chromosome 5
with a LOD score of 2.37, and was flanked by 5007 and 5014. Results of the present
study should be useful for improving rice nutritional quality through
marker-assisted selection.