Basic methods of botanical research

Field methods are aimed at studying plants in their natural habitat. They include route surveys, establishment of sample plots, geobotanical description of plant communities, herbarium specimen collection, and phenological observations (Yakovlev et al., 2006). Field methods serve as the primary source of information on species distribution, ecological preferences, and vegetation dynamics (Graham et al., 2014). This group also includes remote sensing techniques (satellite imagery, GIS analysis), which make it possible to assess vegetation cover at the landscape level (Mauseth, 2017).

Laboratory methods are implemented under stationary conditions using optical and analytical instruments. They include:

Experimental methods involve active intervention by the researcher in the life processes of plants in order to test hypotheses. These include:

These methods are based on comparison of different taxa and reconstruction of evolutionary pathways. They include:

Historical methods are aimed at reconstructing the vegetation cover of past geological epochs and the evolution of taxa over time. The main approaches are:

Each of the above groups of methods solves a specific range of problems; however, in modern botanical research they are rarely used in isolation. On the contrary, their comprehensive combination is widely practiced, making it possible to move from description to understanding the causes and mechanisms of observed phenomena (Stern et al., 2021; Simpson, 2019).

Optical instruments form the basis of morphological, anatomical, and cytological research. Microscopes of various types occupy a key place among them (Stern et al., 2021).

Light microscopes provide magnifications of up to 1500× with a resolution of about 0.2 μm. Several varieties are distinguished:

Electron microscopes use an electron beam instead of light and have significantly higher resolution (down to 0.1–0.2 nm). Two main types are distinguished:

Scanning tunnelling microscopes (STM) — instruments that allow individual atoms and molecules to be visualised. They have found application in the study of macromolecules, including DNA, and do not require complex sample preparation (Stern et al., 2021; Mauseth, 2017).

Specialised processing equipment is used to prepare samples for microscopic and biochemical analysis.

Microtomes are designed to obtain thin sections of plant tissues:

Centrifuges — used for fractionating cellular components (organelles, membranes, macromolecules). Ultracentrifuges make it possible to sediment ribosomes and viruses (Strasburger et al., 1971; Yakovlev et al., 2006).

Spectrophotometers and spectrofluorimeters — for quantitative determination of pigments (chlorophylls, carotenoids), nucleic acids, and proteins (Stern et al., 2021; Graham et al., 2014).

Chromatographs (thin‑layer, gas‑liquid, high‑performance liquid chromatography — HPLC) — for separating and identifying complex mixtures of organic compounds: phytohormones, alkaloids, flavonoids, fatty acids (Mauseth, 2017).

DNA sequencers and PCR thermal cyclers — key instruments for molecular genetic analysis, enabling nucleotide sequences to be determined and DNA fragments to be amplified for subsequent phylogenetic and population genetic analysis (Simpson, 2019; Lersten, 2004).

Specialised chambers and field instruments are used to study physiological processes and plant–environment interactions.

Phytotrons and climate chambers — facilities with fully controlled environmental parameters (temperature, humidity, light, gas composition). They allow any climatic conditions to be simulated and experiments to be conducted under reproducible regimes (Mauseth, 2017; Stern et al., 2021).

Gas analysers (e.g., LI‑COR systems) — for measuring photosynthesis, respiration, and transpiration in real time. The operating principle is based on differential measurement of CO₂ and H₂O in the air stream passing through a measuring chamber containing a leaf or whole plant (Graham et al., 2014; Beck, 2010).

Lysimeters — devices for monitoring water balance and element migration in the soil–plant system. They make it possible to quantify evapotranspiration and nutrient leaching (Serebryakova et al., 2006).

Remote sensing instruments — multispectral cameras, lidars, satellite sensors (e.g., Sentinel, Landsat). In combination with GIS software, they are used for large‑scale vegetation mapping, productivity assessment, and monitoring of vegetation disturbance (Graham et al., 2014; Mauseth, 2017).

