Hort

Horticulture 

  • Hortus = Garden 

  • Culture = cultivation 

  • The science and art of cultivating of fruits vegetables, flowers, and ornamental plants 

Bontany vs. Horticulture

  • Botany is the scientific study of plants A “pure” plant science “book knowledge”

  • Horticulture and applied plant science “How do you grow it”

    • It is interrelated with other disciplines of applied science 

    • More production intensive “more hands-on” 

Main sectors of Horticulture

  • Pomology-the science and practice of fruit and nut culture 

    • The production of fruit trees (growing, harvesting, processing, and marketing) 

    • (what is included) Fruits-Small fruits, vines, tree fruit, brambles Nuts-tree nuts 

  • Olericulture-science and practice of growing vegetables 

    • Production of vegetables, plants grown for their fruits, leaves, roots, pods

    • Herbs-roots, stems, leaves, flavorings, foods, perfumes, medicines 

  • Ornamental horticulture-to make our space look better 

    • Production of ornamental and flowering plants 

    • Floriculture, nursery industry, turf production, etc. 

Viticulture 

  • study, science, and cultivation of grapes 

  • Two classification 

    • Table grapes

    • Wine grapes

  • Includes both grape farming and wine-making 

  • Most come from CA

Floriculture

  • Production and use of flowering plants  

  • Sectors  

    • Bedding plants, houseplants, potted plants, container plants, cut flowers (foliage), seasonal and holiday demand 

Turfgrass industry 

  • Lawn grass maintenance 

    • Homes, commercial sites, athletic fields, golf crocuses 

  • Sod farms

    • Production and harvest of different turfgrass

Nursery Plants 

Hort crop production

  • Wide range of production technologies 

#1 crop consumed is corn (leading protruding country U.S.)



Plant Taxonomy and Classification

Scientific classification of plants 

  • Taxonomy-science of identifying, naming, and classifying organisms

  • How do you distinguish a plant species?

    • Morphology-structural form

    • Anatomy-internal structure 

    • Physiology-plant functions 

    • Phylogeny-genetic relations 

    • Cytology-cell type 

History of Plant Taxonomy 

  • The earliest record of categorizing plants into groups belongs to Theophrastus 

  • Carolus Linnaeus 

    • Published Species Plantarum in 1753 

      • Put more than 1300 plantain “classes”

    • Introduced binomial nomenclature system of plant classification

Binomial Nomenclaturere 

  • Linnaeus pioneered this 

  • Governed by the international code of botanical Nomenclature (ICBN) 

    • Sets rules for naming and renaming plants 

    • Rules are revised as new evidence is found 

Taxonomic Hierarchy 

  • Domain, kingdom, phylum (division), class, order, family, genus, species variety/cultivar

Plant divisions 

  • Nonvasuclar plants 

    • Old, liverworts, hornwarts, and mosses

    • Lack of a vascular system for transporting water and nutrients (like a human does not have blood circulation) 

    • Due to their being old, they can withstand hard conditions 

    • Reproduce 

      • Secualy by spores 

      • Asexually but fragmentation 

  • Vascular plants 

    • 1. Seedless 

      • Has xylem and phloem 

      • True roots, leaves and stems 

      • Reproduces by spores 

      • Lichen 6%?

    • 2. Seeded

    • Gymnosperms 

      • Dont flower but produce seeds, cones 

      • Ex- conifers, cycads, ginkgoes 

    • Angiosperms 

      • The first flower then makes fruit 

      • Flowering plants with their sees in fruit 

      • Diverse in size 



Plant Families

  • Has similar morphological characteristics 

  • Similar floral structures, attract similar pests, attract similar diseases, similar nutrients, same growth requirements 

  • Similar physical traits 

Crop Classification by Family

  • Leguminosae (legumes)

    • Beans, peas (high protein) 

Binomial Nomenclature 

  • Why care about Latin names?

  • Common vs. botanical names 

    • Difference in langues 

    • Regional differences in plant names 

    • The universality of Botanical Latin 

  • Definition-system of naming plants whereby a plant is given a two-part name representing the species 

  • Rules of Plant Naming 

    • Must be underlined or written is italics 

    • Genus names start with an uppercase letter and the species name is written in all lowercase 

    • The name if the person who first decided or named the plant (at the end)

    • Ex- Magnolia grandiflora L.

