Abstract:
Broomrape is a debilitating holoparasiting weed in
tobacco (
Nicotiana
tabacum
L.)
fields with devastating effects on its production.
In this study, the reaction of 89 tobacco
genotypes was evaluated against broomrape (
Orobanche aegyptiaca
) in randomized
complete block design with three replications durin
g two years. In each year, genotypes
were planted in both non-inoculated and inoculated
conditions where the soil of pots was
mixed with 0.06 g of broomrape seed. Considering th
e average data of two years, studied
genotypes did not show infection to broomrape at no
n-inoculated condition, whereas in
inoculated condition, the majority of genotypes sho
wed infection to broomrape. Two
genotypes including ‘TB 22’ and ‘Kramograd NHH 659’
did not show any infection to
broomrape in inoculated condition. In a molecular e
xperiment, the fingerprint of tobacco
genotypes was prepared with 26 SSR loci. Using mode
l-based Bayesian approach, the
studied association panel was divided into three su
bgroups. The D
′
′′
′
was used to test the
LD between pairs of SSR loci using the software pac
kage TASSEL. 7.08% of possible SSR
locus pairs showed significant level of linkage dis
equilibrium (P<0.01). By using mixed
linear model, 5 SSR loci from linkage groups 2, 10,
11 and 18 of tobacco reference map
were identified as DNA markers to be linked to gene
(s) controlling broomrape resistance
in tobacco.
Keywords:
Association analysis,
Broomrape, Linkage disequilibrium, Tobacco.
