Botany is… Basic Botany
… the science of plants, including their structure and function and the environmental factors that affect Master Gardener General Training their growth and development. By Sharon Morrisey Consumer Horticulture Agent Milwaukee Co. UWEX
Horticulture is… MG General Training • Botany –Anatomy – Physiology – Factors affecting plant growth …the science of producing, using • Horticulture and maintaining ornamental plants, – Fruits (pomology & viticulture) – Vegetables (olericulture) fruits and vegetables. – Trees, shrubs and vines (woodies) – Flowers (floriculture) –Lawns – Houseplants It is garden (hortus) culture. • Entomology (insects) • Plant Pathology (diseases) • Soil Science
Life Cycles Terminology & Classification • Annual • Features seed -----vegetative------flowering------seed 1 Year – Life cycle • Biennial – Misc. others vegetative flowering Seed ---(rosette) (“bolt”)----seed st nd • Scientific names 1 Year 2 Year • Perennial – Binomial seed ---vegetative & flowering & seed------– Latin Many Years (some portion survives year to year)
1 Other Terminology Nomenclature
• Stem types: – herbaceous – Woody • Leaf-holding ability: – Deciduous – Evergreen – needle; broadleaf • Habit: –Tree – Shrub –Vine – Groundcover –grass
Binomial nomenclature
• System to classify and name all living things • Developed by Carolus Linneaus in 1750’s • All plants known by two names – Genus – species
Classification
2 Scientific names
•Genus Picea • Species pungens • Variety var. • Cultivar Pneumonic device to remember: King David Came Over From Greece Sunday! ‘Glauca’
Identification Keys Plant Anatomy & Physiology
• Structure • Function • Terminology
Principle Parts of a Vascular Plant Plant Parts
• Roots •Stems • Buds • Leaves •Flowers • Fruits • Seeds
3 Roots Roots
• Functions: – Anchor & support – Absorb nutrients & water – Store “food”
Root Meristem Stems
• Function – Supports leaves, buds, flowers, fruit and seeds – Carries nutrients, water and food • Vascular system –Xylem – Phloem – Adds to girth and height • Cambium (meristem)
Stems Stems –Storage • Modifications – Above ground »Crown » Runner/ stolon » Spur – Below ground »Rhizome »Bulb »Corm » tuber
4 Stems Stems
Stems Stems
Stems Stems
5 Stems Stems Modifications: above ground Modifications: below ground • runner/ stolon •rhizome
Stems Stems Modifications: below ground Modifications: below ground • bulb • corm
Stems Buds Modifications: below ground • tuber • Functions –Produce stems, leaves, flowers (no root buds) –Site of growth meristems
6 Leaves Buds • Functions – Absorb sunlight – Produce sugars through photosynthesis – Transport – Water regulation – Temperature control – Types • Venation • Shapes
Leaves Leaves • Photosynthesis light Carbon dioxide + water------sugar + oxygen chlorophyll • Respiration dark sugar/starch + oxygen ------carbon dioxide + water + energy
Leaves Leaves • Cross-section
7 Leaves Leaves • Transpiration • Stomates with guard cells
Roots Leaves • Transpiration • Translocation – Water – Sugars – nutrients
Leaves
8 Leaves Leaves
Leaves Leaves
Leaves Flowers
• Functions – Produce viable seed(s) through pollination
9 Flowers Flowers
Flowers Asteraceae
Flowers Fruits • Inflorescence • Functions – Carry seeds – Disperse seeds –Is a mature ovary
10 Fruits Fruits
Seeds Seeds •Dicot • Functions – Two seed leaves – Carry genetic information for next generation
Seeds Factors Affecting Growth • Monocot – One seed leaf • Light •Water •Temperature • Carbon/Nitrogen Ratio • Plant Growth Regulators
11 Light Light
• Required for photosynthesis and production • 3 components: of sugars – Quantity
• Involved in transpiration – Quality
• Involved in all chemical reactions – Duration
Light Light
• Quantity • Quantity – Measured in footcandles (fc) – Light meters Outside full sun = 5,000 fc winter • measure in footcandles (fc) 10,000 fc summer Indoor Houseplants: lowest to survive = 50 fc – Degree of contrast of shadow on white paper low light = 50 – 11 fc medium = 100 – 250 fc high = over 250 – 650 fc
Light Light
• Quantity • Quality – Spectrum of light The light level outside in summer • Visible light in dense shade – ROY G. BIV is brighter than a south facing window • Plants need most of red and blue indoors in the winter.