Field weather stations — compact automatic systems that record air and soil temperature, humidity, precipitation, insolation, and wind speed. Data from such stations are essential for ecological and phenological studies (Yakovlev et al., 2006).

Thus, the instrumentation of botanical research encompasses devices ranging from simple hand lenses to complex electron microscopes and space‑borne sensors, making it possible to obtain reliable information about plant objects at all levels of their organisation (Evert, 2006; Simpson, 2019).

Morphological and anatomical methods are aimed at studying the external and internal structure of plant organisms at all stages of their ontogeny (Serebryakova et al., 2006). These methods are among the oldest in botany and retain key importance for systematics, phylogenetics, and applied research (Evert, 2006; Simpson, 2019).

Descriptive morphology is the basic method that includes visual examination and documentation of the shape, size, colour, and arrangement of vegetative and reproductive organs. The objects of study are living plants, herbarium specimens, and fixed material (Stern et al., 2021). Descriptions are made using standardised morphological terminology and are often accompanied by drawings, photographs, or digital models (Mauseth, 2017).

Comparative morphology is based on comparison of homologous and analogous structures in different taxa. It makes it possible to identify evolutionary transformations (metamorphoses) of organs — for example, the conversion of leaves into spines, tendrils, or scales — and to construct morphogenetic series (Evert, 2006; Strasburger et al., 1971).

Anatomical analysis — study of the internal structure of tissues and cells using light and electron microscopy. The main steps are:

Micromorphological methods using scanning electron microscopy (SEM) allow detailed examination of surface structures: stomatal apparatus, trichomes, cuticle, seed surface sculpture, and pollen grains (Stern et al., 2021; Simpson, 2019). For seed coats and pollen, these features often have diagnostic value.

Ultrastructural analysis (TEM) provides information on the structure of cell organelles: chloroplasts (thylakoids, grana, stroma), mitochondria (cristae), the nucleus (nuclear envelope, pores, nucleolus), endoplasmic reticulum, and dictyosomes (Evert, 2006; Beck, 2010). This method is indispensable for studying the fine structure of conducting elements (vessels, sieve tubes) and cell walls (Mauseth, 2017).

Carpological and seed science methods — study of fruit and seed morphology and anatomy. They include macro‑ and microscopic description, determination of fruit type, analysis of seed coat and endosperm. These data are important both for systematics and for assessment of seed quality (Lersten, 2004; Yakovlev et al., 2006).

Dendrochronology — a method based on the analysis of annual rings of wood. It allows determination of tree age, reconstruction of past climatic conditions, and dating of archaeological finds (Stern et al., 2021).

Forensic botanical methods — application of anatomical knowledge to identify plant remains at crime scenes (e.g., leaf fragments, pollen, seeds) in order to establish the time and place of a crime (Mauseth, 2017).

Thus, morphological and anatomical methods provide detailed information about plant structure at the organismal, tissue, and cellular levels, serving as a foundation for taxonomic, phylogenetic, and applied research (Evert, 2006; Simpson, 2019).

Physiological and biochemical methods are aimed at studying the functional processes that occur in the plant body: photosynthesis, respiration, water relations, mineral nutrition, growth, development, and secondary metabolism (Stern et al., 2021; Graham et al., 2014). These methods, as a rule, require strict control of experimental conditions and the use of quantitative measurements.

Vegetation methods (water, sand, and soil cultures) are used to study root nutrition and the influence of external factors on growth and development. The classic experiment of J. B. van Helmont (17th century) and the subsequent work of J. Sachs and W. Pfeffer laid the foundation of this approach (Strasburger et al., 1971; Stern et al., 2021). The water culture method allows precise dosing of macro‑ and microelements and the study of deficiency or toxicity of individual ions (Yakovlev et al., 2006; Mauseth, 2017).

Methods for studying photosynthesis include several approaches:

Methods for studying respiration are based on measurement of O₂ uptake or CO₂ release (respirometry). Manometric methods (Warburg), polarographic oxygen electrodes, and gas analysers are used (Graham et al., 2014). Dark respiration and photorespiration are distinguished; the latter is studied using inhibitor analysis (Strasburger et al., 1971).

