Browsing by Author "Sasikala, M."
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Item Aakasavalli adhava Moodillathali Thenginte Katuveezhcha Rogavyapana Padanathinu Oru Sahayi(1989) Sasikala, M.; Mathen, K.Item Appraisal of the distribution of coconut root wilt and heavy incidence of the disease in Cumbum Valley of Tamil Nadu(2007-02-08) Srinivasan, N.; Koshy, P.K.; Kamalakshi Amma, P.G.; Sasikala, M.; Gunasekaran, M.; Solomon, J.J.Item Breeding for resistance/tolerance to root (wilt) disease(2007-02-08) Nair, R.V.; Jacob, P.M.; Koshy, P.K.; Sasikala, M.; Nampoothiri, K.U.K.Root wilt is a serious disease of coconut in Kerala. The disease affects 16 million palms and cause an annual loss of 968 million nuts. Involvement of phytoplasma in the etiology of this disease has been established. Breeding for evolving root (wilt) resistant varieties - being the lasting solution for the disease is implemented since 1987. In the heavily diseased tracts, some high yielding west coast tall and chowgate green dwarf palms were found to be resistant and serologically negative under field conditions. Studies indicated that CGD palms were having higher level of resistance to the disease compared to that of other varieties. It has also been reported that CDO X WCT hybrids gave higher yield in spite of contracting the disease. Based on these,observations, the following crosses are made - WCT X WCT (inter-se), WCT (self), WCT X CGD, CGD X WCT, CGD (self/inter-se), CDO (self/inter-se). The present crossing programme includes 63 WCT, 97 CGD and 4 CDO palms in the farmers plots.The 2725 progenies were under planted among heavily infested palms for evaluating their resistance and use them as future mother palms. In the seventh year of planting, WCT (open pollinated) seedlings showed 60%disease incidence where as WCT (self) and WCT (inter-se) showed 45% disease incidence and only 31% in CGD X WCT. Four seed gardens have been established by planting 3371 artificially pollinated seedlings.Item Coconut root wilt - The malady and remedy(2007-02-08) Solomon, J.J.; Nair, C.P.R.; Srinivasan, N.; Gunasekaran, M.; Sasikala, M.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 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 Development of varieties of coconut (Cocos nucifera L) resistant/tolerant to root(wilt) disease(2004-12) Nair, R.V.; Jacob, P.M.; Thomas, R.J.; Sasikala, M.Item Diagnosis(2007-02-08) Sasikala, M.; Amma, B.S.K.; Rajagopal, V.Item Early diagnostic techniques on the root (wilt) disease of coconut in India(2007-02-08) Rajagopal, V.; Sasikala, M.; Sumathy Kutty Amma, B.; Chempakam, B.; Rawther, T.S.S.Item Epidemiology of coconut root (wilt) disease(1980-12) Gopinathan Pillai, N.; Sasikala, M.; Mathen, K.Coconut root (wilt) disease of Kerala (S. India) is a debilitating disease of uncertain etiology. Out of 7,40,000 ha of coconut planatation, 2,50,000 ha are affected by this malady causing an annual loss of about 340 million nuts. Associations of fungi, bacteria, nematodes, and a transmissible virus-like pathogen with the disease have been reported. Observations recorded for seven years in 10 coconut gardens, each of approximately one ha in extent with very low percentage of disease incidence revealed indiscriminate spread in sandy, sandy-loam, and alluvial soils. The percentage of infection increased from 2.3 to 18.2 with 2-5 palms contracting infection every year. The spread of the disease was slower in laterite soils, with only one palm developing the disease in two years. The spread was erratic and irregular irrespective of soil conditions and occurred in jumps/leaps. The rate of spread was 1-4 km from the nearest source of infection. The pattern of spatial distribution or galaxial outbreak of the disease is suggestive of the involvement of aerial vector(s).Item Epidemiology of coconut root (wilt) disease(2007-02-08) Gopinathan Pillai, N.; Sasikala, M.; Mathen, K.Coconut root (wilt) disease of Kerala (S. India) is a debilitating disease of uncertain etiology. Out of 7,40,000 ha of coconut planatation, 2,50,000 ha are affected by this malady causing an annual loss of about 340 million nuts. Associations of fungi, bacteria, nematodes, and a transmissible virus-like pathogen with the disease have been reported. Observations recorded for seven years in 10 coconut gardens, each of approximately one ha in extent with very low percentage of disease incidence revealed indiscriminate spread in sandy, sandy-loam, and alluvial soils. The percentage of infection increased from 2.3 to 18.2 with 2-5 palms contracting infection every year. The spread of the disease was slower in laterite soils, with only one palm developing the disease in two years. The spread was erratic and irregular irrespective of soil conditions and occurred in jumps/leaps. The rate of spread was 1-4 km from the nearest source of infection. The pattern of spatial distribution or galaxial outbreak of the disease is suggestive of the involvement of aerial vector(s).Item Evidences towards a mycoplasmal etiology for the root (wilt) disease of coconut in India(2007-02) Solomon, J.J.; Govindankutty, M.P.; Mathen, K.; Nair, C.P.R.; Sasikala, M.; Pillai, N.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 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 Refinement of ELISA and its use in early detection of coconut root (wilt) disease(2005) Sasikala, M.; Prakash, V.R.; Sapna, V.P.; Mayilvaganan, M.; Leena S. NairItem Root wilt A phytoplasmal disease of coconut in south India(2001) Alka Gupta; Sasikala, M.; Mayilvaganan, M.; Solomon, J.J.Rootwilt disease of coconut causes loss of 968 million nuts/year,26 per cent loss in husk 113 per cent loss in copra/oil, nut, and 60 per cent loss in yield/revenue from leaves/palm scientists are developing an improved West Coast tall (WCT) palm cultivar by high-yielding and disease-free WCT palms so that :loss could be checked. resulting in increased coconut production.