    • Variety 

      • Recognized variations (varieties) and species are also underlined or italicized 

    • Cultivar

      • Product of plant breeding or selection 

    • Inter-specific hybrids: the cross between the different species of the same genus 

    • Inter-generic hybrids: the cross between the plants of different genera 

      • X Fatshedera lizei (when different genera “X” goes in the front)


Scientific classification 

  • Genus: a subset of organisms with family that share characteristics

  • Species: lowest and least inclusive ranking of plant classifications and is the basic unit of biological classification

    • Capable of interbreeding, and of fertile offspring

  • Subspecies or variety: a form of a species that is slightly  different but not enough to warrant a new species 

What is a Plant?

  • Autotrophs

    • Plants that use photosynthesis to make their own food 

    • Self-feeders

  • Heterotrophs 

    • Organisms that use external sources of food for energy 

  • Plant: terrestrial, multicellular organisms that are able to capture light energy from the sun and make their own food (sugar) through photosynthesis.

 The cell

  • Basic structure and physical uint of plants 

  • Cytology- a branch of the biology involved in the study of cell components and their function

Plant cell

  • Contain many organelles that drive plant processes

  • Organelles (structures)

    • The suffix -elle means small 

    • Similar functions as the ones found in animals 

  • Cell wall

    • A plant cell is bound by a cell wall

      • Made of cellulose (polysaccharide)

      • Gives strength and rigidity

    • Funtions 

      • Projects protplast

      • Provides structure

    • Protoplast

      • “Living component”

      • Cytoplasm

      • Contains the plants organelles

Cell membrane

  • Plasma membrane 

    • Contoles entry and ecit of suntances 

      • Passive diffusio: gases such as CO2 and o2 

      • Active transport: other ion molecules such as sugars or salts

        • Specialixed proteins: gates 

    • Organizes cellulose production

      • Cell walls 

      • Cell growth and differentiation 

Cell nucleus 

  • Larger organelle that has two primary functions 

    • Cellular activities 

      • When and which proteins produced

    • Genetic information

      • Place and storage 

      • Passes on to daughter cells via cellular division

  • Genetic code for cell functions

  • Contains Deoxyribonucleic acid (DNA)

    • Chain of nucleotides wrapped around a protein

    • DNA condenses during cellular division into shapes referred to as chromosomes. 

    • Genetic code for an individual organism (its genes). 

    • Mistakes in genetic code cause mutations

  • Also contains Ribonucleic acid (RNA)

    • Manufactures proteins based on the genetic information provided by DNA

    • Plays a significant role in gene expression

  • Nucleolus: responsible for the formation of ribosomes

  • Cytoplasm

    • Surrounds the organelles and nucleus, filling the inside of the cell

    • Many substances found in the cytoplasm, such as sugard, enzymes and waste

    • These substances are used by the cell to

      • Produce proteins 

      • Maintain the cell metabolism

      • Keep the ell function successfully 

Chloroplasts and other plastids

  • Chloroplast

    • Most important plastid

    • Where photosynthesis occurs*

    • Primarily contain chlorophyll

    • Chloroplasts can physically adjust themselves to optimize the amount of light captured or even to deflect damage from high light situations.

  • Plastid: organelle that contains food or pigment

  • Chlorophyll

    • Green pigment that is a receptor of light energy in the red and blue wavelengths

    • Green light is reflected instead of absorbed  

    • Found in the stacks of thylakoids and surrounded by the stroma

  • Thylakoids

    • Disc-shaped sacs surrounded by membranes 

    • Where the light reactions of photosynthesis take place

  • Stroma

    • Aqueous space outside the grana (stacks of thylakoids)

  • Chromoplasts*

    • Pigmented plastids that contain carotenoids

    • Responsible for the saturated yellow, orange, and red colors found in flowers, aging leaves, fruit, and some roots such as carrots

  • Leucoplasts*

    • Colorless plastids 

    • Perform functions such as synthesizing starch and forming oils and proteins

Mitochondria

  • Parts of the cell that drive the process of respiration and energy transfer

  • All living organisms need this to survive!

