Introduction to seed banks:
Seed bank can be defined as:
‘Seed banks are simply a source of conservation of different species of seeds in order to restore their population by using natural or artificial methods’.
All over the world people are so conscious about the uncontrolled exploitation and depletion of natural sources. Through Seed banks we are able of storing plant genomes of some specific and important plants in the form of seeds, as it is an important source of restoration of ecology. As restoration of ecology is the re-establishment of those plant species which have disappeared. The re-establishment of plant species can only possible if their seeds are persisted in soil as a memory of old plants.
How seed bank culture started?
A brief history of seed bank culture is as, seed bank idea was given by Charles Darwin in 1859. He took a small quantity of mud from a lake bank. He stored that mud in a cup and after some time period he observed that a large quantity of plants had been grew there. After his observation many of scientist search that what had happen? And that can be made more crucial and beneficial.
Types of seed bank:
There are two major types of seed banks, which are characterized on the basis of preservation techniques.
‘ Natural seed banks.
‘ Artificial seed banks.
Natural seed banks:
Natural seed banks are just as soil seed banks. As through its name we can have an idea that natural seed banks are those in which seeds are stored or buried naturally due to some natural environmental factors like succession (both primary and secondary). Seeds that are being stored naturally they go to dormancy.
Natural storage of seeds mainly depends upon seed longevity. And longevity is simply that time period to which seed remain able to re-germinate. According to longevity (preserving time period) character of seed following types of seeds found there.
‘ Transient seeds:
Those seeds which remain capable to re-germinate even after a longer period of one complete year are called as transient seeds.
‘ Persistent seeds:
Those seeds which remain capable to re-germinate even after a longer period of time.
‘ Short term persistent seeds:
Those seeds that must germinate within one to five years, otherwise they become useless are called as short term persistent seeds.
‘ Long term persistent seeds:
Those seeds that can re-germinate even after more than five years are called as long term persistent seeds.
Some important features of natural seed bank:
‘ Mainly the success of natural seed bank depends on which types of seeds are buried in specific unit area. (Transient, or persistent).
‘ Capacity of seed to bear the unfavorable conditions when it is dormant.
‘ Seed association with ecosystem processes.
Artificial seed banks:
Artificial seed bank is the storage of seeds following artificial steps which may be physical or chemical. Artificial seed storage takes place in laboratories are specially established areas.
For making seed storage successful many new skills are produced that increase the grower’s capacity to make sure the desirable characteristics are present, so that less plants are to be grown that will save the inherent genetic characteristics. Care is necessary as training materials such as the productions of seeds cleaning, storage and maintenance make land victors diverse, stable and more uniform which lost the adaptive characteristics that are valuable.
Method of Artificial seed banking:
‘ First step is to clean the seeds after their collection. This cleaning and drying is done by simply using tissue paper or by using desiccators.
‘ Second step is to kept them in safe place. Or bag where moisture can’t affect them.
‘ If we want to preserve seeds for a long time, safe them in a cool place where the temperature remain constant. Constant low temperature inhibits the activity of enzymes within the seeds and hence inhibiting their germination.
‘ Seeds must be stored in an air tight flask, to avoid moisture. We can also use dehydrating agents to keep seeds dry.
‘ Label all the jars containing seeds. Each jar with its specific seed specie name.
‘ While collecting the seeds from fruits, collect seeds from the most ripen one.
How do artificial seed banks keep their seeds safe?
On the basis of their preservation requirements seeds are divided into two classes;
These seeds can be stored by freezing them up to 180C and drying up moisture. They can be replanted after decades but after a specific time their DNA is destroyed.
Such seeds which cannot be kept at freezing temperature because their DNA is demolished at freezing temperature so they are kept in a cool place but not frozen.
The Svalbard Global Seed Vault is major depository.
Significance of seed banking:
The goal of seed bank is to maintain the seed in better physical and physiological conditions from that time when they are garnered and to the time when they are planted to the soil.
Seed banks are becoming so common and important day by day in our ecology. These are a very easy and effective source of preserving ecologically important species. Sometimes soil seed banks re-invent those plant species which we thought had been extinct from a certain area.
In old days, seed banks were used to conserve seeds from animals’ attacks and severe climate. But nowadays the most crucial reason is crop diversity. As humans plants also have genetic variability. So, that genetic variability must be unspoiled. This can be do so with the help of seed banking culture.
We also store seed due to climate changes natural disaster, to avoid some mortal disease.
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