March 27, 2023 at 3:40 pm | Updated March 27, 2023 at 3:42 pm | 8 min read
- Multifaceted experiments that examine complex internal plant responses to environment and management are standard and require equally sophisticated measuring and analyzing devices.
- A new generation of onsite plant science devices gives novel, rapid, and precise insights into above- and below-ground processes to advance and accelerate research.
- Scientists can use the tools to study diverse morphological and physiological parameters throughout the life cycle of a plant to learn about growth, development, stress response, and productivity.
The need for plant science research is increasing to fulfill demands of food security, biomass for fiber, timber, medicines, ecological restoration, and climate change mitigation, to name a few significant goals. Experiments on these topics are getting more complex, and there is hardly a study focusing only on one feature. Scientists want advanced and improved tools to collect detailed and complicated data about multiple features to help their research.
In response, the industry has begun miniaturizing precision techniques. The small modern devices also come equipped with cutting-edge chemometrics to give real-time analysis and results. CID Bio-Science Inc has been producing state-of-art tools for the last three decades that have become industry standards. This article showcases these tools and how they can be used.
A Hypothetical Experiment
To find out the plant science tools’ applications, consider a hypothetical experiment to drought-proof crops. Since we have to produce more food than before to feed a growing population, scientists are busy breeding drought-resistant or -tolerant cultivars in practically all crops- cereals, tubers, sugar crops, pulses, oilseeds, vegetables, and fruits. This kind of study would not be far from actual research priorities because existing water scarcity has been exacerbated by climate change.
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Cereals that provide staple foods are grown on 20% of the total global land mass or 61% of cultivated land. Cereals are, therefore, the first crops scientists are trying to future-proof.
|Crop Group||Area, 1000 km2||Relative Fraction, %|
|Roots and tubers||734||4|
Table 1: “Area and Relative Proportion of Seven Crop Groups,” Leff et al. 2004. (Image credits: https://doi.org/10.1029/2003gb002108)
Parameters Tested and Useful Tools for the Experiment
Our hypothetical experiment aims to breed new varieties of wheat which are high-yielding and drought resistant or tolerant.
An experiment of this kind would have to study causal factors- vegetative and management practices and the resultant biomass parameters. Both above-ground and below-ground parameters will influence how much photosynthates a plant produces. Moreover, based on genotype, varieties will vary in their allocation of carbon to growth, fight stress, flower, and production of fruits and seeds.
Hence our hypothetical experiment could monitor many of the morphological, physiological, and stress response parameters listed below.
The number, size, and arrangement of leaves, flowers, fruits, and roots can be measured to give an idea of growth, mortality, turnover of leaves and roots, and productivity. Architectural details like plant canopy or root branching highlight plant interaction with the environment.
Though above-ground morphology is the first parameter studied because it is the easiest, underground features were neglected as it was cumbersome to use traditional root examination techniques. Therefore, there is a lacuna of basic information on root number, density, structure, turnover, growth, and development for even crop species. Therefore, scientists must first learn and build the basis of what is happening in the soil while simultaneously probing the how and why.
Morphological features are also the standard form of data while studying ecosystems because of the number of species that co-exist.
Plant canopy determines access to light and growth areas in industrial farming or silviculture that seek to maximize plant population and productivity. Tree canopy is also a standard parameter for estimating carbon sequestration, climate change effects, human impact on natural vegetation, and forest restoration. In natural ecosystems, tree canopy and strata define the forest structure and environment for other plants and animals. Deforestation and fragmentation typically change forest structure.
Tools for Plant Morphology
CID BioScience Inc produces devices to measure and analyze at leaf and plant scales. These parameters are helpful for field experiments and for corroborating remotely sensed imagery data.
- The CI-202 Portable Laser Leaf Area Meter or the CI-203 Handheld Laser Leaf Area Meter can be used to estimate leaf area as an indicator of growth, management practices, and stress since leaves are the main organ of the plant. In all these cases, it is necessary to take repeated measurements to track differences in leaf area. Since the Leaf Area Meters are non-destructive and come with GPS, scientists can tag individual leaves and follow their condition through the crop cycle and abiotic and biotic stress events.
The tools can measure leaves of varying thicknesses, 1.4 cm to 15 cm, and the CI-202 and CI-203 can measure leaves 36 cm and 300 cm long. Therefore, the leaf meters are suitable for an extensive range of species. Besides area, the devices also estimate leaf length, width, perimeter, and shape factor. The CI-203 Conveyor Attachment can measure several detached leaves too. Scientists have used both devices also to measure seeds and wings.
- CI-110 Plant Canopy imager can be used for non-destructive estimation of Leaf Area Index used in crop science to predict crop yield, crop optimization, nutrition and water requirement, and forest productivity. The tool has a self-leveling camera with a 150° fish eye lens to capture images of the canopy. The associated software uses the Gap Fraction Method to calculate how much sky is visible from under the plants. Choosing filters that will also take RGB (Red-Green-Blue) images is possible.
The long handle of the device has 24 photosynthetically active radiation (PAR) sensors to detect light and sun flecks. Using the images and light radiation data, the device provides non-destructive LAI estimation. The GPS in the device is connected to four satellite constellations allowing for accurate tagging and image accuracy.
- Minirhizotron CI-600 In-Situ Root Imager or CI-602 Narrow Gauge Root Imager provides information through one-time observations to study root length, depth, width, branching, area, volume, and mycorrhizal root tips. Crucially also through non-destructive time series data allow monitoring to track fine-root turnover, root mortality, nodule formations, root cysts, and phenotypic plasticity to stress or response to nutrient and water management practices.
The transparent root tubes around 6 feet deep are installed into the soil, allowing the roots to grow around it. The minirhizotrons or root imagers are inserted into the root tubes, and the head camera takes scans from all sides. An accompanying software RootSnap! enables rapid and accurate distinction between soil and roots and analysis of the root parameters.
New devices like the minirhizotron allow scientists insights into the underground root and rhizosphere processes, which are essential to track local and carbon cycles.
Information on crucial physiological processes like the rate of photosynthesis, transpiration, stomatal conductance, respiration, and chlorophyll fluorescence can tell scientists about a plant’s growth, survival, health, and productivity.
Experiments to find physiological responses are increasing because climate change-associated temperature rises and drought affects plant functioning. Plants in drier locations are driven by soil moisture, whereas temperature changes drive plants in cooler places. Scientists use these data to find new cultivars or understand how to conserve natural vegetations that are a precious carbon sink.
Tools for Plant Physiology
Tools for physiology include those for above- and underground processes.
- CI-340 Handheld Photosynthesis System manufactured by CID Bio-Science Inc is a versatile Infrared tool for all plant gas exchanges used by scientists in agronomy, horticulture, climate change, and ecology studies. Light, carbon dioxide, water, and temperature modules help control the individual factors to monitor their effect on the gas exchanges. Ten customized leaf chambers allow the device to be used for leaves of different shapes, sizes, and thicknesses, including grasses and conifer needles.
- Rate of photosynthesis: By measuring the difference between carbon dioxide at the inlet and outlet, the tool estimates the rate of photosynthesis as a measure of crop growth, development, health, and climate change effects and acts as a direct predictor of biomass, yield, and productivity.
- Inter-connection: The tool can also measure transpiration and stomatal conductance under varying environmental conditions and irrigation regimes to study crop drought response and irrigation regimes. Each of these two physiological processes is important in its own right. However, measuring photosynthesis, transpiration rate, and stomatal conductance can be advantageous in drought or watering studies. The three physiological processes are interlinked to control water-use efficiency and photosynthesis rate.
- Chlorophyll fluorescence: Which Is red and far-red wavelength reflectance, is increasingly used to measure photosynthetic efficiency, phenotyping, and screening crop plants. The parameter’s importance is partly because remotely sensed imagery relies on spectral information to estimate photosynthetic rate. Chlorophyll fluorescence which can be measured remotely, is a standard method. However, field studies to validate chlorophyll fluorescence-based models require field data collection too. An additional module for chlorophyll fluorescence can be attached to measure the reflectance.
- Plant Respiration must be measured as it uses photosynthates to maintain plant structure, growth, and reproduction. About 40-60% of the carbon fixed by photosynthesis is used for respiration, making the process crucial for the individual and global carbon cycle. CI-340 is also helpful in collecting soil respiration data in crop and ecosystem studies.
- Minirhizotrons like CI-600 In-Situ Root Imager or CI-602 Narrow Gauge Root Imager can measure water efficiency or the response of cultivars within a species to drought. Cultivars will have different strategies to cope with drought, making varieties suitable for varying cultivation conditions (rainfed or irrigated).
The factors that cause stress must be measured, like the amount of water, air and soil temperature, pests, or diseases. Then effects of the stress on the growth and performance of above and below-ground morphology and physiology in different stages of the crop can show how the plant is coping with stress. Scientists use this information to select species or cultivars for a region that can maintain productivity despite the stresses in crops, forests, or for phytoremediation.
Tools for Plant Stress Detection
Several devices can directly detect stress, while others do so indirectly by identifying the impact of stress.
- CI-710s SpectraVue Leaf Spectrometer was designed to detect transmission, absorption, and reflection of the light spectrum between 360-1100nm from plants and then integrated into vegetation indices. Since the spectral signature of plants in stress changes, scientists have often used this device for non-destructive stress detection, monitoring plant health, and response to management practices. The device can also be used for color analysis, to estimate chemical concentrations and photochemical reactions, and quantify film thickness, extinction coefficient, and index of refraction.
- Chlorophyll fluorescence measured by CI-340 can also be used to detect stress because there is a shift in the red-to-far-red fluorescence ratio (F687/F760). Chlorophyll fluorescence can also be used to detect heavy metal pollution in soils
- Minirhizotrons can also show mortality due to water stress, diseases, and pests.
- The Leaf Area Meters CI-202 or the CI-203 will show any reduction in leaf area due to water scarcity or herbivory.
To estimate the effect of environmental factors or new management practices, scientists usually also quantify the output, which can be measured as biomass, or the number of flowers, fruits/grains, seeds, and their individual and total weight per plant. Nowadays, the quality of food is also increasingly being controlled to ensure that consumer satisfaction is achieved.
Plant Science Experiments
Plant science research is increasing in number and importance to satisfy people’s basic needs to keep up with improving living standards and a growing population. Instead of expensive laboratory techniques, nowadays, scientists can use the new onsite plant science tools for data collection and analysis on farms, greenhouses, or natural ecosystems. A precise, rapid, and reliable toolkit that is also portable will be essential for plant scientists to meet our varied global challenges.
Higgins, S.I., Conradi, T. & Muhoko, E. (2023). Shifts in vegetation activity of terrestrial ecosystems attributable to climate trends. Nat. Geosci. 16, 147–153 https://doi.org/10.1038/s41561-022-01114-x
Leff, B., Ramankutty, N., & Foley, J. A. (2004). Geographic distribution of major crops across the world. Global Biogeochemical Cycles, 18(1). https://doi.org/10.1029/2003gb002108
University of California. Drought-Resistant Crops and Varieties. (2016, Aug). Retrieved from
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