Crop production MIDTERM

• The plant body is composed of three organs

  • Leaf - for photosynthesis
  • Stem - for support
  • Root - for anchorage and absorption of water and minerals
• The flowering plants (angiosperm - 250,000 species) cover almost the earth's vegetation
• Seed


  Contains embryo and cotyledon (endosperm) which are protected with a seed coat
• Seed growth


  1. Grows under favorable condition (moisture, temperature, oxygen and sometimes light)

  2. From the embryo, the root and shoot develop

  3. The seedling grows due to cell division in the meristematic tissues

  4. After juvenile stage, plant produces flowers and fruits (after pollination and fertilization)

  5. Fruits contain seeds thus completing the life cycle of the plant
• Tissue


  • Composed of cells usually similar in structure and function
  • It is simple if it contains one cell type
  • It is more complex it is made up of several types of cells
• Organ


  Composed of several tissues with distinct structures and functions
• System


  Composed of interacting organs that coordinate as a functional complex in the life of the organ
• Plant tissues and tissue system

  • Meristematic tissue
  • Permanent tissue
• Meristematic tissue


  • Part of plant where cell division (mitosis) or production of new cells occurs
  • Apical meristem - tip of stem and roots (shoot or root apical meristem); give rise to primary meristem
  • Lateral meristem - stem and roots
  • Vascular cambium
  • Phellogen (cork cambium)
  • Intercallary meristem - internodes and bases of young leaves
• Permanent tissue


  • Derived from meristems which have attained maturity form thus perform their specific function or functions
• Types of permanent tissue

  • Epidermis
  • Parenchyma
  • Collenchyma
  • Sclerenchyma
  • Cork
• Epidermis


  • Outermost layer of cells of the primary plant body
  • Contain stomata, trichomes (appendages)
• Parenchyma


  • Found in the cortical regions of stems and roots and in the mesophyll of the leaves
  • These are living cells that have diverse functions ranging from storage and support to photosynthesis and phloem loading
  • Apart from the xylem and phloem in its vascular bundles, leaves are composed mainly of parenchyma cells
  • Some parenchyma cells, as in the epidermis, are specialized for light penetration and focusing or regulation of gas exchange
• Collenchyma


  • Thickened tissue found in the cortex of the stem and petioles or along the veins of the leaves
  • Collenchyma 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
• Sclerenchyma


  • Sclerenchyma cells (from the Greek skleros, hard) are hard and tough cells with a function in mechanical support
  • Scattered throughout the plant, found in both primary and secondary tissues
  • Fibers - known as bast fibers, long, thin cells with very thick walls often dead at maturity
  • Schleroids or stone cells - similar with fibers thick wall and lignified; may be living or dead at maturity
• Cork


  Outermost tissue; impregnated with suberin (waxy substance)
• Types of vascular tissues

  • Xylem
  • Phloem
• Xylem


  • Conduct water and mineral salts upward the plant body
  • Consist of: tracheids, vessel membrane, xylem fibers, xylem parenchyma
• 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 sclerenchyma cells
• Major plant tissue system

  • Ground tissue
  • Dermal tissue
  • Vascular tissue
• Ground tissue


  • This packing and supportive tissue accounts for much of the bulk of the young plants
  • It also functions in food manufacture and storage
  • It contains three main cell types: parenchyma, collenchymas, and sclerenchyma
• Dermal tissue


  • This is 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
• Regions of the Root

  • Root cap - protects the tender apex (absent in aquatic plants)
  • 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)
  • Region of elongation - lies above meristematic region; extends to 1-5 mm; undergo rapid elongation and enlargement; responsible for growth in length of the root
  • Region of maturation - lies above meristematic region of elongation, this region produces root hairs
• Types of Roots

  • Tap root system
  • Adventitious root system
  • Fibrous root system
  • Foliar root system
• Tap root system


  • Primary root grows vertical downward; branches grows downward or horizontally outwards
  • Functions: absorb water, mineral, salts from soil, anchorage
• Adventitious root system


  Roots that grow from any part of the plant of the plant body other than radicle
• Fibrous root system


  In monocots (with all adventitious roots)
• Foliar root system


  From leaves mainly petiole or vein (spontaneous or due to injury)
• Major parts of Stem

  • Bark, pith and wood (composed of xylem made up of vessels, fibers, and parenchyma cells)
• Types of stem

  • Bulb, culm, offset, rhizome, runner or stolon, sucker, tendril, tiller, tuber, corm
• Forms of Stems

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

  • Leaf base - part attached to stem, Petiole - stalk of leaf, Leaf blade or lamina - green expanded portion of the leaf
• Leaf Venations

  • Reticulate - network-type of veins, Parallel - veins parallel to each other
• Major parts of Flower

  • Calyx - lowermost whorl of modified leaves, also known as sepals, Corolla - whorl of petals above the petals, 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
• Complete Flower


  Has all four parts of the flower (sepals, petals, pistil and stamen)
• Incomplete Flower


  A flower lacking sepals, petals, pistil or stamen
• 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 (shoot), 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 (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, Recalcitrant, Intermediate
• Orthodox seed


  • Dries out naturally on mother plant to a low MC (20%)
  • Can be dried to low MC (5%) without damage
  • Can be stored at low temperature
  • Ex. rice, corn, beans, vegetable seeds, pili, etc.