Monday 21 January 2013


SEED BANKS:


       Did you ever stop to think about what might happen if the crops disappeared? Right now, for example, our wheat supply is dwindling. The world's stockpiles are at their lowest numbers in thirty years. Consumption is exceeding production, and farmers are having a tough time keeping up. But what if it's not? Or, what if a natural disaster wipes out the majority of wheat and other important crops? Scientists think they have hit upon a solution -- seed banks.

Think of a seed bank as a savings account. Seeds are "deposited" into secure storage with the intention of "withdrawing" them in the future when they are needed. Just as you might keep money saved for an unforeseen emergency, scientists are saving up seeds to use for replanting in case certain crops die out or are destroyed. When stored correctly, seeds can remain viable for decades or even centuries.

Case Study of Coleanthus subtilis:


Seed banks may play important roles in conservation of genetic diversity and natural restoration to wetland vegetation as well as to recover endangered plant species. Red data books document extinction and threat of species. The ephemeral species Coleanthus subtilis has not been reported for decades in the vegetation cover of any Austrian habitat. Positive experiences controlling Coleanthus localities documented by older herbarium material generally encouraged the idea to compare (old) herbar material of today highly endangered or extinct plant species with seeds of soil samples collected in corresponding localities. Most of those species, like the ones growing along the shoreline, need unique conditions to survive. Shoreline plants are able to colonize ephemeric semiaquatic environments, That means, conditions alternating between terrestric and hydric (BERNHARDT & POSCHLOD 1993). One characteristic of such plants is their capacity to survive in the soil seed bank during unsuitable conditions. Due to the longevity of seeds, those species remain present for decades (LECK 1989, BERNHARDT & POSCHLOD 1993). Therefore, the soil seed bank contains an important portion of the species diversity as well as the genetic diversity of populations. After its rediscovery the population biology of Coleanthus subtilis was investigated, especially the life cycle, germination, dormancy, presence in soil seed bank and seed bank dynamics.

Result of soil seed bank


We found a number of individuals of Coleanthus subtilis are represented in the soil seed bank. Coleanthus is still living in situ with a high density of seeds in the soil seed bank and it results in a higher appearance of Coleanthus in vegetation cover.

To conclude the study, the investigation shows that species listed as extinct or highly endangered might be recovered in the soil seed bank. This “in situ storage” as seed bank remained in the wetlands is an potential candidate for restoration of genetic variation and diversity of semiaquatic plant species, having high reproduction rates as it is characteristic for colonizing species and they are able to survive for a long time (BERNHARD Tet al. 2004). The reason why they do not grow up is most likely the lack of water level fluctuations (HEINY 1962, 1964, BERNHARDT 1999).

A seedbank stores seeds as a source for planting in case seed reserves elsewhere are destroyed. It is a type of gene bank. The seeds stored may be food crops, or those of rare species to protect biodiversity. The reasons for storing seeds may be varied. In the case of food crops, many useful plants that were developed over centuries are now no longer used for commercial agricultural production and are becoming rare. Storing seeds also guards against catastrophic events like natural disasters, outbreaks of disease, or war. Unlike seed libraries or seed swaps that encourage frequent reuse and sharing of seeds, seedbanks are not typically open to the public.
Stored specimens have to be regularly replanted when they begin to lose viability.
Only a limited part of the world's biodiversity is stored
It is difficult or impossible to store recalcitrant seeds.
There is a need to improve cataloging and data management. The documentation should include identity of the plant stored, location of the sampling, number of seeds stored and viability state. Other information, such as farming systems in which the crops were grown, or rotations they formed, should also be available to future farmers.
Facilities are expensive for third world countries which contain the most biodiversity.
Many of the same issues apply to seed banks as with fallout shelters. With regards to its use as an insurance policy against cataclysmic events, it's highly questionable whether a seed bank would be at all usable in staving off starvation and societal collapse in almost any conceivable situation.

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