Methods for studying water relations include:

Methods for studying phytohormones (auxins, gibberellins, cytokinins, abscisic acid, ethylene, brassinosteroids). The following are used:

Methods for studying mineral metabolism include analysis of macro‑ and microelement content in tissues after wet or dry ashing. Atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP‑MS), and ion chromatography are used (Yakovlev et al., 2006; Mauseth, 2017).

Methods for analysing secondary metabolites (alkaloids, phenolic compounds, terpenoids, glycosides). They include extraction with polar or non‑polar solvents, column purification, and subsequent analysis by HPLC, TLC, GC‑MS, and NMR (Graham et al., 2014; Stern et al., 2021). These methods are important for pharmacognosy, chemosystematics, and biochemical ecology (Yakovlev et al., 2006).

Isotope methods — use of stable (¹³С, ¹⁵N, ¹⁸O) and radioactive (¹⁴С, ³Н, ³²Р) isotopes. They are applied to study assimilate transport pathways, photosynthetic rates, nitrogen fixation, and plant age (radiocarbon dating) (Beck, 2010; Mauseth, 2017).

Thus, physiological and biochemical methods allow quantitative assessment of the rate and direction of key metabolic processes, which is necessary for understanding adaptations, productivity, and resistance of plants to stress factors (Stern et al., 2021; Graham et al., 2014).

Ecological and geobotanical methods are aimed at studying the relationships of plants with each other and with the abiotic environment, as well as investigating the structure, dynamics, and distribution of plant communities (phytocenoses) (Graham et al., 2014; Serebryakova et al., 2006). These methods are of fundamental importance for understanding the organisational patterns of the biosphere, as well as having applied value for the rational use of natural resources and the protection of vegetation cover (Mauseth, 2017).

Geobotanical description is the basic field method, which involves laying out sample plots (usually 1 to 100 m² depending on the vegetation type) on which a complete species inventory is carried out, along with assessment of abundance (using Drude – Braun‑Blanquet or Ramensky scales), projective cover, layering, and phenological state (Yakovlev et al., 2006). For each species, its occurrence, vitality, and distribution pattern are recorded (Serebryakova et al., 2006).

The method of ecological scales (Ramensky – Ellenberg scales) makes it possible to assess the ecological regimes of habitats (moisture, soil richness, acidity, light, salinity) using indicator plant species without the use of instruments. Each species is assigned scores for each factor; the weighted average over the species list gives a numerical estimate of the conditions (Graham et al., 2014; Yakovlev et al., 2006).

Floristic analysis — compilation and critical processing of floristic lists of specific territories (floras). It includes determination of taxonomic composition, analysis of geographical elements (range types) and ecological groups, assessment of the proportion of endemic, relict, and adventive (alien) species (Simpson, 2019). Similarity coefficients (e.g., Jaccard or Sørensen coefficient) are used to compare floras (Mauseth, 2017).

Life form analysis — classification of plants according to their external appearance (habit) and adaptive strategy. The most widespread system is that of C. Raunkiaer, based on the position of renewal buds relative to the soil surface: phanerophytes, chamaephytes, hemicryptophytes, cryptophytes (geophytes, helophytes, hydrophytes), and therophytes (Serebryakova et al., 2006). This classification reflects adaptation to unfavourable seasons (Graham et al., 2014).

Methods for studying productivity and biological turnover include determination of phytomass (above‑ground and below‑ground), annual increment (production), and litter. Measurement is carried out by mowing, taking model trees, coring, and subsequent laboratory analysis (weighing, ashing, determination of carbon and nitrogen content) (Yakovlev et al., 2006; Stern et al., 2021).

Vegetation mapping — delineation of vegetation community units on a topographic base. It is carried out in the field using a route method with GPS receivers and satellite images. Digital vegetation maps (vegetation maps) are created using GIS (ArcGIS, QGIS) and serve as a basis for land monitoring and biological resource assessment (Graham et al., 2014; Mauseth, 2017).

