The National Gene Bank

The Directorate Genetic Resources is concerned with the conservation of genetic resources for food and agriculture, genetic resources being any plant or animal material containing genetic information (DNA) that can be conserved. It is a global concern that biological diversity is being significantly reduced by human activities such  as :

	Destruction of natural habitats
	Over-exploitation
	Introduction of exotic species
	Changes in agricultural practices
	Natural / manmade calamities

All of the above might have caused approximately 25-35 % of genetic diversity to have been lost by the year 2000. 

For this reasons it is necessary to conserve genetic resources. This can be achieved using three methods:

1. In situ—nature reserves

2. Ex situ—more applicable for agricultural crops and can be done in 2 basic ways depending on the seed characteristics of the specie concerned

   Moisture reduction sensitive (recalcitrant seeds)—field gene bank

   Moisture reduction non-sensitive (orthodox seeds)—seed gene bank

3.   On-farm—conserving locally developed traditional crops by small-scale farmers using traditional agricultural systems.

The science of long-term seed storage is based on the combined reduction in seed moisture and temperature. In order to store the highest quality of seeds a precise gene banking has to be adhered to. 

The National Gene Bank is mainly concerned with ex situ conservation in a seed gene bank of the following mandate species:

	Indigenous crops of the region such as sorghum, millets, cowpeas, cucurbits, bambara nuts, traditional vegetables and their wild relatives.
	Utilised wild and weedy plant species such as medicinal plants.
	Introduced crops such as maize, rice, cassava, sweet potato and beans that have become adapted to the region.

COLLECTION 

The National Gene Bank has done extensive collections of landraces in the former homelands of Venda, KwaNdebele and Gazankulu. The National Gene Bank conserves over 1000 landrace accessions of mainly the following species: