Ex situ conservation of rare and valuable forest tree species through seed-gene bank

Abstract

There is growing concern throughout the world about the uncontrolled exploitation and depletion of the earth's natural resources, especially affecting the plant biodiversity of tropical forests. The extinction potential of a species is related to the degree of its biological vulnerability and the degree of threat by biotic and abiotic factors. Therefore, the need for conservation is exceptionally high and of paramount importance to preserve this plant heritage for posterity. One of the most effective biological techniques to conserve this biodiversity is the establishment of gene banks, i.e. ex situ conservation. Conventional seed storage is believed to be a safe, effective and inexpensive method of ex situ conservation of plant genetic resources, which not only maintains its viability but also its vigour without hampering the genetic makeup. The elucidation of various factors that regulate seed viability and vigour in storage is essential. An ideal condition to prolong the seed longevity is mainly dependent on seed moisture content, temperature and type of container used during storage. The optimum stage of seed maturity, seed-lot quality, their processing and harvesting techniques, germination eco-physiology and degree of dormancy too play a crucial role in maintaining seed longevity that need to be considered before large-scale seed storage is initiated. The present review is an attempt to discuss the importance of the aforementioned aspects of forest tree seeds in detail, to conserve their germplasm for ex situ conservation through seed-gene bank.