Remote sensing methods — use of satellite sensors (Landsat, Sentinel, MODIS) for large‑scale assessment of vegetation condition. Vegetation indices (NDVI, EVI) are calculated, reflecting photosynthetic activity, biomass, and plant stress. These methods are indispensable for monitoring forests, steppes, and agroecosystems at regional and global levels (Stern et al., 2021; Graham et al., 2014).

Phenological observations — recording of seasonal phenomena (bud break, flowering, fruiting, leaf fall). They are carried out along permanent routes and on monitoring plots with a frequency of 1–3 times per week. Phenological data are used to predict the timing of agricultural work, assess plant responses to climate change, and model phenoclimatic relationships (Serebryakova et al., 2006; Yakovlev et al., 2006).

Methods for assessing anthropogenic dynamics — comparison of floras and vegetation at different times (using literature, herbarium, and field data), establishment of permanent sample plots for succession monitoring, and analysis of synanthropic (weedy and ruderal) vegetation. They make it possible to identify trends in flora impoverishment, the spread of alien (invasive) species, and regeneration processes (Mauseth, 2017; Stern et al., 2021).

Thus, ecological and geobotanical methods allow assessment of plant distribution in space and time, identification of factors determining the structure and dynamics of vegetation cover, and development of scientific bases for the conservation and use of plant resources (Graham et al., 2014; Serebryakova et al., 2006).

Systematic and evolutionary methods are aimed at identifying relationships between taxa, their classification, and reconstruction of the phylogeny (evolutionary history) of plants (Simpson, 2019; Yakovlev et al., 2006). These methods integrate data from morphology, anatomy, embryology, palaeobotany, molecular biology, and biogeography (Evert, 2006; Beck, 2010).

Comparative morphology and anatomy — the traditional foundation of systematics. Researchers compare the structure of vegetative and generative organs (flowers, fruits, seeds, leaves, stems, roots) among different species and genera. Identification of homologous structures (having a common origin) makes it possible to construct morphogenetic series and propose hypotheses about the evolution of characters (Evert, 2006; Strasburger et al., 1971). So‑called “key” characters are particularly important: flower structure (symmetry, fusion of parts), fruit type, wood anatomy, and stomatal type (Simpson, 2019).

Micromorphological and ultrastructural characters — use of SEM and TEM to detail the structure of pollen grains (palynomorphology), seed coats, leaf surfaces, and cuticles. These characters are often highly specific to taxa and are preserved even in fossil material (Graham et al., 2014; Stern et al., 2021).

Embryological methods — study of the development of the male (microsporogenesis) and female (megasporogenesis, embryo sac development) gametophytes, the process of double fertilisation, and the development of endosperm and embryo. The pattern of embryonic structures (type of embryo sac — Polygonum, Oenothera, Allium, etc., type of endosperm, number of cells in the seedling) is used to substantiate the relationships of major taxa (Lersten, 2004; Evert, 2006).

Molecular phylogenetic methods have become the basis of modern systematics. They include:

Cladistic analysis — a method for identifying monophyletic groups (clades) based on shared derived characters (synapomorphies). Unlike phenetic classifications (based on overall similarity), cladistics aims to reflect evolutionary history (Simpson, 2019). The result is presented in the form of a cladogram — a branching diagram indicating the order of lineage divergence (Beck, 2010).

Chemosystematics (biochemical systematics) — use of the composition of secondary metabolites (alkaloids, flavonoids, terpenoids), proteins (electrophoresis), and low‑molecular‑weight compounds (fatty acids) to characterise taxa. The presence or absence of certain compounds can serve as a synapomorphy at different levels of the hierarchy (Graham et al., 2014; Yakovlev et al., 2006).

