Method for measuring three-dimensional shape of seed plant dispersal body based on video stereomicroscope

Abstract

The present application belongs to the technical field of plant morphology, and particularly relates to a seed plant propagule three-dimensional shape measurement method based on a video stereomicroscope, comprising: collecting seed plant propagules at the mature stage and air-drying to a constant weight; classifying the propagules according to the seed, fruit shape and surface accessory structure, and determining the measurement criteria of the shape of different categories of propagules; scanning the three-dimensional structure of each category of propagule by using a video stereomicroscope, and accurately measuring the shape parameters length, width and thickness of the propagule; normalizing each category of propagule, calculating the shape index of the propagule, and representing the closeness to a spherical shape. The method quantifies the complex three-dimensional shape characteristics of the seed plant propagule into a comprehensive shape index, realizes accurate quantitative measurement and digitization of the morphological characteristics of the propagule, solves the pain point of determining the shape of the propagule by using a traditional observation tool, and facilitates the comparative identification of the three-dimensional shapes of different categories of seed plant propagules.

Description

Technical Field

[0001] This invention belongs to the field of plant morphology technology, specifically relating to a method for calculating the three-dimensional shape of seed plant dispersals based on video stereomicroscopy. It is applicable to the quantitative characterization and comparative analysis of the shape of seed plant dispersals using seeds and fruits as dispersal units. Background Technology

[0002] The morphological characteristics of seed plant dispersants (seeds and fruits) are core elements influencing individual plant reproduction and population expansion. Precisely quantifying dispersant shape is an important means of gaining a deeper understanding of plant adaptive evolution, and plays a crucial indicative role in predicting their dispersal capabilities (dispersal mode, dispersal distance, dispersal range), determining the persistence of soil seed banks (species composition, dormancy), and assessing the natural regeneration potential of species (seed germination, seedling establishment, population stability).

[0003] Seed plants have evolved unique propagation structures (such as caryopsis, capsule, achene, aggregate fruit, etc.) in specific environments over a long period of time, and different types of propagation structures have developed specialized appendage features (hairy, winged, spiny, etc.). These, together with the seed or fruit itself, constitute a complex and heterogeneous appearance, making it extremely challenging to accurately measure their three-dimensional shape.

[0004] Existing methods for studying the morphological characteristics of seed plant dispersals have significant limitations. Traditional measurement methods often rely on visual, manual caliper measurements. For lightweight, small, and morphologically complex dispersals, the numerical values ​​obtained using vernier calipers are prone to significant errors and are inefficient, while also damaging the appearance of the dispersal. More importantly, there is currently a lack of shape measurement criteria for seed plant dispersals based on different species and appendage characteristics. Manual measurements are highly subjective and have poor repeatability, leading to a relatively lagging quantitative study of the three-dimensional shape of dispersals, which severely hinders a deeper understanding of the relationship between dispersal morphology and ecological function. Therefore, there is an urgent need in this field for a precise methodological system for measuring the three-dimensional shape of structurally complex and diverse dispersals. Summary of the Invention

[0005] To address the limitations of existing methods for studying the morphology of seed plant dispersals in meeting the quantitative analysis needs of dispersals of different species and with unique appendages, and to overcome prominent technical challenges such as incomplete descriptions of dispersal morphology, inconsistent standards for measuring three-dimensional shape parameters, and inaccurate calculation of comprehensive quantitative indicators, this patent provides a method for measuring the shape of dispersals applicable to different species and types of seed plant dispersals. This method establishes a subdivided system of seed plant dispersals based on seed or fruit type and appendage structure. Utilizing video stereomicroscopy for three-dimensional scanning and digital image processing technology, it accurately measures the length, width, and thickness parameters of the dispersal body and quantifies the shape index, enabling precise quantitative analysis and objective comparison of the three-dimensional morphology of complex and diverse seed plant dispersals.

[0006] This invention is implemented by providing a method for calculating the three-dimensional shape of seed plant dispersals based on a video stereomicroscope, comprising the following steps: S1: Collect mature seed plant propagators in the wild, air dry them naturally to constant weight to eliminate the influence of moisture on morphological measurements and ensure that the physical state of subsequent propagators is consistent. S2: Establish a subdivision system based on the type of seed plant propagator and the characteristics of its surface appendages, and define the measurement criteria for the three-dimensional shape (length L, width W, thickness D) of the seed plant propagator for each category; The length L of a seed plant propagator is defined as the longest axis dimension from the base to the top of the seed or fruit, the width W is defined as the second longest axis dimension of the cross section perpendicular to the length axis, and the thickness D is defined as the third axis dimension perpendicular to the length axis and the width axis. The seed plant propagators include two forms: seeds and fruits. Fruits can be classified into caryopsis, capsule, achene, aggregate fruit, and fleshy fruit according to plant morphology classification standards. The measurement of different types of seed plant propagators follows the following guidelines: caryopsis and achenes are measured as a single fruit, and aggregate fruits and capsules are measured as the appearance of a completely unopened fruit. Fleshy fruits, which are difficult to extract seeds from, are measured as the appearance of a dried fruit with flesh attached.

[0007] Based on their influence on the appearance structure, dispersal ability, and colonization method of seed plant dispersants, the surface appendages are categorized into types such as hairy, winged, spiny, awned, and non-attached. For each type of seed plant dispersant, corresponding measurement criteria are determined according to whether the length, width, and thickness of the surface appendages are included: for seed plant dispersants without appendages, the fruit or seed itself is used as the measurement reference; for dispersants with pappus or downy hairs, the hairs must be included in the measurement; for dispersants with awns, the lemma and awns must be included in the measurement; for fleshy fruits from which seeds are difficult to separate, the shape of the fleshy outer surface is measured; for spiny dispersants, the spins must be included in the measurement; for winged or winged dispersants, the wings or wing-like structures must be intact during measurement. S3: Use a high-precision video stereomicroscope to scan each type of propagator and obtain its three-dimensional morphological image; based on the measurement criteria defined in S2, use digital image processing and analysis software to extract the length L, width W and thickness D values ​​of the three-dimensional shape of each type of propagator; S4: Normalize the original values ​​of the three-dimensional shape parameters of the propagating body by dividing the length L, width W, and thickness D of the propagating body by the maximum value of the three, i.e., the length L, to obtain the dimensionless normalized length L′, normalized width W′, and normalized thickness D′; then calculate the overall variance of L′, W′, and D′, which is defined as the propagating body shape index SI, characterizing its deviation from the ideal sphere. The formula for calculating SI is: u=(L′+W′+D′) / 3 SI=[(L′-u) 2 +(W′-u) 2 +(D′-u) 2 ] / 3 Where u is the arithmetic mean of the normalized values ​​of length, width and thickness, and SI takes the range of 1>SI≥0. SI=0 indicates that the shape of the propagator is a perfect sphere. The larger the SI value, the more the shape of the propagator gradually deviates from the sphere and tends to be ellipsoidal, disc-shaped, rod-shaped or needle-shaped, etc.

[0008] Compared with the prior art, the advantages of the present invention are as follows: 1. Based on plant morphology theories, this invention establishes a refined classification system and shape measurement criteria based on the types of seed plant propagators and appendages, which solves the problem that the complex morphological structures (seeds, fruits) and irregular appearance contours (appendage types) formed by seed plants through long-term evolution in specific environments make it difficult to quantify their apparent morphology. 2. This invention utilizes high-precision video stereomicroscope 3D scanning technology to obtain complete spatial structure information of the propagator. Combined with digital image processing technology, it performs background separation, appearance contour extraction, and precise 3D size measurement. This overcomes the problems of subjective judgment and large errors in the 3D size of the propagator that exist in traditional manual measurement, and ensures the accuracy and repeatability of the measurement of the 3D shape parameters of the seed plant propagator. 3. This invention normalizes the three-dimensional shape parameters of seed plant propagators, eliminating the dimensionality of the original measurements. The overall variance of the normalized length, width, and thickness is defined as the shape index SI. A statistically significant comprehensive quantitative index is used to characterize the degree of deviation of its three-dimensional shape from a sphere, providing a unified and convenient measurement standard for comparing the shapes of different species and types of propagators.

