botany = plant science agronomy - field crops, wheat, corn, soybeans horticulture - fruits, veggies,...

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Botany = Plant Science Agronomy - field crops, wheat, corn, soybeans Horticulture - fruits, veggies, woody ornamentals and floriculture crops Forestry - wood and pulp production, recreation, wildlife and watershed management Weed science - deal with controlling and management of unwanted plants.

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Botany = Plant Science

Agronomy - field crops, wheat, corn, soybeans

Horticulture - fruits, veggies, woody ornamentals and floriculture crops

Forestry - wood and pulp production, recreation, wildlife and watershed management

Weed science - deal with controlling and management of unwanted plants.

Major Uses of Plants as FOOD

Grains – wheat, corn, oats, rye, barley, millet and grain sorghum

Starchy Foods – potatoes, sweet potato, cassava, yam, banana

Vegetables - sweet corn, snap bea, pea, bean, lettuce Fruits – apples, strawberries, blueberries, raspberries,

watermelon Sugar Crops – sugar beets, sugar cane, (corn syrup) Oil Crops – soybean, sunflower, peanut, corn,

cottonseed, olive Nuts - Walnut, Pecan; Spices – Vanilla, Pepper, Allspice, Oregano;

Beverages – Coffee, Chocolate, Tea

Nonfood Uses of Plants

Fiber Crops Cotton and Flax

Natural fibers have been replaced with synthetics. Nylon, rayon, polyester

Common to see a blend of natural and synthetic fibers Cotton/polyester blend

Timber, Fuel and Pulp Aesthetic Uses

Cut flowers, turf grasses, green foliage

Other Plant Products

Medicines Drugs Perfumes Cosmetics Insecticides Industrial chemicals

Careers in Plant Science - (with a high school diploma)

Greenhouse caretaker Plant propagator Orchard Care Taker Pesticide Applicator Groundskeeper Tractor Operator Combine harvester

Careers in Plant Science with a 2-year (associate's) degree

Greenhouse manager Golf course manager Pesticide dealer Crop supply salesperson Greenhouse supply

salesperson

4-year degree job opportunities in Plant Science

Crop marketing specialist Crop production specialist Fertilizer technologist Erosion control scientist Soil conservationist Seed technologist Turf grass specialist

Graduate level careers in Plant Science

Plant geneticist Plant breeder Biotechnologist Genetic engineer Plant pathologist Plant physiologist Statistician Weed scientist

Basic Botany

RootsStemsLeavesFlowersSeeds

Plant Classifications Angiosperm: produces seeds enclosed in a fruit

Ex: corn, deciduous trees 1.  Monocot: one seed leaf (cotyledon)

ex. Corn, grass 2.  Dicot: two seed leaves

ex. Beans, trees

Gymnosperms: produces seeds enclosed in cones Ex: evergreen and pine trees

Root Functions

Absorption of water and nutrients (root hairs take up oxygen and water and

it is transported through the xylem tissue in the plant)

Transportation of water and nutrients to stem

Anchor plant to maintain stability Stores food and water

Root System

Primary root: short-lived, develops from embryo

Secondary root: branches from primary root, fibrous root, becomes primary root

Root hairs: extensions reach between soil particles; absorbs water and nutrients; needs care when transplanting

Parts of Roots

Root hairs - site of absorption, one-celled, white, fuzzy hair-like growths that develop near the end of the root branches

Root tip - where the root grows in length (4 to 6 cm of the “free end”)

Root cap - provides protection for the root tip Epidermis - the outermost layer of cells Cortex: - undifferentiated plant tissue from which

new cells arise at the tips of roots (under root cap)

Root Hairs on a Tomato Plant

Parts of Roots

Growing point - just back of the root cap where active cell division

Vascular tissue - is within the cortex, contains cells which transport water, nutrients, and minerals to all parts of the plant.

Elongation region - where rapid growth in the length of the root takes place.

Region of maturation - lies behind the growing point and is where secondary roots emerge.

Types of Root Systems

1. Taproots: primary roots; reach deep into soil ex. Carrot, dandelions, oak

 2. Fibrous: no real primary roots; many fine roots, spread out at soil surface ex. Annuals, grasses, shrubs

3. Fleshy: become food reservoirs, store surplus food ex. Carrots, turnips, beets

Basic Plant Parts

STEMS

Function of Stems

Attachment point for leaves, flowers, fruit

Support Leaves have to

have access to light and air

Function of Stems

Transport FOOD, WATER,

MINERALS Through Capillary Action Vascular System:

Xylem = water and nutrients taken from roots to leaves

Phloem = manufactured food distributed to all parts of the plants

Storage = of water, nutrients, waste

Vascular Systems

Monocot: bundles scattered throughout stem

Dicots: segregated into circular pattern; separated by cambium layer (produces new xylem & phloem cells)

