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• Major plant tissue systems

  • Ground: This packing and supportive tissue accounts for much of the bulk of the young plants. It also functions as food manufacture and storage. It contains three main cell types: parenchyma, collenchyma, and sclerenchyma
  • Dermal Tissue: This is the plant's protective outer covering in contact with the environment. It facilitates water and ion uptake in roots and regulates gas exchange in leaves and stems
  • Vascular Tissue: Together the phloem and xylem form a continuous vascular system throughout the plant. This tissue conducts water and solutes between organs and also provides mechanical support
• Secretory organs of plants

  • Nectaries: Secret nectars
  • Hydatodes: Secret pure water
  • Sweat glands: Found in desert plants
  • Osmophores: Secrete fragrance in flowers
  • Digestive glands: Found in insect-eating plants
  • Adhesive cells: Secrete materials that aid attachment between host and parasite
  • Resin ducts: Secrete sticky resin
  • Mucilage cells: Found in the growing tip of the roots, aid the passage of roots through the soil
  • Oil chambers: Secrete aromatic oils
  • Gum ducts: Cell wall modification resulting in the production of gums
  • Laticifers: Latex-secreting glands
  • Myrosin cells: Secrete enzymes called myrosinase that produce toxic oil called isothiocyanate
• Plant tissues and tissue system

  1. Meristematic Tissue: Part of a plant where cell division (mitosis) or production of new cells occurs. a. Apical meristem: Tip of stem and roots (shoot or root apical meristem); give rise to the primary meristem. b. Lateral meristem: Stem and roots. b1. Vascular cambium. b2. Phellogen (cork cambium). c. Intercalary meristem: Internodes and bases of young leaves

  2. Permanent Tissues: Derived from meristems which have attained maturity form thus perform their specific function. a. Epidermis: Outermost layers of cells of the primary plant body. Contain stomata, trichomes (appendages). b. Parenchyma: Found in the cortical regions of stems and roots and in the mesophyll of the leaves. Living cells that have diverse functions ranging from storage and support to photosynthesis and phloem loading, specialized for light penetration and regulation of gas exchange. c. Collenchyma: Thickened tissue found in the cortex of the stem and petioles or along the veins of the leaves. Its cells are alive at maturity and have only a primary wall
• Tissues


  Derived from meristems which have attained maturity form thus perform their specific function
• Collenchyma


  • Thickened tissue found in the cortex of the stem and petioles or along the veins of the leaves
  • Its cells are alive at maturity and have only a primary wall
  • These cells mature from meristem derivatives that initially resemble parenchyma, but differences quickly become apparent
• Permanent Tissues


  Derived from meristems which have attained maturity form thus perform their specific function
• Sclerenchyma


  • Hard and tough cells with a function in mechanical support
  • Scattered throughout the plant
  • Found in both primary and secondary tissues
• Types of Sclerenchyma


  • Fibers (bast fibers)
  • Schleroids or stone cells (similar with fiber thick walls and lignified, may be living or dead at maturity)
• Cork


  • Outermost tissue; impregnated with suberin (waxy substance)
• Complex permanent tissue/types of vascular tissues


  1. Xylem conducts water and mineral salts upward the plant body

  2. Consists of Tracheids, vessel membrane, xylem fibers, xylem parenchyma

  3. Phloem distributes the dissolved food materials between the source and sinks consists of sieve tube element (Chief food conducting element), companion cells (Parenchyma cells always found besides the sieve tubes; moves food in and out of the sieve-tube member), phloem parenchyma (Like ordinary parenchyma cells), phloem fibers (Like schlerenchyma cells)
• Regions of the root

  1. Root cap protects the tender apex

  2. Region of cell division 1 to few mm above the root cap; have small cells with thin walls, dense with protoplasm; undergo repeated cell division (meristematic region)

  3. Region of elongation lies above meristematic region; extends to 1-5 mm; undergo rapid elongation and enlargement

  4. Region of maturation lies above meristematic region of elongation, this region produces root hairs
• Tap root System


  1. Primary root grows vertical downward

  2. Branches grow downward or horizontally outwards

  3. Functions: Absorb water, mineral salts from soil, anchorage
• Adventitious Root System


  Roots that grow from any part of the plant body other than radicle
• Fibrous Root System


  In monocots (with all adventitious roots)
• Semi roots


  Derived from the seeds of grasses
• Foliar Root System


  From leaves mainly petiole or vein (spontaneous or due to injury)
• Supporting and conducting organ initially developed from the epicotyl

  Major parts: Bark, Pith and Wood (Composed of xylem made up of vessels, fibers and parenchyma cells)
• Parts of Cell Wall

  • Part 1
  • Part 2
  • Part 3
• Forms of stem


  • Erect or strong stems - unbranched; erect; cylindrical; stout; slim jointed stem with solid nodes and hollow internodes
  • Weak stems - Weak trailing stem on the ground without rooting at the nodes
  • Creeping stem - runner, stolon, offset or sucker
  • Climbing stem - attaches or climbs objects (vines)
• Modified Stem Forms


  • bulb - Short, erect underground stem
  • culm - Flowering stem of grasses and sedges
  • offset - Like runner originates from leaf axil as a short and thickened branch away from the mother plant
  • rhizome - Horizontal underground stem
  • runner - Intermediate aboveground stem with internodes and new plantlet at the tip
  • sucker - Shoot arising below the ground from old stem
  • tendril - Slender coiling branch for climbing
  • tiller - Shoot produced from the base of the stem or culm
  • tuber - Thick storage underground stem
  • corm - Enlarged solid fleshy base
  • Stolon - Slender just like the stem of grasses
  • CROWN - modified stem with very short internodes
• Functions of stem
• Functions of stem


