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Marijuana Botany by Robert Connel Clark
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<blockquote data-quote="cannebosanac" data-source="post: 20012" data-attributes="member: 1357"><p>poglavlje 2 nastavak</p><p></p><p>Modern fiber or hemp farmers use commercially pro- </p><p>duced high fiber content strains of even maturation. Mono- </p><p>ecious strains are often used because they mature more </p><p>evenly than dioecious strains. The hemp breeder sets up </p><p>test plots where phenotypes can be recorded and controlled </p><p>crosses can be made. A farmer may leave a portion of his </p><p>crop to develop mature seeds which he collects for the fol- </p><p>lowing year. If a hybrid variety is grown, the offspring will </p><p>not ail resemble the parent crop and desirable character- </p><p>istics may be lost. </p><p>Growers of seeded marijuana for smoking or hashish </p><p>production collect vast quantities of seeds that fall from </p><p>the flowers during harvesting, drying, and processing. A </p><p>mature pistillate plant can produce tens of thousands of </p><p>seeds if freely pollinated. Sinsemilla marijuana is grown by </p><p>removing all the staminate plants from a patch, eliminating </p><p>every pollen source, and allowing the pistillate plants to </p><p>produce massive clusters of unfertilized flowers. </p><p>Various theories have arisen to explain the unusually </p><p>potent psychoactive properties of unfertilized Cannabis. </p><p>In general these theories have as their central theme the </p><p>extraordinarily long, frustrated struggle of the pistillate </p><p>plant to reproduce, and many theories are both twisted and </p><p>romantic. What actually happens when a pistillate plant </p><p>remains unfertilized for its entire life and how this ulti- </p><p>mately affects the cannabinoid (class of molecules found </p><p>only in Cannabis) and terpene (a class of aromatic organic </p><p>compounds) levels remains a mystery. It is assumed, how- </p><p>ever, that seeding cuts the life of the plant short and THC </p><p>(tetrahydrocannabinol the major psychoactive compound </p><p>in Cannabis) does not have enough time to accumulate. </p><p>Hormonal changes associated with seeding definitely affect </p><p>all metabolic processes within the plant including canna- </p><p>binoid biosynthesis. The exact nature of these changes is </p><p>unknown but probably involves imbalance in the enzymatic </p><p>systems controlling cannabinoid production. Upon fertili- </p><p>zation the plant's energies are channeled into seed produc- </p><p>tion instead of increased resin production. Sinsemilla plants </p><p>continue to produce new floral clusters until late fail, while </p><p>seeded plants cease floral production. It is also suspected </p><p>that capitate-stalked trichome production might cease </p><p>when the calyx is fertilized. If this is the case, then sinse- </p><p>milla may be higher in THC because of uninterrupted floral </p><p>growth, trichome formation and cannabinoid production. </p><p>What is important with respect to propagation is that once </p><p>again the farmer has interfered with the life cycle and no </p><p>naturally fertilized seeds have been produced. </p><p>The careful propagator, however, can produce as </p><p>many seeds of pure types as needed for future research </p><p>without risk of pollinating the precious crop. Staminate </p><p>parents exhibiting favorable characteristics are reproduc- </p><p>tively isolated while pollen is carefully collected and </p><p>applied to only selected flowers of the pistillate parents. </p><p>Many cultivators overlook the staminate plant, con- </p><p>sidering it useless if not detrimental. But the staminate </p><p>plant contributes half of the genotype expressed in the </p><p>offspring. Not only are staminate plants preserved for </p><p>breeding, but they must be allowed to mature, uninhibited, </p><p>until their phenotypes can be determined and the most </p><p>favorable individuals selected. Pollen may also be stored </p><p>for short periods of time for later breeding. Biology of Pollination </p><p>Pollination is the event of pollen landing on a stig- </p><p>matic surface such as the pistil, and fertilization is the </p><p>union of the staminate chromosomes from the pollen with </p><p>the pistillate chromosomes from the ovule. </p><p>Pollination begins with dehiscence (release of pollen) </p><p>from staminate flowers. Millions of pollen grains float </p><p>through the air on light breezes, and many land on the </p><p>stigmatic surfaces of nearby pistillate plants. If the pistil is </p><p>ripe, the pollen grain will germinate and send out a long </p><p>pollen tube much as a seed pushes out a root. The tube </p><p>contains a haploid (in) generative nucleus and grows </p><p>downward toward the ovule at the base of the pistils. </p><p>When the pollen tube reaches the ovule, the staminate </p><p>haploid nucleus fuses with the pistillate haploid nucleus </p><p>and the diploid condition is restored. Germination of the </p><p>pollen grain occurs 15 to 20 minutes after contact with </p><p>the stigmatic surface (pistil); fertilization may take up to </p><p>two days in cooler temperatures. Soon after fertilization, </p><p>the pistils wither away as the ovule and surrounding calyx </p><p>begin to swell. If the plant is properly watered, seed will </p><p>form and sexual reproduction is complete. It is crucial that </p><p>no part of the cycle be interrupted or viable seed will not </p><p>form. If the pollen is subjected to extremes of tempera- </p><p>ture, humidity, or moisture, it will fail to germinate, the </p><p>pollen tube will die prior to fertilization, or the embryo </p><p>will