How Da Fukk Do You Create Strains? [Archive] - Green Grass Forums

esrabalamir

11-01-2005, 09:28 AM

here ya info:

Controlled hand pollination consists of two basic
steps: collecting pollen from the anthers of the staminate
parent and applying pollen to the receptive stigmatic sur-
faces of the pistillate parent. Both steps are carefully con-
trolled so that no pollen escapes to cause random pollina-
tions. Since Cannabis is a wind-pollinated species, enclo-
sures are employed which isolate the ripe flowers from
wind, eliminating pollination, yet allowing enough light
penetration and air circulation for the pollen and seeds to
develop without suffocating. Paper and very tightly woven
cloth seem to be the most suitable materials. Coarse cloth
allows pollen to escape and plastic materials tend to col-
lect transpired water and rot the flowers. Light-colored
opaque or translucent reflective materials remain cooler in
the sun than dark or transparent materials, which either
absorb solar heat directly or create a greenhouse effect,
heating the flowers inside and killing the pollen. Pollina-
tion bags are easily constructed by gluing together vege-
table parchment (a strong breathable paper for steaming
vegetables) and clear nylon oven bags (for observation win-
dows) with silicon glue. Breathable synthetic fabrics such
as Gore-Tex are used with great success. Seed production
requires both successful pollination and fertilization, so the
conditions inside the enclosures must remain suitable for
pollen-tube growth and fertilization. It is most convenient
and effective to use the same enclosure to collect pollen
and apply it, reducing contamination during pollen trans-
fer. Controlled "free" pollinations may also be made if
only one pollen parent is allowed to remain in an isolated
area of the field and no pollinations are caused by her-
maphrodites or late-maturing staminate plants. If the
selected staminate parent drops pollen when there are only
a few primordial flowers on the pistillate seed parent, then
only a few seeds will form in the basal flowers and the rest
of the flower cluster will be seedless. Early fertilization
might also help fix the sex of the pistillate plant, helping
to prevent hermaphrodism. Later, hand pollinations can be
performed on the same pistillate parent by removing the
early seeds from each limb to be re-pollinated, so avoiding
confusion. Hermaphrodite or monoecious plants may be
isolated from the remainder of the population and allowed
to freely self-pollinate if pure-breeding offspring are desired
to preserve a selected trait. Selfed hermaphrodites usually
give rise to hermaphrodite offspring.
Pollen may be collected in several ways. If the propa-
gator has an isolated area where staminate plants can grow
separate from each other to avoid mutual contamination
and can be allowed to shed pollen without endangering
the remainder of the population, then direct collection
may be used. A small vial, glass plate, or mirror is held
beneath a recently-opened staminate flower which appears
to be releasing pollen, and the pollen is dislodged by tap-
ping the anthers. Pollen may also be collected by placing
whole limbs or clusters of staminate flowers on a piece of
paper or glass and allowing them to dry in a cool, still
place. Pollen will drop from some of the anthers as they
dry, and this may be scraped up and stored for a short time
in a cool, dark, dry spot. A simple method is to place the
open pollen vial or folded paper in a larger sealable con-
tamer with a dozen or more fresh, dry soda crackers or a
cup of dry white rice. The sealed container is stored in the
refrigerator and the dry crackers or rice act as a desiccant,
absorbing moisture from the pollen.
Any breeze may interfere with collection and cause
contamination with pollen from neighboring plants. Early
morning is the best time to collect pollen as it has not been
exposed to the heat of the day. All equipment used for col-
lection, including hands, must be cleaned before continuing
to the next pollen source. This ensures protection of each
pollen sample from contamination with pollen from differ-
ent plants.
Staminate flowers will often open several hours before
the onset of pollen release. If flowers are collected at this
time they can be placed in a covered bottle where they will