  • Food manufacture (PS)
  • Exchange of gases (PS and RN)
  • Evaporative of water (transpiration)
• Parts of leaf


  • Leaf base - part attached to the stem
  • Petiole - stalk of leaf
  • Leaf blade or lamina - green expanded portion of the leaf
  • Reticulate - network-type of veins
  • Parallel - veins parallel to each other
• Reproductive structure of flowering plants

  • calyx - Lowermost whorl of modified leaves, also known as sepal
  • corolla - Whorl of petals above the sepals
  • gynoecium or pistil - Group of carpels in the center or at the top of the flower
  • gynophore - Stipe of a pistil or carpel
  • pedicel - Stalk of a flower
  • Perianth - Combined calyx and corolla
  • petal - A unit of corolla
  • sepal - A unit of calyx
  • Stamen - Male sporophyll within the flower
• Types of Flower


  • Complete flower - Has all four parts of the flowers (sepals, petals, pistil, and stamen)
  • Incomplete flower - A flower lacking sepals, petals, pistil, or stamen
  • Perfect Flower - have both stamen and pistil
  • Imperfect Flower - have no both stamen and pistil
• Definition of seed
• Parts of a Seed

  • Embryo - Developing plant still inside the seed. The embryo has cotyledons (embryonic leaves), a root cap, a food source, and a plumule (shot)
  • Hilum - The scar on a seed coat at the location where it was attached to the plant's stalk during development
  • Micropyle - The small pore in a seed that allows water absorption
  • Root (Radicle) - responsible for root development
  • stem (hypocotyl) - The part of the stem of a sprouting plant that is above the root and below the stalk of the cotyledon (seed leaves)
  • Seed coat (testa) - Seed coat is the outer, protective layer covering the seed
  • seed leaf (cotyledon) - The embryonic leaf within a seed
  • Plumule - The shoot of an embryo
• Types of Seed


  • Orthodox - Dries out naturally on the mother plant to a low MC less than or equal to 20%. Can be dried to low MC less than 5% without damage. Can be stored at low temperature. Ex. Rice, corn, beans, vegetable seeds, pill, etc.
  • Recalcitrant - Do not dry out normally on the mother plant, shed in moist condition (50-70% MC). Seed larger than orthodox-embryo is only 15% of the orthodox. Killed if MC is reduced below critical values (12-30%). Susceptible to freezing (below 0 degrees C) or chilling (10-15 degrees C). Ex. Seeds of aquatic species, large seeded species, wild rice, tropical fruit crops, jackfruit, cacao, rambutan, lanzones
• Orthodox-embryo


  Only 15% of the orthodox, killed if moisture content is reduced below critical values (12-30%), susceptible to freezing (below 0 degree C) or chilling (10-15 degree C)
• Orthodox-embryo seeds


  • Seeds of aquatic species, large seeded species, wild rice, tropical fruit crops, jackfruit, cacao, rambutan, lanzones, etc.
• Types of Seed


  • Intermediate seeds can withstand desiccation to about 10-12% moisture content and can be stored under hermetic conditions
  • Intermediate seeds lose viability more rapidly at low temperatures (less than 10 degree C) than at warm temperatures (12-21 degree C)
• Fruit


  It is a mature, ripened ovary containing the seed (ripened ovules) and pericarp (the tissue that surrounds the seeds)
• Types of Fruits


  • Simple fruit
  • Aggregate fruits
  • Multiple or Composite fruits
  • Fleshy fruit (juicy)
• Fleshy fruit (juicy) types

  • Berry - Has an entirely fleshy ovary. Ex. Tomatoes, dates, blueberries, bananas, peppers, cranberries, strawberry
  • Hesperidium - Have a leathery rind. Examples include oranges, grapefruits, lemons, and limes
  • Pepo - Is a type of fruit defined by hard rind and a fleshy inner matrix. Ex. Watermelons, cantaloupe, squash, pumpkins
  • Drupe - Is a fruit with a fleshy exterior and a single hard, stony pit surrounding the seed. Ex. Cherries, peaches, olives, mango, raspberry, coconut, plums
• Indehiscent fruits types


  • Achene - Is a single-seeded fruit with seed attached at only one place to the pericarp. Ex. Sunflower, strawberry, buckwheat
  • Caryopsis - A fruit is similar to an achene; however, the pericarp sticks or clings to the seed. Ex. Corn, rice, barley, rye, amaranth, sorghum, oat, wheat
  • Samara - Is usually single-seeded with a membranous wing. Ex. Maple, elm, ash
  • Nut - Is a hard, one-seeded fruit. Ex. Oak, walnut, filbert, hickory
  • Uricle - Is like an achene, but the ovary wall fits loosely around the seed. Ex. Finger millet, pigweed
  • Nutlet - Is a small version of a nut. Ex. Birch, hornbeam
• Dehiscent fruits types


  • Legume (pod) - Is composed of a single carpel and has two longitudinal sutures. Ex. Soybeans, green beans, peas
  • Follicle - Is composed of a single carpel and splits open along one suture. Ex. Milkweed
  • Capsule - Is composed of more than one carpel that are united and form many seeded fruits. Ex. Okra, cotton
  • Pyxis - Is a type of capsule with a lid that falls from the fruit. Ex. Purslane
• Parthenocarpy literally means virgin fruit
• Parthenocarpy is the production of fruit without fertilization, making the fruit seedless
• The oldest parthenocarpic fig was first grown at least 11,200 years ago
• Stimulative parthenocarpy


  Pollination or other stimulation is required for parthenocarpy. Examples include banana and watermelon