BC Growers Association

Colchicine





General notes and posts

Induction and Recognition of Polyploidy - by Wright

The Induction of Polyploids - by Watts



General notes and posts



Colchicine Information



Posted by PAXCO on March 21, 1999 at 11:41:04:



Polyploidy (favorable traits in Cannabis) has not been shown to occur naturally in Cannabis; however, it

may be induced artificially with colchicine treatments. Colchicine is a poi- sonous compound extracted

from the roots of certain Colchicum species; it inhibits chromosome segregation to daughter cells and

cell wall formation, resulting in larger than average daughter cells with multiple chromosome sets. The

studies of H. E. Warmke et al. (1942-1944) seem to indicate that colchicine raised drug levels in

Cannabis. It is unfortunate that Warmke was unaware of the actual psychoactive ingredients of Cannabis

and was therefore unable to extract THC. His crude acetone extract and archaic techniques of bioassay

using killifish and small freshwater crustaceans are far from conclusive. He was, however, able to produce

both triploid and tetraploid strains of Cannabis with up to twice the potency of dip- bid strains (in their

ability to kill small aquatic organisms). The aim of his research was to "produce a strain of hemp with

materially reduced marijuana content" and his results indicated that polyploidy raised the potency of

Cannabis without any apparent increase in fiber quality or yield. Warmke's work with polyploids shed

light on the nature of sexual determination in Cannabis. He also illus- trated that potency is genetically

determined by creating a lower potency strain of hemp through selective breeding with low potency

parents. More recent research by A. I. Zhatov (1979) with fiber Cannabis showed that some

economically valuable traits such as fiber quantity may be improved through polyploidy. Polyploids

require more water and are usually more sensitive to changes in environment. Vegetative growth cycles

are extended by up to 30-40% in polyploids. An extended vegetative period could delay the flowering of

polyploid drug strains and interfere with the formation of floral clusters. It would be difficult to determine if

canna- binoid levels had been raised by polyploidy if polyploid plants were not able to mature fully in the

favorable part of the season when cannabinoid production is promoted by plentiful light and warm

temperatures. Greenhouses and artificial lighting can be used to extend the season and test polyploid

strains. The height of tetraploid (4n) Cannabis in these exper- iments often exceeded the height of the

original diploid plants by 25-30%. Tetraploids were intensely colored, with dark green leaves and stems

and a well developed gross phenotype. Increased height and vigorous growth, as a rule, vanish in

subsequent generations. Tetraploid plants often revert back to the diploid condition, making it diffi- cult to

support tetraploid populations. Frequent tests are performed to determine if ploidy is changing. Triploid

(3n) strains were formed with great difficulty by crossing artificially created tetraploids (4n) with dip- bids

(2n). Triploids proved to be inferior to both diploids and tetraploids in many cases. De Pasquale et al.

(1979) conducted experiments with Cannabis which was treated with 0.25% and 0.50% solu- tions of

colchicine at the primary meristem seven days after generation. Treated plants were slightly taller and

possessed slightly larger leaves than the controls, Anoma- lies in leaf growth occurred in 20% and 39%,

respectively, of the surviving treated plants. In the first group (0.25%) cannabinoid levels were highest in

the plants without anomalies, and in the second group (0.50%) cannabinoid levels were highest in plants

with anomalies, Overall, treated plants showed a 166-250% increase in THC with respect to controls and

a decrease of CBD (30-33%) and CBN (39-65%). CBD (cannabidiol) and CBN (cannabinol) are

cannabinoids involved in the biosynthesis and degrada- tion of THC. THC levels in the control plants were

very low (less than 1%). Possibly colchicine or the resulting polyploidy interferes with cannabinoid

biogenesis to favor THC. In treated plants with deformed leaf lamina, 90% of the cells are tetraploid (4n

40) and 10% diploid (2n 20). In treated plants without deformed lamina a few cells are tetraploid and the

remainder are triploid or diploid. The transformation of diploid plants to the tetraploid level inevitably

results in the formation of a few plants with an unbalanced set of chromosomes (2n + 1, 2n - 1, etc.).

These plants are called aneuploids. Aneuploids are inferior to polyploids in every economic respect.