Karyosystematics — analysis of the number, shape, and structure of chromosomes (karyotype). The following are taken into account: chromosome number (2n), the presence of polyploid series, chromosome size and centromere position, the presence of satellites and secondary constrictions. Karyotypes are stable within a species and often differ between related species (Simpson, 2019; Stern et al., 2021).

Palaeobotanical methods in systematics — study of fossil remains to determine the divergence times of clades (molecular clocks are calibrated using palaeontological data). Phylogenies built on extant taxa are tested against fossil evidence (e.g., leaves, wood, flowers, seeds) (Beck, 2010; Strasburger et al., 1971).

Methods of hybridisation and experimental systematics (biosystematics). They include artificial crossing to determine reproductive isolation, analysis of meiosis in hybrids (study of chromosome pairing), and use of molecular markers to analyse gene flow between populations. They make it possible to refine species boundaries and identify hybridogenous taxa (Simpson, 2019; Mauseth, 2017).

Thus, systematic and evolutionary methods — from classical morphology to genomics — provide the construction of a natural system of organisms that reflects their phylogeny. This is the foundation for any comparative research in botany and a necessary condition for the conservation of biodiversity (Simpson, 2019; Yakovlev et al., 2006).

Palaeobotanical methods are aimed at reconstructing the evolution of plants and vegetation cover of the Earth in the geological past. They are based on the study of fossil remains — from macroscopic fragments (trunks, leaves, fruits, seeds) to microscopic objects (spores, pollen, phytoliths) (Strasburger et al., 1971; Beck, 2010).

Macroremain analysis — the study of fossilised wood (palaeoxylology), leaves, reproductive organs, and their imprints in sedimentary rocks. Samples are extracted from outcrops, drill cores, and quarries, then cleaned and sometimes made into thin sections. From the anatomy of fossil wood (structure of vessels, tracheids, rays), systematic affinity is determined and palaeoclimate is reconstructed (Beck, 2010; Stern et al., 2021).

Palynological analysis — the study of fossil pollen and spores (palynomorphs). Due to the high resistance of sporopollenin, pollen and spores are preserved in peats, sapropels, marine and continental sediments. The method includes chemical treatment (with acids and alkalis) to release palynomorphs, their microscopy (light and scanning electron microscopy), and identification. Palynology allows reconstruction of the history of vegetation, climate, and human economic activity (Graham et al., 2014; Serebryakova et al., 2006).

Phytolith analysis — the study of siliceous bodies formed in plant cells. Phytoliths are species‑specific in shape and are preserved in soils and deposits after complete decomposition of organic matter. They are extracted by elutriation or using heavy liquids, then identified under a microscope. The method is particularly important for reconstructing herbaceous communities where pollen is poorly preserved (Mauseth, 2017; Graham et al., 2014).

Isotope methods in palaeobotany — analysis of stable isotope ratios of carbon (δ¹³C), oxygen (δ¹⁸O), and nitrogen (δ¹⁵N) in fossil wood, leaves, and soil organic matter. These indicators serve as proxies for temperature, humidity, and the type of photosynthetic metabolism (C₃, C₄, CAM) of ancient plants (Beck, 2010; Mauseth, 2017).

Dendrochronology — a method for dating wood remains by annual rings. It makes it possible to determine the age of archaeological and palaeontological wood samples with year‑by‑year accuracy, as well as to reconstruct past climate fluctuations (Stern et al., 2021). Cross‑dating connects ring series from living trees with ancient wood.

Reconstruction of palaeophytocenoses — a comprehensive analysis of all available remains (macro‑ and micro‑) from the same stratigraphic level. It allows reconstruction of the structure of ancient plant communities, dominant species, and succession dynamics over a scale of millennia (Strasburger et al., 1971; Graham et al., 2014).

Thus, palaeobotanical methods provide the only opportunity to directly observe the course of plant and vegetation evolution, calibrate molecular clocks, and understand the long‑term responses of the biosphere to climate change and geological events (Beck, 2010; Stern et al., 2021).

