TY - BOOK AU - Sinijadas, K AU - Joy, M (Guide) TI - Management of banana bract mosaic virus using beneficial fungal root endophyte, Piriformospora indica U1 - 632.3 PY - 2024/// CY - Vellayani PB - Department of Plant Pathology, College of Agriculture KW - Plant Pathology KW - Agriculture KW - Banana KW - Mosaic virus KW - Endophyte KW - Piriformospora indica N1 - Ph.D N2 - The research work entitled “Management of Banana bract mosaic virus using beneficial fungal root endophyte, Piriformospora indica” was carried out at the Department of Plant Pathology, College of Agriculture, Vellayani, Thiruvananthapuram during the academic year 2018-2022. The objective was to evaluate the beneficial fungal root endophyte, P. indica for the management of Banana bract mosaic virus (BBrMV); and to elucidate the role of antioxidants and plastids in this tripartite interaction. The characteristic symptoms of BBrMV viz., reddish spindle shaped streaks on pseudostem, black necrotic streaks on peduncle, chlorotic spindle lesions on leaves and underdeveloped fruits were observed during the survey conducted in five agro-climatic zones (ACZ) of Kerala. Percent disease incidence (PDI) and vulnerability index (VI) of the disease recorded from different zones showed the highest in banana var. Nendran (PDI - 61.66 & VI – 44.03) from southern zone and lowest in var. Poovan (PDI – 7.29 & VI – 6.29) in central zone. Serological and molecular detection confirmed the presence of BBrMV in banana var. Nendran. The sequence similarity analysis of the coat protein (CP) gene of BBrMV southern zone isolate (Vellayani) showed 99.12 percent genetic closeness to its Tamil Nadu isolates compared to the Kerala isolates (98.38 percent). Screening of the most virulent strain of BBrMV from five different ACZ of Kerala was done based on early symptom development in TC banana plants var. Nendran. The BBrMV strain from southern zone could produce the symptoms on var. Nendran within 30 days (lowest) followed by central zone (55 days) on artificial inoculation with viruliferous aphids, Pentalonia nigronervosa. The cross-infection study of virulent strain of BBrMV (southern zone) of Nendran on Nendran developed chlorotic spindle lesions on leaves at 30 days after inoculation followed by Nendran on Robusta (75 days). P. indica-colonization in banana var. Nendran was carried out using standardized medium. The chlamydospores of the fungus were observed