open and release pollen within two days. A carefully sealed
paper cover allows air circulation, facilitates the release of
pollen, and prevents mold.
Both of the previously described methods of pollen
collection are susceptible to gusts of wind which may cause
contamination problems if the staminate pollen plants
grow at all close to the remaining pistillate plants. There-
fore, a method has been designed so that controlled pollen
collection and application can be performed in the same
area without the need to move staminate plants from their
original location. Besides the advantages of convenience,
the pollen parents mature under the same conditions
as the seed parents, thus more accurately expressing their
phenotypes.
The first step in collecting pollen is, of course, the
selection of a staminate or pollen parent. Healthy individ-
uals with well-developed clusters of flowers are chosen.
The appearance of the first staminate primordia or male
sex signs often brings a feeling of panic ("stamenoia") to
the cultivator of seedless Cannabis, and potential pollen
parents are prematurely removed. Staminate primordia
need to develop from one to five weeks before the flowers
open and pollen is released. During this period the selected
pollen plants are carefully watched, daily or hourly if neces-
sary, for developmental rates vary greatly and pollen may
be released quite early in some strains. The remaining
staminate plants that are unsuitable for breeding are de-
stroyed and the pollen plants specially labeled to avoid
confusion and extra work.
As the first flowers begin to swell, they are removed
prior to pollen release and destroyed. Tossing them on the
ground is ineffective because they may release pollen as
they dry. When the staminate plant enters its full floral
condition and more ripe flowers appear than can be easily
controlled, limbs with the most ripe flowers are chosen. It
is usually safest to collect pollen from two limbs for each
intended cross, in case one fails to develop. If there are ten
prospective seed parents, pollen from twenty limbs on the
pollen parent is collected. In this case, the twenty most-
flowered limb tips are selected and all the remaining flow-
ering clusters on the plant are removed to prevent stray
pollinations. Large leaves are left on the remainder of the
plant but are removed at the limb tips to minimize conden-
sation of water vapor released inside the enclosure. The
portions removed from the pollen parent are saved for
later analysis and phenotype characterization.
The pollination enclosures are secured and the plant
is checked for any shoots where flowers might develop
outside the enclosure. The completely open enclosure is
slipped over the limb tip and secured with a tight but
stretchable seal such as a rubber band, elastic, or plastic
plant tie-tape to ensure a tight seal and prevent crushing of
the vascular tissues of the stem. String and wire are
avoided. If enclosures are tied to weak limbs they may be
supported; the bags will also remain cooler if they are
shaded. Hands are always washed before and after handling
each pollen sample to prevent accidental pollen transfer
and contamination.
Enclosures for collecting and applying pollen and
preventing stray pollination are simple in design and con-
struction. Paper bags make convenient enclosures. Long
narrow bags such as light-gauge quart-bottle bags, giant
popcorn bags or bakery bags provide a convenient shape
for covering the limb tip. The thinner the paper used the
more air circulation is allowed, and the better the flowers
will develop. Very thick paper or plastic bags are never
used. Most available bags are made with water soluble glue
and may come apart after rain or watering. All seams are
sealed with waterproof tape or silicon glue and the bags
should not be handled when wet since they tear easily.
Bags of Gore-Tex cloth or vegetable parchment will not
tear when wet. Paper bags make labeling easy and each bag
is marked in waterproof ink with the number of the indi-
vidual pollen parent, the date and time the enclosure was
secured, and any useful notes. Room is left to add the date
of pollen collection and necessary information about the
future seed parent it will pollinate.
Pollen release is fairly rapid inside the bags, and after
two days to a week the limbs may be removed and dried in
a cool dark place, unless the bags are placed too early or
the pollen parent develops very slowly. To inspect the
progress of pollen release, a flashlight is held behind the
bag at night and the silhouettes of the opening flowers are
easily seen. In some cases, clear nylon windows are in-
stalled with silicon glue for greater visibility. When flower-
ing is at its peak and many flowers have just opened,
collection is completed, and the limb, with its bag attached,
is cut. If the limb is cut too early, the flowers will not have
shed any pollen; if the bag remains on the plant too long,
most of the pollen will be dropped inside the bag where
heat and moisture will destroy it. When flowering is at its
peak, millions of pollen grains are released and many more
flowers will open after the limbs are collected. The bags are
collected early in the morning before the sun has time to
heat them up. The bags and their contents are dried in a
cool dark place to avoid mold and pollen spoilage. If pollen
