Reference "Identification and fine mapping of Pi33, the rice resistance gene corresponding to the Magnaporthe grisea avirulence gene ACE1"

Reference ID

8274

Title

Identification and fine mapping of Pi33, the rice resistance gene corresponding to the Magnaporthe grisea avirulence gene ACE1

Source

Theoretical and applied genetics, 2003, vol. 107, pp. 1139-1147

Authors (8)

Berruyer-R	Adreit-H
Milazzo-J	Gaillard-S
Berger-A	Dioh-W
Lebrun-M-H	Tharreau-D

Abstract

Rice blast disease is a major constraint for rice breeding. Nevertheless, the
genetic basis of resistance remains poorly understood for most rice varieties,
and new resistance genes remain to be identified. We identified the resistance
gene corresponding to the cloned avirulence gene ACE1 using pairs of isogenic
strains of Magnaporthe grisea differing only by their ACE1 allele. This
resistance gene was mapped on the short arm of rice chromosome 8 using progenies
from the crosses IR64 (resistant) x Azucena (susceptible) and Azucena x Bala
(resistant). The isogenic strains also permitted the detection of this
resistance gene in several rice varieties, including the differential isogenic
line C101LAC. Allelism tests permitted us to distinguish this gene from two
other resistance genes [ Pi11 and Pi-29(t)] that are present on the short arm of
chromosome 8. Segregation analysis in F(2) populations was in agreement with the
existence of a single dominant gene, designated as Pi33. Finally, Pi33 was
finely mapped between two molecular markers of the rice genetic map that are
separated by a distance of 1.6 cM. Detection of Pi33 in different semi-dwarf
indica varieties indicated that this gene could originate from either one or a
few varieties.