llamabox
10-06-2007, 11:12 PM
Re-post by Buggsy.....
So you to think you can create a big nasty, high yielding, plant with monster 5 inch wide colas with humongous amounts of swelled resin on them all put together in a plant more beautiful then a Mona Lisa?
I thought this would be a good place to start this thread as there has been much discussion of breeding here for the guys who want to know how. In a few links, with a few getting a bit of base we clouded up the issue.
Remember most of all is the basic Punnett Square that always shows how recessive traits will come back to haunt you.
Good luck there Doctor Frankenstein…
Heredity
Cannabis plants inherit their genetic characteristics from their sets of parents. Natural heredity laws define why offspring inherit different traits from the same parents. These laws assist breeders to forecast the number of offspring that stand to inherit a specific trait. Anybody who is serious about breeding has a good background in the laws of heredity. It’s essential.
All plant cells contains chromosomes, microscopic forms inside cells. Genes occur in pairs within these chromosomes. Chromosomes are building blocks of genes and genes determine the characteristics of cannabis. Every cannabis cell contains two genes (one chromosome) for each characteristic. To illustrate, lets look at sex. Each plant has one male gene and one female gene. Cannabis has 10 pairs of chromosomes which makes a total of 20 chromosomes.
Diploid plants have the normal set of chromosomes that occur in pairs within the cells. Polyploid plants have multiple sets of chromosomes within one cell. Instead of having chromosomes in pairs, polyploid plants have chromosomes in groups of three or four.
Tetraploid plants have groups of four chromosomes per cell. Many breeders have experimented with polyploid and tetraploid plants believing they would produce more potent plants. Polyploids can be induced with applications of colchicine. However colchicine is poisonous and polyploid plants are not more THC-potent, nor do they have any other redeeming qualities.
When the male and female germ cells join at fertilization, each adds one gene for each characteristic so that the new seed then has two genes for each attribute. The diverse combinations of each parents’ genes determine the traits of the offspring and of future generations.
Inbreeding establishes a pure breed.
A pure breed has consistent chromosomes. That is, the genetic makeup of offspring is relatively uniform. This true or pure breed is necessary so common growth characteristics may be established. If the plants are not a pure breed, it will be near impossible to predict the outcome of the hybrid plant. After the 4th to 6th generation of inbreeding, negative characteristics, like low potency, legginess and lack of vigor tend to dominate. Inbreeding is necessary to establish a true breed, but has been shied away from after the strain has been established.
Inbreeding establishes a stable reference point or plant to start from. The chosen females are bred back (back crossed) with males of the same strain. This will establish a true breed, plants with the same growth characteristics. These plants, of known ancestry and growth characteristics will be used to breed hybrid plants.
Outbreeding or producing hybrid seed is the practice of crossing two plants from different genetic backgrounds. An F1 hybrid is a first generation cross of two true breeding plants. F1 varieties are the most sought after plants available because they grow approximately 25 percent faster and larger than other crosses. This phenomena is known as hybrid vigor.
The offspring of F1 plants are called F2 and the offspring of F2 plants are called F3 ,etc. The subsequent generations after F1 do not experience hybrid vigor. F1 hybrids from seed companies must be brought back to true bred plants before they serve as consistent breeding stock.
NOTE: Most often grower’s do not breed, they cross plants without stabilizing any particular plant, or developing true breeding strains. Once they find a plant they like, they take clones of it and grow it out under lights. Often this is process is confused with breeding. It is much more difficult to select plants, stabilize them into true breeding plants and produce F1 hybrids. Often when 10 seeds purchased from a disreputable seed company are planted, the result is 10 plants that all look different, so beware!
Choosing from a large and varied plant stock, is the key to successful breeding. There is no guarantee for a breeder, planting only a few seeds, that they will grow into vigorous plants, even if the seeds are from excellent stock. The best solution is to grow many strains to have many plants to choose from.
You can't tell by looking at a plant the exact genes it contains. For instance, a female could have one gene for short stature and one for medium stature, but only medium stature is evident; by looking at the plant you have no way of knowing about the short stature gene. Yet, the gene for short stature is in the cells of the plant and some of the offspring will inherit it, and pass the gene on to their offspring. If enough plants and offspring are inbred, some offspring will be short. By observing enough offspring, a breeder can discern what genes parents have and how they interact.