  • Plants produce glucose - series of chemical rxns in mitochondria -  eventually produces Adenosine triphosphate (ATP) 

  • (have their own DNA and reproduce on their own)

Vacuoles

  • Stores up to 90% of cell volume

    • Cell sap

    • Waste products

    • Pigments

    • Other liquids

  • Tonoplast: permeable membrane that regulates the entrance and exit of materials

    • Inorganic salts, pigments, sugars, organic acids, toxins

  • Turgor: rigidity and support to plant structures (what makes a plant firm)

  • Vacuoles may also store anthocyanin pigments

    • Blue, violet, purple, dark red, or scarlet colors

How do plants stand tall? (with no water no turgor presser from the water)

  • Turgor within the cell + cellulose in the cell wall =  leaf and stem support 

Plant Tissues 

  • Groups of organised cells of similar structure that performs a collective function

  • Meristematic Tissue

    • Actively dividing cells that differentiate into other tissues

    • Found in areas of active growth

      • Root and shoot tip

  • Permanent Tissues

    • Fully differentiated cells

    • Divided into Simple and Complex Tissues

Meristematic Tissues

  • Apical Meristem

    • Shoot meristem found at the end of shoots

    • Produce Simple and Complex Tissues

    • Produce new buds and leave at the terminus and laterally along stems

  • Meristem Patterns

    • Opposite →  meristem across from each other

    • Alternate → meristem alternate side to side along stem

    • Whorled → meristem are close together to form a spiral

  • Root Meristem

    • Found at the tips of roots behind the root cap

    • Produce permanent tissues

  • Meristem Patterns

    • Tap Root →   main root with few lateral roots

    • Fibrous Root → branches of roots in all directions

  • Subapical Meristem

    • Produces new cells in the region a few micrometers behind an active shoot

    • True meristem in that it produces leaves in a rosette form i.e.) beets, carrots, lettuce and only elongates at bolting or flowering.

  • Lateral Meristem

    • Produces secondary growth often called the vascular cambium producing new xylem and phloem 

  • Cork Cambium

    • Causes increase in stem girth in woody plants 

Why Do Trees Have Rings?

Permanent Tissues

  • Fully differentiated cells

  • Created in meristems

  • Can be simple or complex

  • Simple Tissues

    • Uniform, composed of 1 type of cell

    • Three types of cells

      • Parenchyma

      • Collenchyma

      • Sclerenchyma

  • Parenchyma

    • Found in herbaceous plants, flesh of fruit, swollen roots, succulents

    • Most common plant tissue and forms greatest portion of the plant

    • Thin-walled cells with large vacuoles found under the epidermal cells

    • Contain chloroplast and can become meristematic to heal wounds

    • Storage, gas exchange, secretion/excretion of substances

  • Collenchyma

    • Cells thickened by cellulose

    • Found primarily in young stems, leaves and veins of leaves

    • Structural support, flexibility 

    • Celery 

  • Sclerenchyma

    • Thick-walled cells found as lignified fibers throughout the plant

    • Protoplast dies and becomes nonliving

    • Common in stems and bark

  • Complex Tissues

    • Epidermis

    • Secretory Tissue

    • Vascular Tissue

  • Epidermis

    • Outermost layer of cells on all parts of the plant, but absent from apical and root meristems

    • Minimizes water loss and provides site for gas exchange of carbon dioxide and oxygen

    • Protects plant from

      • Environmental factors, Heat, Insects, Pathogens

    • Guard cells: specialized epidermal cells that control the opening or closing of the stomata 

    • Stomata: pores on the leaves that allow for gas exchange and control water loss

  • Secretory Tissue

    • Permanent Tissues

  • Vascular Tissue

    • 2 primary vascular tissues

    • Xylem

      • Conducts water and dissolved minerals from the roots to all parts of the plant

    • Phloem

      • Conducts food and metabolites from leaves (source) to stems flowers, fruit, roots and storage organs (sink)

Xylem

  • Conducts water & minerals

    • One-way flow 

  • Nonliving tissue

  • Structural support

    • Lignin (give support to plant, how it stands up)

  • Space to store food

  •  No end walls

Phloem

  • Carries photosynthetic products

    • two-way flow 

  • Living tissue

  • Sieve cells

  • Structural support

  • End walls with perforations

Plant organs

  • Stems

  • Buds

  • Leaves

  • Roots

  • Flowers

  • Fruit

  • Seed

Plant classification

  • Gymnosperms

    • Produce seed

    • Seed found in cones

    • Narrow, needle-like leaf structure

    • Generally evergreen species

  • Angiosperms

    • Produce seed

    • Seed found in a fruit structure

    • Broadleaf or grass-like leaf structure

    • Both evergreen and deciduous species

    • Monocotyledons  ⇨  Monocots 

      • Grasses and grass-like plants

    • Dicotyledons   ⇨  Dicots

      • Broad-leaved plants

  • Cotyledons: seed leaves

  • The first leaf-like structure seen on young plants

  • An angiosperm can be classified as a

    • Monocotyledon  ⇨ 1 cotyledon 

    • Dicotyledon ⇨ 2 cotyledons

  • Contain stored food for the young plant

Plant anatomy- Stems, buds, leaves and roots

Roots

  • Come from the radicle (the seed root)

