Reference "Identification of trait-improving quantitative trait loci alleles from a wild rice relative, Oryza rufipogon"

Reference ID

5359

Title

Identification of trait-improving quantitative trait loci alleles from a wild rice relative, Oryza rufipogon

Source

Genetics, 1998, vol. 150, pp. 899-909

Authors (7)

Xiao-J-H	Li-J
Grandillo-S	Ahn-S-N
Yuan-L	Tanksley-S-D
McCouch-S-R

Abstract

Wild species are valued as a unique source of genetic variation, but they have
rarely been used for the genetic improvement of quantitative traits. To identify
trait-improving quantitative trait loci (QTL) alleles from exotic species, an
accession of Oryza rufipogon, a relative of cultivated rice, was chosen on the
basis of a genetic diversity study. An interspecific BC2 testcross population
(V20A/O. rufipogon//V20B///V20B////Ce64) consisting of 300 families was
evaluated for 12 agronomically important quantitative traits. The O. rufipogon
accession was phenotypically inferior for all 12 traits. However, transgressive
segregants that outperformed the original elite hybrid variety, V20A/Ce64, were
observed for all traits examined. A set of 122 RFLP and microsatellite markers
was used to identify QTL. A total of 68 significant QTL were identified, and of
these, 35 (51%) had beneficial alleles derived from the phenotypically inferior
O. rufipogon parent. Nineteen (54%) of these beneficial QTL alleles were free of
deleterious effects on other characters. O. rufipogon alleles at two QTL on
chromosomes 1 and 2 were associated with an 18 and 17% increase in grain yield
per plant, respectively, without delaying maturity or increasing plant height.
This discovery suggests that the innovative use of molecular maps and markers
can alter the way geneticists utilize wild and exotic germplasm.