Bull. Spec. CORESTA Congress, Jerez de la Frontera, 1992, p. 170, PPOST8, ISSN.0525-6240

Screening germplasm resistance of tobacco to Phytophthora parasitica f. nicotianae causing black shank disease

REDDY T.S.N.; NAGARAJAN K.
Central Tobacco Research Institute (CTRI), Rajahmundry (A.P.) India
Black shank (Phytophthora parasitica f. nicotianae) is a serious fungal disease in most of the tobacco growing tracts in India. The predominant race of the fungus in Andhra Pradesh is race O. In order to identify resistant/tolerant donors to this race of the fungus, the germplasm consisting of 895 accessions were screened. Among them, Beinhart 1000-1 was resistant, Mc.Nair-12, N.C.2326, PD.468, Bhavya, Sel.1117 were tolerant and the rest were susceptible. Among the 35 Nicotiana spp. screened, N. nesophila, N. suaveolens, N. plumbaginifolia and N. longiflora were resistant; N. exigua, N. megalosiphon, N. solanifolia and N. trigonophylla were moderately resistant to race"O". Resistant genes from Beinhart 1000-1, Mc. Nair-12 and N. plumbaginifolia were successfully transferred by recurrent selections and pedigree methods to commonly cultivated FCV and Burley varieties. Several selections possessing 100% resistance to black shank have been isolated and carried forward for further studies on yield and quality parameters. A few selections of FCV types possess resistance to both black shank and tobacco mosaic virus.