RAPD marker linked Potato Virus Y resistant potato cultivars and treated with ribosome inactivating proteins (RIPs)

Ribosome inactivating proteins (RIPs) isolated from Phytolacca sp. and Mirabilis jalapa, which inhibit the necrotic tuber necrosis strain of potato virus Y (PVYNTN) infection by catalytically removing a specific adenine residue from the 28S RNA. The primary objective of this study was the development of a simple and novel strategy for controlling PVYNTN by using of leaf extracts from Phytolacca sp., and M. jalapa plants. In addition, assessment of genetic variability among PVYNTN resistant, susceptible, and the healthy control potato plants was carried out by Random amplified polymorphic DNA (RAPD). Spraying extracts on five potato cultivars ('Selan', 'Spunta', 'Cara', 'Diamond' and 'Nicola') before virus inoculation resulted in 100% inhibition of PVYNTN infection; these results were confirmed by DAS-ELISA. Analysis of variance showed there were no significant differences in number, weight and volume of tubers between extract-treated potato plants and healthy control in all five potato cultivars. RAPD marker generated by five arbitrary decamers was used to determine DNA polymorphism among the PVYNTN resistant, infected and healthy control potato plants. A total of 65 reproducible fragments ranging from 100 – 1200 bp were scored using five primers. Thirty-three out of 65 (50.77%) bands were polymorphic, and the remaining 32 (49.23%) were monomorphic. The number of bands for each primer varied from 5 to 22 fragments. Among the 65 fragments, 18 (27.69%) turned out to be reproducible and regarded as reliable RAPD markers for further analyses. Extract treated potato cultivars and the PVYNTN resistance varied considerably using the five primers of RAPD-PCR, whereas the 'Selan' cultivar appeared to have the highest number of markers (7), followed by 'Spunta' (6), while 'Cara' scored the lowest number from unique markers (1). This information should be taken into consideration in future breeding programs. The use of leaf extract sprays as those from P. americana, P. acinosa and M. jalapa on various crops are expected to prevent or control viral infection.