Vanitha K.,Directorate of Cashew Research |
Bhat P.S.,Directorate of Cashew Research |
Raviprasad T.N.,Directorate of Cashew Research |
Srikumar K.K.,UPASI Tea Research Institute
International Journal of Pest Management | Year: 2016
The biology and behaviour of a common predator in cashew plantations, Ephestiasula pictipes (Wood-Mason), were studied under captivity for three seasons using greater wax moth larvae as prey. During Feb–May, incubation and nymphal developmental period were shorter when compared with Jun–Sep and Oct–Jan. The female mantids laid ootheca once in every 3–4 days, for a period of 70–77 days. Adult longevity and oviposition period were significantly higher during Feb–May, while no significant difference was observed in sex ratio, oviposition interval and pre oviposition period during different seasons. Sexual behaviour consisted of preliminary courtship and copulation, involving 14 activities in sequence. Duration of mounting, copulation and riding around on the female by the male widely varied from 2 min to 28 h; 5.15 to 6.10 h; and 2 to 74 h, respectively. High fertility, high fecundity, shorter life cycle, multivoltinism and feasibility of laboratory rearing throughout the year are the advantageous features of E. pictipes that permits for its mass rearing and emergence as a viable biocontrol agent in future. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Characteristic variation in pigment composition, photosynthetic carbon assimilation and phytonutrients content of Dendrophthoe falcata, a hemiparasite growing on host trees of saline and non-saline environments
Arumugam R.,Government of Tamilnadu |
Venkatesalu V.,Annamalai University |
Rajkumar R.,UPASI Tea Research Institute
Russian Journal of Plant Physiology | Year: 2015
The Indian Mistletoe Dendrophthoe falcata (L.f) Ettingsh is highly specialized perennial flowering plant adapted to parasitic life on aerial parts of their hosts. Photosynthetic characteristics in leaves of D. falcata growing on a halophilic (Rhizophora mucronata) and a glycophilic (Albizia lebbeck) host trees were determined. The chlorophyll a/b ratio was lower (1.0–1.5) and showed no significant difference between the leaf samples collected from both the host species. The CO2 assimilation rate (PN) was significantly lower (5.2 µmol/(m2 s)) in the parasite growing on R. mucronata, compared to the other host A. lebbeck (6.7 µmol/(m2s)). There was no host-specific variation in the activity of ribulose-1,5-bisphosphate carboxylse (Rubisco) and phosphoenolpyruvate carboxylase (PEPC); however, D. falcata infecting R. mucronata showed significantly higher activity of Rubisco (6.63 mmol CO2/(s kg protein)). The Fourier transform infrared (FTIR) spectral studies revealed the presence of quercitrin in the leaf samples of D. falcata, which is reported as a taxonomic marker of the Loranthaceae family. The non host-specific hemiparasite, D. falcate, exhibited significant variation among the halophilic and glycophilic host trees, particularly in photosynthetic activity and nutrients accumulation. © 2015, Pleiades Publishing, Ltd.
Maria John K.M.,Konkuk University |
Premkumar R.,UPASI Tea Research Institute
Research Journal of Phytochemistry | Year: 2012
Tea is one of the popular beverages which immensely have therapeutic activity against various diseases. The biochemical and therapeutic properties of tea was observed to be varying because of its seasonal and varietal difference which will reflect in the quality of the end product. Yield and quality are the major factors determining the profit. So, research is still going on to search high quality tea plant among the huge tea seedling population. This process is basically a time involving (in years) or cost of selection will be high. The present study, grouping of tea plant was made by using total catechins and polyphenols activity against free radicals such as DPPH and Hydroxyl radicals. UPASI-17 registered the highest polyphenol, catechin content as well as its scavenging activity against free radicals than that of other tea cultivars. When considering the catechin and polyphenols scavenging activity, catechin influence higher than that of polyphenols against DPPH and Hydroxyl radicals. IV distinct groups were observed through Principal Compound Analysis (PCA) and dendrogram analysis based on individual clones free radical scavenging activity. By this analysis all clones have high free radical scavenging property was grouped separately. By adapting this method of analysis, it will reduce the time and cost involvement in the screening of new tea varieties from the seedling population and help in the production of high free radical scavenging black tea. © 2012 Academic Journals Inc.
Radhakrishnan B.,UPASI Tea Research Institute |
Vasanthakumar D.,UPASI Tea Research Institute
Pestology | Year: 2012
Abamectin is one of the broad spectrum microbial insecticides derived from the soil actinomycete, Streptomyces avermitilis and is effective against several pests in many of crops. Field studies were conducted to evaluate the efficacy of Abamectin 1.9 EC against the red spider mite (RSM) infesting tea. Different dosage rates of Abamectin 1.9 EC (80,100,120,140 &280 ml/ha) were tested with the standard treatment of Propargite 57 EC @ 500 ml/ha. Studies were also conducted to assess the impact of the application of Abamectin 1.9 EC on Phytotoxicity to tea leaves and natural enemies (Sthethorus sp.) of RSM. Results of the study revealed that Abamectin 1.9 was very effective against RSM, non phytotoxic and safer to natural enemies of RSM.
Suppressive Subtractive Hybridization Approach Revealed Differential Expression of Hypersensitive Response and Reactive Oxygen Species Production Genes in Tea (Camellia sinensis (L.) O. Kuntze) Leaves during Pestalotiopsis thea Infection
Senthilkumar P.,UPASI Tea Research Institute |
Thirugnanasambantham K.,UPASI Tea Research Institute |
Mandal A.K.A.,Vellore Institute of Technology
Applied Biochemistry and Biotechnology | Year: 2012
Tea (Camellia sinensis (L.) O. Kuntze) is an economically important plant cultivated for its leaves. Infection of Pestalotiopsis theae in leaves causes gray blight disease and enormous loss to the tea industry. We used suppressive subtractive hybridization (SSH) technique to unravel the differential gene expression pattern during gray blight disease development in tea. Complementary DNA from P. theae-infected and uninfected leaves of disease tolerant cultivar UPASI-10 was used as tester and driver populations respectively. Subtraction efficiency was confirmed by comparing abundance of β-actin gene. A total of 377 and 720 clones with insert size >250 bp from forward and reverse library respectively were sequenced and analyzed. Basic Local Alignment Search Tool analysis revealed 17 sequences in forward SSH library have high degree of similarity with disease and hypersensitive response related genes and 20 sequences with hypothetical proteins while in reverse SSH library, 23 sequences have high degree of similarity with disease and stress response-related genes and 15 sequences with hypothetical proteins. Functional analysis indicated unknown (61 and 59 %) or hypothetical functions (23 and 18 %) for most of the differentially regulated genes in forward and reverse SSH library, respectively, while others have important role in different cellular activities. Majority of the upregulated genes are related to hypersensitive response and reactive oxygen species production. Based on these expressed sequence tag data, putative role of differentially expressed genes were discussed in relation to disease. We also demonstrated the efficiency of SSH as a tool in enriching gray blight disease related up- and downregulated genes in tea. The present study revealed that many genes related to disease resistance were suppressed during P. theae infection and enhancing these genes by the application of inducers may impart better disease tolerance to the plants. © 2012 Springer Science+Business Media New York.