IN-SITU & EX-SITU CONSERVATION

 CONSERVATION OF PLANT GENETIC RESOURCES

Plant genetic diversity is vulnerable to "genetic erosion", the loss of genes and alleles from populations, especially in locally adapted landraces. The replacement of local varieties with modern hybrid varieties and cultivars causes genetic erosion. This is intensified by the emergence of new pests, weeds, diseases, urbanization, and land clearing. 

There are two important methods of conservation.

1) In situ conservation

2) Ex situ conservation.

In situ conservation is the conservation of genetic resources at its original habitat as a natural population. An organism is conserved in the same area where it is naturally found. Examples are

Biosphere reserves, National parks, Wildlife Sanctuaries, and Biodiversity hotspots.

Biosphere reserves cover very large areas, more than 5000 sq. km. Currently, India has 18 BRs. Eg: Sundarbans (WB).

National Parks are regions that cover 100 to 500 sq. km. There are 103 NPs in India. Eg. Kaziranga- Assam- One Horned Rhino.

Wild Life Sanctuary- Aimed to conserve animal diversity, usually in small areas. There are 551 WLS in India. Eg- Aralam WLS - Malabar Civet.

Biodiversity hotspots - These are regions with at least 1500 vascular plants as endemics and 70% of the original habitat is lost. There are currently 36 hotspots all over the world, out of which 4 are in India. Eg: Eastern Himalayas, and Western Ghats.

Ex situ conservation

It is an 'off-site' conservation, in which an endangered species is protected outside its natural habitat, by removing or transferring the species from a threatened habitat. Botanical gardens, Zoos etc are examples. Lalbagh Bangalore, Royal Botanical Garden, Kew, etc.

Cryopreservation is another method of ex-situ conservation, in which seeds, pollen, tissues, and embryos are conserved in liquid nitrogen. 

Seed banks are also considered  as ex-situ conservation, in which dried seeds are stored in glass vessels or paper covers in a systematic manner.