Glandular Trichomes Viewed with a Scanning Electron Microscope (SEM)

Glandular Trichomes Viewed with a Scanning Electron Microscope (SEM)
Professor DeBacco

Research Article
Punja, Z. K., Sutton, D. B., & Kim, T. (2023). Glandular trichome development, morphology, and maturation are influenced by plant age and genotype in high THC-containing cannabis (Cannabis sativa L.) inflorescences. Journal of Cannabis Research, 5(1), 12.
https://link.springer.com/article/10....
https://creativecommons.org/licenses/...

Varieties Grown in Study
Moby Dick (MD)
Space Queen (SQ)

Assessing Trichome Maturation
Assessing trichome maturation in cannabis. a Changes in translucency and b changes in red score in trichome heads of genotype “Hash Plant” progressing from 3 weeks to 7 weeks of the flowering period.
A sharp reduction in translucency and a rise in red score can be seen.
c Bract tissues in week 8 of the flowering period in which reddish-brown stalked-capitate glandular heads can be seen (arrow), especially on the lower half of the bract.
d A representation of the proportion of glandular heads that are clear (blue circles), translucent (white circles) and red-brown (red circles) using the CIELAB color space.
e Comparison of the appearance of stalked-capitate glandular heads under visible light (left) and under UV light (right) showing blue autofluorescence that is associated with the glandular head.
f Close-up of glandular heads with an enhanced exposure showing autofluorescence under UV light.
Some aggregation of the glandular heads due to resin secretion can be seen (arrow)

Effect of Post-Harvest Handling
The effect of post-harvest handling practice on capitate trichome integrity of cannabis genotype “Pink Kush.”
a A sample that was hand-trimmed to remove the inflorescence leaves before drying shows the majority of trichomes are intact and glandular heads are present.
b Close-up view of trichomes in a hand-trimmed sample showing all glandular heads are intact.
c A sample that was mechanically-trimmed to remove the inflorescence leaves shows a loss of trichomes and many heads have become detached (arrows).
d Close-up view of trichomes in a mechanically trimmed sample showing many glandular heads are broken off or shriveled (arrow), especially at the edges of the bracts.
e, f The dried stalks after 5 days of drying at 50–55% relative humidity show the outlines of the epidermal/hypodermal cells that make up the stalk. Most glandular heads are intact; a few have broken off (arrows).
The cuticle is intact

Post-harvest Impact on Trichomes
A comparison of capitate trichome density and maturation in four cannabis genotypes that have undergone the post-harvest drying process. All samples were hand-trimmed and images were obtained at the same magnification.
Data were recorded from 25 trichomes in three replicate samples (n=75).
a Genotype ‘Skunk’. Glandular heads are fully formed, trichome stalks are short, and no resin is released (arrow).
b Genotype ‘Temple Spice’. Trichome stalks are intermediate in length and heads are releasing resin (arrow).
c Genotype ‘Healer’. Trichome stalks are long, most have secreted resin (arrow).
d Genotype ‘Terpenade’. Trichome stalks are long, many glandular heads have released resin, and many heads have detached.
e Comparison of trichome density in four cannabis genotypes based on data collected directly from SEM images.
Standard errors of the means are shown.
f Comparison of the proportion of stalked:unstalked trichomes in four genotypes.
g Comparison of the proportion of dehisced and senescent trichomes in four genotypes

Link to Lecture Slides: https://drive.google.com/file/d/1jGA5...

*Due to the description character limit the full work cited for "Glandular Trichomes Viewed with a Scanning Electron Microscope (SEM)" can be viewed at... https://docs.google.com/document/d/1k...