Bull. Spec. CORESTA Symposium, Kallithea, 1990, p. 170, P13, ISSN.0525-6240

Genetic study of the PMR Burley 21 variety with regard to its resistance to Erysiphe cichoracearum DC

Bulgarian Academy of Science, Institute of Genetics, Sofia, Bulgaria.
The aim of our study was to investigate the genetic control of the resistance to powdery mildew, of the tobacco cultivar BMR Burley 21, resistance derived from Nicotiana tabacum. The resistance was estimated under normal full field cultivation conditions and under glass, after artificial inoculation of the plants with Erysiphe cichoracearum DC by the Ternosvki method (1967). The number of genes controlling the resistance to E. cichoracearum DC was determined by the Chi2 method. Analysis of the hybrid F1 population derived from crosses of PMR Burley 21 (a mildew-resistant variety) with sensitive varieties : Trumpf, Virginia 0514, Virginia 348, Virginia 385 and R x T, have shown that inheritance of the resistance of the PMR Burley 21 cultivar to E. cichoracearum is recessive. The F2 plants consist of sensitive and resistant plants in a ratio of 15/1. Statistical analysis of the results has shown that the resistance of the PMR Burley 21 cultivar to Erysiphe cichoracearum DC is controlled by two (2) recessive genes.