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.
Description:
A Thesis
Submitted to the Faculty of Agriculture
Sher-e-Bangla Agricultural University, Dhaka,
In partial fulfillment of the requirements
For the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY