Resistance of Bulgarian Dry Bean Cultivars (Phaseolus vulgaris L.) to Bacterial Wilt

I. KIRYAKOV and D. GENCHEV

Institute of Wheat and Sunflower "Dobroudja", BG-9520 General Toshevo, Bulgaria

Abstract

KIRYAKOV , I. and D. GENCHEV, 2000. Resistance of Bulgarian dry bean cultivars (Phaseolus vulgaris L.) to bacterial wilt. Bulg. J. Agric. Sci., 6: 411-414

The response of 19 Bulgarian dry bean (Ph. vulgaris L.) cultivars to four strains of Curtobacterium flaccumfaciens pv. flaccumfaciens (Hedges) Collins and Jones, the cause agent of bacterial wilt, was studied. Plants were inoculated at stage primary leaves by pricking the stem in the cotyledonary nod with a needle dipped in the bacterial suspension of the respective strain. After inoculation, plants were transferred to a climatic chamber at 30 0.5 0C day temperature and 20 0.5 0C night temperature, 60-70 % relative humidity and a photoperiod of 16/8 hours. The disease reaction was recorded 21 days after inoculation according to a 9-degree scale. Among the studied cultivars, Kristal 137 demonstrated resistance to three out of the four pathogen strains. The cultivars Plovdiv 164 and Roussenski ran were resistant or moderately resistant to two of the pathogen strains tested, and the cultivars Prelom and No 1028 were resistant to one strain. A positive correlation (r = 0.88) was established between the cultivar disease reaction and the virulence of the pathogen strains included in the study.

Key words: Bulgarian dry bean cultivars, Phaseolus vulgaris L., bacterial wilt, resistance