Abstract:
Bacterial leaf streak (BLS) caused by
Xanthomonas translucens
pv.
cerealis
(
Xtc
) is an
important disease of wheat (
Triticum aestivum
L.) worldwide. The management methods
presently in practice are insufficient to meet curr
ent safety and/or efficacy standards.
Therefore, use of resistant genotypes is the best a
pproach to manage BLS. The present
study was undertaken to identify possible sources o
f resistance to
Xtc
in cereal cultivars
and germplasm. Twelve strains of
Xtc
were isolated from symptomatic leaves in several
regions in Kerman province. Out of twelve, nine str
ains produced the expected
Xtc
-
specific 120 bp fragment using PCR and the primer p
airs PABr/PBf. Six strains produced
water-soaked streaks covered with exudates on wheat
cultivars, whereas the three
remaining strains incited only chlorotic streaks wi
th no water-soaking on leaves. A highly
virulent strain that caused conspicuous water-soaki
ng and necrosis was used for
inoculation of 645 winter and spring wheat, barley,
and rye accessions to identify possible
sources of resistance to BLS. The fourth leaves of
test plants were infiltrated with
bacterial suspension and scored after seven to ten
days. Among all the accessions
evaluated, only two rye accessions, namely, 4538 an
d 4794, were resistant to BLS. These
two rye accessions can potentially be used in breed
ing rye and triticale cultivars for
resistance to BLS.
Keywords
: Bacterial leaf streak, Barley, Resistance, Rye, W
heat.