Aneu- ploid Cannabis is characterized by extremely small seeds. The weight of 1,000 seeds ranges from

7 to 9 grams (1/4 to 1/3 ounce). Under natural conditions diploid plants do not have such small seeds

and average 14-19 grams (1/2- 2/3 ounce) per 1,000 (Zhatov 1979). Once again, little emphasis has

been placed on the relationship between flower or resin production and poly- ploidy. Further research to

determine the effect of poly- ploidy on these and other economically valuable traits of Cannabis is

needed.

Colchicine is sold by laboratory supply houses, and breeders have used it to induce polyploldy in

Cannabis. However, colchicine is poisonous, so special care is exer- cised by the breeder in any use of

it. Many clandestine cultivators have started polyploid strains with colchicine. Except for changes in leaf

shape and phyllotaxy, no out- standing characteristics have developed in these strains and potency

seems unaffected. However, none of the strains have been examined to determine if they are actually

poly ploid or if they were merely treated with colchicine to no effect. Seed treatment is the most effective

and safest way to apply colchicine. * In this way, the entire plant growing from a colchicine-treated seed

could be polyploid and if any colchicine exists at the end of the growing season the amount would be

infinitesimal. Colchicine is nearly always lethal to Cannabis seeds, and in the treatment there is a very

fine line between polyploidy and death. In other words, if 100 viable seeds are treated with colchicine and

40 of them germinate it is unlikely that the treatment in- duced polyploidy in any of the survivors. On the

other hand, if 1,000 viable treated seeds give rise to 3 seedlings, the chances are better that they are

polyploid since the treatment killed all of the seeds but those three. It is still necessary to determine if

the offspring are actually poly- ploid by microscopic examination. The work of Menzel (1964) presents

us with a crude map of the chromosomes of Cannabis, Chromosomes 2-6 and 9 are distinguished by the

length of each arm. Chromo- some 1 is distinguished by a large knob on one end and a dark chromomere

1 micron from the knob. Chromosome 7 is extremely short and dense, and chromosome 8 is assumed to

be the sex chromosome. In the future, chromosome *The word "safest" is used here as a relative term.

Coichicine has received recent media attention as a dangerous poison and while these accounts are

probably a bit too lurid, the real dangers of expo- iure to coichicine have not been fully researched. The

possibility of bodily harm exists and this is multiplied when breeders inexperi- enced in handling toxins

use colchicine. Seed treatment might be safer than spraying a grown plant but the safest method of all is

to not use colchicine. mapping will enable us to picture the location of the genes influencing the

phenotype of Cannabis. This will enable geneticists to determine and manipulate the important

characteristics contained in the gene pool. For each trait the number of genes in control will be known,

which chromosomes carry them, and where they are located along those chromosomes.

PAXCO



Author: ike loan

Subject: Colchicine Information

Description:

good post, cant remember where i got mine from, i tried it about 10 years ago, its available in a pill

used to treat gout. thats what i used and i treated over 200 good seed with it. i got 15 or so to sprout

and was real happy about that. but as they grew they were horrible looking mutants. one had leaves

growing almost sideways and most were twisting and contorting. i think i wound up with 3 that didnt

die. after 3 months of growing them i got rid of them, i didnt have any that had the favorable

characteristics i had read about, and since its so poisonous i was a little worried about an adverse

reaction in some way... im sure if i had continued i would have came up with some with super growth

and yield. the possibilites exist to mutate the common dipliod cannabis and develop a super

strain.that might grow very fast produce more branchs, and much higher yeilds and the plant might

be indistinguishable from the normal looking cannabis. thanks and keep up the good work... ike





Author: the Fool

Subject: Colchicine Information

Description:

About 25 years ago, when "head shops" were the rage, a bud and I bought a book about growing. We

set up a couple of shop floros in a closet over 3 gallon buckets of SuperSoil as suggested in the

book. Lights were left on 24/7 and we smoked the leaves. The book never even explained how to

flower. The first batch was like hay. The book also talked about soaking seeds in Colchicine derived

from the Autumn Crocus. It's readily available at nurseries in the month of September. We bought a

bulb, squeezed it in a garlic press, added a little water and soaked the seeds. The result was the

best smoke that he and I ever remember. And it was just leaves! Cloned a closet full of the best plant for

each of us and kept the plants going for at least a year. We are convinced that the difference was the

Colchicine but it could have just been an excellent seed to start with. Wish I knew then what I know

now so I could report on the flowers but I can't.



