Genetic variation within and among the populations of Podophyllum hexandrumRoyle (Podophyllaceae) in western Himalaya.
IR@CSIR-IHBT
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Title |
Genetic variation within and among the populations of Podophyllum hexandrumRoyle (Podophyllaceae) in western Himalaya.
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Creator |
Kharkwal, A
Singh , D S, Rajkumar Ahuja, Paramvir Singh |
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Subject |
Plant sciences
Plant Biotechnology |
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Description |
Podophyllum hexandrum Royle is an herbaceous, rhizomatous species of medicinal importance that is now endangered in India (Nayar and Sastry 1990). The rhizomes and roots of P. hexandrum contain lignans with anti-tumour properties, such as podophyllotoxin, 4’-demethyl podophyllotoxin and podophyllotoxin 4-o-glucoside (Tyler et al.1988; Broomhead and Dewick 1990). Among these, podophyllotoxin is the most important for its use in the partial synthesis of the anti-cancer drugs etoposide and teniposide (Issell et al. 1984). The podophyllotoxin content of Himalayan mayapple is high (4.3%) compared with other species of Podophyllum, notably P. peltatum (0.25%), the most common species in the American subcontinent (Jackson and Dewick 1984). There is considerable variation in morphological characters such as plant height, leaf characteristics, fruit weight, seed weight and seed colour and in chemical characters such as podophylloresin and podophyllotoxin content in rhizomes (Airi et al. 1997; Purohit et al. 1999). Esterase isozyme analysis has indicated the existence of high inter- and intrapopulation variation in P. hexandrum from Garhwal Himalaya (Bhadula et al. 1996). At least four distinct morphological variants, with 1, 2, 3 and 4 leaves, have been reported (Purohit et al. 1998). Polypeptide profiles in seeds of these variants indicate that they may be genetically distinct from each other. The population of P. hexandrum in western Himalaya is declining, and in some areas the plant has almost disappeared as a result of anthropogenic activities and overexploitation (Bhadula et al. 1996). Thus, there is a pressing need to understand and conserve the genetic diversity of this important medicinal plant. Attempts have been made to conserve this plant through in vitro propagation and artificial breaking of seed dormancy (Nautiyal et al. 1987; Nadeem et al. 2000). Efforts to collect and maintain germplasm have been mainly centred on clearly defined characters recognizable in a phenotype. However, there is now a paradigm shift in looking for characters or genes using molecular markers (Tanksley and McCouch 1997). Such data help to provide bases for decisions about allocation of resources towards maintenance and utilization of genetic diversity. In western Himalaya, two populations of P. hexandrum have been characterized for their inter- and intrapopulation genetic variation using RAPD analysis (Sharma et al. 2000). Considering the wide distribution of P. hexandrum throughout western Himalaya, the above analysis did not reflect the genetic diversity of the species. Hence, it is necessary to assess genetic diversity of P. hexandrum at inter- and intrapopulation level in disturbed and undisturbed habitats. This paper attempts to describe variation in the genetic diversity of populations collected from five geographical locations. |
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Date |
2009
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Type |
Article
PeerReviewed |
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Identifier |
Kharkwal, A and Singh , D and S, Rajkumar and Ahuja, Paramvir Singh (2009) Genetic variation within and among the populations of Podophyllum hexandrumRoyle (Podophyllaceae) in western Himalaya. Plant Genetic Resources Newsletter, 156. pp. 67-71.
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Relation |
http://ihbt.csircentral.net/726/
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