Study - One For the Trich Nerds

Discussion in 'Advanced Growing Techniques' started by Storm Crow, Apr 7, 2023.

  1. This one has quite a few close-ups of trichs and goes into great detail about how they mature. And they even named the two cultivars (strains) that they used. :biggrin:

    Glandular trichome development, morphology, and maturation are influenced by plant age and genotype in high THC-containing cannabis (Cannabis sativa L.) inflorescences. (Canada) (full – 2023)

    Background: Glandular capitate trichomes which form on bract tissues of female inflorescences of high THC-containing Cannabis sativa L. plants are important sources of terpenes and cannabinoids. The influence of plant age and cannabis genotype on capitate trichome development, morphology, and maturation has not been extensively studied. Knowledge of the various developmental changes that occur in trichomes over time and the influence of genotype and plant age on distribution, numbers, and morphological features should lead to a better understanding of cannabis quality and consistency.

    Methods: Bract tissues of two genotypes-"Moby Dick" and "Space Queen"-were examined from 3 weeks to 8 weeks of flower development using light and scanning electron microscopy. Numbers of capitate trichomes on upper and lower bract surfaces were recorded at different positions within the inflorescence. Observations on distribution, extent of stalk formation, glandular head diameter, production of resin, and extent of dehiscence and senescence were made at various time points. The effects of post-harvesting handling and drying on trichome morphology were examined in an additional five genotypes.

    Results: Two glandular trichome types-bulbous and capitate (sessile or stalked)-were observed. Capitate trichome numbers and stalk length were significantly (P = 0.05) greater in "Space Queen" compared to "Moby Dick" at 3 and 6 weeks of flower development. Significantly more stalked-capitate trichomes were present on lower compared to upper bract surfaces at 6 weeks in both genotypes, while sessile-capitate trichomes predominated at 3 weeks. Epidermal and hypodermal cells elongated to different extents during stalk formation, producing significant variation in length (from 20 to 1100 μm). Glandular heads ranged from 40 to 110 μm in diameter. Maturation of stalked-capitate glandular heads was accompanied by a brown color development, reduced UV autofluorescence, and head senescence and dehiscence. Secreted resinous material from glandular heads appeared as droplets on the cuticular surface that caused many heads to stick together or collapse. Trichome morphology was affected by the drying process.

    Conclusion: Capitate trichome numbers, development, and degree of maturation were influenced by cannabis genotype and plant age. The observations of trichome development indicate that asynchronous formation leads to different stages of trichome maturity on bracts. Trichome stalk lengths also varied between the two genotypes selected for study as well as over time. The variability in developmental stage and maturation between genotypes can potentially lead to variation in total cannabinoid levels in final product. Post-harvest handling and drying were shown to affect trichome morphology.

    And a few of the photos-


    Granny :wave:
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  2. Nice, thank you
  3. After reading through, here are my abbreviated take aways.
    Basically trich density and raw numbers of trich vary by overall maturation, life cycle stage, and genotype (strain)

    Basically trichs fill, mature and brown at different times (not synchronized) on your bud sites, a lot of growers have probably observed this, that top colas may mature faster than larf or lower buds.

    Pretty straightforward conclusion, if the trichs develop at different times and rates across the whole plant, then different bud sites may test with higher or lower levels of cannaboids and likely THC-a)

    The "at home" version of this imo is to simply take some 40-100x times magnification shots of purchased bud from a dispensary vs one you know you handled and dried with care.
    Look at a bud that just came off my drying racks vs something that just came out of a dispensary bag (obviously with unknown length of storage and handling. I think the nice tall white trichs of mine (top) vs the crushed up browns (bottom) of the store bought also illustrate this point

    Either way, while some of this info was not new, its always worthwhile imo to continue to build a larger body of legit research on cannabis cultivation for anyone interested in growing quality buds.

    Thanks to Granny for the link, would likely have not come across it on my own.
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  4. Shwale has been doing some amazing work based on trichome observations. They are a breeder that selects purely for extract. Their pix are jaw dropping. They are on Insta, not sure where else.
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  5. What doesn't seem to have been explored is if it is possible to influence what terpenes come to bear to influence the complexity of your product. From this it may be possible to understand what nutrients to work with at what stage to develop a preferred profile from any given seed. Or these nuances may be locked within their genetic code and all we're able to manipulate is the optimum harvest from any given bud site.
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