be unable to develop into a mature seed. Techniques </p><p>for successful pollination have been designed with all these </p><p>criteria in mind. </p><p>Controlled versus Random Pollinations </p><p>The seeds with which most cultivators begin represent </p><p>varied genotypes even when they originate from the same </p><p>floral cluster of marijuana, and not all of these genotypes </p><p>will prove favorable. Seeds collected from imported ship- </p><p>ments are the result of totally random pollinations among </p><p>many genotypes. If elimination of pollination was at- </p><p>tempted and only a few seeds appear, the likelihood is very </p><p>high that these pollinations were caused by a late flowering </p><p>staminate plant or a hermaphrodite, adversely affecting the </p><p>genotype of the offspring. Once the offspring of imported </p><p>strains are in the hands of a competent breeder, selection </p><p>and replication of favorable phenotypes by controlled </p><p>breeding may begin. Only one or two individuals out of </p><p>many may prove acceptable as parents. If the cultivator </p><p>allows random pollination to occur again, the population </p><p>not only fails to improve, it may even degenerate through </p><p>natural and accidental selection of unfavorable traits. We </p><p>must therefore turn to techniques of controlled pollination </p><p>by which the breeder attempts to take control and deter- </p><p>mine the genotype of future offspring. </p><p>Data Collection </p><p>Keeping accurate notes and records is a key to suc- </p><p>cessful plant-breeding. Crosses among ten pure strains (ten </p><p>staminate and ten pistillate parents) result in ten pure and </p><p>ninety hybrid crosses. It is an endless and inefficient task </p><p>to attempt to remember the significance of each little num- </p><p>ber and colored tag associated with each cross. The well- </p><p>organized breeder will free himself from this mental burden </p><p>and possible confusion by entering vital data about crosses, </p><p>phenotypes, and growth conditions in a system with one </p><p>number corresponding to each member of the population. </p><p>The single most important task in the proper collec- </p><p>tion of data is to establish undeniable credibility. Memory </p><p>fails, and remembering the steps that might possibly have </p><p>led to the production of a favorable strain does not con- </p><p>stitute the data needed to reproduce that strain. Data is </p><p>always written down; memory is not a reliable record. A </p><p>record book contains a numbered page for each plant, and </p><p>each separate cross is tagged on the pistillate parent and </p><p>recorded as follows: "seed of pistillate parent X pollen or </p><p>staminate parent." Also the date of pollination is included </p><p>and room is left for the date of seed harvest. Samples of </p><p>the parental plants are saved as voucher specimens for later </p><p>characterization and analysis. </p><p>Pollination Techniques </p><p>Controlled hand pollination consists of two basic </p><p>steps: collecting pollen from the anthers of the staminate </p><p>parent and applying pollen to the receptive stigmatic sur- </p><p>faces of the pistillate parent. Both steps are carefully con- </p><p>trolled so that no pollen escapes to cause random pollina- </p><p>tions. Since Cannabis is a wind-pollinated species, enclo- </p><p>sures are employed which isolate the ripe flowers from </p><p>wind, eliminating pollination, yet allowing enough light </p><p>penetration and air circulation for the pollen and seeds to </p><p>develop without suffocating. Paper and very tightly woven </p><p>cloth seem to be the most suitable materials.</p></blockquote><p></p>
[QUOTE="cannebosanac, post: 20012, member: 1357"] poglavlje 2 nastavak Modern fiber or hemp farmers use commercially pro- duced high fiber content strains of even maturation. Mono- ecious strains are often used because they mature more evenly than dioecious strains. The hemp breeder sets up test plots where phenotypes can be recorded and controlled crosses can be made. A farmer may leave a portion of his crop to develop mature seeds which he collects for the fol- lowing year. If a hybrid variety is grown, the offspring will not ail resemble the parent crop and desirable character- istics may be lost. Growers of seeded marijuana for smoking or hashish production collect vast quantities of seeds that fall from the flowers during harvesting, drying, and processing. A mature pistillate plant can produce tens of thousands of seeds if freely pollinated. Sinsemilla marijuana is grown by removing all the staminate plants from a patch, eliminating every pollen source, and allowing the pistillate plants to produce massive clusters of unfertilized flowers. Various theories have arisen to explain the unusually potent psychoactive properties of unfertilized Cannabis. In general these theories have as their central theme the extraordinarily long, frustrated struggle of the pistillate plant to reproduce, and many theories are both twisted and romantic. What actually happens when a pistillate plant remains unfertilized for its entire life and how this ulti- mately affects the cannabinoid (class of molecules found only in Cannabis) and terpene (a class of aromatic organic compounds) levels remains a mystery. It is assumed, how- ever, that seeding cuts the life of the plant short and THC (tetrahydrocannabinol the major psychoactive compound in Cannabis) does not have enough time to accumulate. Hormonal changes associated with seeding definitely affect all metabolic processes within the plant including canna- binoid biosynthesis. The exact nature of these changes is unknown but probably involves imbalance in the enzymatic systems controlling