Monocot StemEPIDERMIS

BUNDLE CAP

XYLEM

PHLOEM

Vascular bundles in a scattered arrangement

Monocot Stem

Dicot Stem

Epidermis Bundle Cap

Xylem

Phloem

Cambium Layer

Vascular bundles in a circular arrangement

Dicot Stem

Woody = accumulated dead xylem cells

Herbaceous = nonwoody - succulent (corn, weeds, beans, annual flowers)

Stem Structure:

Terminal bud = tip of stem, point of elongation (cut it off and it’ll get a bushy plant)

Auxillary bud = located above each leaf Node = where the leaf is attached Internode = region between nodes

Stem Growth

Growth in LENGTH = meristematic cells = active cell division Apical meristems = tips

Growth in DIAMETER = cambium layer (rings) Cells divide between xylem and phloem Stem grows in diameter when: cambium layer divides on inner side of stem =

new xylem and on outer side of stem = new phloem

Trees in dormant seasons add different colors to the growth layers = rings

Basic Plant Parts

LEAVES

  Function

To absorb sunlight for the manufacturing of plant sugars

Photosynthesis Flattened surfaces present a large area for

absorption of light energy To make food used by plants for growth

& reproduction

Types of Leaves

Scale leaves - small, leathery, protective leaves, enclose & protect buds

Seed leaves - cotyledons, are modified leaves (storage organs).

Spines and tendrils - modified leaves that protect or assist in supporting stems

Types of Leaves

Storage leaves - found in bulbs and succulents, serve as food storage

Bracts - which are often brightly colored (poinsettia)

Conifers,(pines, firs, spruce)needles- waxy cuticles with sunken stomata resin canals on sides of vascular system

to guard against insect damage

Dicot Parts of a Leaf

Blade - broad, thin part of leaf Petiole - thin stem attaching leaf to stem Sessile - leaves with no petiole Midrib - large, central vein Margin - edge of leaf Secondary vein - branches from main vein Apex or tip - top of leaf Base - bottom of leaf

Monocots

Sheath - portion of leaf blade surrounding stem

Ligule - “collar” extension of sheath curving around stem

Auricles - appendages that surround stem at junction of blade and sheath

Cross-Section of A Leaf Epidermis - protection of leaf tissue Cuticle - waxy substance (cutin) protects leaf from

dehydration Guard cells - open and close, regulate passage of

H2O, O2, and CO2 Stoma - openings in leaf surface Mesophyll - middle layer of leaf, where

photosynthesis occurs Palisade layer - dense upper layer Spongy mesophyll - lower layer air space

Chloroplasts - actual sites of photosynthesis

Leaf Characteristics

Simple - one blade per leaf ex: grass, oak, apple

Compound - several leaflets ex: sumac, locust 2 Types:

Palmate Pinnate

Leaf Arrangement along a Stem

Rosulate - basal leaves form a rosette around stem

Alternate - leaves occur at alternate spots on stem; single leaf at each node oak, beech

Opposite - leaves occur two at a node on opposite sides of stem maple, ash, dogwood

Whorled - 3 or more leaves at each node

Looks compound but is actually simple

Venation - arrangement of veins

Parallel - from base to tip in parallel lines ex. Grasses/monocots

Net-veined - veins branch from main midrib(s) and subdivide to finer veinlets more resistant to tearing Pinnate - veins are lateral from midrib to edge Palmate venation - principal vein extends

outward, like ribs of a fan ex. Dicots, apple, maple leaves

Tomatoes - Spiral Leaf Arrangement

Unpruned vs. Pruned

Flowers

Basic Plant Parts

Purpose of Flowers

POLLINATION = Plant Sexual Reproduction Brightly colored & fragrant to attract bees,

insects, birds Pollination occurs by animals, wind,

human activity

Flowers

Dicots - typically have four or five sepals and/or petals, or multiples thereof

Monocots - typically come in threes or multiples of three

Flowers Contain 4 Parts

Sepals: small, green, leaflike structures located at the base of a flower - protects opening bud and flower; supports petals; also called a calyx

Petals: highly colored portions of a flower to attract pollination

Stamen: male part of the flower Pistil: female part of the flower

Female Part of the Flower (PISTIL) Stigma: pollen-collecting

structure at top of pistil Style: support structure

connecting ovary and stigma Ovary: enlarged base of the

pistil contains ovules (eggs), if an egg is fertilized, the ovule develops into a seed.

Pollination: pollen is collected at stigma, travels down style and reaches the ovary

Male parts of the flower

Stamen: Anther: pollen sac - located

at top of structure...Contains pollen

Filament: stalk supporting anther, holds the anther in position, making the pollen available for dispersement by wind, insects, or birds

Tomato Flower

Types of Flowers

Complete/Perfect: flower with all four parts Incomplete/Imperfect: flower missing any

of the four parts

Corn plant: male and female parts in different places on one plant Male part = tassel Female part = ears

Incomplete FlowerIncomplete Flower

Has ONLY male parts or female parts Has ONLY male parts or female parts Male flower – sepals, petals & stamens but Male flower – sepals, petals & stamens but

no pistilno pistil Female flower – sepals, petals, & pistil, but Female flower – sepals, petals, & pistil, but

no stamensno stamens Examples: Kiwi, GinkgoExamples: Kiwi, Ginkgo

Plants are classified by reproduction life spans

Annual: completes life cycle in one year Ex: bedding plants, vegetables, corn, wheat