[0009] 4. The seed plant propagator shape measurement data involved in this invention provides direct data support for studying the propagation dynamics and propagation capacity of seeds or fruits. It also lays the foundation for in-depth research on natural plant regeneration strategies such as soil seed bank composition and persistence, seed dormancy and germination, individual establishment and population expansion. It has important theoretical significance and practical application value in the fields of plant morphology and restoration ecology. Attached Figure Description

[0010] To more clearly illustrate the overall technical solution of the methods or embodiments used in this invention, the core content of this invention is briefly described in the form of accompanying drawings. For those skilled in the art, the three-dimensional shape numerical information of other plant propagators not explicitly mentioned but covered by this invention can be further obtained based on the description in the accompanying drawings.

[0011] Figure 1 This is a flowchart illustrating the implementation of the method for calculating the three-dimensional shape of seed plant propagation bodies according to the present invention. Figure 2 This is a digital scan image of the three-dimensional morphology of a typical seed plant propagator in sandy areas, as presented in this invention. Figure 3 This is a schematic diagram of the measurement of three-dimensional shape parameters of typical seed plant propagators in sandy areas according to the present invention. (a), (b), (c), and (d) represent, in order, the propagator type without appendages, with awns, with wings / wings, and with spines. Detailed Implementation

[0012] To make the purpose, technical solution and advantages of this patent clearer, the invention will be further described in detail below with reference to the appendices, drawings and embodiments.

[0013] The core of this invention lies in establishing a method system for calculating the three-dimensional shape of seed plant dispersals based on video stereomicroscopy, including the following steps: (1) Collection and pretreatment of seed plant propagators ① Collect mature seed plant propagators (seeds or fruits) in the wild, number and record them one by one, remove impurities, and air dry them naturally in a well-ventilated indoor environment.

[0014] ② After the propagators have been dried for 5-7 days, 100 seeds are weighed using an electronic balance (accuracy 0.001 g). A constant weight is considered achieved if the error between two consecutive measurements is less than 0.5%, thus eliminating the influence of moisture content changes on the appearance of the propagators. Each type of propagator is sampled and measured three times. This ensures that the test specimens are prepared under uniform physical conditions, guaranteeing data comparability.

[0015] (2) Subdivision system of epimorphological features of seed plant propagators and shape measurement criteria ①The propagation agents include two categories: seeds and fruits. According to the plant morphological classification standards, fruits can be divided into types such as caryopsis, achenes, capsules, aggregate fruits, and fleshy fruits.

[0016] For individual fruits such as caryopsis and achenes, measure their overall outline; For aggregate fruits, capsules, etc., measure the external outline of the fruit that is completely unopened; The appearance profile of the dried fruit with flesh is measured for fleshy fruits that are not easily separated from seeds.

[0017] ② The characteristics of the appendages of the propagating body affect the accuracy of shape measurement. Based on the morphology and propagation function of the appendages, a three-dimensional shape measurement benchmark is determined for propagating bodies with different appendages, and the type of appendage must not be arbitrarily changed. Dispersants without appendages: the fruit or seed itself is used as the measurement reference; For hairy propagators: If it is a pappus, the length is measured based on the longest distance from the base of the fruit / seed to the tip of the pappus, while the width and thickness are measured only on the fruit / seed itself; if it is a soft hair, the length, width, and thickness are measured to the outer contour boundary of the hair in its naturally extended state. Winged or wing-shaped propagators: Length is measured as the longest dimension along the longitudinal axis of the wing or wing (with wings), width is measured as the maximum span along the transverse axis of the wing or wing, and thickness is measured as the fruit / seed body; Spiked propagator: The length, width, and thickness measurement boundaries extend to the outermost edge of the spike; Awned propagator: Length is the longest dimension from the base of the seed to the tip of the awn, while width and thickness are measured by the edge dimensions of the seed with the lemma.

[0018] (3) Three-dimensional structural scanning and digital image processing of seed plant propagators ① Three-dimensional structure scanning of the propagating body: Using a video stereomicroscope system with micro-viewing distance, high resolution and three-dimensional reconstruction functions, the propagating body to be tested is placed on a stage with high background contrast. By adjusting the microscope illumination system and viewing distance system, all details of the propagating body's appendages are ensured to be clear in the imaging system. The propagating body is rotated or the lens is moved to acquire high-resolution three-dimensional shape images from multiple perspectives (at least two orthogonal directions).

