TY  - BOOK
AU  - Saru Sara Sam
AU  - Joy, M (Guide)
TI  - Evaluation of beneficial fungal root endophyte, Piriformospora indica for the management of Tomato leaf curl virus
U1  - 632.3 
PY  - 2021///
CY  - Vellayani
PB  - Department of Plant Pathology, College of Agriculture
KW  - Plant Pathology
KW  - Piriformospora indica
KW  - Tomato leaf curl virus
N1  - M Sc
N2  - The research work entitled “Evaluation of beneficial fungal root endophyte, 
Piriformospora indica for the management of Tomato leaf curl virus” was done at the 
Department of Plant Pathology, College of Agriculture, Vellayani, 
Thiruvananthapuram during the academic year 2019-2021 with the objectives of 
evaluation of the beneficial fungal root endophyte Piriformospora indica for the 
management of Tomato leaf curl virus (ToLCV) in tomato; and elucidating the role of 
reactive oxygen species (ROS) and antioxidant enzymes in the tripartite interaction.
ToLCV symptoms were assessed and maintained in insect proof nets from the 
various field at College of Agriculture, Vellayani, Thiruvananthapuram. The major 
symptoms observed includes mild curling with yellow speckles, severe leaf curling 
with blisters on leaf, stunted growth and reduced leaf size with flower abortion. 
Tomato variety Vellayani Vijay showed a disease incidence of 72.3 to 100 per cent 
with vulnerability index of 68.5 to 71.0 at different fields, while Anagha variety 
recorded an incidence of 67.0 per cent and vulnerability index of 54. The presence of 
ToLCV was confirmed using the universal primers viz., Deng and AV/AC that 
amplifies the coat protein of Begomovirus which produce amplicons of 520 bp and 
575 bp respectively under specified conditions.
P. indica-colonization in tomato variety Vellayani Vijay was done in portray 
mixture amended with 2 per cent gram flour. P. indica spores were observed from 3 
day after colonization (DAC) and the spore size increased by subsequent days. 
P.indica-colonization enhanced the growth parameters including plant height, shoot 
height, and root and shoot biomass. The tomato plants colonized with P. indica
showed an increase in shoot height, number of branches, number of leaves, number of 
flower, fresh shoot weight, dried shoot weight, fresh root weight and dried shoot 
weight by 34, 117, 96, 86, 45, 66, 45 and 120 per cent respectively compared to the 
control at 60 DAC. The days taken for flowering in P. indica-colonized plants were 
decreased by 12 days and the yield per plant in P. indica-colonized was 892.46 g 
against 449.51g.
P.indica-colonization decreased incidence and severity of fungal and bacterial 
diseases under field conditions. Moreover, it recorded a drastic reduction in the 
severity of ToLCD by 58 percent. Tomato plants were subjected to pre- and postcolonization of P. indica challenged with ToLCV through wedge grafting at 2, 5, 10 
and 15 days interval. Pre-colonized tomato plants decreased the severity of ToLCD by 
66 per cent, while post-colonization decreased the severity by 26 per cent at various 
intervals of treatments. Further, P. indica-colonization promoted flowering and fruit 
set against complete flower abortion in non-colonized plants challenged with ToLCV 
under pot studies. The best treatments selected from pre- and post- inoculation of the 
fungus include P. indica-colonization followed by graft transmission of the virus after 
15 days, and graft transmission of the virus followed by P. indica-colonization after 2 
days respectively. Amplification of the virus by polymerase chain reaction (PCR) 
using Deng and AV/AC primers also revealed that the virus titer was the least in P. 
indica-pre-colonized plants that were inoculated with the virus after 45 DAC, 
followed by post-colonized plants that were inoculated with the virus. 
Nitro blue tetrazolium (NBT) for superoxides and diamino benzidine (DAB) 
for H2O2 staining recorded a reduction in ROS production in both pre- and post- P. 
indica-colonized tomato plants artificially inoculated with ToLCV against the virus 
alone. The decrease in ROS production and disease severity in the fungus colonized 
plants inoculated with the virus were attributed to the increased total soluble proteins 
and enhanced activities of antioxidant enzymes. The substantial increase in 
antioxidant enzymes viz., peroxidase, phosphatase, superoxide dismutase, catalase and 
glutathione reductase and glutamate synthase were observed in P. indica-colonized 
plants against the control; and for both pre- and post- P. indica-colonized plants 
artificially inoculated with ToLCV against the virus alone. 
Thus, the present study reveals that P. indica can be exploited for the 
management of ToLCV on prophylactic and curative bases with the best results in the 
former. P. indica colonized plants enhanced the over all growth and productivity; and 
drastically reduced the severity of ToLCD under both controlled and open field 
conditions
ER  -