iris@hort.net
- Subject: Re: Semi-Dormant / Hard Dormant etc.
- From: i*@aim.com
- Date: Tue, 02 Feb 2010 23:56:16 -0500
There is additional evidence that auricantiaca is a hybrid, besides the
two significant traits in heterozygous state. It hasn't been found in wild,.
Generally accepted as being a hybrid.
While a dormancy gene could indeed beB modified to form a "evergreen gene",
that is a nonfunctional dormancy gene, all the evidence in crosses with
evergreen X dormantB so far indicatesB thatB evergereens seem to always
contain a dormancy gene.
It doesn't make biological sense that a single plant in a series of plants
(Hemerocalis species) would have anB "evergreen" gene. A gene that would not
add any biologicalB benefits, and a number of disadvantages.B B In all other
plants evolved in a climate near to frost areas would then have compensatingB
biological functions, such as a high tolerance of frost. Evergreen dayliliy
foliage would seem to be very vulnerable to frost damage.
With the senerio you suggest, there would indeed be some evergreens that are
homozygous for this gene.B If this condition shows up it would present
problems for this theory.
So if you see any examples, that seem to be homozygousB for "evergreen", let
me know. In the meantime I'm continuing my research.
Chuck Chapman
-----Original Message-----
From: gerrit snoek <gjsnoek@gmail.com>
To: dayliliesfornorthernclimates@yahoogroups.com
Sent: Tue, Feb 2, 2010 4:05 pm
Subject: Re: [dayliliesfornorthernclimates] Re: Semi-Dormant / Hard Dormant
etc.
B
Chuck,
B
Just throwing this out here: if there is no evergeen gene per se could not
the evergreen condition be a consequence of the ABSENCE or perhaps also a
downregulation of a domancy gene?
B
Also, I do have certain reservations on your axiom that if a plant is
heterozygous for a certain trait it cannot be a species - in this particular
case the absence of a dormancy gene would much better fit the inheritance
decribed.
B
Just wondering,
B
Gerrit Snoek
The Netherlands
B
Where we have just cleared the first January with a negative average
temperature in 13 years!
Scoring cold climate points here.
2010/2/2 <irischapman@aim.com>
This is a situation where Lang's definitions ofB dormancy gets us into
difficulties. As Ecodormant is basically the same as quiescence it presents
problems as all daylilies are "Ecodormant" during winter based on the winter
observations.
Quiescence is the non growth of plantsB because the conditions theat enable
biological process enabling active growth is absent.B Thus using the term
EcodormantB would mean that evergreen daylilies are "dormant", thus all
daylilies are dormant.B This usage definitely willB confuse discussion and
drive everyone crazy
I prefer saving these terms for scientific discussion and using the more
generic terms dormant and non-dormant in daylily discussions.
On this basis we have
1) "Anticipatory" dormants that go dormant with three days in a row with min
temperature of 9C or lower. They come out of dormancy with three days in a row
with minimum temperature above 11C or higher. As plants we see these go
dormant early and come out of dormancy latest.B There very likely is several
groupings of these with different onset temperatures and different break
dormancy. They don't start growing in spring when there is suitable growing
temperatures, until theB 'break dormancy' temperatures occur.
B B B B B B With these plants you can have a start of dormancy followed by
a 'Break dormancy'B temperature in fallB resulting in them starting to grow
before onset of winter. This will show as outside leaves being dry andB a
burst of green growth in centre of clump.
B B B B B B B If onset of frost occurs before the 'Start dormancy' signal
arrives then they will,B at that time, be indistinguishable from evergreen or
semi-evergreen. There would seem to be some climates where this occurs
regularly. This may interfere with how they form dormant buds.
B B B B B B In warm climates, such as central Florida, they can (and do, as
I have checked temperature for area around Orlando Florida) get 'onset
dormancy' trigger in mid November. With central Florida,B temperatures low
enough toB trigger onset of dormancy can also occur with high daytime
temperatures Thus you can see the plants going dormant while daytime
temperatures can be be in 80's, Fahrenheit that is. This has been referred to
as "photoperiod" triggered dormancy, but obviously isn't so as onset of
dormancy is dependent on temperature , and not photoperiod. It occurs at
different times in different locals.
B B B There is aB secondary factor affecting onset of dormancy. That is
plant growth hormone, gibberellin acid. That is if a plant is in active growth
in the fall, then the plant will not react normally to 'onset dormancy'
trigger. This shows in two basic conditions. First year seedlings are usually
in active growth in their first year, and are delayed in there 'onset
dormancy'B reactions. thus first year seedlings just can't be evaluated
properly as to their dormancy type. This has been noticed by a number of
Northern hybridizers, and I have observed it myself.
B B B B B Another time when this occurs is when plants have been
transplanted late in theB growing season. I certainly have seen this a number
of times, where the same cultivar that hasn't been moved is going dormant,
whileB another piece of the same cultivar transplanted late, is still very
green for some time. This probably prevents plants that have started growing
in the spring from going dormant during a cool spell.
