Prevalence of major potato viruses and aphid population dynamics in Punjab, India

A survey was conducted over six major potato growing districts of Punjab during December of 2014 and 2015, respectively. Leaf samples of 190 potato plants showing various virus diseases like symptoms were collected during the survey for the two consecutive years. These leaf samples were crushed in extraction buffer and were exposed against antisera of seven major potato viruses viz. PVX, PVYn, PVYo/c, PVA, PVM, PVS and PAMV in DAS/TAS-ELISA. Study on various symptoms produced by these viruses on potato was done. Among the potato viruses, the highest incidence was recorded for PVX, 41.36 % and 89.47 % in the year 2014 and 2015, respectively. Maximum collection of infected potato plants were found to be co-infected with PVX and PVYn (73.68 %) in 2015 which exhibited rugose mosaic type of symptoms. Potato plants infected simultaneously with multiple potato viruses showed malformation of leaves, rosetting and severe stunting. The per cent viral disease incidence recorded was correlated with aphid populations observed over potato grown in these districts. The highest viral disease incidence was recorded in Hoshiarpur district, 17.47 % and 21.07 % for the year 2014 and 2015, respectively. This was due to relatively more abundance of aphid population in Hoshiarpur district among others. The incidence of PVX, PVYn, PVYo/c, PVA, PVM, PVS was higher during 2015 as compared to the year 2014 due to increase in mean aphid population during the potato growing seasons.