Browsing by Author "Saxena, Gauri"

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Field performance of somaclones of rose scented geranium (Pelargonium graveolens L’ Her Ex Ait.) for evaluation of their essential oil yield and composition
(Elsevier B.V., 2008) Saxena, Gauri; Rahman, Laiq-ur; Verma, Praveen Chandra; Banerjee, Suchitra; Kumar, Sushil
Several randomly selected glasshouse grown somaclones of rose scented geranium, Pelargonium graveolens L’Her Ex Ait. cv. Hemanti were successfully transferred to the field in Northern India for evaluation. Two distinct morphotypes were described on the basis of leaf dentation-one resembling the parental cultivar in having highly dentated leaves (HDL) and the other with less dentated leaves (LDL). After repeated field-testing for 3 consecutive years, the HDL clones closely resembled the parental cultivar with respect to the different quantity and quality determining traits, while the LDL group was clearly different. The field established LDL somaclones possessed higher herb yield, number of branches and other oil yield attributing traits as compared to the HDL clones and the parent cultivar. The chemical investigations of the essential oil revealed significant differences between the LDL clones, the HDL clones and the control. Selection of such somaclones, which are superior to the parental in most of the quantitative and qualitative traits and show better adaptability to different areas of cultivation, will help towards commercialization of geranium in India.
Selection of leaf blight resistant Pelargonium graveolens plants regenerated from callus resistant to culture filterate of Alternaria alternata
(Elsevier B.V., 2008) Saxena, Gauri; Verma, Praveen Chandra; Rahman, Laiq-ur; Banerjee, Suchitra; Shukla, R.S.; Kumar, Sushil
A protocol has been established for the induction of disease resistance in callus cultures of rose-scented geranium, Pelargonium graveolens cv. Hemanti against leaf blight disease caused by the fungal pathogen Alternaria alternata. The callus cultures were raised and maintained on semi-solid Murashige and Skoog's (MS) medium supplemented with 10 mg/l Kn and 1.0 mg/l NAA. The calli were subjected to various concentrations of culture filtrate (0%, 4%, 8%, 12%, 16% and 20%) obtained from A. alternata. Resistant calli were selected and placed on regeneration medium (MS supplemented with 0.5 mg/l BAP and 0.1 mg/l NAA). The regenerants were confirmed for A. alternata resistance by exposing their leaves to the same concentrations of culture filtrate as used previously. While the parental wild type demonstrated typical susceptibility, the leaves of putative resistant clones remained green and viable in the presence of toxin and regenerated shoots directly on the toxin-free regeneration medium (MS supplemented with 5 mg/l Kn and 1 mg/l NAA). The above experiment demonstrated the induction of disease resistance in rose-scented geranium plants at the cellular level. This approach could be successfully exploited in raising new disease-resistant cultivars in geranium against various fungal pathogens.