Embryological methods study the processes of formation and development of male and female gametophytes, fertilisation (including double fertilisation in flowering plants), as well as the formation of the embryo, endosperm, and seed coat (Lersten, 2004; Evert, 2006). These methods are important for systematics, breeding, biotechnology, and understanding plant reproductive biology.

Cytoembryological analysis — the principal method, which includes fixation of buds, inflorescences, or ovules at different developmental stages. Fixatives: FAA (formalin – acetic acid – ethanol), Carnoy’s solution, glutaraldehyde (for electron microscopy). After fixation, the material is dehydrated, embedded in paraffin or epoxy resins, and serial sections 5–10 μm thick (for light microscopy) or 1 μm semithin sections are prepared (Lersten, 2004; Evert, 2006).

Staining of embryological preparations — for visualisation of nuclei, chromosomes, cell walls, and storage substances. The following are used: Ehrlich’s or Delafield’s haematoxylin (nuclei), safranin – azure II (general structure), Feulgen staining (DNA‑specific), aniline blue (for callose in companion cells and sieve tubes) (Lersten, 2004; Evert, 2006).

Clearing method (whole‑mount preparations) — for studying whole ovules and anthers without sectioning. Samples are treated with sodium hydroxide or chloral hydrate until transparent, then stained (e.g., with brilliant blue or fluorescent dye). It allows assessment of embryo sac development and microsporogenesis stages in three‑dimensional projection (Lersten, 2004; Stern et al., 2021).

Microsporogenesis and pollen analysis — study of meiosis in anthers and pollen grain (microgametophyte) development. Methods include preparation of squashes (acetocarmine, aceto‑orcein) for observing meiotic chromosomes, as well as assessment of pollen fertility (staining with acetocarmine or fluorescein diacetate) (Simpson, 2019; Mauseth, 2017).

Megasporogenesis and embryo sac development — study of meiosis in the ovule nucellus, formation of the functional megaspore, and subsequent multiple mitoses leading to the mature embryo sac (female gametophyte). Serial sections or clearing methods are used. Different types of embryo sacs (Polygonum, Oenothera, Allium, Drusa, etc.) are distinguished, which have diagnostic value (Lersten, 2004; Evert, 2006).

Culture of isolated embryos and ovules in vitro — embryo culture. This method is used to “rescue” hybrid embryos that die at early stages during distant hybridisation, to study embryo morphogenesis, and to obtain haploid plants (by culturing unfertilised ovules or anthers) (Lersten, 2004; Stern et al., 2021).

Study of double fertilisation — a classical embryological method based on observation of pollen tube germination, entry of two sperm cells into the embryo sac, and their fusion with the egg cell and central cell. Fixed material with serial sections or fluorescence microscopy with callose staining is used (Lersten, 2004; Evert, 2006).

Endosperm analysis — study of the type of endosperm development (nuclear, cellular, helobial), its cytology, and the accumulation of storage substances. The endosperm type is often constant within a family and is used in systematics (Simpson, 2019; Lersten, 2004).

Quantitative embryology — use of stereological methods to estimate the volumes of nuclei, cells, and tissues at different stages of embryogenesis. It allows correlations between reproductive structure size and fertility, as well as the influence of stress factors on seed development, to be identified (Evert, 2006).

Thus, embryological methods provide a detailed picture of the development of the plant reproductive sphere, which is necessary for understanding reproductive barriers, improving breeding processes, and establishing phylogenetic relationships (Lersten, 2004; Simpson, 2019).

Methods of biotechnology and genetic engineering are based on manipulations with cells, tissues, and DNA molecules in order to obtain new plant forms with desired traits, study gene functions, and accelerate the breeding process (Stern et al., 2021; Mauseth, 2017). These methods have powerful applied potential in agriculture, pharmacy, and restoration ecology.

In vitro tissue and organ culture — growing isolated plant parts (explants) on artificial nutrient media under sterile conditions. Different types include:

Micropropagation — a method of vegetative reproduction in vitro that allows thousands of genetically identical plants (clones) to be obtained from a single explant in a short time. Meristematic tissues (shoot tips, axillary buds) are used on a medium with cytokinins (Stern et al., 2021; Graham et al., 2014).

