Mutagenesislnducing Variation

If variation does not exist for the trail or traits of interest, or cannot be found in other populations, it is theoretically possible to induce variation by exposing seeds or other tissues to radiation, alkylating agents, or other mutagens such as colchicine or EMS (ethylmethylsulfonate). These treatments cause changes at the DNA level that have the remote potential to result in desirable, novel phenotypes.

There is much rumour and speculation about this technique amongst breeders and growers. It's a common myth that treating seeds with colchicine and growing the plants results in more potent cannabis plants. Let's put this myth to rest; it is completely untrue. While the possibility does exist on a theoretical level, no valid experiments have ever shown this to be true. Potential breeders would be better off using their time and space for selecting better plants than trying this technique as a method for improving plant stock.

That being said, "let's take a look at the theory behind the concept.

Imagine you have a population of plants which, when grown from seed and inbred within the population, consistently produces higlv

THC plants. It is theoretically possible to treat many of these seeds with a mutagen, grow and inbreed the seeds, and find plants in subsequent generations that produce no THC. These mutagens can destroy genes along a chromosome, and when copies of this chromosome are inherited by future generations, a new or "novel" phenotype can appear. In our example, the no THC condition is the novel phenotype.

These mutations, however, occur at random and are extremely unreliable. The probability of finding plants which have a desired mutation in the gene of interest is veiy low. A breeder may treat many thousands of seeds, grow 100,000 plants, and still not see the desired altered phenotypes. This technique is costly in both time and space. It is often used in the breeding of "legal plants" when growing out thousands of individuals and searching for these novel phenotypes is not problematic. Performing such population screens in cannabis is not practical, especially for clandestine breeders. The potentially hazardous nature of these mutagenic agents is another very good reason to choose other breeding options. Inducing variability is likely not the best option, at least for the hobby breeder.

If you are serious about breeding cannabis, check out Marijuana Botany, An Advanced Study: The Propagation and Breeding of Distinctive Cannabis, by Robert Connell Clarke, Ronin Press. Using understandable scientific detail, Clarke discusses genetics and breeding, chemistry, and much more of interest to the budding breeder, This book is worth its weight in 'Haze' buds. If you can't find it at the bookstore, check out our web site: www.marijuana growing.com or order via our TOLL FREE number 1-877-989-4800, or t-360-837-3368.

1 Chapter SEVENTEEN

APPENDIX

Conversion Charts and Tables

Carbon Dioxide Facts and Figures

molecular weight = 44 grams/mole sublimes (solid to gas) at 78.5°C at 1 atmosphere - air density = 1.2928 grams/liter (i.e., at equal temperatures and pressures carbon dioxide is heavier than air, and CO, will fall to the bottom of an air/ CO., mixture.

psi = 1 atmosphere

Physical properties of Propane:

specific gravity of gas (air = 1) pounds per gallon of liquid @ 60°F (I5°C) gallons per pound of liquid @ 60°F (15UC) Btu per cubic foot of gas @ 60°F (15°C) Btu per pound of gas Btu per gallon of gas @ 60°F cubic feet of gas per gallon of liquid octane number

1.50 4.23 0.236 2488 21548 90502 36.38 100+

cubic feet of air to burn 1 gallon of propane cubic feet of CO., per gallon of Propane burned cubic feet of nitrogen per gallon of propane burned pounds of CO, per gallon of propane burned pounds of nitrogen per gallon of propane burned pounds of water vapor per gallon of propane burned 1 pound of propane produces in l<Wh Btu's per kW hour

873.6 109.2 688 12.7 51.2 6.8 6.3 3412

1 Therm 100,000 Btu Specific gravity of liquid 1 cubic foot natural gas 1000 Btu Vapor pressure (psig) OOF 1 pound steam 970 Btu Vapor pressure (psig) 700 F 1 kilowatt 3413 Btu Vapor pressure (psig) 1000 F

0.509 23.5 109 172

Calculations for Metric Users

1 cubic meter = 1 rn x 1 m x 1 m = 1000 liters fans are rated at liters per minute or liters per second

cubic feet = L x W x H cubic meters = L x w x H

Buy a fan that will clear the grow room volume of air in one to five minutes. Run the fan for twice

!!

459

Work out the amount of CO, gas to add:

For example, if you want 1500 ppm and ambient CO., is 350 ppm, you will need to add: 1500 ppm minus 350 ppm = 1150 ppm C0r

A poorly sealed grow room can have 20 percent leakage which should be added to the amount of CO, required.

For example, to get the desired 1500 ppm of CO; for a grow room with 21.6 cubic meters, add: 21.4 x 1150 = 24.61 liters x t.2 = 29.53 liters.

This information tells you to set the flow meter to 6 liters per minute and run the gas for 5 minutes.

Leave the gas-enriched air for 20 minutes and exhaust the air from the garden room.

Metric Conversion Chart -Approximations

When You Know Multiply by To Find Length millimeters 0.01

centimeters 0.39

meters 3,28

kilometers 0.62

inches 25.40

inches 2.54

feet 30.48

yards 0.91

miles 1.16

Area sq. centimeters 0.16

square meters 1.20 square kilometers 0.39

hectares 2.47

sq. inches 6.45

square feet 0.09

square yards 0.81

square miles 2.60

acres 0.10

Volume milliliters 0.20

milliliters 0.60

milliliters 0.03

liters 4,23

liters 2.12

inches inches feet miles millimeters centimeters centimeters meters kilometers square inches square yards square miles acres sq. centimeters square meters square meters sq. kilometers hectares teaspoons tablespoons fluid ounces cups pints

liters

1.06

quarts

liters

0,26

gallons

cubic meters

35.32

cubic feet

cubic meters

1.35

cubic yards

teaspoons

4,93

milliliters

tablespoons

11.78

milliliters

fluid ounces

29.57

milliliters

cups

0.21

liters

pints

0.47

liters

quarts

0.95

liters

gallons

3.790

liters

Mass and Weight

gram = 0.035 ounces kilogram = 2,21 pounds ounce = 28.35 grams pound = 0.45 kilograms inch (in) = 25.4 millimeters (mm) foot (1?. in) = 0.3018 meters (m) yard (3 ft ■ 0.9144 meters mile = 1.60937 kilometers square inch = 615.16 square millimeters square foot = 0.0929 square meters square yard = 0,8361 square meters square mile = 2.59 square kilometers

Liquid Measure Conversion pint (UK) = 0,56826 liters pint dry (USA) = 0.55059 liters pint liquid (USA) = 0.47318 liters gallon (UK) (8 pints) = 4.5459 liters gallon dry (USA) = 4.4047 liters gallon liquid (USA) = 3.7853 liters ounce = 28.3195 grams pound (16 ounces) =0.453592 kilograms gram = 15.4325 grains kilogram = 2.2046223 pounds millimeter = 0.03937014 inches (UK) millimeter = 0.03937 inches (USA) centimeter = 0.3937014 inches (UK) centimeter = 0.3937 inches (USA) meter = 3.280845 feet (UK) meter = 3.280833 feet (USA) kilometer = 0.6213722 miles cm = 0.001 meter

SEVENTEEN

APPENDIX

mm = 0.0001 meter nm = 0.000 000 001 meter gm = grams sq = squared

EC = electrical conductivity ppm = parts per million

Celsius to Fahrenheit

Light Conversion

lux = I lumen/square meters lumens per square foot = lumens per meter squared cfm (cubic feet per minute) = liters per hour Inches of rain = liters per meter squared psi (pounds per square inch) = kg per square meter

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