Powdery scab of potato was first reported in Pakistan in 1986 on the basis of tuber symptoms. However, the presence of pathogen was confirmed only from Astak valley in Northern Area in 1994 on the basis of serology, electron microscopy and bioassay. As the disease is both seed and soil-borne and seed potatoes are brought from Northern Areas to other potato growing areas, therefore, from quarantine point of view, it is necessary to probe different potato growing soils in Northern Areas for the presence of Spongospora subterranea. Probing of the soils of sixteen locations of potato growing areas in Gilgit and Hunza valley was done through bioassay by using tomato bait plants. Soils of eleven locations including Sust, Morkhun, Galapan, Gulmit, Shishcut, Aliabad, Nasirabad, Nagar, Thol, Naltre Bala and Naltre Paen gave root infection score for the presence of zoosporangia in a bioassay test.
Shamim Iftikhar , Iftikhar Ahmad and Atiq-ur-Rehman Rattu , 2000. Presence of Spongospora subterranea in Soils of Potato Production Area in Gilgit and Hunza Valleys of Pakisrtan. Pakistan Journal of Biological Sciences, 3: 848-849.