Author: cowboy

Subject: Introduction

Description:

hi guys,i was once 13 and first trying my hand at growing,but that was more than 25 years ago. and i

must add im slightly burnt but still smokin,ha ha.you guys just hang in there were your at and youll do

fine.dont take any b.s. about being to young to do what your doing,age is a frame of mind.i for one am

glad to see some young dudes in here.and the comment about the older angry guys gave me a

pretty good chuckle.you young dudes seem to have hit the nail right on the head(mine included).in the

days when i started, my first grow manual was a hand me down from one of my brothers,it was

basically in cartoon form and was one that dealt with colchicine and grafting MJ onto hops,things

have come a long way,and i believe with young and old blood mixing here things will go a lot farther than

i could have ever imagined.i guess they already have.well this ramble was caused by the good

feeling i got when i read you young dudes post.if i can ever help just let me know.thanks for the

memories. later cowboy



Author: ike loan

Subject: Getting supplies?

Description:

never needed em but, you can make your own colchicine . like this, colchicine is derived from

bulbs of the winter or autum crocus[colchicum]. mash the bulbs and add an equal part of water.

strain through coffee filters or paper towels. soak seeds in the solution and plant when they start to

germinate.cultivate as usual. only some of the seeds will become polyploid. polyploids generally have

thicker stems, and the leaves are often unusually shaped, with uneven sized blades or more blades

than usual. as the plant grows leaves should return to normal but still have larger and with more blades..

the above was copied from the book mj growers guide by frank . it also says it cannot guaratee one

can safely smoke colchicine treated plants as it is highly poisnous. as for g.a. i read you could get that

stuff at a nursery. ive never used it though its poison too.. hope someone else can help you with it.

p.s i think you can get the col. at nurseries too.

peace



Cochesene toxicality

Posted by ChronX on December 19, 1998 at 16:39:05:

i have heard that the use of the chemical "colchesene"in the forks betwen leaves and soaking seeds in it gives the

plant a poly-ploid structure instead of bi-ploid.the catch is that the 1st generation is toxic. i think that the 2nd is

too but i cant remember. anybody know?





Re: colchicine toxicity by Kohala

on December 19, 1998 at 18:23:14

Colchicine itself is extremely toxic, but it does not make the plant treated toxic. There is no literature available that

I am aware of that describes work done with this chemical on cannabis. Colchicine is used to create polyploidy in

many other plants and the result is often bigger yield, and bigger fruit and flowers.





Re: Cochesene toxicality by loki

on December 19, 1998 at 17:52:09

The substance I believe you are reffering to is an alkaloid called colchicine.Colchicine is extracted from the autumn crocus and is approximately 5 times as toxic as potassium cyanide.

One of the more interesting sidelines of this substance is that it serves as a mutagen when applied to cannabis seeds.

The mutation usually attributed to colchicine treatment is a marked increase in potency. Whether this is true or not is yet to be conclusivley proven.

The story goes, the U.S govt. was experimenting with improving known hemp strains when they noticed THC. present in plants treated with colchicine!This might just be folk lore but this is what I've read.

What I do Know is that colchicine is EXTEMELY toxic and not worth screwing with unless you really know what you are doing. There are already a ton of good kickass strains available don't fix 'em if they ain't broke.





Re: Cochesene toxicality by Chronic Cough

on December 19, 1998 at 22:45:48

Polyploidy in marijauna plants is not stable. Polyploidy is when the cells contain extra chromosomes. Diploid is

the normal state that occurs in marijuana plants(one set of chromosomes from the male pollen and one set from the

female pistil). Colchicine is poisonous and should be handled carefully. It will cost $35/gram. If you treat 1000

seeds with colchicine and 10 germinate, they will probably be polyploid. In other words, this substance is more

likely to kill your seeds than to make them any better. Polyploid plants may or may not pass on this trait. I have

read many sources that say seeds from these plants will be normal, but many say they will be like the mother

plant. These plants will often have extremely abnormal leaf formation and will have thicker stems. As to making

the plant more potent...who knows. Look on the net. Search "Colchicine" and "Marijuana"- you can view the

OPINIONS of other people.

Also, colchicine is a treatment of gout(in small amounts). In concentration it would be a good idea to wear latex

gloves to prevent absorption through the skin. Do I have to say birth defects?

Dont high with poisons play when!!