[0019] ② Shape recognition and length, width and thickness measurement of the propagating body: The high-resolution image of the propagating body is imported into professional image analysis software. According to the shape measurement criteria of each type of propagating body, the measurement reference points for length, width and thickness are determined. The Euclidean distance of the three-dimensional structure of the propagating body is measured using image processing software to obtain accurate original measurement values ​​of length, width and thickness.

[0020] At least five different individuals of each type of propagator were selected for high-resolution three-dimensional structural scanning and digital image measurement to reduce errors caused by differences between propagator individuals.

[0021] (4) Quantitative calculation of the three-dimensional shape of seed plant propagators ① The original measurements of the three-dimensional shape of the propagating body are normalized to eliminate interference from factors such as individual size and phenotypic variation in shape comparison. Specifically, the reciprocal of the length of each propagating body (1 / L) is used as a conversion factor. The original measurements of the three-dimensional dimensions are multiplied by this conversion factor to obtain the dimensionless normalized length L′, normalized width W′, and normalized thickness D′, all within the range [0, 1]. The specific calculation formulas are: L′=L / L=1, W′=W / L, D′=D / L.

[0022] ② Calculation of the propagation body shape index: The population variance is calculated based on the above three-dimensional shape normalization values. The calculation process is as follows: First, calculate the arithmetic mean of the normalized values: u = (L′ + W′ + D′) / 3 Then, calculate the shape index: SI = [(L′ - u)] 2 +(W′-u) 2 +(D′-u) 2 ] / 3 SI is dimensionless, and its value ranges from 1 to SI ≥ 0. SI = 0 indicates that the dimensions of the propagator are consistent in all three-dimensional space and its shape is a perfect sphere. When the SI value is close to 0, it indicates that the shape of the propagator is close to a sphere. The larger the SI value (>0), the more the shape of the propagator deviates from a sphere and tends to be ellipsoidal, disc-shaped, rod-shaped, or needle-shaped.

[0023] ③ Comparison of shapes of different types of propagators: By directly comparing SI values, we can achieve objective judgment, quantitative ranking and comparative analysis of the three-dimensional shapes of different types of plant propagators, and further explore their association with related ecological functions. Example

[0024] To illustrate the application effect of this invention in the measurement of the three-dimensional shape of different types of seed dispersants, the embodiments provide the process of calculating the three-dimensional shape of seed plant dispersants in the Horqin Sandy Land. Figure 1 For the specific process.

[0025] During the maturity period of seed plant propagators, 78 species of plant propagators, including those from the Asteraceae, Poaceae, Fabaceae, Chenopodiaceae, Asclepiadaceae, and Zygophyllaceae families, were collected from the Horqin Sandy Land. Each species was numbered and recorded, and then naturally air-dried in a well-ventilated environment.

[0026] One hundred seeds of each type of propagator were weighed using a 0.01 g electronic balance. The sampling and measurement were repeated three times. When the propagator reached a constant weight, it was prepared as a test specimen.

[0027] According to the propagator type and appendage structure described in this invention, the apparent shape subcategories of all 78 types of propagators to be tested are determined, and the measurement criteria for the length, width, and thickness of each type of propagator are defined.

[0028] Seventy-eight plant propagation organisms were scanned one by one using a video stereomicroscope. Taking into account factors such as the propagation organism's appearance, structure, color, gloss, microscope light intensity and angle, and image clarity, a background with high contrast to the propagation organism itself was selected to acquire high-resolution three-dimensional morphological images of each type of propagation organism (e.g., [images of the propagation organism]). Figure 2 ).

[0029] Import the scanned images of the propagating body into image processing and analysis software (such as ImageJ), and use the software's measurement module to obtain the raw measurement values ​​of the length, width, and thickness of each type of propagating body (e.g., ...). Figure 3 For each type of vector, five different individuals were measured repeatedly.

[0030] Referring to the formulas for normalizing three-dimensional shape parameters and calculating the overall variance, the shape index of each type of propagator was calculated (see Table 1).