12 Light
• Quality – Blue light responses • Photosynthesis • Petiole length • Internode length • Leaf expansion • Phototropic reactions
13 Light
• Quality – Red & Far Red responses • Photosynthesis • Seed germination, seedling growth • Fruit ripening • Tuber and bulb formation • Photoperiodism •flowering
Light Light
– Indoor Lighting • Duration • Incandescent bulbs – Photoperiod – Mostly yellow to red and far red • Length of day/ night – Produce heat • Varies with the season • Fluorescent bulbs – Cool white – blues • May be artificially manipulated – Warm white - reds • “Grow Lights” – Try to mimic spectrum of natural sunlight » May have extra far red to promote flowering
Photoperiod Photoperiod
14 Light Light
• Longest day/ shortest night • Plant reactions to photoperiod st – Summer Solstice, June 21 – Long Day Plants (short night) – Midsummer’s day • Inhibits flowering • Shortest day / Longest night • Vegetative growth in summer; bloom in fall or spring – Winter Solstice December 21 (Long day onions, form bulbs ) • Half way between – Vernal equinox, March 20 – Short Day Plants (long night) – Autumnal equinox, September 20 • Promotes flowering (Chrysanthemums, pointsettias) • Ground Hog’s Day • Vegetative growth in spring; bloom in summer – February 2 – Exactly halfway between Winter Solstice and Vernal Equinox – Day Neutral Plants
Light
• Other Plant Reactions to Light – Germination • Some plants require light to germinate – Excess light • Burning • Stunting – Inadequate light • Etiolation –Pale – Stretched (“leggy’) – Long internodes
Water Water
• Functions: • Factors affecting: – Solvent for minerals & photosynthates – Soil moisture – Required for chemical reactions • On soil particles – Germination • In pore spaces – Temperature control • On organic matter – Turgor pressure • Mulch to retain – Movement of minerals & photosynthates • In containers •Diffusion •Osmosis • Transpiration
15 Water Water
• Factors affecting: • Methods of watering: – Light – Overhead – Air temperature • sprinklers – Air humidity – Directed –Wind • Watering can • Watering wand • Soaker hoses Transpiration increases when humidity is low, • Drip & trickle irrigation temperature is high and on windy conditions.
Water Temperature
• Timing: • Affects the rate of chemical reactions – Q10 Effect – Early in the day • Reaction rate doubles with every increase of 10 degrees C. • Allows leaves to dry – Photosynthesis (to 90 degrees) – Respiration • Droplets DO NOT act like magnifiers and burn • Only to a point leaves –Flowering – During flowering & fruit production • Respiration without photosynthesis leads to breakdown of carbohydrates.
– Transpiration • Higher temps. Increase evaporation which “boils” water off leaf surfaces which must be replaced by more pulled from soil
Temperature Temperature
Other • Transpiration • Heat cause bitterness in lettuce – Regulated by stomates • Heat causes “bolting” of cool season crops • Cold treatment • Stomates close due to: – Required for dormany which is required for flowering of many plants including bulbs, fruit crops, etc. – Water stress (too little) – causes vernalization of “cole” crops (broccoli, cauliflower, – High temperatures cabbage, etc.) • Heat and cold cause abortion of flowers and fruits – High CO2 • Heat and cold may cause death of non-hardy plants – Darkness • Germination occurs at specific temperatures • Cold soil reduces nutrient uptake
16 Carbon/ Nitrogen Ratio Carbon/ Nitrogen Ratio
– Sources of Carbon: – Carbon & photosynthesis • Photosynthates – sugars & starches • Increased photosynthesis creates more • Wood, dry leaves, dry plant parts carbohydrates
– Sources of Nitrogen: – Carbon & respiration • Absorbed from soil • Increased respiration breaks down carbohydrate • Lightning • Releases energy • Green leaves, stems and plant parts • Fertilizer • Manure
Carbon/ Nitrogen Ratio Plant Growth Regulators
– Low C/N ratio – Hormones • More N than C (high N fertilizer) • Auxin • Little C being produced (low photosynthesis) • Gibberellins • C being broken down (high respiration) • Cytokinin • Abscisic acid – High C/ N ratio • ethylene • Increases flowering and fruiting • Mulches – high carbon – Require extra nitrogen
Plant Growth Regulators
– Auxin • Promote cell elongation • Inhibit lateral bud development (apical dominance) • Promote lateral and adventitious roots (rooting hormones) • Involved in phototropism • Promote flowering and fruit development • High concentrations used as herbicides (broadleaf weed killers)
17 Plant Growth Regulators
– Gibberellins • Promote stem elongation • Promote germination • Causes bolting in biennials • May break bud and seed dormancy in plants usually needing light or low temps. to break dormancy • May induce flowering in long-day plants • Gibberellins often work in concert with auxin
Plant Growth Regulators
– Cytokinins • Regulate cell division • Are needed for germination • Are found in meristems and immature fruits • Migrate from roots to the shoot systems of plants • Promote cytokinesis and cell differentiation • May promote axilllary bud growth • May retard leaf senescence
18 Plant Growth Regulators
– Abscisic Acid • Growth-inhibiting hormone • It goes into action during periods of stress • Promotes dormancy activities such as formation of bud scales and seed dormancy. • Promotes stomata closure during leaf water deficit conditions by activating K ions in the guard cells • Plays role in senescence, the breakdown of cell components before cell death.
Plant Growth Regulators
– Ethylene • Inhibits cell elongation • Promotes ripening in fruits • Is the direct cause of leaf and fruit abscission • Is produced by bruised tissues • Is produced by some seeds when difficulties arise during germination, which stimulates changes that may help push the shoot t the soil surface. • Promotes sprouting of many buds • Can cause flowers to wilt
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