Environment and Stress
Always give plants the absolute most stable environment possible. Stable environment allows plants to follow their genetic traits without interference. Stress plants by altering the environment and genetic characteristics are affected. Some likely characteristics of environmental stress include abnormal flowers and flowering traits. Often rookie breeders turn the lights out for a day or two or leave the lights on too long after a consistent 12 hour light/dark period is maintained and plants produce abnormal flowers - female flowers with male parts, a stigma protruding from a male flower or female flowers bearing male anthers.
Sex reversal is often result from stressed plants.
Sporadic male flowers on a predominately female plant frequently occur on stressed plants. These sexually confused plants are not natural hermaphrodites. They are stressed plants with intersex tendencies manifested as hermaphrodite or monocious plants. Do not confuse these deviations to be a new variety or a hermaphrodite plant. Such plants are the result of stress and not suitable for breeding stock. Had these plants been grown properly, they would be suitable for selective breeding. Stressed plants with hermaphroditic tendencies are generally less potent and low yielding. A person must learn to be a good grower before they can become a good breeder.
Environmental conditions that provoke sexual deviation include photoperiod fluctuation, marginal light intensity, ultraviolet light, nutrient imbalances, cold temperatures, abscisic acid, giberillic acid, old age and mutilation. The world’s top cannabis breeders are good growers and prefer to use naturally occurring genetic traits of plants rather than inducing environmental stimulus to achieve desired results. Altering a plants sex with environmental characteristics could cause the genetic deviation to be picked up by subsequent generations.
Favorable characteristics most breeders look for include general vigor, potency, resin content, flower to leaf ratio, large floral clusters, quality of high - long lasting, soaring, sedative - therapeutic effects, taste and aroma, short stature, early maturation, and mold and mite resistance.
Usually varieties that perform well under artificial lights will also perform well outside or in a glass house under natural sunlight. The converse does not hold true nearly as often. Varieties that perform well outside often prove to be a disappointment when grown under artificial light.
So you to think you can create a big nasty, high yielding, plant with monster 5 inch wide colas with humongous amounts of swelled resin on them all put together in a plant more beautiful then a Mona Lisa?
I thought this would be a good place to start this thread as there has been much discussion of breeding here for the guys who want to know how. In a few links, with a few getting a bit of base we clouded up the issue.
Remember most of all is the basic Punnett Square that always shows how recessive traits will come back to haunt you.
Good luck there Doctor Frankenstein…
Heredity
Cannabis plants inherit their genetic characteristics from their sets of parents. Natural heredity laws define why offspring inherit different traits from the same parents. These laws assist breeders to forecast the number of offspring that stand to inherit a specific trait. Anybody who is serious about breeding has a good background in the laws of heredity. It’s essential.
All plant cells contains chromosomes, microscopic forms inside cells. Genes occur in pairs within these chromosomes. Chromosomes are building blocks of genes and genes determine the characteristics of cannabis. Every cannabis cell contains two genes (one chromosome) for each characteristic. To illustrate, lets look at sex. Each plant has one male gene and one female gene. Cannabis has 10 pairs of chromosomes which makes a total of 20 chromosomes.
Diploid plants have the normal set of chromosomes that occur in pairs within the cells. Polyploid plants have multiple sets of chromosomes within one cell. Instead of having chromosomes in pairs, polyploid plants have chromosomes in groups of three or four.
Tetraploid plants have groups of four chromosomes per cell. Many breeders have experimented with polyploid and tetraploid plants believing they would produce more potent plants. Polyploids can be induced with applications of colchicine. However colchicine is poisonous and polyploid plants are not more THC-potent, nor do they have any other redeeming qualities.
When the male and female germ cells join at fertilization, each adds one gene for each characteristic so that the new seed then has two genes for each attribute. The diverse combinations of each parents’ genes determine the traits of the offspring and of future generations.
Inbreeding establishes a pure breed.