=========================================================================



Time 15:03, 3 Apr 1998

From Mr. Two-Footer (mrtwofooter@yahoo.com)

Does anyone know: Is it worth poisoning my first generation with colcichine (to

disable the meieotic spindle apparatus) to create polyploid plants (sometimes called

"Gold" varieties) or is this just a waste of a generation (since you can't smoke

colcichine-poisoned plants)?If anyone has tried this I would be very interested to

know their results.

========================================================================







Time 10:24, 5 Apr 1998

From insider





Can anybody here relate to 25 mg of colchocine in 100 cc water, soaking a seed that

had sprouted the previous day, and soaking for about 6 hours.If memory serves me

right, that produced good crop of what I think was a potent polyploid that was some

of Konas finest in the mid 70's.I'm back, and interested in swaping botantical info

and getting in tune with what is going in in genetics.









Time 11:47, 5 Apr 1998

From insider

uncle Joe:

Colchicine is a chenmical that inhibits cell division, but allows chromososmes to

multipily.Orchid growers in the past, when I grew, used it to play with genetics, it is

like throwing the dice, one never knows what will result.

Years ago I had heard that some growers were painting colchicine in matu5e

flowering plants, and then not using that plant, but letting it go to seed and planting the

seeds.

I knew no one with real botanical knowledge, purchased some colchicine under

disguise as orchid grower, and tried the (if memory serves me right) the 25 mg in 100

cc of water for about 6 hours, diring which cell devision is haulted, but chromosomes

will divide.

The produce was killer, had about half dozen plants, and it was one hit la la land.I

just for friends, lived in Kona, non commercial.I moved and have not been able to

grow for many years, am now interested in using, I am in need of medical use, so am

joining revolution. I would guess colchocine is a controlled substance, but available

through chemical wearhouse and school labs.Cost in 70's was abut $40 a gram.

Research in any university libraty will yiels all necessary information, I wlll search on

net and get back, no library here.

Also, know of any chemical that will keep deer from a pach?I have heard pool

chlorine, mothballs, any info appreciated.





Time 13:05, 5 Apr 1998

From Occam's Razor

In 1993 Colchicine was available for $6.80/100mg. at my favourite

micropropagation supply house, however access was limited to professionals, and

occasionally students and others who had legitimate uses for it.

You can make your own colchicine by crushing the bulbs of Colchicum

autumnale,(the plant that the chemical is obtained from) commonly known as the

autumn crocus or meadow saffron, in a garlic press and collecting the juice. The % of

colchicine will vary with the time of year, plant genetics, and environmental factors,

but diluting one part bulb juice to three parts distilled water should get a solution

strength of ~.05%, about ideal for use as a mutating agent.

Colchicine is VERY toxic, wisdom should govern it's use, WEAR RUBBER

GLOVES WHEN HANDLING!

grovver

posted September 05, 1999 08:31 AM

Does anybody know anything about KOLCHICIN, it is a poison. But applyed on seeds in some ratio in water

for few hours makes them to mutate.

The result is a very potent plant, more likely the first generation is used as a seed producer, the second

generation is prodicing smokeable budz, though the first generation is SAFE to smoke....

Another sign of mutated seeds many bladed leafs, up to 17 blades!!!



Vic High

posted September 05, 1999 09:57 AM

Easiest way is to plant some fall purple crocus bulbs. Then squash the bulbs and soak your seeds in the

juice. All natuaral colchicine!! Or you can pretend you have gout and get a prescription from the doc.

But only do this with seeds you don't need, to be effective, the cochicine is reported to need to be strong

enough to kill most of the seeds. Something like 1 in a 100 or 1000 will survive. Of the survivers, it's a crap

shoot whether or not the mutation was a good one.

If you want more, check out the weedbase search that is featured here. Try various spelling for cochicine

though, we all seem to spell it differently cholchicine, colchicine, cholcine, kolchicine, etc, haha



iibro

posted September 10, 1999 01:21 AM

there is some good reading on this subject in a book i bought quite a while back called the cultivator's

handbook of marijuana by bill drake. he goes right into this treatment method. he explains three different

methods to treat marijuana with colchicine. in seed and as seedlings and clones.

just so you know...... the colchicine extract is derived from the bulb of meadow saffron which is a member

of the crocus family. the botanical name of meadow saffron is colchicum autumnale. this is not a popular

plant but they should be in most nursery catalogues and no one should have any trouble ordering

them.....hope this helps.



