Browsing by Author "Rajeev, G."
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Item Comparison of enzyme activities with diagnostic potential in healthy and root (wilt) diseased coconut palms, differing in cultivars and growth stages(2012-08) Chaturvedi, V.K.; Srinivasan, N.; Sasikala, M.; Jacob, P.M.; Rajeev, G.Activities of superoxide dismutase (SOD), succinic dehydrogenase (SucDH), exochitinase (Cht) and 1, 4 β-glucanase (Glucn) were quantified to assess their diagnostic potential for detection of, or their role in imparting tolerance against, root (wilt) disease (RWD). The enzymes were determined in healthy and infected palms of contrasting coconut cultivars - Chowghat Green Dwarf (CGD) and/or Malayan Green Dwarf (MGD) tolerant and West Coast Tall (WCT) - susceptible, in the adult palms and in some at the seedling growth stage. Healthy and RWD plants differed little and that too inconsistently with respect to the activities, specific activities and soluble protein content of all the 4 enzymes, offering no diagnostic potential, in the three cultivars. However, cultivars and growth stage differences for enzyme activities were found to be significant for some enzymes. The RWD tolerant cultivar CGD (10-year old palms) had higher SOD and SucDH activity, higher soluble protein in the SOD and SucDH extract and lesser SOD specific activity than the RWD susceptible cultivar WCT (40-year old palms). The RWD tolerant cultivar MGD had lesser SOD activity than WCT in the seedling stage, lesser SOD specific activity in the adult stage (15-year old palms), higher SucDH activity and specific activity, higher soluble protein in the SOD extract, but lesser soluble protein in the Cht extract than 40-year old WCT adult palms. Seedlings of WCT and MGD had higher SOD activity than their adult plants. Seedlings of WCT and CGD had higher soluble protein in SOD extract than their adult plants. Seedlings of CGD had higher soluble protein in SucDH extract than its adult plants. Metabolic differences in enzyme activities indicated that the cultivars CGD followed by MGD and the seedling stage or younger plants seem to have a better capacity in resisting the effects of root (wilt) disease.Item Confirmation of occurrence of root (wilt) disease of coconut in Dakshina Kannada district of Karnataka state(2005-11) Sasikala, M.; Chandra Mohanan, R.; Prakash, V.R.; Ajith Kumar, R.; Sapna, V.P.; Rajeev, G.Item Detection of Mycoplasma-like organisms in Proutista moesta (Westwood) a putative vector of yellow leaf disease of arecanut(2007-02-08) Ponnamma, K.N.; Rajeev, G.; Solomon, J.J.Item Detection of Root (Wilt) Disease of Coconut (Cocos nucifera L.) based on polyacrylamide gel electrophoresis(2016) Chaturvedi, V. K.; Rajeev, G.; Nampoothiri, C. K.Item Developing a polymerase chain reaction based detection method for coconut root (wilt) phytoplasma(2007) Mayilvaganan, M.; Gunasekaran, M.; Sheenakumari, T.K.; Geetha, L.; Rajeev, G.; Solomon, J.J.; Sasikala, M.Item Development of DAC Indirect Elisa for the rapid detection of coconut root (wilt) disease(2001) Sasikala, M.; Chithra, K.R.; Solomon, J.J.; Rajeev, G.Item Evidences for transmission of yellow leaf disease of areca palm, Areca catechu L. by Proutista moesta (Westwood) (Homoptera : Derbidae)(2007-02) Ponnamma, K.N.; Solomon, J.J.; Rajeev, G.; Govindankutty, M.P.; Karnavar, G.K.Item Field management of coconut leaf rot disease with biological control agents, their bioformulation and viability in organics(2011) Srinivasan, N.; Bharathi, R.; Shanty Issak; Rajeev, G.Leaf rot disease is an integral part of root (wilt) disease of coconut and hence its control a great importance. Potential of biological control agents against leaf rot pathogens have been established. Field performance of talc-based B. subtilis and P. fluorescens against leaf rot (individually and in consortium mode), growth of bioagents in coconut water-based media for enriching bioformulations and viability of the bioagents in organic carriers based formulations were evaluated. A field experiment conducted with treatments of B. subtilis, P. fluorescens, B. subtilis + P. fluorescens