A pure breed has consistent chromosomes. That is, the genetic makeup of offspring is relatively uniform. This true or pure breed is necessary so common growth characteristics may be established. If the plants are not a pure breed, it will be near impossible to predict the outcome of the hybrid plant. After the 4th to 6th generation of inbreeding, negative characteristics, like low potency, legginess and lack of vigor tend to dominate. Inbreeding is necessary to establish a true breed, but has been shied away from after the strain has been established.
Inbreeding establishes a stable reference point or plant to start from. The chosen females are bred back (back crossed) with males of the same strain. This will establish a true breed, plants with the same growth characteristics. These plants, of known ancestry and growth characteristics will be used to breed hybrid plants.
Outbreeding or producing hybrid seed is the practice of crossing two plants from different genetic backgrounds. An F1 hybrid is a first generation cross of two true breeding plants. F1 varieties are the most sought after plants available because they grow approximately 25 percent faster and larger than other crosses. This phenomena is known as hybrid vigor.
The offspring of F1 plants are called F2 and the offspring of F2 plants are called F3 ,etc. The subsequent generations after F1 do not experience hybrid vigor. F1 hybrids from seed companies must be brought back to true bred plants before they serve as consistent breeding stock.
NOTE: Most often grower’s do not breed, they cross plants without stabilizing any particular plant, or developing true breeding strains. Once they find a plant they like, they take clones of it and grow it out under lights. Often this is process is confused with breeding. It is much more difficult to select plants, stabilize them into true breeding plants and produce F1 hybrids. Often when 10 seeds purchased from a disreputable seed company are planted, the result is 10 plants that all look different, so beware!
Choosing from a large and varied plant stock, is the key to successful breeding. There is no guarantee for a breeder, planting only a few seeds, that they will grow into vigorous plants, even if the seeds are from excellent stock. The best solution is to grow many strains to have many plants to choose from.
You can't tell by looking at a plant the exact genes it contains. For instance, a female could have one gene for short stature and one for medium stature, but only medium stature is evident; by looking at the plant you have no way of knowing about the short stature gene. Yet, the gene for short stature is in the cells of the plant and some of the offspring will inherit it, and pass the gene on to their offspring. If enough plants and offspring are inbred, some offspring will be short. By observing enough offspring, a breeder can discern what genes parents have and how they interact.
Environment and Stress
Always give plants the absolute most stable environment possible. Stable environment allows plants to follow their genetic traits without interference. Stress plants by altering the environment and genetic characteristics are affected. Some likely characteristics of environmental stress include abnormal flowers and flowering traits. Often rookie breeders turn the lights out for a day or two or leave the lights on too long after a consistent 12 hour light/dark period is maintained and plants produce abnormal flowers - female flowers with male parts, a stigma protruding from a male flower or female flowers bearing male anthers.
Sex reversal is often result from stressed plants.
Sporadic male flowers on a predominately female plant frequently occur on stressed plants. These sexually confused plants are not natural hermaphrodites. They are stressed plants with intersex tendencies manifested as hermaphrodite or monocious plants. Do not confuse these deviations to be a new variety or a hermaphrodite plant. Such plants are the result of stress and not suitable for breeding stock. Had these plants been grown properly, they would be suitable for selective breeding. Stressed plants with hermaphroditic tendencies are generally less potent and low yielding. A person must learn to be a good grower before they can become a good breeder.
Environmental conditions that provoke sexual deviation include photoperiod fluctuation, marginal light intensity, ultraviolet light, nutrient imbalances, cold temperatures, abscisic acid, giberillic acid, old age and mutilation. The world’s top cannabis breeders are good growers and prefer to use naturally occurring genetic traits of plants rather than inducing environmental stimulus to achieve desired results. Altering a plants sex with environmental characteristics could cause the genetic deviation to be picked up by subsequent generations.
Favorable characteristics most breeders look for include general vigor, potency, resin content, flower to leaf ratio, large floral clusters, quality of high - long lasting, soaring, sedative - therapeutic effects, taste and aroma, short stature, early maturation, and mold and mite resistance.
Usually varieties that perform well under artificial lights will also perform well outside or in a glass house under natural sunlight. The converse does not hold true nearly as often. Varieties that perform well outside often prove to be a disappointment when grown under artificial light.