Vic High

posted September 11, 1999 11:03 PM

Hey Libro, good timing on your post. I was just reading today that I was spreading a little mis-information

about using the fall purple crocus for getting colchicine. I was just repeating what I was told, hehe. You

were closer to the truth, but also with a small mistake By coincidence today, I picked up the September

issue of a local magazine called The Coastal Grower. In it, there is an article on Colchicum, or the meadow

saffron as it's also called, and it's use in gardening. This is the plant who's bulb contains colchicine.

"Botanically colchicums reside in the lily family (Liliaceae) like tulips and lilies, not the iris family

(Iridaceae)as do crocuses."



iibro

posted September 12, 1999 09:52 AM

you are right vic. the meadow saffron is a plant from the lily family. thanx for the correction, my mistake.

Author: webfish179

Subject: MrSoul Colchicine?

Description:

MrSoul im sure you have read the works of

HEwarnike and understand it but could you explain it

to me ?The article is on the use of Colchicine to

create triploid and tetratriploid polyploid versions of

the diploid marijuana plant doubling the potency

what is Colchicine ?how is it applied?Is any of this

true or just crap?



Author: MrSoul

Subject: MrSoul Colchicine?

Description:

That's H.E. Warmke. He claimed to have doubled the

potency (measured by it's toxicity to fish) but his

methodology seems flawed to me. The colchicine

(EXTREMELY poisonous stuff) was more likely the

cause of the fish deaths than increased levels of

THC; which isn't very toxic even in very high

concentrations.My take on polyploidy is that it's

best left to research projects. I think the

uncertainty of positive results and possibilty of

poisoning oneself with colchicine make it a

dangerous waste of time for most growers. The art

of breeding cannabis is sufficiently complex without

the added complications of polyploidy. Read pages

70 - 75 of Tom Flowers' "Marijuana Flower Forcing"

and form your own opinion. I feel there is no need to

play games with polyploidy when there are so many

fine, potent strains available.

Author: A-1

Subject: MrSoul Colchicine?

Description:

Mrsoul already knows this, most plants we have are

poly's already! It happened in the early 80's. Some

breeders all read that book, baby. Including me.



Author: crane

Subject: MrSoul Colchicine?

Description:

No offense A-1, but I don't know if that's right. I've

never messed wih colchicine, but apparently even if

you overcome the difficulty of creating a tetraploid

plant in the first place, it's very difficult to keep it

that way. It's supposed to be a very difficult thing

to pass on to the next generation, and polyploid

plants even revert back to a diploid state all on their

own, so it would be difficult to propagate even with

cloning.My catalog from nirvana claims their master

kush is tetraploid, but it doesn't seem very likely to

me. Everything I've heard about polys sound like

they're unpredictable, plagued by abnormal growth,

slow to flower etc. Not ideal stuff for the home

grower.Do correct me if you have contrary info, I'd

be interested if a more up to date study has been

done than the ones I've seen.

Author: Kumquat

Subject: Bugs - FrankenQuat

Description:

Very interesting! I wonder if alcohol is penetrating

the tissues? (my guess is yes). Then this solvent

may be a very good carrier for the colchicine tabs i

have. I'm gonna have to do some 'speriments now!

Nurse, voltage please! But seriously, there is about

a truckload of things a person can do to mess with

plant genes, everything from alternating magnetic

fields to chemicals to ionizing radiation. Did you

know that Coleman gas light mantles are emmiters of

a fair amount of alpha particles? Not exactly

ionizing, but prolly the closesst i'll come to my dream

of cobalt-60 for quite some time LOL! But UV is

ionizing and it's easy to do a timed exposure

titration of pollen prior to pollenation. (try saying

that 3 times real fast!)I haven't put Richards seeds

in just yet. They will have to wait until later this fall.

On your advice of low germ rate, I think i'll add a

spritz of gibb acid to the soak water as that is

claimed to enhance germ rates of marginal

seeds.Good seeing you here and other places,

Jacker.



Author: jackerspackle

Subject: Bugs - FrankenQuat

Description:

I'd be concerned about Colemen's mantles modifying

MY genes!I think X-rays can be included in your

list...Clarke says that the key with colchicine is to

kill off most of the seeds - that way, the ones that

sprout are more likely to be mutated.. Seems like a

good approach with ANY mutagen, no?