[0031] Table 1. Classification system and shape index of plant propagation organisms in Horqin Sandy Land This patent is based on the principles of plant morphometry and combines plant morphology classification with high-precision three-dimensional digital imaging technology to quantify the complex three-dimensional shape of seed plant propagators into a comparable comprehensive shape index.

[0032] This patent is simple in principle, low in cost, and easy to promote. It makes it more convenient to quantify the three-dimensional shape of seed plant propagators and conduct species comparison analysis. It has important ecological significance for a deeper understanding of plant reproductive strategies, predicting the propagation potential of propagators, protecting species diversity, and promoting the stable restoration of ecosystems.

[0033] The above description is merely an embodiment of this patent and is not intended to limit the scope of protection of this patent. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of this patent are included within the scope of protection of this patent.

Claims

1. A method for calculating the three-dimensional shape of seed plant dispersals based on video stereomicroscopy, characterized in that, Includes the following steps: S1: Mature seed plant propagators collected in the wild and air-dried to constant weight; S2: Based on the type of seed plant propagator and the characteristics of its surface appendages, define the measurement criteria for the length L, width W, and thickness D of the seed plant propagator; S3: Using a video stereomicroscope to scan the three-dimensional structure of various seed plant propagators, and based on the measurement criteria defined in S2, using digital image measurement technology to determine the values ​​of the length L, width W, and thickness D of the seed plant propagator; S4: Normalize the length L, width W, and thickness D of the seed plant propagator, and calculate the overall variance as the propagator shape index SI to characterize the degree of deviation of the seed plant propagator shape from a spherical shape.

2. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 1, characterized in that, In S1, the plant propagator is allowed to air dry naturally to eliminate the influence of moisture on the shape measurement of the plant propagator.

3. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 1, characterized in that, In S2, the seed plant propagator uses seeds or fruits as carriers. The fruits are classified into achenes, caryopsis, capsules, aggregate fruits, and fleshy fruits based on structural differences.

4. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 3, characterized in that, In S2, the surface appendages are characterized by having hair, wings or barbs, awns, or no appendages.

5. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 3, characterized in that, In S2, the length L of the seed plant propagator is defined as the longest axis dimension from the base to the top of the seed or fruit, the width W is defined as the second longest axis dimension of the cross section perpendicular to the length axis, and the thickness D is defined as the third axis dimension perpendicular to the length axis and the width axis.

6. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 4, characterized in that, In S2, the measurement criteria for the length L, width W, and thickness D of the seed plant propagator are as follows: For seed plant propagators without surface appendages, the fruit or seed itself is measured; for hairy seed plant propagators, the hairs must be included in the measurement; for awned seed plant propagators, the lemma and awn must be included in the measurement; for fleshy fruits from which seeds are not easily separated, the external shape of the fleshy fruit is measured; for spiny seed plant propagators, the spins must be included in the measurement; for winged seed plant propagators, the wings or wing-like structures must be kept intact during measurement.

7. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 1, characterized in that, In S3, the video stereomicroscope is used to acquire high-resolution, multi-view three-dimensional images of the seed plant dispersing organism, and the three-dimensional structural parameters of the seed plant dispersing organism are measured using image processing software.

8. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 1, characterized in that, In S4, the normalization parameter of the seed plant propagator shape uses the reciprocal of the length as the conversion coefficient. The normalized length value is L′=L / L=1, and the normalized width and thickness values ​​are W′=W / L and D′=D / L, respectively.

9. The method for calculating the three-dimensional shape of seed plant dispersing bodies based on video stereomicroscopy according to claim 8, characterized in that, In S4, the formula for calculating the propagation body shape index SI is: IF=[(L′-u) 2 +(W′-u) 2 +(D′-u) 2 ] / 3 u=(L′+W′+D′) / 3 SI is dimensionless and its value ranges from 1 to 0. SI = 0 indicates that the shape of the seed plant propagator is a perfect sphere. The larger the SI value, the more the shape of the seed plant propagator deviates from a sphere and tends to be ellipsoidal, disc-shaped, rod-shaped, or needle-shaped.

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