cannabinoid production. Upon fertili- zation the plant's energies are channeled into seed produc- tion instead of increased resin production. Sinsemilla plants continue to produce new floral clusters until late fail, while seeded plants cease floral production. It is also suspected that capitate-stalked trichome production might cease when the calyx is fertilized. If this is the case, then sinse- milla may be higher in THC because of uninterrupted floral growth, trichome formation and cannabinoid production. What is important with respect to propagation is that once again the farmer has interfered with the life cycle and no naturally fertilized seeds have been produced. The careful propagator, however, can produce as many seeds of pure types as needed for future research without risk of pollinating the precious crop. Staminate parents exhibiting favorable characteristics are reproduc- tively isolated while pollen is carefully collected and applied to only selected flowers of the pistillate parents. Many cultivators overlook the staminate plant, con- sidering it useless if not detrimental. But the staminate plant contributes half of the genotype expressed in the offspring. Not only are staminate plants preserved for breeding, but they must be allowed to mature, uninhibited, until their phenotypes can be determined and the most favorable individuals selected. Pollen may also be stored for short periods of time for later breeding. Biology of Pollination Pollination is the event of pollen landing on a stig- matic surface such as the pistil, and fertilization is the union of the staminate chromosomes from the pollen with the pistillate chromosomes from the ovule. Pollination begins with dehiscence (release of pollen) from staminate flowers. Millions of pollen grains float through the air on light breezes, and many land on the stigmatic surfaces of nearby pistillate plants. If the pistil is ripe, the pollen grain will germinate and send out a long pollen tube much as a seed pushes out a root. The tube contains a haploid (in) generative nucleus and grows downward toward the ovule at the base of the pistils. When the pollen tube reaches the ovule, the staminate haploid nucleus fuses with the pistillate haploid nucleus and the diploid condition is restored. Germination of the pollen grain occurs 15 to 20 minutes after contact with the stigmatic surface (pistil); fertilization may take up to two days in cooler temperatures. Soon after fertilization, the pistils wither away as the ovule and surrounding calyx begin to swell. If the plant is properly watered, seed will form and sexual reproduction is complete. It is crucial that no part of the cycle be interrupted or viable seed will not form. If the pollen is subjected to extremes of tempera- ture, humidity, or moisture, it will fail to germinate, the pollen tube will die prior to fertilization, or the embryo will be unable to develop into a mature seed. Techniques for successful pollination have been designed with all these criteria in mind. Controlled versus Random Pollinations The seeds with which most cultivators begin represent varied genotypes even when they originate from the same floral cluster of marijuana, and not all of these genotypes will prove favorable. Seeds collected from imported ship- ments are the result of totally random pollinations among many genotypes. If elimination of pollination was at- tempted and only a few seeds appear, the likelihood is very high that these pollinations were caused by a late flowering staminate plant or a hermaphrodite, adversely affecting the genotype of the offspring. Once the offspring of imported strains are in the hands of a competent breeder, selection and replication of favorable phenotypes by controlled breeding may begin. Only one or two individuals out of many may prove acceptable as parents. If the cultivator allows random pollination to occur again, the population not only fails to improve, it may even degenerate through natural and accidental selection of unfavorable traits. We must therefore turn to techniques of controlled pollination by which the breeder attempts to take control and deter- mine the genotype of future offspring. Data Collection Keeping accurate notes and records is a key to suc- cessful plant-breeding. Crosses among ten pure strains (ten staminate and ten pistillate parents) result in ten pure and ninety hybrid crosses. It is an endless and inefficient task to attempt to remember the significance of each little num- ber and colored tag associated with each cross. The well- organized breeder will free himself from this mental burden and possible confusion by entering vital data about crosses, phenotypes, and growth conditions in a system with one number corresponding to each member of the population. The single most important task in the proper collec- tion of data is to establish undeniable credibility. Memory fails, and remembering the steps that might possibly have led to the production of a favorable strain does not con- stitute the data needed to reproduce that strain. Data is always written down; memory is not a reliable record. A record book contains a numbered page for each plant, and each separate cross is tagged on the pistillate parent and recorded as follows: "seed of pistillate parent X pollen or staminate parent." Also the date of pollination is included and room is left for the date of seed harvest. Samples of the parental plants are saved as voucher specimens for later characterization and analysis. Pollination Techniques 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. [/QUOTE]
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Marijuana Botany by Robert Connel Clark
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