Author: Kohjala

Subject: crocus bulbs/colchicine

Description:

Fall crocus bulbs are a natural source of the mitotic

agent colchicine, but a purer source is medical

grade colchicine. Colchicine is a drug used in the

treatment of Gout, and is available at low cost in 5

mg. tablets from any pharmacy. It does require a

physicians prescription, or the address of a mail

order pharmacy in mexico in mexico.You do havce a

lot of questions, and a trip to the local library to

look up books on introductory genetics would be

helpful.



Author: big man

Subject: Colchicine is highly toxic. It can be used in

Description:

plants to disable the meieotic spindle apparatus and

create a ployploid plant. You need to soak several

seeds tho, because some will die. If you search

"colchicine" on the www you might find a pamphlet

detailing how to use colchicine. I read it a couple

of years ago. The guy who wrote it was of the

opinion that the plant you used it on should not be

smoked (I tend to agree with Kohala) and also

stated that all future generations would be

polyploid. Polyploid plants are used in commercial ag

as well. I believe triticale, or winter wheat, is a

hexaploid plant, with 8 pairs of chromosomes,

making it exceptionally hardy.

Author: MrSoul

Subject: colchicine = Polyploids

Description:

Colchicine is a powerful chemical that can actually

affect the chromosomes. Seeds soaked in a DILUTE

solution of colchicine will MOSTLY die from it, but

the few survivors will have a conditon known as

"Polyploidy", which means that instead of the normal

TWO sets of 10 chromosomes, the plants could have

3, 4, or another number. The chromosomal

re-arrangement often causes strange traits like

gigantic plants, oddly coloured plants or highly

potent ones as well as usually causing such plants

to be sterile. The germination rate of reated seeds is

EXTREMELY low(~5% survivors). Not too many

people see a future in using colchicine in MJ

breeding. Experiments already done by Warmke, et

al. were inconclusive. There are many POTENT

strains available already and colchicine is VERY

DANGEROUS to humans...the risks outweigh any

slight possibility of creating a special plant are not

worth it. This substance should be left to the

scientists to play with, it's not for amateur pot

breeders IMO.



Author: Moonbeam

Subject: colchicine

Description:

MrSoul pretty much has it right concerning

colchicine, I seen the same episode on Quincy a

few years back...where kids were dying smoking the

pot sprayed w/ colch.? Kinda HOLLYWOOD, but I

have read extensively about plant mutations & when

you treat the seeds it is not always potency that is

affected...poly=several, and when you start playing

with the chromosome to mutate, nothing is

exact...another method that has been used to

polyploid is radiation, simply X-ray your seeds! I

ordered a book on plant mutations from the

inter-library loan while I was in prison & of te

different methods used, this seemed the safest &

actually the most beneficial for the benefits we wish

to achieve as MJ cultivators. I would be real

interested in hearing from anyone who try's

this...once again the chromo. will go poly. making

the signal to produce, 4 to 5 times the normal

ratio...could have huge plants could have extremely

potent, could have wierd-looking hermaphrodites

Induction and Recognition of Polyploidy



An excerpt from:

Wright JW. 1976. Introduction to Forest Genetics. Academic Press, New York. pages 415-417

Induction by Colchicine and Podophyllin

These chemicals are the most common means of inducing polyploidy.

They do not affect chromosome division as much as they inhibit the

spindle fiber mechanism by which divided chromosomes are drawn to

the poles. Thus the chromosomes divide but do not pass poleward and

a 2n cell becomes 4n.

Of the two chemicals, colchicine is used most commonly. It is usually

applied as a weak (0.1 to 0.5%) aqueous solution for a period of several

hours or several days. It is effective on any actively growing tissue,

such as a root tip or germinating pollen grain. However, the goal is

a tree or branch capable of producing 4n flowers. To achieve that goal

it must be applied to an actively growing apical meristem, such as in

a germinating seed or an actively growing bud. Germinating seeds can

be soaked in a colchicine solution. Growing buds can be surrounded

by colchicine-soaked cotton. Einspahr (1965) obtained 50 4n aspen seed-

lings by soaking entire female catkins in a 0.3% solution for 1 day at

a time when the fertilized embryos consisted of a few cells. At the

Hessian Forest Research Institute, good results have been obtained by

treating young seedlings having only one leaf with a 0.3 to 0.4% colchicine

solution for 72 hr (Anonymous, 1975). -The third year after treatment

approximately 40% of the seedlings were polyploid or mixoploid.

