SCREENING OF SELECTED POTATO VARIETIES FOR VIRUSES (PLRV AND PVY) THROUGH GROWTH CHARACTERISTICS AND ELISA TEST

Abstract

An experiment was conducted in glass house and laboratory of BADC to screen selected potato varieties viz. Asterix, Cardinal, Diamant, Lalpakri and Desiree against PLRV and PVY through growth characteristics and it was further confirmed through ELISA test. ELISA test followed by in vitro meristem culture performed in order to produce virusfree and sufficient amount of potato seed tubers. Among the selected potato varieties, the

highest disease

incidence of PVY and PLRV (1.22 and 1.89%) was recorded in Lalpakri and the lowest (0.33 and 0.44%) was in Asterix respectively. In Diamant, disease incidence of PLRV and PVY was 0.39% and 0.83% respectively. In Cardinal, disease incidence of PLRV and PVY was 1.56% and 1.11% respectively. In Desiree, disease incidence of PLRV and PVY was 0.44% and 1.22% respectively. Numbers of stems/hill of the virus free as well as infected cultivar were significantly different from each other. In both cases, Asterix showed the highest number of stems/hill followed by Cardinal, Desiree, Diament and Lalpakri. Numbers of nodes production of the virus free as well as infected cultivar were significantly different from each other. In both cases, Asterix showed the highest number of nodes production followed by Desiree, Cardinal, Diament and Lalpakri. The cultivars Asterix (12.12 tubers/plant) produced more tubers/plant followed by Desiree (10.43), Diamant (9.31), Cardinal (9.25) and Lalpakri (8.10). It was also observed that among the potato varieties tested against PLRV and PVY, Diamant produced 23.98 mm size tuber when infected with PLRV but PVY infection produced 21.43 mm size tuber. PVY infected Cardinal produced 22.88 mm size tuber but PLRV infection reduced size to 21.13 mm. Desiree produced 24.32 mm and 23.56 mm size tuber when infected with PVY and PLRV, respectively. Highest dry weight of whole plant was recorded in varieties Asterix (1.81 g) followed by Desiree (1.68 g), Diamant (1.66 g), Cardinal (1.63 g) and Lalpakri (1.55 g), respectively. Diamant produced 1.66 g dry weight/plant in PLRV and 1.52 g dry weight/plant in PVY infection. In PVY and PLRV infection Cardinal produced 1.60 g and 1.52 g dry weight/plant, respectively whereas Desiree produced 1.63 g dry weight/plant in PVY and 1.60 g dry weight/plant in PLRV infection. Asterix gave the highest percentage (92.7%) of survivability of plantlets followed by Lalpakri (90%), Desiree (87.5%), Cardinal (86.7%) and Diamant (71.7%). Asterix gave the highest percentage (99.70%) of virus free plantlets followed by Desiree (99.48%), Cardinal (99.47%), Diamant (99.10%) and Lalpakri (91.44%). From the results of this study it may be concluded that presence of viruses in potato plants hamper photosynthetic production and assimilation consequently all the growth characteristics which also depends on nature of viruses and potato varieties and Asterix are the most resistant to the both PVY and PLRV.