in roots at 20 days after colonization (DAC). In both in vitro and in vivo experiments, P. indicacolonized plants showed reduced disease severity irrespective of the virusinoculation stage with a vulnerability index of 6.7 percent in BBrMV (+Pi / +V); and 20.0 percent in the virus-infected plants post-colonized with P. indica (+V / +Pi) compared to 53.3 percent in the virus alone infected plants. Further, PCR analysis with BBrMV coat protein specific primer yielded amplicon of low intensity in P. indica-colonized plants inoculated with the virus compared to the control plants indicating the ability of the fungus to inhibit the virus. Further, P. indica precolonized plants inoculated with BBrMV had improved growth and yield parameters compared to non-colonized plants. Field trial was laid out with two treatments (P. indica-colonized and noncolonized banana plants var. Nendran) at Instructional Farm, College of Agriculture, Vellayani. P. indica-colonized plants recorded a drastic reduction in the severity of BBrMV by 33 to 58 percent compared to non-colonised control plants. Enhanced plant height (30 percent), collar girth (45 percent), number of leaves (25 percent), leaf length (30 percent), leaf width (27 percent), fresh weight of shoot (34 percent), number of secondary roots (62 percent), number of tertiary roots (76 percent) and root weight (86 percent) were observed in P. indica-colonized plants at 90 days after treatment. P. indica-colonization also improved the bunch weight (32.9 percent) and fruit quality. Biochemical detection of superoxides using nitroblue tetrazolium (NBT) and H2O2 with diamino benzidine (DAB) stains at 5, 10, 15, 30 and 45 days revealed a reduction in reactive oxygen species (ROS) accumulation in both P. indica-colonized plants challenged with BBrMV (+Pi / +V) and virus infected plants post-colonized with P. indica (+V / +Pi) compared to BBrMV alone. The decrease in ROS production and disease severity in the endophyte-colonized plants inoculated with the virus were attributed to the increased activities of antioxidant enzymes viz., peroxidase, superoxide dismutase, catalase, glutamate synthase and ascorbic acid oxidase. The molecular analysis of genes involved in the symptom development indicated the beneficial effect of P. indica on BBrMV infection in banana. P. indica reduced the symptoms by up-regulating chlorophyll biosynthesis gene (chlorophyll synthase-CHLG) and