An actively growing apical meristem in a germinating seed or bud

consists of two self-perpetuating tissues, the outer tunica and the inner

corpus. These in turn differentiate into other meristems, such as leaf

primordia, flower primordia, and cambium. The exact meristems derived

from the tunica and corpus, respectively, vary among groups of trees.

Both the tunica and the corpus consist of several dividing cells.

It is relatively easy to find a concentration of colchicine which can

cause chromosome doubling in a few cells of the tunica, but it is difficult

to obtain a concentration that will cause simultaneous chromosome dou-

bling in all cells of both layers. Trial and error is the best method.

The best concentrations and times are those which result in some mor-

tality and in a high percentage of seedlings or shoots with gross abnor-

malities. The best results have been obtained with small-seeded species,

such as the poplars, willows, ehns, birches, and alders. In these species

it has been easiest to obtain good penetration into both tunica and

corpus.



Recognition and Treatment of Polyploids after Colchicine Treatment

The poisonous effects of colchicine seem to last for several cell

generations, and newly induced 4n tissue seems to grow more slowly

than surrounding 2n tissue. As colchicine rarely acts on all cells in a

growing point, artificial induction usually results in mixtures (called

mixoploids or chimeras) of 2n and 4n tissue. These mixtures may be of

various types, i.e., one branch 4n and another branch 2n, top of leaf 2n

and bottom of leaf 4n. If part of the top of a leaf is 4n and the bottom

is faster growing 2n, the leaf curls upward; if the reverse is true the leaf

curls downward. Thus, misshapen leaves, crooked branches, and general

growth abnormalities are the first indications of successful colchicine

treatment. The abnormalities gradually lessen and totally disappear as a

branch or tree becomes wholly 4n or 2n.

After the disappearance of such abnormalities, 4n cells usually have

twice the volume and 20 to 25% greater length or width than 2n cells.

Such increases in cell size are detected most easily in stomatal guard

cells, which can be measured at magnffications of about 100 X with

a light-reflecting microscope. Stomatal measurement is a quick way to

determine whether all or most of the leaves on a branch are polyploid.

Leaf size is also a convenient way to determine approximate chromo-

some number.'ln conifers generally, polyploidy is usually accompanied

by a decrease in rate of cell division so that leaves are apt to be

small in spite of the increase in cell size. In many hardwoods there

is no change in rate of cell division so that leaves and other organs

are apt to be larger than normal.

However, since the tunica and corpus give rise to different organs,

the presence of 4n leaves on a branch is no guarantee that the branch

will produce 4n flowers. Thus final proof must come at time of flowering.

This can be done by examination of pollen grains (4n grains are usually

larger than 2n grains), by actual chromosome counts in dividing gameto-

phytic cells, or by actual chromosome counts of seedlings produced

by the branch.

As already noted, there is a tendency for newly produced 4n tissue

to grow more slowly than surrounding 2n tissue. Therefore complete

reversion to the 2n condition is common. To overcome this tendency

it is advisable to observe treated seedlings at frequent intervals, identify

2n and 4n sectors quickly, and remove 2n buds or branches.

Anonymous. 1975. "Hessische Forstliche Versuchsanstalt, Jahresbericht

1974." Hann.-Munden.

Einspahr DW. 1965. Colchicine treatment of newly formed embryos of

quaking aspen. Forest Sci. 11,456-459.





The Induction of Polyploids



An excerpt from:

Watts, Leslie. 1980. Flower & Vegetable Plant Breeding Grower Books, London



The artificial induction of polypioids as recommended under (f) above can be

practised in a number of ways, using colchicine at a concentration of 0.5 to 1.0

per cent. At these concentrations, the length and method of exposure to

colchicine are critical and can only be satisfactorily decided by experimentation.

Since actively growing plant tissue must be treated, the most common methods

of using colchicine are;

(a) by applying it to seed which has already imbibed enough water for

germination - by transferring seed from a water-soaked to a colchicine-soaked

filter paper for approximately 24 hours.

(b) by applying droplets of solution to the growing points of seedlings.

(c) by applying colchicine in lanolin paste to growing points of seedlings.

(d) by applying droplets as in (b) or (c) to active buds on mature plants - but

removing all untreated bud growth.

Mixed tissues (diploid as well as polypioid) may arise after treatment and for

successful results it is important to remove all shoots of the original non-

polypioid, more vigorous type.









