Interception of Peronospora manshurica in soybean germplasm imported during 1976–2005

Quarantine processing of 20,108 soybean germplasm samples received during 1976–2005 resulted in the interception of Peronospora manshurica, the downy mildew fungus in 1994 samples (9.91%) from 16 countries, including Malaysia and Indonesia, from where it has not been reported. The interception has great quarantine significance in view of the fact that this fungus has not yet been reported from India, is destructive in nature, its oospores can survive for several years in seed and soil, a large number of physiological races exist and zero tolerance limit is prescribed for quarantine purposes. Country-wise details on the introduction of germplasm and interception of downy mildew are presented.