Response of cultivars and breeding lines of tobacco (Nicotiana tabacum L.) under natural field infection to blue mold (Peronospora tabacina Adam.).

Dorota Laskowska

Institute of Soil Science and Plant Cultivation, Osada Pałacowa, 24-100 Puławy, Poland (Poland)

Berbeć Apoloniusz

Institute of Soil Science and Plant Cultivation, Osada Pałacowa, 24-100 Puławy, Poland (Poland)

Abstract

Towards the end of June of 1997 a massive outbreak of blue mold caused by Peronospora tabacina on the experiment plots of the Institute of Soil Science and Plant Cultivation gave an opportunity to observe and record the response to that disease of 192 different N. tabacum genotypes held at the institute’s tobacco germplasm collection. Both the date of the onset of the first symptoms and the intensity of the symptoms varied. Symptoms were from very severe (e. g. Virgin Mutant A, Burley White) to severe, moderate, mild and none. Less than 10% of the accessions scored for blue mold were symptom-free. They belonged to the flue-cured type (15 out of 71) and dark air-cured (5 out of 49). All the remaining entries including orientals and semi-orientals, burleys and cigar tobaccos were affected to some extent. Except the very susceptible Virgin A Mutant systemic symptoms were rare probably because the fungus attacked relatively late in the season when the majority of accessions had already grown out of the most vulnerable stage and were at either budding or flowering.

Keywords:

blue mold, natural field infection, tobacco cultivars