Method for inducing improved seed germination in podophyllum hexandrum royle

Abstract

The present invention describes a method for inducing improved seed germination in a high altitude medicinal plant, Podophyllum hexandrum Royle through hot water treatment at 40° C.-100° C. for 30-120 seconds.

Description

[0001] The present invention relates to a method for inducing improved seed germination in a high altitude, medicinal and endangered plant, Podophyllum hexandrum Royle.[0002] Podophyllum hexandrum Royle is an important medicinal plant, which grows in the inner ranges of Himalayas at an altitude of 2700-4200 m from Kashmir to Sikkim (Badhawar and Sharma 1963), extending up to south west of China.[0003] The rhizomes of Podophyllum hexandrum are rich in podophyllotoxins and have anticancer and antitumor properties (Kamil and Dewick, 1986). The podophyllotoxins are lignans whose semi-synthetic derivatives--etoposide (VP-16-213) and teniposide (VM-26) are approved drugs for the treatment of testicular and lung cancer (Stahelin and Warburg, 1991). P. hexandrum has the maximum podophyllotoxins up to about 4% from dried roots as compared to 0.25% of P. peltatum (Jackson and Dewick, 1984a).[0004] Ever increasing demand for this drug in modern medicine, coupled with its existing use in tradit...

AI Technical Summary

Benefits of technology

0043] In other words, the present invention describes a method for inducing improved seed germination in a high altitude medicinal plant, Podophyllum hexandrum Royle through hot water treatment at 40.degree. C.-100.degree. C. for 30-120 seconds. Seed germination commenced after 30 days of seed sowing in potting mix under green house. Up to 100% seed germination was achieved within 70 days of seed sowing. True leaf emergence to the extent of 40% was also achieved within 90 days of seed sowing. Very high seedling survival percent (90%) was achieved

Problems solved by technology

Ever increasing demand for this drug in modern medicine, coupled with its existing use in traditional system of medicine has resulted in ruthless uprooting of the underground parts of the plant leading to intense collection coupled with the lack of organized cultivation.

However, since rhizomes are also the source of podophyllotoxins, considerable loss is incurred either in terms of propagules (when uprooted) or important harvestable materials of pharmaceutical importance (when conserved) (Sadowska et al., 1997).

Seed germination is erratic and is further limited by long periods of seed coat imposed or mechanical and endosperm dormancy which cannot be generally broken by traditional methods (Badhawar and Sharma, 1963).

More than the germinability of the seeds, the structural barrier in the seedlings i.e. the hypocotyl (Purohit and Nautiyal, 1986) may also reduce the chances of its survival in nature (Nautiyal et al., 1987).

Thus, it is not surprising that despite the urgent necessity of mass propagation and conservation of Podophyllum, the work done till date has been limited only to academic interests with respect to the small number of plants propagated.

A similar report of Bhadawar and Sharma (1963) wherein they also indicated the (i) the presence of a dormancy period of about 9-10 months in the seeds and poor germination of about 7-45 % (ii) different treatments like soaking of seeds in luke warm water for 24 hrs, 60% H.sub.2SO.sub.4 for five minutes and chipping of seeds with a blade all failed to break seed dormancy and induce germination The drawbacks include (i) the reports does not provide a method for germination of seeds in large numbers (ii) the time taken for complete seed germination was relatively long (iii) seed germination was poor (iv) there is no mention of growth conditions required for seed germination and hence, the method cannot be reproduced (v) a long dormancy period of about 9-10 months which could not be overcome by any of the treatments tested; therefore, the time required for seed germination could not be shortened (vii) the treatments that were employed for breaking seed dormancy were not effective.

The drawbacks are (i) poor seed germination (24.4%) and (ii) seedling mortality rate beyond acceptable limits.

The drawbacks are (i) no germination of fr

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