Re: HYB: daylength vs temperature & bloom initiation

From: "David G. Holm" <sherlock@amigo.net>

On 5 Apr 99, at 13:35, Donald Eaves wrote:

> Would your following comment be acclimatization?  For how long
> would the memory last?  One season, two?  I know this is unlikely
> to have a definitive answer.  Your best educated guess?
 
Donald, I would say that the "memory" that I was referring to probably
does not last more than one season.  In other words, 1998's growing
season conditions, will have some influence on 1999's plants.  I
doubt that the influence would carry on, at least to any significant
amount into 2000.


> Is memory contained in the seed along with genetic factors?  Or does
> germination and current growing conditions determine the memory 
> aspect?

Perhaps this would be a good place for a brief short course dealing with 
genetics.  The phenotype (P - the plant we observe growing in the garden) 
is the result of the genetic make up of the plant (G) plus the influence of the 
environment (E) on the plant plus the interaction of the genetic component 
and the enviornmental componet GxE or P=G+E+(GxE).

A generalization would be that plants have two forms of memory (G and E). 
The genetic memory (G) is long term memory or the genetic makeup of the 
plant.  This doesn't change unless a mutation occurs.  The environmental 
memory (E) is short term and does change from year-to-year.  The 
environmental determines whether the plant in the current growing season 
has good or bad "memories" of the previous season.  

You mentioned acclimatization.  Both genetics and environment impact how
well a cultivar acclimates.  Some cultivars acclimate very well over several
differing environments.  This is probably the result of good genetics. Other
cultivars have to be pampered.  This is where we have to know the cultual
management tricks to facilitate those hard to grow cultivars.  Here we are
playing with the environmental componet.


   Would growing from seed be likely to enhance genetic
> factors already present to create better odds for survival than
> transplanting
> and do vegetative increase acquire memory foreign to the mother plant?

If I understand your question correctly, my response would be that growing 
from seed or from transplants does not change the genetic factors and 
ultimate survivability.  In other words, I believe that there is a poor 
correlation between survivability of plants from seeds germinated under poor 
conditions versus those produced under favorable conditions.  Otherwise, 
germinate seed under the best possible conditions and have more to plants 
to select from later.

Lastly (again I am not sure I understand your question),  vegetative 
increase from a mother plant cannot acquire foreign "memory".  However 
the genetic component, or long term memory,  of a vegetative increase 
could change if a mutation were to occur.

Dave


Dave Holm
Professor of Horticulture (Potato Breeding)
Colorado State University
sherlock@amigo.net

------------------------------------------------------------------------
Have you visited our new web site?
http://www.onelist.com
Onelist: Helping to create Internet communities
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index