Determination of vein islet number, vein islet termination and palisade ratio
Determination of vein islet number, vein islet termination
The vein islet is the minute area of photosynthetic tissue encircled by the ultimate division of the conducting strands. The vein termination number is the number of veinlet terminations per mm of the leaf surface. A piece of the leaf was cleared by boiling in chloral hydrate solution and camera lucida and drawings board were arranged and a 1 mm line was drawn with help of stage mm. A square was constructed on this line in the centre of the field. The slide was placed on the stage.
The veins included within the square were traced off, completing the outline of those islets which overlap two adjustment sides of the square. The average number of vein islets from the four adjoining squares, to get the value for one square mm was calculated. The number of veinlet termination present within the square was counted and the average number of veinlet termination numbers from the four adjoining squares to get the value for 1 square mm was found known as vein termination number.
Determination of palisade ratio
A piece of the leaf was boiled in chloral hydrate and was placed under the microscope. Camera lucida and drawing board were arranged and the outline of four cells of the epidermis was traced using a 4 mm objective. Then, the palisade layer was focused down and sufficient cells for covering the tracing of the epidermal cells were traced off. The outline of those palisade cells which were intersected by the epidermal walls was completed.
The palisade cells under the four epidermal cells (including cells which are more than half and excluding cells which are less than half within the area of epidermal cells) were counted. The determination for five groups of four epidermal cells from different parts of the leaf was repeated. The average number of cells beneath epidermal cells was calculated known as the palisade ratio.
Frequently Asked Questions (FAQs) about Vein Islet Number and palisade ratio
Vein islet number refers to the count or density of vascular bundles or veinlets in plant leaves. It is an important morphological characteristic that can provide insights into the plant’s taxonomy, identification, and potential medicinal properties.
Vein islet number is significant in pharmacognosy because it can help distinguish between different plant species, subspecies, or varieties. This information aids in the correct identification of medicinal plants, which is crucial for ensuring the safety and efficacy of herbal remedies.
Vein islet number is determined by counting the number of veinlets or vascular bundles present between two adjacent secondary veins in a plant leaf. This count is usually performed under a microscope, and the average number is calculated based on multiple measurements.
A high vein islet number typically indicates a higher density of vascular bundles or veinlets in the leaf. This characteristic may have taxonomic significance and could be used to differentiate closely related plant species or subspecies.
A low vein islet number suggests a lower density of vascular bundles in the leaf. This trait can also have taxonomic implications and help distinguish between different plant groups.
Vein islet number, when combined with other morphological and anatomical features, can aid in accurate plant identification. It adds another layer of detail for distinguishing between similar-looking plant species and ensuring that the correct plant is used for medicinal purposes.
While vein islet number itself may not directly correlate with specific medicinal properties, it contributes to the overall botanical characterization of a plant. Different species may have distinct phytochemical profiles, which could influence their potential medicinal uses.
Yes, vein islet number can potentially be used as one of the parameters to detect adulteration in herbal products. Adulteration with a different species that has a significantly different vein islet number could be identified through careful morphological analysis.
Yes, there are limitations. Vein islet number should be considered alongside other characteristics, such as leaf shape, venation pattern, trichomes, and microscopic features, for accurate plant identification. It may not be sufficient on its own to distinguish all plant species.
Vein islet number is one of several morphological features studied in pharmacognosy. Its importance depends on the specific plant group under investigation and its taxonomic relevance. Researchers often use a combination of traits to comprehensively characterize medicinal plants.
The palisade ratio is a quantitative measure used in pharmacognosy to assess the quality of plant leaves. It refers to the ratio of the palisade parenchyma, a type of plant tissue responsible for photosynthesis, to the spongy parenchyma within the leaf.
The palisade ratio provides valuable information about the efficiency of photosynthesis and the overall quality of the plant material. A higher palisade ratio indicates a greater potential for photosynthesis and, consequently, a higher concentration of bioactive compounds in medicinal plants.
The palisade ratio is calculated by measuring the thickness of the palisade parenchyma and the spongy parenchyma in a leaf section. The ratio is expressed as the thickness of palisade parenchyma divided by the thickness of the spongy parenchyma.
The palisade ratio can be influenced by various factors, including the plant species, environmental conditions (such as light intensity and humidity), age of the plant, and the presence of pests or diseases.
Medicinal plants with a higher palisade ratio are often considered to have better quality because they are more likely to contain higher concentrations of bioactive compounds, such as alkaloids, flavonoids, and other secondary metabolites.
While there are no universally established standards for palisade ratios in medicinal plants, certain guidelines and references may provide target ranges for specific plant species based on their known medicinal properties.
Yes, the palisade ratio can be used as a potential tool to detect adulteration or substitution of medicinal plants. If the palisade ratio significantly deviates from the expected range for a particular plant species, it may indicate the presence of adulterants.
To measure the palisade ratio, a thin cross-section of a plant leaf is obtained and examined under a microscope. The thickness of the palisade and spongy parenchyma layers is measured using calibrated eyepiece graticules.
The palisade ratio is a useful parameter for quality assessment, but it should be considered alongside other factors, such as phytochemical analysis and biological activity testing, to comprehensively evaluate the quality of medicinal plants.
Yes, there are limitations. The palisade ratio provides a structural assessment of leaves and does not directly measure the content of bioactive compounds. Additionally, variations in leaf anatomy and environmental conditions can impact the accuracy of measurements. Therefore, a holistic approach to quality assessment is recommended.
Second Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise
Suggested readings:
