tag:blogger.com,1999:blog-74060562461325385732024-02-20T03:36:55.140-08:00PhD Thesis: SabuTitle of PhD Thesis: Intraspecific variation of Andrographis paniculata Nees
Supervisor: Dr. S. Seeni
Institution: Work carried out at Tropical Botanic Garden and Research Institute (TBGRI), India and degree awarded by University of Kerala.Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-7406056246132538573.post-83437414925278264892012-06-08T10:01:00.001-07:002012-06-08T10:01:50.836-07:00Introduction-4
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A. paniculata is distributed in tropical Asian countries often in isolated patches. It can be found in a variety of habitats viz. plains, hill slopes, waste lands, farms, dry or wet lands, sea shore and even road sides. Native populations of A. paniculata are spread throughout south India and Sri Lanka which perhaps represent the centre of origin and Sabuhttp://www.blogger.com/profile/05841761784430959893noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-14735722481559478132012-06-08T09:57:00.001-07:002012-07-26T07:33:54.642-07:00Introduction-3
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India is a known mega-diversity centre harbouring a multitude of medicinal plant species each presumably studded with as yet unknown genetic and chemical variations of economic importance. Out of an estimated 17,000 higher plant species occurring in India, more than 1000 species are used over several centuries in the traditional systems of medicine viz.Sabuhttp://www.blogger.com/profile/05841761784430959893noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-74656034305876659122012-06-08T09:53:00.000-07:002012-06-08T10:01:50.830-07:00Introduction-2
Previous page < Introduction
A wide spectrum of simple and overlapping variations is now documented in plants (Sen and Sharma, 1990; Connoly et al, 1994; Stewart and Porter, 1995; Demeke et al, 1996; Sonnante et al, 1997; James and Ashburner, 1997). In general, all observed variations are broadly grouped into two categories: epigenetic and genetic. Genetic variations in Sabuhttp://www.blogger.com/profile/05841761784430959893noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-21188889165138465722006-11-12T01:13:00.002-08:002012-06-08T09:54:40.898-07:00Introduction
Previous page < Introduction
In the wilderness of the tropics, plants grow in extreme situations along longitudinal, latitudinal and temperature gradients and therefore variations within and between populations of a species are not uncommon. Although plants in general show habitat and distribution preferences, there are many a species which are neutral and adapted to other Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-28798261289216232852006-11-12T01:13:00.001-08:002010-10-17T03:36:48.850-07:00Review of LiteratureThe word ‘species’ literally means outward or visible form. It comprises groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups (Mayr, 1940). The Linnaean concept of species as relatively constant unit with most of the variations occurring among them is different from Darwin’s theory of evolution by gradual change, which statesSabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-50909183521096569472006-11-12T01:12:00.001-08:002010-10-17T03:39:32.324-07:00Materials and Methods3.1 Materials
3.1.1 Plant materials
Representative samples of A. paniculata collected from various regions in India and other countries of Asia were used for the study. Seeds from foreign sources were either collected (Malaysia) or received as gift. Four-month-old plants raised through seed propagation and reared under identical conditions served as the source of young leaf tissues used in Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-79921523033065771082006-11-12T01:11:00.001-08:002006-11-12T01:11:41.458-08:00Results 4.1 Germplasm collection Fifty six populations of A. paniculata were sampled (Fig. 4.1; Appendix I) from different geographical regions of tropical Asia. Out of 52 plant populations from India, 28 were from Kerala, 18 from Tamil Nadu, 2 each from Karnataka and Andhra Pradesh and 1 each from Assam and Maharashtra. There were 4 foreign populations, each from Indonesia, Malaysia, Sri Lanka and Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-60360812308860671102006-11-12T01:10:00.001-08:002006-11-12T01:10:56.755-08:00Discussion The prerequisite of any program aimed at studying genetic variations is to understand distribution pattern of the target species (Bothmer and Seberg, 1995). Because the sampling procedures should recover the greatest amount of the genetic variation of the species, irrespective of the relative frequency or rarity of any genes or linked genetic combinations (Bogyo et al., 1980). In the present Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-19084943825762788912006-11-12T01:09:00.000-08:002006-11-12T01:10:01.817-08:00Summary and Conclusion For the biodiversity rich developing countries in the tropics, chemical and genetic prospecting of their plant genetic resources is a priority area not only to fish out genotypes/molecules of potential economic importance but also to add value to them. The present study essentially directed towards this objective, involves analysis of intraspecific variations in Andrographis paniculata Nees (Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.comtag:blogger.com,1999:blog-7406056246132538573.post-83384186431056474652006-11-11T10:54:00.000-08:002006-11-11T10:57:00.962-08:00ReferencesAdams, W.T., D.B. Neale, A.H. Doerksen and D.B. Smith. 1991. Inheritance and linkage of isozyme variants from seed and vegetative bud tissues in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Silvae Genetica 39: 153-167.Ahmad, M and M. Asmawi. 1992. A study of the hypoglycaemic property of Andrographis paniculata Nees. 7th Asian Symposium on Med Plants, Spices and Sabuhttp://www.blogger.com/profile/08478597650715236084noreply@blogger.com