and Phytosanitation + B. subtilis + P. fluorescens in comparison with control showed a decline of disease index in newly emerged leaves of treated palms (higher disease ameliorative effect through consortium of B. subtilis and P. fluorescens). Multiplication of bacterial (P. fluorescens) and fungal (Trichoderma viride) bioagents could be achieved in coconut water-based media - moderate-good growth of P. fluorescens in coconut water (pH adjusted to 7.0), coconut water amended with peptone at 1 % or jaggery at 5 % or 10 % levels comparable with its growth in King’s B broth; moderate-good mycelial yield of T. viride in coconut water-based media with or without jaggery amendment comparable to its growth in potato dextrose broth. The bacterial and fungal biocontrol agents as grown in coconut water-based media could be processed into talcbased bioformulations (quality comparable with such products evolved using conventional media). The talc-based formulations admixed with organics viz., neem cake, vermicompost and coir pith-(1: 1w/w) that were individually packed also assured reasonable period shelf-life (six months) of bioagents, compared well to corresponding other media. Thus mass production of popular biological control agents in coconut water based medium followed by their bioformulations through fortifications with popular organics has been successfully evolved.Item An Insight into the Regime of Soil Borne Plant Pathogens(2018) Daliyamol; Merin Babu; Rajeev, G.Item An Insight into the Regime of Soil Borne Plant Pathogens(2018) Daliyamol; Merin Babu; Rajeev, G.Item Modified protocol of ELISA for rapid detection of coconut root (wilt) disease(2010) Sasikala, M.; Rajeev, G.; Prakash, V.R.; Amith, S.Root (wilt) disease of coconut is a phytoplasmal malady causing heavy economic loss to the coconut farmers in Kerala and Tamil Nadu. The disease is generally recognized based on foliar symptoms. But the development of foliar symptoms in coconut palms is very slow and there is a time lag between infection and symptom expression. To identify such latent infected palms, Direct Antigen Coated (DAC) indirect ELISA had been standardized earlier. But this ELISA system was not rapid. Though subsequently it was refined, 24 h was required for the completion of the test. Hence, a modified protocol was developed using leaf disc as test antigen. The modified protocol is simple, rapid and results could be obtained within 7 h. The test yielded very high sensitivity of 98 % with respect to visual observations. The modified protocol is being used for the routine screening of coconut palms for selection of disease-free mother palms for developing root (wilt) resistant/tolerant varieties. Besides this, the test is being used for confirmation of root (wilt) disease in coconut palms seen in mildly disease affected and disease outbreaks in new areas.Item Molecular characterization of phytoplasma associated with phyllody of Pedalium murex - a common weed in coconut plantations(2015) Merin Babu; Josephrajkumar, A.; Rajumon, M.; Devika, S.; Rajeev, G.; Gangaraj, K.P.; Vinayaka HegdeItem Molecular Detection of 16SrXI Group Phytoplasma Associated with Root (Wilt) Disease of Coconut (Cocos nucifera) in India(2010-05) Manimekalai, R.; Soumya, V.P.; Sathish Kumar, R.; Selvarajan, R.; Reddy, K.; Thomas, G.V.; Sasikala, M.; Rajeev, G.; Baranwal, V.K.Item Occurrence of Root (wilt) Disease in Kasaragod District of Kerala State(2007-02) Solomon, J.J.; Gunasekaran, M.; Sasikala, M.; Rajeev, G.; Thamban, C.; Rohini IyerItem Preparation of Coconut Root (wilt) Phytoplasma specific Antiserum and its use in Disease Detection(2007-02) Sasikala, M.; Solomon, J.J.; Chithra, K.R.; Rajeev, G.; Mayilvaganan, M.Item Southern Chapter : Prophylactic and curative effect of combined application of fungicide and insecticide on leaf rot disease of coconut(2000) Koshy, P.K.; Jacob, P.M.; Sasikala, M.; Rajeev, G.Item Ultra-structural studies in establishing the etiology of yellow leaf disease of arecanut and the vector role of the plant hopper proutista moesta (Westwood)(1999) Solomon, J.J.; Ponnamma, K.N.; Rajeev, G.; Geetha, L.