Anther and microspore culture — a method for obtaining haploid plants, which are then diploidised (e.g., with colchicine) to create completely homozygous lines — doubled haploids. This dramatically reduces the breeding time of self‑pollinated crops (Mauseth, 2017; Simpson, 2019).

Somatic hybridisation — fusion of isolated protoplasts from two different species (including distantly related ones) using polyethylene glycol or electroporation. The resulting hybrid cells regenerate into whole plants, making it possible to overcome incompatibility barriers in sexual crossing (Lersten, 2004; Evert, 2006).

Genetic transformation methods — transfer of foreign genes (transgenes) into the plant genome to confer new traits (herbicide resistance, insect resistance, virus resistance, improved fruit quality). The main approaches are:

Genome editing (CRISPR/Cas9 and other editing systems) — a technology that allows targeted changes (knockouts, substitutions, insertions) to be made in specific genes. Unlike transgenesis, editing can result in changes indistinguishable from natural mutations. The method is actively used to improve crop plants (disease resistance, improved oil composition, increased yield) (Stern et al., 2021; Mauseth, 2017).

Molecular markers in breeding and systematics — use of PCR‑based markers (RAPD, SSR, AFLP) and SNPs (single nucleotide polymorphisms) to assess genetic diversity, variety identification, construction of genetic maps, and marker‑assisted selection (MAS). These methods are covered in detail in the sections on molecular phylogenetics (Simpson, 2019; Graham et al., 2014).

Bioinformatics methods — processing of large genomic and transcriptomic data (next‑generation sequencing, NGS) using computer algorithms. They allow gene identification, prediction of protein functions, analysis of gene expression, and evolutionary relationships (Stern et al., 2021; Simpson, 2019).

Phytoremediation — the use of plants and associated microorganisms to clean up contaminated soils, water, and air. Although this is an ecological method, it often includes biotechnological approaches: selection of hyperaccumulators, creation of transgenic plants with enhanced ability to accumulate heavy metals or degrade xenobiotics (Mauseth, 2017; Graham et al., 2014).

Thus, the methods of biotechnology and genetic engineering significantly expand the capabilities of traditional botany, allowing directed modification of plant hereditary traits, overcoming interspecific barriers, and accelerating the creation of new varieties with desired characteristics (Stern et al., 2021; Mauseth, 2017).

A classic example of the integrative approach is systematics and phylogenetics. Here, data from comparative morphology, anatomy, embryology, and palaeobotany are combined with molecular genetic (DNA sequencing) and biochemical (chemosystematics) data. This synthesis makes it possible to construct phylogenetic trees that are simultaneously consistent with morphological characters and molecular markers, and then calibrated using fossil remains (Simpson, 2019; Graham et al., 2014).

Another example is ecology and geobotany. Classical descriptions of plant communities and establishment of sample plots are supplemented by remote sensing (satellite imagery, NDVI) and GIS analysis, as well as field physiological measurements (gas exchange, water potential). As a result, the researcher obtains not only a static vegetation map but also models of productivity, seasonal dynamics, and responses to climatic anomalies (Mauseth, 2017; Stern et al., 2021).

In plant physiology, vegetation experiments and biochemical analyses are increasingly combined with molecular biology methods (gene knockouts, transgenic plants, expression analysis) and high‑resolution microscopy (confocal, TEM), which makes it possible to identify adaptation mechanisms at the cellular and subcellular levels (Evert, 2006; Lersten, 2004).

Modern botany is gradually evolving towards systems biology — a discipline that studies living systems as integral hierarchical structures. In this context, methods of mathematical modelling, big data analysis, and bioinformatics become an integral part of the research arsenal (Stern et al., 2021; Simpson, 2019).

