Producing Female Seeds by e+br
If it were possible to know which seeds are female and which are male, marijuana growing would be even simpler than it is. There is not practical way to discern the gender of a seed - but there is a simpler procedure for producing seeds that will all grow into female plants.
To produce female seeds, the plants are fertilised with pollen with male flowers that appear on a basically female plant. Such flowers appear on intersexes, reversed females, and hermaphrodites. Female plants have an XX complement of sex chromosomes; therefore, the pollen from the male flowers that form on female plants can only carry an X chromosome. All seeds produced from flowers fertilised with this "female" pollen will thus have an XX pair of sex chromosomes, which is the female genotype.
Although the male Cannabis plant can produce female flowers, it cannot produce seed; so there is no chance of mistakenly producing seed on a male plant. It is possible to use pollen from an intersexual plant that is basically male (XY); the resulting crop of seeds will have the normal 1:1 ratio of males to females. For this reason, choose a plant that is distinctly female as a pollen source. A female plant with a few random male-flower clusters, or a female plant that has reversed sex are both good pollen sources. The seed bearer can be any female, female intersex, or reversed-female plant.
In most crops, careful inspection of all the females usually reveals a few male flowers. And often, when females are left flowering for an extended period of time, some male flowers will develop. If no male flowers form, you can help to induce male flowers on female plants by severe pruning. One such procedure is to take the bulk of the harvest, but to leave behind some green leaves to maintain growth. Most of the plants will continue to form female flowers, but male flowers are also likely to form. At times, the plants may not grow particularly well, and may in fact form distorted and twisted leaves, but they will produce viable seeds as long as some stigmas were white when pollinated. (Remember, it only takes a few fertile buds to produce hundreds of seeds.) Pollinate the female flowers by hand as soon as pollen becomes available.
Breeding
Breeding Cannabis is done simply by selecting certain plants to be the pollinators and the seeds bearers. Characteristics such as fast growth, early maturation, and high potency might be the reasons for choosing one plant over another. Selection can be by means of the male plants, the females, or both. A simple procedure would be to harvest all male plants, sample each for potency, and use the most potent plant for the pollen source. At harvest, compare the seeded females for potency, and use seeds from the most potent plant for the pollen source. At harvest, compare the seeded females for potency, and use seeds from the most potent plant for the following generation.
There are two basic approaches to breeding. One is inbreeding, and the other is outbreeding. Inbreeding involves starting with a single variety and crossing individuals to produce seeds. In this way, certain desirable characteristics that the parents have in common will probably be perpetuated by the offspring.
Certain variants with unusual characteristics, such as three leaves to a node instead of the usual two leaves, can be inbred continuously until all progeny carry the trait. One problem with inbreeding is that other desirable characteristics may be lost as the new population becomes more homogeneous. Inbreeding plants indoors seems to lead in a loss in potency by the fourth generation. (Preceding generations were considered comparable to the original imported grass.)
Outbreeding is crossing two different varieties. Offspring from parents of two different varieties are called hybrids. Cannabis hybrids exhibit a common phenomenon on plants called "hybrid vigour." For reasons not wholly understood, hybrids are often healthier, larger, and more vigorous than either of their parents. A reference to cannabinoid content of hybrids from crosses between chemotypes was made in a 1972 study by the Canadian Department of Agriculture: "The ratio of THC to CBD in hybrids was approximately intermediate between the parents ... there was also occasionally a small but significant deviation toward one of the parents - not necessarily the one with the higher or lower ratio of THC to CBD." 51 This means that a cross between a midwestern weedy hemp (type III) and a fine Mexican marijuana (type I) would yield offspring with intermediate amounts of THC and CBD, and which hence would be considered type II plants.
Homegrowers have mentioned that inbreeding plants often led to a decrease in potency after several generation. Outbreeding maintained potency, and sometimes (some growers claimed) led to increases in potency.
One area in which breeding can be useful for homegrowers is the breeding of early-maturing plants for northern farmer. Farmers in the north should always plant several varieties of marijuana. Mexican varieties generally are the fastest to mature. Individual plants that mature early and are also satisfactorily potent are used for the seed source in next year's crop. This crop should also mature early. Some growers cross plants from homegrown seed with plants from imported seed each year. This assures a maintenance of high-potency stock.
LUDACRIS.