Biennial: 2 year life cycle. Grows vegetation in one year. Flowers and dies off second year Ex. Celery, asparagus, wild carrot

Perennial: life span of 2 + years Ex. Trees, shrubs

Tomato Reproductive Cycle

Developing Buds Immature Flowers Mature Flower

Fertilized Flower Developing Fruit

Immature Fruit Mature Fruit

SEXUAL & ASEXUAL REPRODUCTION

Sexual & Asexual Reproduction

Sexual: Propagation is by seed

Asexual: Propagation is the increase of plants by vegetative methods.

Sexual Reproduction

Advantages more economical easier longer storage time

Disadvantages do not breed true slow growth do not produce viable seeds

How do pollen grains fertilize the ovules?

Pollen grains are carried by wind, water, or animals

Pollen lands on stigma, pollen tubes move toward ovary

Fertilization happens in ovary Embryo is formed Embryo grows outward and forms fruit or

seed

Sexual Reproduction Self-fertilization, pollen and ovules are made by the

same plant. Repeated self-fertilization results in inbreeding. Inbred plants

often show reduced vigor and make fewer fruits and seeds. Cross-fertilization, pollen and ovules come from

genetically different plants. Cross-fertilization often leads to vigorous, highly productive

plants, an effect called hybrid vigor. Cross-pollination is useful in plant breeding

Can be done by removing anthers from a plant before pollination, so that the grower can supply pollen from another selected plant

Some plants cannot self-pollinate. Some plants have distinct male and female individuals.

Asexual Reproduction

Vegetative reproduction is asexual a= without

Three types of cuttings: Tip cutting Leaf section, leaf petiole, or cutting veins Cutting of roots

Ensure new plants are identical to parent plants

Maintain desirable species

Common types of asexual propagation

Cuttings - portion of plant removed and forms roots (shrubs/houseplants)

Grafting - shoot removed from parent plant and placed on another (apple/fruit trees)

Budding - bud removed from parent plant and placed on stock (fruit trees/ornamentals roses)

Division - clumps of plants dug up and separated (hostas, mums, lilies)

Rhizomes - rhizomes dug up, cut into sections and planted (iris)

Stolon - new plants root at nodes (strawberries

SEEDS

   Sexual Reproduction

Requires flowers to form, pollination & fertilization to occur, seeds develop and grow

Pollen from anther falls on stigma of pistil from anther of stamen

Fertilization occurs in ovary Ovary develops into fruit and ovules

become seed

Seeds are living or dormant

3 parts: 1. seed coat

2. endosperm/cotyledon

3. embryo

Parts of the Seed

Seed Coat Protective outer covering of the seed Helps transport seeds and keep them

viable (alive) Endosperm

Stores plant food (starch & protein) Feeds the growing embryo during

germination

Parts of the Seed

Cotyledon Seed leaf - first leaves seen on a plant. Feeds

the plant during first growth Dicots = 2 Monocots = 1

Embryo New plant that develops as a result of fertilization Epicotyl - forms all plant parts above the first

node of the stem. Hypocotyl - forms the lower stem and roots

Seeds

Angiosperm— flowering plants, seeds are born in an enclosed ovary (some 250,000 species)

Gymnosperm— seeds of gymnosperms are born naked with no ovary (pines, spruces, and ginkgo 700 species)

Germination

1. Seed coat softened by water

2. Favorable temperatures must exist

3. Endosperm feeds growing plant

4. Epicotyl - grows away from gravity

5. Hypocotyl - grows toward gravitational attraction

Monocots vs. DicotsMonocots vs. Dicots

Cotyledons

Monocots - (grasses); remains inside seed for a longer period

Dicots - push up through the soil at germination and act as true leaves

Monocot Growth

Dicot Growth

FRUIT

Fruit Consists of:

Fertilized and mature ovules = SEEDS Ovary wall

Fleshy, as in the apple, or dry and hard as in a maple fruit

Seeds enclosed within the ovary apples, peaches, oranges, squash, cucumbers

Seeds situated on outside of fruit tissue corn, strawberry

Types of Fruit - Simple

Develop from a single ovary Cherries and peaches (drupe), pears and

apples (pome), and tomatoes (berries) Tomatoes are a botanical fruit since they

develop from the flower, as do squash, cucumbers, and eggplant

DRY: (fruit wall becomes papery and hard) Peanut (legumes), poppy (capsule), maple

(samara), and walnut (nut)

Tomato

Types of Fruit - Aggregate

Come from a single flower which has many ovaries

Ovaries are fertilized separately and independently

Strawberry and blackberry have an edible, enlarged receptacle

Types of Fruit - Multiple

Tight cluster of separate, independent flowers on a single structure

Each flower will have its own calyx and corolla Pineapple, fig and

the beet seed