Browsing by Author "Radha, E."
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Item Assessment of genetic fidelity of arecanut plantlets derived through direct somatic embryogenesis by RAPD markers(Indian Society for Plantation Crops, 2008) Anitha Karun; Radha, E.; Sangeetha Vijayan, P.; Jiji George; Rajesh, M.K.; Ananda, K.S.Item Coconut plumule : Tissue with an efficient regeneration capacity(2004-06) Rajesh, M.K.; Radha, E.; Sajini, K.K.; Anitha KarunItem Effect of cytokinins on growth and maturation of direct somatic embryos in arecanut (Areca catechu L.)(2008) Radha, E.; Anitha Karun; Rajesh, M.K.; Nancy J. MariyaItem Efficacy of CPCRI protocol of coconut embryo culture in germplasm expedition(2004-12) Anitha Karun; Sajini, K.K.; Radha, E.; Parthasarathy, V.A.The CPCRI protocol of coconut zygotic embryo culture was utilized for five germplasm expeditions during the period 1997- 2001. A total of 4182 embryos of 45 accessions were collected from 8 countries viz., Mauritius, Madagascar, Seychelles, Maldives, Comoros, Reunion, Sri Lanka and Bangladesh. The per cent retrieval of embryos varied among the location and among accessions. A major cause of differential germination was the contamination of cultures, which could be partially attributed to the personal skill and the conditions of the site at the time of collection. Treatment of cultures with tetracycline (2 ppm) be effective in treatments of cultures with mild bacterial contamination. The per cent germination varied between 54 (Sri Lanka) to 82.2 % (Bangladesh) between expeditions. In earlier expeditions when seed nuts were brought, the germination ranged from 2.0 - 87.0%. The observation on in vitro retrieval of embryos and their ex vitro establishment suggest that, about 300 to 400 embryos/accessions needed to be collected for field establishment of 100 plants in a gene bank.Item Histological Studies on Callogenesis of Cocoa(2011) Bhavyashree, U.; Radha, E.; Anitha KarunItem Histological Studies on Callogenesis of Cocoa(2011) Bhavyashree, U.; Radha, E.; Anitha KarunItem In Vitro Embryo Retrieval Technique for Arecanut (Areca Catechu Linn.)(2002) Anitha Karun; Siril, E.A.; Radha, E.; Parthasarathy, V.A.An in vitro germination technique for the rapid germination of arecanut embryos has been developed. Seven-month-old embryos collected from four varieties viz. Mangala, Sumangala, Sree Mangala and South Kanara Local were cultured in vitro on agar gelled hormone free EeuewensY3, + strength MS or Full strength MS medium. Embryos cultured in Y3 medium supplemented with 3% sucrose showed maximum (93.3%) germination. Varietal differences with respect to germination was also recorded and showed Sumangala and South Kanara local were most responsive. In vitro seedlings after 8 weeks in germination media were transferred to liquid media containing reduced (1.5%) sucrose for the development of roots and expansion of leaves. Fully developed in vitro seedlings are being acclimatized. Developed protocol will serve as a basis for the future in vitro conservation (cryopreservation) studies on arecanut and is also useful in the areas of safe and convenient germplasm movement, rare embryo rescue etc.Item Leaf anatomy and molecular characterization of healthy and root (wilt) affected coconut palms(2012-11) Chinchu, K.; Fayas, T.P.; Radha, E.; Regi Jacob Thomas; Muralidharan, K.; Rejusha Ramakrishnan, P.; Anitha KarunItem Metabolic Changes in Coconut Embryo Culture with Various Antioxidants(2010) Anitha Karun; Anuradha Upadhyay; Radha, E.; Parthasarathy, V.A.Item Plant regeneration from embryo-derived callus of oil palm - the effect of exogenous polyamines(2003) Rajesh, M.K.; Radha, E.; Anitha Karun; Parthasarathy, V.A.Item Plant regeneration through organogenesis and somatic embryogenesis from plumular explants of coconut(Cocos nucifera L.)(2005) Rajesh, M.K.; Radha, E.; Sajini, K.K.; Anitha Karun; Parthasarathy, V.A.A procedure is outlined for regeneration of complete plantlets via organogenesis from plumular tissues of coconut. Callus was induced from plumular tissues in Y3 media supplemented with either 2,4-D (74.6 M) alone or 2,4-D (74.6 M) in combination with TDZ (4.54 M). The frequency of callus induction increased and the browning of explants was reduced when cytokinin (TDZ) was added along with the auxin (2.4-D) in the calus induction medium. The calli were subcultured at monthly intervals to media containing lower levels of 2,4-D and a constant level of either cytokinins (BA and TDZ) of polyamines (spermine and putrescine). Higher percentages of embryogenic calli, somatic embryoids and meristemoids were obtained in Y3 media supplemented with either sprernine of BA. Plantlets with balancedshoot and root formation were transferred to pots and established in the greenhouse. Histological studies of the differentiated tissues confirmed the development of shoot buds (organogenesis) and typical bipolar embryoids (somatic embryogenesis). Abbreviatipns: BA: 6-benzyladenine; 2.4-D: 2,4-dichlorophenoxyacetic acid; 1BA:indole-3butryic acid; TDZ : 1 - phenyl - 3(1,2,3-thiadiazol-5-yl) urea (Thidiazuron)Item Plantlet regeneration via direct and indirect somatic embryogenesis from inflorescence explants of arecanut palms (Areca catechu L.)(2006) Radha, E.; Anitha Karun; Ananda, K.S.; Kumaran, P.M.Plantlet regeneration from inflorescence explants of yellow leaf disease (YLD) resistant arecanut cultivar south kanara local was achieved by both direct and indirect somatic embryogenesis. This is the first report of direct somatic embryogenesis from inflorescence explants of arecanut. A total of 10 inflorescences were extracted from healthy palms of YLD· hot spot areas from Sullia in Dakshina Kannada during 2005 and 2006. Out of these, direct somatic embryogenesis was obtained from six inflorescences, which is ideal because it allows the production of plants without a callus phase leading to somaclonal variation and hence useful for efficient genetic transformation. The vigour ofdirectly differentiated somatic embryos was much higher than indirect somatic embryo development. This was achieved in Y3 basal medium supplemented with two levels of picloram (1oollM, 200IlM). Induction of embryogenic potency and formation of somatic embryos were noticed when the cultures were passed from higher to lower concentration of picloram and then to a hormone free medium. Somatic embryos proliferated rapidly in subsequent cultures. Maturation of somatic embryos and germination occurred in Vz MS medium supplemented with Imgll BA and subsequent plantlet development was achieved by transferring them to same basal medium supplemented with 5 mg/l BA and O.5mgll IBA, followed by lOmgll BA, lmgll IBA and Img/l NAA. Anatomical studies were conducted at various developmental stages of both direct and indirect somatic embryogenesis. Histological studies revealed that somatic embryos arose indirectly from a single callus cell whereas the origin of direct somatic embryos was multicellular, without a callus phaseItem Polyamine-induced somatic embryogenesis and plantlet regeneration in vitro from plumular explants of dwarf cultivars of coconut (Cocos nucifera)(2014-04) Rajesh, M.K.; Radha, E.; Sajini, K.K.; Anitha KarunItem Somatic embryogenesis and plantlet regeneration from leaf and inflorescence explants of arecanut(Areca catechu L.)(2004-06) Anitha Karun; Siril, E.A.; Radha, E.; Parthasarathy, V.A.