Reference "Gene actions of QTLs affecting several agronomic traits resolved in a recombinant inbred rice population and two testcross populations"

Reference ID

7971

Title

Gene actions of QTLs affecting several agronomic traits resolved in a recombinant inbred rice population and two testcross populations

Source

Theoretical and applied genetics, 2003, vol. 107, pp. 89-101

Authors (8)

Mei-H-W	Luo-L-J
Ying-C-S	Wang-Y-P
Yu-X-Q	Guo-L-B
Paterson-A-H	Li-Z-K

Abstract

To understand the types of gene action controlling seven quantitative traits in
rice, QTL mapping was performed to dissect the main effect (M-QTLs) and digenic
epistatic (E-QTLs) QTLs responsible for the trait performance of 254 recombinant
inbred lines (RILs) of "Lemont/Teqing", and two testcross (TC) F(1) populations
derived from these RILs. The correlation analyses reveal a general pattern, i.e.
trait heritability in the RILs was negatively correlated to trait heterosis in
the TC hybrids. A large number of M-QTLs and E-QTLs affecting seven traits,
including heading date (HD), plant height (PH), flag leaf length (FLL), flag
leaf width (FLW), panicle length (PL), spikelet number per panicle (SN) and
spikelet fertility (SF), were identified and could be classified into two
predominant groups, additive QTLs detected primarily in the RILs, and
overdominant QTLs identified exclusively in the TC populations. There is little
overlap between QTLs identified in the RILs and in the TC populations. This
result implied that additive gene action is largely independent from non-
additive gene action in the genetic control of quantitative traits of rice. The
detected E-QTLs collectively explained a much greater portion of the total
phenotypic variation than the M-QTLs, supporting prior findings that epistasis
has played an important role in the genetic control of quantitative traits in
rice. The implications of these results to the development of inbred and hybrid
cultivars were discussed.