B B B B B B In practical terms, it means that Florida hybridizers, that
divide and move their new introductions in the fall, need to have evaluated
dormancy in a season where there isn't late dividing, as otherwise the plants
won't their true dormancy. Thus a number of Florida plants classified as
evergreen or semi evergreen, that are actually "anticipatory" (hard dormant)
as they were evaluatedB as to type onB registration, after a late move.
B B B B B B
B B B B Dormancy bud would appear to be underground.
2) "Reactive " dormants. Onset of dormancy would appear to be very low
temperatures or perhaps even freezing temperatures.B More data needs to be
gathered on this. After onset of dormancy theyB don't grow until they hve
undergone a resting period (perhaps a cold resting period) . This would seem
to be about 6 weeks. Before they have had their resting period, they won't
grow in warmer temperatures. So if they are potted up and brought indoors,
they won't start growing immediately, as the "anticipatory" dormants do. In
spring they will have had their necessary resting period and will start
growing as soon as temperatures are suitable to enable growth. They will start
growing at same time as , or shortly after evergreen daylilies start growing.
B Resting buds may very well be at or slightly above ground level.
3) Non-dormants. Classified as evergreen or sometimes semi-evergreen. these
plants will try to grow at any time that temperatures are suitable. No need
for resting period or need for 'break dormancy' signal.
B B WhileB they are not growing duringB adverse or unsuitable growing
conditions, I would call this a "quiescent" state rather then a dormant, as in
"Eco-dormant" state, as this is a confusing use of the termB "dormant" for
the general daylily grower.
B No resting or dormant bud under any conditions. A new shoot that hasn't
started growingB will show as a bud, but after start of growth, no resting or
dormancy bud.
B B Possibly starts growth slightly before "reactive dormants" , but more
observations needed.
Photoperiod DormantsB Theoretically these should exist, and if they do, they
are a third type of dormant daylilies. After a long search for these by myself
and others, there so far have not been any daylily cultivar of speciesB that
is clearly triggered into dormancy by short day (or long night). AllB
cultivars that have been suggested to be photoperiod dormant would appear to
be "anticipatory dormant" The search continues.
GENETICS
The only 'species' daylilies that are evergreen are auticantiaca and
auticantiaca Major.B Dr. Stout did a lot of work with auticantiaca and was
very clear that it was heterozygous for both 'Fulvous" andB "evergreen"
trait. Thus very clearly not a genuine species but an interspecies hybrid. In
any cross of auticantiaca to a dormant, both dormants and evergreen
seedlings.B If the evergreen characteristic of auticantiaca is a mixed
dormancy gene effect, as I have speculated, then in diploids, it doesn't
matter which type of dormant is crossed with an evergreen diploid. Half of the
offspring will be dormant, and half evergreen. Of course this is based on
seeds having proper stratification Cold period). I say this as I have a
sneaking suspicion, that the seeds requiring stratification before
germinating, are the "reactive dormant" seedlings. I say this as the "reactive
dormant" cultivars need a resting period before breaking dormancy. This is
something that needs to be put to the test.
B B B B B B As, according to this theory, there is no "evergreen" gene, it
can't be either recessive or dominant.B One could call the "evergreen
condition" a dominant condition, as in actually both of the recessive types
are recessive, but not compatible with each other.B Thus any combination of
heterozygous dormancy genes will result in the "evergreen" or non-dormant
state, as neither dormancy gene is in the homozygous (all the same) that is
necessary to work, that is be dormant , or react to the triggers needed to
produce dormancy.
B B B B B B Crossing two similar dormants to each other will produce all
dormants of that type. Crossing two different dormants to each other will
produce all evergreen plants. ( some people have spoken of this, but when
asked about itB have not been able to provide details). Crossing a dormant to
an evergreen will produce dormants.(many reports of this)B With diploids this
will be 50%, but with tetraplois, will depend onB dormancy genetics of the
tetraploid. Tets may very wellB have three genes of one type of dormant and
one of the other. So outcome will depend on which type of dormant is crossed
to it.
B B B Crossing two evergreens to each other should produce some dormants,
and reports suggest that this does indeed happen.
B B B Part of this theory would say that as there isn't an "evergreen" gene
that therefore there would not be any plants that are homozygous "evergreen"B
So the existence of a homozygous evergreen would present a problem for this
theory.
A long post. But important information for consideration. Of course this
theory so far is development stage so will likely have to undergo some
revisions as relevant data is gathered.
Chuck Chapman
-----Original Message-----
From: Sue B <daylilyss@yahoo.ca>
To: dayliliesfornorthernclimates@yahoogroups.com
Sent: Mon, Feb 1, 2010 10:04 am
Subject: Re: [dayliliesfornorthernclimates] Re: Semi-Dormant / Hard Dormant
etc.
B Hi Chuck and All,
irischapman@aim.com wrote:
So wouldn't your "anticipatory dormants" be what is classified as
ecodormant in current (Lang) dormancy terminology, and "reactive
dormants" would be endodormant?
> So far it would appear to me that the evergreen daylilies are ones with
> a mix of different dormancy
> genes such that neither set can properly act to enable either type of
> dormancy.
How might this fit in with Stout's observation that evergreen is
"decidedly dominant over the dormant habit"?
Sue B
nr. Ottawa, USDA Zone 4
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