Reference "Dissection of a QTL reveals an adaptive, interacting gene complex associated with transgressive variation for flowering time in rice"

Reference ID

51485

Title

Dissection of a QTL reveals an adaptive, interacting gene complex associated with transgressive variation for flowering time in rice

Source

Theor Appl Genet, 2010, vol. 120, pp. 895-908

Authors (3)

Maas-L-F	McClung-A
McCouch-S

Abstract

A days to heading QTL (dth1.1) located on the short arm of rice chromosome 1 was
sub-divided into eight sub-introgression lines (SILs) to analyze the genetic
basis of transgressive variation for flowering time. Each SIL contained one or
more introgression(s) from O. rufipogon in the genetic background of the elite
Oryza sativa cultivar, Jefferson. Each introgression was defined at high
resolution using molecular markers and those in the dth1.1 region were
associated with the presence of one or more flowering time genes (GI, SOC1, FT-
L8, EMF1, and PNZIP). SILs and controls were evaluated for flowering time under
both short- and long-day growing conditions. Under short-day lengths, lines with
introgressions carrying combinations of linked flowering time genes (GI/SOC1,
SOC1/FT-L8, GI/SOC1/FT-L8 and EMF1/PNZIP) from the late parent, O. rufipogon,
flowered earlier than the recurrent parent, Jefferson, while recombinant lines
carrying smaller introgressions marked by the presence of GI, SOC1, EMF1 or
PNZIP alone no longer flowered early. Under long-day length, lines carrying SOC1/FT-
L8, SOC1 or PNZIP flowered early, while those carrying GI or EMF1 delayed
flowering. Across all experiments and in the field, only SIL_SOC1/FT-L8 was
consistently early. A preliminary yield evaluation indicated that the
transgressive early flowering observed in several of the SILs was also
associated with a measurable and positive effect on yield. These SILs represent
a new source of variation that can be used in breeding programs to manipulate
flowering time in rice cultivars without the reduction in yield that is often
associated with early maturing phenotypes.