down-regulating chlorophyll degradation genes (chlorphyllase CLH1 & CLH2; and pheophytin pheophorbide hydrolase - PPH), carotenoidbiosynthesis genes (phytoene synthase-PSY1 and PSY2), carotenoid degradation gene (Phytoene desaturase - PDS) and the virus specific genes responsible for symptom development (Hc-Pro and P3). Thus, the present study reveals that P. indica enhances tolerance against BBrMV in addition to improved growth promotion, yield and fruit quality in banana plant. േവരിൽ അ􀅵ർവ􀅖ാപനേശഷിയു􀆄 മി􀅗തകുമിളായ പിരിേഫാർേമാ􀅏േപാറ ഇൻഡി􀅚 ഉപേയാഗി􀅢് വാഴയിെല െകാ􀅚ാൻ ൈവറസി􀅀െറ നിയ􀅗􀅵ണം” എ􀅹 വിഷയെ􀅮 ആ􀅏പദമാ􀅚ി തിരുവന􀅵പുരം െവ􀆄ായണി കാർഷിക േകാേളജിെല സസ􀅖 േരാഗ വിഭാഗ􀅮ിൽ 2018 – 2023 കാലയളവിൽ ഗേവഷണ പഠനം നട􀅚ുകയു􀅪ായി. വാഴയിെല െകാ􀅚ാൻ േരാഗ (ബനാന 􀅗ബാ􀄭􀆃് െമാൈസ􀄭 ൈവറ􀅏 􀇦􀀃 ബി ബി ആർ എം വി􀈌􀀃 നിയ􀅗􀅵ണ􀅮ി􀅀 􀅗പേയാജനകരമായ മി􀅗തകുമിളായ പി. ഇൻഡി􀅚െയ വിലയിരു􀅮ുകയും􀇢􀀃 വാഴ - മി􀅗തകുമിൾ - ൈവറ􀅏 (􀅗തിക􀅜ി) ഇടെപടലിൽ നിേരാ􀄭സീകരണ എൻൈസമുകള􀆧െടയും 􀆗ാ􀆊ിഡുകള􀆧െടയും പ􀅠് മനസിലാ􀅚ുകയുമാ􀄻 ഈ പഠന􀅮ി􀅀െറ ല􀅜􀅖ം. േകരള􀅮ിെല അ􀅦് കാർഷിക-കാലാവ􀆉ാ േമഖലകളിൽ (􀀄􀀆􀀝􀈌􀀃 നട􀅮ിയ സർേവയിൽ􀇡 െകാ􀅚ാൻ േരാഗ􀅮ി􀅀െറ വിവിധ ല􀅜ണ􀅡ളായ ത􀅪ിൽ ചുവ􀅹 കതിർ ആകൃതിയിലു􀆄 വരകൾ􀇡􀀃 പൂ􀅠ുല􀅮􀅪ിൽ കറു􀅮 െനേ􀅗കാ􀆃ി􀄭 വരകൾ􀇡􀀃 ഇലകളിൽ മ􀅧 നിറ􀅮ിലു􀆄 􀅏പിൻഡിൽ വരകൾ, 􀀃വളർ􀅢 മുരടി􀅢 കാ􀅆കൾ എ􀅹ിവ കെ􀅪􀅮ി. വിവിധ േമഖലകളിൽ നട􀅮ിയ സർെവ 􀅗പകാരം െകാ􀅚ാൻ ൈവറ􀅏 േരാഗബാധയും (􀀇􀀌􀈌􀇡􀀃 േരാഗ തീ􀅗വതയും (􀀙􀀌􀈌􀀃 ഏ􀆃വും കൂടുതൽ െത􀅚ൻ േമഖലയിെല േന􀅗􀅵ൻ ഇന􀅮ിലും (􀀓􀀇􀀌􀀃􀇦􀀃􀍸􀍳􀇤􀍸􀍸 %􀀃􀆬􀀃􀀙􀀌􀀃􀈂􀀃􀍶􀍶􀇤􀍲􀍵􀈌 ഏ􀆃വും കുറ􀅌 മധ􀅖േമഖലയിെല പൂവൻ (DI – 7.29 % & VI – 6.29) ഇന􀅮ിലും കാണാൻ സാധി􀅢􀆧.􀀃 . സീേറാളജി􀅚ൽ􀇡􀀃 േമാളിക􀅖ുലാർ വിദ􀅖കളിലൂെട വാഴയിൽ െകാ􀅚ാൻ ൈവറ􀅏 േരാഗ􀅮ി􀅀െറ സാ􀅹ിധ􀅖ം 􀆉ിരീകരി􀅢􀆧. െത􀅚ൻ േമഖലയിൽ നി􀅹ും േന􀅗􀅵ൻ ഇന􀅮ിൽ കെ􀅪􀅮ിയ െകാ􀅚ാൻ ൈവറ􀅏 ഐെസാേല􀆃ിൻ്െറ (െവ􀆄ായണി) േകാ􀅨് േ􀅗പാ􀅨ീൻ (സി􀀃 പി) ജനിതക ഘടന വിശകലനം െച􀅆തതിൽ നി􀅹ും􀀃 ഈ􀀃 പഠന􀅮ിെല െകാ􀅚ാൻ ൈവറ􀅏, ബി ബിആർ എം വി േകരള ഐെസാേല􀆃􀆧കെള അേപ􀅜ി􀅢് (98.38􀀃 􀎨) തമി􀅋നാ􀄷 ഐെസാേല􀆃􀆧കള􀆧മായി 99.12 ശതമാനം ജനിതക അടു􀅼ം കാണി􀅚ു􀅹ു എ􀅹ു വ􀅖􀅛മായി. 􀀃 ടിഷ􀅖ൂ കൾ􀅢ർ വാഴെ􀅢ടികളിെല േരാഗല􀅜ണ􀅡െള അടി􀆉ാനമാ􀅚ി􀀃 നട􀅮ിയ പഠന􀅮ിൽ നി􀅹ും േകരള􀅮ിെല അ􀅦് വ􀅖ത􀅖􀅏ത കാർഷിക-കാലാവ􀆉ാ േമഖലകളിൽ നി􀅹ു􀆄 ഐേസാല􀆃􀆧കളിൽ, ഏ􀆃വും തീ􀅗വതേയറിയ 􀅏െ􀅗ടയിനിെന കെ􀅪􀅮ി. െത􀅚ൻ േമഖലയിൽ നി􀅹ു􀆄 ബി ബി ആർ എം വി 􀀃 􀅏െ􀅗ടയിൻ 30 ദിവസ􀅮ിനു􀆄ിലും (ഏ􀆃വും കുറ􀅌 സമയം) തുടർ􀅹് മധ􀅖 േമഖലയിൽ നി􀅹ു􀆄 􀅏െ􀅗ടയിൻ 55 ദിവസതിനു􀆄ിലും േരാഗ ല􀅜ണ􀅡ൾ കാണി􀅚ുകയു􀅪ായി. േരാഗ വാഹകരായ മു􀅧􀇡􀀃 (െപൻ്റേലാണിയ ൈനേ􀅗ഗാെനർേവാസ) ഉപേയാഗി􀅢് കൃ􀅗തിമ േരാഗ സം􀅗കമണ പഠനം നട􀅮ി. അതിൻ 􀅗പകാരം െത􀅚ൻ േമഖലയിൽ നി􀅹ു􀆄 ബി ബി ആർ എം വി 􀀃􀀃 ൈവറൽ 􀅏െ􀅗ടയിനിൻ കൃ􀅗തിമ േരാഗ സം􀅗കമണ􀅮ി􀅀 േശഷം േന􀅗􀅵ൻ ഇന􀅮ിൽ 30 ദിവസ􀅮ിനു􀆄ിലും േറാബ􀆊യിൽ 75 ദിവസ􀅮ിനു􀆄ിലും െകാ􀅚ാൻ േരാഗ􀅮ി􀅀െറ ല􀅜ണ􀅡ളായ ഇലകളിൽ മ􀅧 നിറ􀅮ിലു􀆄 വരകൾ രൂപെ􀅼ടു􀅹􀄼 നിരീ􀅜ി􀅢􀆧. 􀀃 UR - https://krishikosh.egranth.ac.in/handle/1/5810220683 ER -