becomes moist, it will germinate and spoil, therefore dry
storage is imperative.
After the staminate limbs have dried and pollen re-
lease has stopped, the bags are shaken vigorously, allowed
to settle, and carefully untied. The limbs and loose flowers
are removed, since they are a source of moisture that
could promote mold growth, and the pollen bags are re-
sealed. The bags may be stored as they are until the seed
parent is ready for pollination, or the pollen may be re-
moved and stored in cool, dry, dark vials for later use and
hand application. Before storing pollen, any other plant
parts present are removed with a screen. A piece of fuel
filter screening placed across the top of a mason jar works
well, as does a fine-mesh tea strainer.
Now a pistillate plant is chosen as the seed parent. A
pistillate flower cluster is ripe for fertilization so long as
pale, slender pistils emerge from the calyxes. Withered,
dark pistils protruding from swollen, resin encrusted ca-
lyxes are a sign that the reproductive peak has long passed.
Cannabis plants can be successfully pollinated as soon as
the first primordia show pistils and until just before har-
vest, but the largest yield of uniform, healthy seeds is
achieved by pollinating in the peak floral stage. At this
time, the seed plant is covered with thick clusters of white
pistils. Few pistils are brown and withered, and resin pro-
duction has just begun. This is the most receptive time for
fertilization, still early in the seed plant's life, with plenty
of time remaining for the seeds to mature. Healthy, well-
flowered lower limbs on the shaded side of the plant are
selected. Shaded buds will not heat up in the bags as much
as buds in the hot sun, and this will help protect the sensi-
tive pistils. When possible, two terminal clusters of pistillate
flowers are chosen for each pollen bag. In this way, with
two pollen bags for each seed parent and two clusters of
pistillate flowers for each bag, there are four opportunities
to perform the cross successfully. Remember that produc
tion of viable seed requires successful pollination, fertiliza-
tion and embryo development. Since interfering with any
part of this cycle precludes seed development, fertilization
failure is guarded against by duplicating all steps.
Before the pollen bags are used, the seed parent infor-
mation is added to the pollen parent data. Included is the
number of the seed parent, the date of pollination, and any
comments about the phenotypes of both parents. Also, for
each of the selected pistillate clusters, a tag containing the
same information is made and secured to the limb below
the closure of the bag. A warm, windless evening is chosen
for pollination so the pollen tube has time to grow before
sunrise. After removing most of the shade leaves from the
tips of the limbs to be pollinated, the pollen is tapped away
from the mouth of the bag. The bag is then carefully
opened and slipped over two inverted limb tips, taking care
not to release any pollen, and tied securely with an ex-
pandable band. The bag is shaken vigorously, so the pollen
will be evenly dispersed throughout the bag, facilitating
complete pollination. Fresh bags are sometimes used, either
charged with pollen prior to being placed over the limb tip,
or injected with pollen, using a large syringe or atomizer,
after the bag is placed. However, the risk of accidental
pollination with injection is higher.
If only a small quantity of pollen is available it may
be used more sparingly by diluting with a neutral powder
such as flour before it is used. When pure pollen is used,
many pollen grains may land on each pistil when only one
is needed for fertilization. Diluted pollen will go further
and still produce high fertilization rates. Diluting 1 part
pollen with 10 to 100 parts flour is common. Powdered
fungicides can also be used since this helps retard the
growth of molds in the maturing, seeded, floral clusters.
The bags may remain on the seed parent for some
time; seeds usually begin to develop within a few days, but
their development will be retarded by the bags. The propa-
gator waits three full sunny days, then carefully removes
and sterilizes or destroys the bags. This way there is little
chance of stray pollination. Any viable pollen that failed
to pollinate the seed parent will germinate in the warm
moist bag and die within three days, along with many of
the unpollinated pistils. In particularly cool or overcast
conditions a week may be necessary, but the bag is re-
moved at the earliest safe time to ensure proper seed devel-
opment without stray pollinations. As soon as the bag is
removed, the calyxes begin to swell with seed, indicating
successful fertilization. Seed parents then need good irriga-
tion or development will be retarded, resulting in small,
immature, and nonviable seeds. Seeds develop fastest in
warm weather and take usually from two to four weeks to
mature completely. In cold weather seeds may take up to
two months to mature. If seeds get wet in fall rains, they
may sprout. Seeds are removed when the calyx begins to
dry up and the dark shiny perianth (seed coat) can be seen
protruding from the drying calyx. Seeds are labeled and
stored in a cool, dark, dry place,
This is the method employed by breeders to create
seeds of known parentage used to study and improve Can-
nabis genetics.