Устойчивост на български сортове зрял фасул към група щамове на Xanthomonas axonopodis pv. phaseoli и X. fuscans subsp. fuscans
Иван Киряков • Димитър Генчев
Добруджански земеделски институт - Генерал Тошево, Генерал Тошево, България
Резюме
Common bacterial blight caused by phytopathogenic bacteria Xanthomonas
axonopodis pv. phaseoli (Xaph) and X. fuscans subsp. fuscans (Xff) is a key disease
of dry bean (Phaseolus vulgaris L.) in Bulgaria. The use of resistant varieties is
considered to be the most effective and economically justifiable disease control
tools. In recent years, three dry beans varieties have been breed in DAI - General
Toshevo with moderate to high resistance to several highly aggressive strains of
the pathogens used as markers in the breeding process. This publication presents
data on the response of these varieties to 4 Xaph and 14 Xff strains. The disease
reaction of ‘Elixir’, ‘Beslet’ and ‘GTB Skitiya’ varieties was studied under field
conditions. The ‘GTB Ustrem’ variety was used as susceptible and the lines ‘VAX– 3’ and ‘VAX-4’ as resistant checks. The inoculation of the leaves was carried
out in flowering by the multiple needle method. A bacterial suspension (108 cfu /
ml) of 24 h cultures of the strains studied was used for the inoculum. The disease
reaction was recorded 13 days after inoculation by 9-degree scale. The variety
‘GTB Ustrem’ used as a susceptible check showed a moderate resistance to one,
susceptibility to 8 and a high susceptibility to 9 of the strains studied. The line
‘VAX -4’ was highly resistant to all strains and ‘VAX-3’ was highly resistant to 15
and resistant to 3 strains. The variety ‘Elixir’ shows a moderately resistant response
to two of the strains studied. The variety ‘Beslet’ has high leaf resistance to 12
of the strains studied, with the response to the rest being resistant (4 strains) to
moderately resistant (2 strains). The ‘GTB Skitiya’ variety was highly resistant to
8, resistant to 9 and moderately resistant to one of the strains tested. The presented
results show a high efficacy of achieved resistance in ‘Beslet’ and ‘GTB Skitiya’
varieties in terms of aggressive and virulent diversity in Xaph and Xff populations.
Key words:Phaseolus vulgaris, common bacterial blight, resistance
