Temperature-dependent reproduction in Douglas-fir (Pseudotsuga menziesii): Machine learning-based phenotyping reveals a distinct reproductive thermal niche
Data files
Sep 25, 2026 version files 1.06 MB
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pollen_gp.csv
1.05 MB
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README.md
4.54 KB
Abstract
Pollen germination and elongation are temperature-sensitive processes that can influence plant reproduction, seed production, and forest regeneration, but their quantification is labor-intensive. This study developed a deep learning-based approach for pollen phenotyping and characterized the temperature dependence of pollen germination and elongation in Douglas-fir (Pseudotsuga menziesii). A convolutional neural network (CNN) was trained to segment pollen grains and classify germination status from microscopic images. We quantified germination percentage and pollen length at incubation temperatures from 5 to 40 °C and fitted gamma functions to estimate optimal temperatures across populations collected along an elevational gradient. See the Materials & Methods section in the corresponding manuscript for a more detailed description of data collection and analysis.
Dataset DOI: 10.5061/dryad.djh9w0wgg
Description of the data and file structure
Files and variables
File: pollen_gp.csv
Description: Pollen germination percentage, average length, average width, etc. in individual microscopic images. 3677 rows x 30 columns
Variables
- ID: Unique name of image analysed.
- Temperature: Pollen incubation temperatures from 5 to 40 degrees Celsius with an interval of 5 °C
- Elevation: Pollen collection elevations; unit: meters
- Replicate: The test round of pollen germination from rounds one to three. Each round has one vial.
- Subsample: The sample collected in each round, i.e., samples collected from each vial. Two subsamples in each round.
- GP 95: Percent of pollen germinated, calculated using a 95 % confidence interval based on length to determine germination; NA: no data
- Length: Average length (major axis of ellipse) of all pollen in a set of images in micrometers
- Width: Average width (minor axis of ellipse) of all pollen in a set of images in micrometers
- Length*total: Length of pollen multiplied by the number of pollen (used in calculations); unit: micrometers
- Ave Length/Ave. Width: Ratio between average length and average width of pollen in images; no unit
- Ave Germ length: Average length of germinated pollen in micrometers; NA: no data
- Ave Germ Width: Average width of germinated pollen in micrometers; NA: no data
- Germinated 95: Number of germinated pollen grains, calculated using a 95 % confidence interval based on length to determine germination
- Ungerminated 95: Number of ungerminated pollen grains, calculated using a 95 % confidence interval based on length to determine germination
- Total: Total number of pollen grains counted in the images using the length-based method & 95 % CI
- GP calculated with Ratio: Percentage of pollen germinated calculated using a 95 % confidence interval based on length-to-width ratio to determine germination; unit: %
- Ratio Germ: Number of pollen grains germinated, calculated using a 95 % confidence interval based on the ratio of length to width to determine germination
- Ratio Ungerm: Number of pollen grains ungerminated, calculated using a 95 % confidence interval based on the ratio of length to width to determine germination
- Ratio Too small: Number of detected pollen grains whose length-to-width ratios were excluded from the germination percentage calculations because they were too small to be classified
- Ratio total: Total number of pollen grains counted in the image using ratio-based method & 95 % CI
- Ave length * # germ: Average length of pollen multiplied by the number of germinated pollen classified by the length-based method & 95 % CI (used in calculations); unit: micrometers
- Ave width*# germ: Average width of pollen multiplied by the number of germinated pollen classified by the length-based method & 95 % CI (used in calculations); unit: micrometers
- Ratio Ave Germ length: Average length of germinated pollen classified using the ratio-based method & 95 % CI; unit: micrometers; NA: no data
- Ratio Ave Germ width: Average width of germinated pollen classified using the ratio-based method & 95 % CI; unit: micrometers; NA: no data
- Ratio ave length * # germ: Average length of pollen multiplied by the number of germinated pollen classified using the ratio-based method & 95 % CI (used in calculations); unit: micrometers; NA: no data
- Ratio ave width * # germ: Average width of pollen multiplied by the number of germinated pollen classified using the ratio-based method & 95 % CI (used in calculations); unit: micrometers; NA: no data
- Ratio Ave Area: Average area of germinated pollen classified using the ratio-based method & 95 % CI; unit: square micrometers; NA: no data
- Ave Area (Length Based): Average area of germinated pollen classified using the length-based method & 95 % CI; unit: square micrometers; NA: no data
- Area * number germinated: Average area of pollen multiplied by the number of germinated pollen classified by the length-based method & 95 % CI (used in calculations); unit: square micrometers; NA: no data
- Ratio Area * number germinated: Average area of pollen multiplied by the number of germinated pollen classified by the ratio-based method & 95 % CI (used in calculations); unit: square micrometers; NA: no data