  • Essential Functions

    • Anchorage and support

    • Uptake of water and nutrients

    • Storage of nutrients and food

    • Roots can account for ¼ to ⅓ of the plant's total dry weight (dw)

  • Categorized as either a taproot system or a fibrous food system

  • Taproots

    • Grow directly downward

    • Strong

  • Fibours 

    • holds water well

    • Excellent erosion control

    • Shallow and dense 

  • Adventitious roots

    • Root that arises at any point other than the reticle

    • Prop or anchor the plant

      • For climbing plants

  • Air roots

    • Provide aeration

    • Require oxygen for respiration, limiting plants from growing in very wet ground

  • Apical meristem 

    • Region of cells that divide and grow

    • Created within apical meristem to direct plants toward water and nutrients

  • Quiescent center

    • Rarely dividing poll of stem cells

    • Cells can resume meristematic activity when the issue surrounding them is damaged

  • Root cap

    • Consists of parenchyma cells and dead cells

    • Protects the QC

    • Secreates mucilage to ease the movement of roots through the soil

Stems

  • Mechanical support 

    • Supporting leaves, flowers, and fruit

  • Contain vascular tissues

    • Wate and nutrients through the xylem

    • Photosynthesis through plume 

Stem anatomy

  • Nodes 

    • Where plants can grow from

  • Internodes 

  • Axil

  • Buds

    • Leaf buds

    • Flower buds

    • Lateral buds

    • Terminal buds 

  • lenticels - 

    • regulate gasses, allowing o2 in and co2 and water out of the plant

    • Works at night (when plant no photosynthates)

    • Stomata work during the day

Specialized stem structures

  • Runner: forms new plants at the tip (strawberry)

  • Crown: stem found at the soil surface, near the transition of root to shoot, compacted stem tissue

  • Suckers: adventitious shoot hat develops from root tissue and can be used to propagate plants 

  • Corm: shor, swollen, underground stem

  • Bulb: large short stem surrounded but modified leaves called scales, adventurous roots emerge from the stem bottom

  • Rhizome: horizontal underground stem produces roots and shoots 

Leaf function

  • The primary sight of photosynthesis

  • Exchanges of gasses 

    • Photosynthesis and respiration

  • Transpiration

    • Water loss through stomata 

    • Colling the plant

Leaf blade (lamina)

  • Flat, elongated, and ribbon-like 

  • attached to the stem by a stalk called petiole

Leaf-sheath

  • protects the younger part of the shoot  

  • Supports the whole plant

Stipule

  • Foliar appendages at the base of the leaf sheath

  • Function is to protect the bud

Leaf type: Simple

  • Singular and naver divided into smaller leaflets

  • Always attached to a twig by the petiole

  • Margins can be smooth, jagged, lobed, or parted

  • Lobed leaves will have gaps that will never reach the midrib (space between lobs called sinus) 

Leaf type: compound

  • Has leaflets, which are attached to the middle vein and have their own stalks (rachis)

  • Three types

    • Pinnately

    • Double pinnately 

    • Palmately

Leaf or leaflet?

  • Located lateral bud along the twig branch

  • All leaves will have a bid node at the place of a petiole attached to the twig

  • Compound have a

Leaf ventilation

  • Parallel veins- run in parallel lines found in all monocots

  • Palmate veins-the main veins of the leaf begin at a common point fan out to the leaf tips and look similar to the palm of a had

Sessile leaves 

  • Lack petioles 

  • Leaf connects directly to steam

Leaf of Gymnosperms

  • Fasciales hold together needles for trees (depending on how many needles are in them can help identify the tree)

  • Dichotomous venation: a vascular arrangement in leaves such that the veins are forked, each vein dividing at intervals into smaller veins (ginkgo biloba has this) 

Seeds

  • Made of three main component

    • Embryo

      • Has DNA for plant

    • Endosperm

      • Food for embryo

    • Seed coat

      • Projects embryo

  • Monocost (one cotyledon)