The systems approach makes it possible to link molecular processes (gene expression, metabolic pathways) with physiological responses (photosynthesis, transpiration) and, further, with ecological characteristics (drought tolerance, competitive ability). Such integrative models have high predictive value, especially under conditions of global climate change (Graham et al., 2014; Mauseth, 2017).

In recent years, machine learning and artificial intelligence (AI) methods have been actively introduced into botany. These technologies are particularly effective when working with large data sets that cannot be processed manually.

Automated species identification — using convolutional neural networks (CNNs) to recognise plants from images of leaves, flowers, bark, or seeds. Mobile applications (e.g., PlantNet, iNaturalist) already allow species identification from photographs with accuracy comparable to that of an expert (Stern et al., 2021).

Satellite image analysis and forecasting — machine learning algorithms are used for automatic classification of vegetation types, identification of forest degradation hotspots, biomass estimation, and crop yield forecasting (Graham et al., 2014; Mauseth, 2017).

Microscopic image processing — neural networks successfully segment cells, count stomata, measure cell wall thickness, and automatically detect organelles in electron microscopy images (Evert, 2006; Beck, 2010).

Genomics and transcriptomics — deep learning methods are used to predict the functions of unknown genes, search for promoter regions, analyse expression patterns, and identify associations between genotype and phenotype (Simpson, 2019).

Phenological forecasting — models based on random forests or gradient boosting make it possible to predict the timing of flowering, fruiting, and leaf fall taking into account climatic variables, which is important for agriculture and climate change monitoring (Stern et al., 2021).

Three‑dimensional reconstruction and virtual reality — laser scanning (LiDAR) and photogrammetry allow accurate 3D models of plants to be created, which can be analysed in a virtual environment. This opens up new possibilities for studying crown architecture, light perception, and pollinator interactions (Mauseth, 2017).

Wearable sensors and the Internet of Things (IoT) — miniature sensors of humidity, temperature, and gas exchange, attached to plants, transmit data in real time. In combination with automatic irrigation and protection systems, they form “smart” greenhouses and phytotrons (Graham et al., 2014).

Microfluidic systems (lab‑on‑a‑chip) — for analysing plant physiological responses at very small volumes of media. They make it possible to study root exudates, pollen germination, and early stages of interaction with pathogens (Evert, 2006).

Synthetic biology — the design of new genetic circuits and metabolic pathways in plants. In the future, it may be possible to create plants with completely new properties: biosensors, biopolymer production, or light‑emitting organs (Stern et al., 2021).

The widespread adoption of AI and automation raises new questions for botanists. How can the reproducibility of algorithmic results be ensured? How can overfitting of models on a small number of samples be avoided? How can the expert knowledge of botanists be integrated with the “black boxes” of neural networks? Solving these problems requires close collaboration between biologists, mathematicians, and IT specialists (Simpson, 2019; Mauseth, 2017).

Nevertheless, it is already obvious that combining classical botanical methods with modern computational technologies makes it possible to approach problems that seemed unattainable only recently: global biodiversity monitoring, forecasting the spread of invasive species, creating digital atlases of flora and fauna, and managing the evolution of crop plants (Stern et al., 2021; Graham et al., 2014).

The integrative approach, combining methods from classical morphology to artificial intelligence, is the main pathway for the development of botanical science. It does not abolish the need for deep knowledge of traditional morphology, anatomy, and systematics, but it multiplies the analytical capabilities of the researcher (Simpson, 2019; Evert, 2006).

The future of botany is a science in which a field botanist, armed with a smartphone with a neural network and a pocket DNA sequencer, will work in collaboration with GIS specialists, bioinformaticians, and climatologists. Such interdisciplinary synthesis is the only way to conserve biodiversity, ensure food security, and understand how plants support life on Earth in the Anthropocene epoch (Mauseth, 2017; Stern et al., 2021).

Thus, the methods of botanical research are not a frozen list of techniques. They are continuously developing, absorbing the achievements of related sciences and technologies, and it is precisely this capacity for renewal that secures botany a place among the leaders of modern biology (Graham et al., 2014; Simpson, 2019).