Reference "Construction of introgression lines carrying wild rice (Oryza rufipogon Griff.) segments in cultivated rice (Oryza sativa L.) background and characterization of introgressed segments associated with yield-related traits"

Reference ID

11004

Title

Construction of introgression lines carrying wild rice (Oryza rufipogon Griff.) segments in cultivated rice (Oryza sativa L.) background and characterization of introgressed segments associated with yield-related traits

Source

Theor Appl Genet, 2005, vol. , pp. 1-11

Authors (7)

Tian-F	Li-D-J
Fu-Q	Zhu-Z-F
Fu-Y-C	Wang-X-K
Sun-C-Q

Abstract

Introgression lines (ILs) are useful tools for precise mapping of quantitative
trait loci (QTLs) and the evaluation of gene action or interaction in
theoretical studies. A set of 159 ILs carrying variant introgressed segments
from Chinese common wild rice (Oryza rufipogon Griff.), collected from Dongxiang
county, Jiangxi Province, in the background of Indica cultivar (Oryza sativa
L.), Guichao 2, was developed using 126 polymorphic simple sequence repeats
(SSR) loci. The 159 ILs represented 67.5% of the genome of O. rufipogon. All the
ILs have the proportions of the recurrent parent ranging from 92.4 to 99.9%,
with an average of 97.4%. The average proportion of the donor genome for the
BC(4)F(4) population was about 2.2%. The mean numbers of homozygous and
heterozygous donor segments were 2 (ranging 0-8) and 1 (ranging 0-7),
respectively, and the majority of these segments had sizes less than 10 cM. QTL
analysis was conducted based on evaluation of yield-related traits of the 159
ILs at two sites, in Beijing and Hainan. For 6 out of 17 QTLs identified at two
sites corresponding to three traits (panicles per plant, grains per panicle and
filled grains per plant, respectively), the QTLs derived from O. rufipogon were
usually associated with an improvement of the target trait, although the overall
phenotypic characters of O. rufipogon were inferior to that of the recurrent
parent. Of the 17 QTLs, 5 specific QTLs strongly associated with more than one
trait were observed. Further analysis of the high-yielding and low-yielding ILs
revealed that the high-yielding ILs contained relatively less introgressed
segments than the low-yielding ILs, and that the yield increase or decrease was
mainly due to the number of grain. On the other hand, low-yielding ILs contained
more negative QTLs or disharmonious interactions between QTLs which masked trait-
enchancing QTLs. These ILs will be useful in identifying the traits of yield,
tolerance to low temperature and drought stress, and detecting favorable genes
of common wild rice.