[MPWG] Dr. Leaman' s Question 3 & 4

botresearchusa botresearchusa at academicplanet.com
Tue Feb 3 09:55:57 CST 2004


Question 3:  How can we monitor the long-term result and contribution to conservation of re-introduction / enrichment of populations?   If maintaining or enhancing the production value of a population is an objective, this would be encouraged, at least in the short term, by selecting for desirable qualities, such as root mass, shape, chemical composition, and the result would become evident in a genetic shift in-situ towards these characteristics (unless the process of selection has the perverse impact of diminishing the survivorship/competitive/reproductive advantage) of these individuals and the population overall).  The long-term result, however, has potential to be decreased natural and adaptive genetic diversity in these now-managed populations.  

 

To my way of thinking, monitoring a long term contribution to the conservation of a specie would involve periodic examination of a number of factors and a comparison between cloned and wild populations over a period of years. The first consideration would be that of volume. Is the amount of cloned plantlets sufficient to achieve a reversal in the current status of concern for this specie in the short term. Next I would begin the comparisons between the introduced clones and those which originated in the wild. These comparisons would include rate of growth, seed set, seed weight and volume,  germination rate, root mass, leaf size, inflorescense size, height and width at maturity, chemical composition, and tolerance to environmental changes.I would make these evaluations quarterly over a period of five years.

 

Since in my example we would be dealing with non-selected clones, we should expect little if any variance in our comparisons. If however there was selection for traits, the variance in the comparisons would be greater. This could as you have pointed out result in either a superior or inferior competitive, reproductive, or survivorship rate and could replace the original population or perish and fail to provide the desired increase intended. In plants intended for growing in commercial fields for marketing selection would be desirable, but in those being returned to the wild should not be altered in any way.



Question 4:  Is it feasible to use biotechnology, such as tissue culture, to maintain intra-specific genetic diversity as a primary objective?  Or, assuming that we could document and select for the broad range of existing genetic diversity in a species, might we run the risk of competing with natural selection by working to preserve genotypes that are no longer of adaptive value to a species in nature, however desireable they might be to us as sources of medicine?

 

It is feasible to use tissue culture to maintain genetic diversity but selection does compete with natural selection and may produce desirable results from a chemical standpoint but sacrifice its adaptability and survivability.
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