Environment of Earth

January 12, 2011

Diversity of domesticated plants

Filed under: Diversity,plants — gargpk @ 8:11 am
Tags:

Plant Genetic Resources: General

Perspective – R.S. Paroda and R.K.

Arora

http://www2.bioversityinternational.org/publications/Web_version/174/ch05.htm#TopOfPage


Summary

The importance of plant genetic resources as basic materials for crop improvement has been highlighted. The circumstances leading to settled agriculture, and the dynamics of plant domestication resulting into changes in plants from wild to cultivated forms has been discussed. A broad picture has been presented on the centres of origin/diversity in crop-plants and recent views on this topic are expressed. The spectrum of genetic diversity covering different categories of genetic resources is indicated. The importance of crop plant diversity for increased food production is stressed, both in terms of its collection and conservation. The concern on genetic uniformity and genetic vulnerability vis-a-vis genetic erosion has been emphasized. Finally, the subject of genetic conservation has been introduced, both for in-situ and ex-situ systems.

Introduction
Change from nomadic life to settled agriculture
Dynamics of plant domestication
Regions of crop plant diversity
Spectrum of genetic resources
Value of crop plant diversity
Threat to genetic diversity
Conservation of genetic diversity
Summary
References
Appendix I. World centres of diversity of cultivated plants (Hawkes, 1983)
Appendix II. Cultivated plants and their regions of diversity (refer Fig. 3)

Plant Diversity in India

Filed under: Diversity,plants — gargpk @ 8:01 am
Tags:

Plant Diversity in the Indian Gene

Centre – R.K. Arora

http://www2.bioversityinternational.org/publications/Web_version/174/ch06.htm

Introduction
Antiquity of Indian agriculture
Indian subcontinent as gene centre
Diversity in other economic plants
Summary
References
Appendix I (a). Crops and areas where rich diversity in landraces and primitive cultivars occurs (Mehra and Arora, 1982; with additions by the author)
Appendix I (b). Rice varieties from Kerala with useful genes (Khoshoo, 1986)
Appendix II (a). Distribution of important wild relatives and related types in different phyto-geographical zones (Arora and Nayar, 1984)
Appendix II (b). Wild relatives and related endemic and/or rare species including endemic cultigens (Arora and Nayar, 1984)

Summary

India is one of the centres/regions of crop plant diversity. It is equally rich, unique and interesting in its floristic wealth. About 15,000 species of higher plants occur, of which over 30 percent are endemic. These also include the wild relatives of crop plants. An effort has been made to briefly deal with the distribution and extent of this diversity located in different phyto-geographical/agro-ecological zones of the country. 166 cultivated plant species, of which about 50 are truly of Indian origin, exhibit rich diversity in this subcontinent. Further, about 320 species of wild relatives of crop plants occur and their distribution and diversity is discussed. Besides, the indigenous diversity in medicinal plants, forest trees, wild forage legumes and grasses, and in native ornamental plants has also been listed, thus pointing to overall richness of plant resources of India. Antiquity of Indian agriculture and its rich heritage, which is even evident today by the prevalence of ethnic diversity and traditional cultivation as in the north-eastern and peninsular regions, has been highlighted. It is pointed out that climate apart, cultural and historical factors have effectively contributed to the introduction of several crops of African, American, European and South-east/East Asian origin. The Indian subcontinent, thus holds prominence as one of ‘the twelve regions of diversity in crop plants in global perspective.