  • Dicot (two cotyledons)

  • Mature ovule- seed

  • Mature ovary- fruit 

Flower and Fruit Anatomy

Common parts of a Plant

  • Stem, roots, leaves, seeds, flowers

  • Flowers play a vital role in classification of flowering plants

  • Not all plants produce flowers

  • Angiosperms vs. Gymnosperms

Flowers 

  • Arrangement of specialized leaves that function in sexual reproduction 

  • Functions

    • Adds aesthetic value and therapeutic benefits to a garden 

    • The means of reproduction in angiosperms

    • Assists the transfer of pollen

      • Pollination

    • Inflorescences: clusters of single flowers gathered on a stem

Flower anatomy: 

Carpel

  • Female reproductive organ parts 

    • Called the Gynoecium

  • Pistil=1 or more carpels 

  • Consist of three structures 

    • Style: tubular structure capped by the stigma

    • Stigma: receptacle for receiving pollen grains

    • Ovary: contains ovules

Steman

  • Male reproductive organ parts 

    • Called Androecium

  • Consist of two structures 

    • Filament: a stalk that gives rise to the anther

    • Anther: sack that contains the pollen grains

Sepal

  • The outer parts of the flower that enclose a developing bud

    • Often green and leaf-like 

    • Modifications 

  • All sepals of a flower are collectively called a calyx 

Pedicel and receptacle 

  • Receptacle : the part of a flower stalk where the parts of the flower are attached to the pedicel 

  • Pedicel: flower stalk

Petals 

  • Showiest part of the flower

  • All petals of a flower are collectively called a corolla

  • Texture may be smooth or have hair like structures called trichomes

  • Differences in petal size, shao and symmetry 

    • Actinomorphic 

    • Zygomorphic

    • Apopetalous

    • Sympetalous

Actinomorphic Flower 

  • Petala are same size and shape and are equidistant from each other - radial symmetrical 

Zygomorphic  flower 

  • Different types of petals on on flower 

  • At least one petal of the corolla is different 

  • Bilateral symmetry

Apopetalous flower

  • Spatial distribution and attachment of peTALS

  • PETALS ARE DISTINCT 

Sympetalous flower

  • Petals are fused forming a Corolla tube 

  • Often have a cylindrical basel tube, a gradually expanding throat, a flaring limb, typically lobed

Inflorescence 

  • Flowers many occur individually (solitary), one flower per stem 

  • May also occur in a bunch or cluster of flowers (Inflorescence)

  • Plants within a family have similar patterns

Four Whorls of a flower

  • Cayx (speals 

  • Corolla (pearls)

  • Steams (androecium)

  • Caepels (gynoecium)

Types of flowers

  • Complete- all four whorls 

  • Incomplete-missing one or more whorl

  • Perfect-have both stamens  and carpels 

  • Impartect-missing stamens or carpels 

Plant sexas

  • Most plants are hermaphrodites

    • Have both male and female reproductive structures 

  • Monoecious plants 

    • Male and female reproductive structures on same plant

  • Dioecious plant

    • Male and female reproductive on different plants 

Monoecious plants 

  • Sweet corn- pollen from the male flower (tassel) mist land on female flowers (silk and ear) for fertilization to occur

  • Florala structures in 3’s 

Dioecious plants 

  • Male and female on separate individuals 

  • One plant is exclusively male or female 

  • More than one plant required for pollination 

  • Florala structures in 4-5’s 

Fruit 

  • Ripened ovary of a flower, together with the seeds within the ovary

  • Surrounds the seed, protect seeds, aids seed dispersal

  • The ripened ovary wall: pericarp 

  • Exocarp: the outer layer of the pericarp

  • Mesocarp: the middle layer 

  • Endocarp: the inner layer

Types of fruits: 

simple

  • Fruit formed from one flower with one carpel or multiple fused carpels

  • Ovary wall surrounding the carpel ripens into indepeed fruit

Aggregate

  • Fruit formed from multiple ripened ovaries present in one flower 

  • Ripened ovaries from one flower coalesce into one larger unit 

Multiple

  • Multiple ovaries from multiple flowers 

  • Fuse together into one structure 

Accessory 

  • Derived from plant tissue other than the ovary 

  • “False fruit”

  • Adheres to the outside of the ovary wall (hypanthium) 

Fruit types 

  • Also categorized according to whether the pericarp at mature is:

Fleshy fruit 

  • barry