EEB 304 Lecture 3 – Plant
Manipulation and Naming
Optional Assignment
List the continents that would be included under the
designations “Old World” and “New World”
Return as hard copy or send by e-mail to receive credit
Due Thursday 1/20/11
“What’s in a name? That which we call a rose
By any other name would smell so sweet.”
“What’s in a name? That which we call a rose
By any other name would smell so sweet.”
Shakespeare, “Romeo and Juliet”
Mystery Plant
- This plant is a native of the Old World that has multiple uses
Mystery Plant
- This plant is a native of the Old World that has multiple uses
- It is used for its fibers to make rope, fishnets, clothing, etc.
Mystery Plant
- This plant is a native of the Old World that has multiple uses
- It is used for its fibers to make rope, fishnets, clothing, etc.
- Because its importance as a source of fibers, it was widely planted in the U.S.
midwest during World War II
Mystery Plant
- This plant is a native of the Old World that has multiple uses
- It is used for its fibers to make rope, fishnets, clothing, etc.
- Because its importance as a source of fibers, it was widely planted in the U.S.
midwest during World War II
- It is also the source of a psychoactive drug, which has led to its possession and
using being considered a criminal offense in the U.S.
Mystery Plant
- This plant is a native of the Old World that has multiple uses
- It is used for its fibers to make rope, fishnets, clothing, etc.
- Because its importance as a source of fibers, it was widely planted in the U.S.
midwest during World War II
- It is also the source of a psychoactive drug, which has led to its possession and
using being considered a criminal offense in the U.S.
- In the 1960s and 1970s, court battles ranged that centered on the name for the
plant, with both prosecution and defense enlisting the services of expert botanists.
Mystery Plant
- This plant is a native of the Old World that has multiple uses
- It is used for its fibers to make rope, fishnets, clothing, etc.
- Because its importance as a source of fibers, it was widely planted in the U.S.
midwest during World War II
- It is also the source of a psychoactive drug, which has led to its possession and
using being considered a criminal offense in the U.S.
- In the 1960s and 1970s, court battles ranged that centered on the name for the
plant, with both prosecution and defense enlisting the services of expert botanists.
1. What is the plant?
2. Why was there a dispute about its name?
3. What was the legal resolution of the issue about
its name?
Quiz
1. A scientific name for an organism consists of how
many words? In what language is it written?
2. What is polyploidy? How common is it in plants?
Give an example of a crop species that is polyploid.
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plants eaten regularly by people – ca
2,500 species
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plants eaten regularly by people – ca
2,500 species
– ca
150 species
Plants in World Commerce
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plants eaten regularly by people – ca
2,500 species
Plants in World Commerce
– ca
150 species
Major Economic Importance
– ca
20 species
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plants eaten regularly by people – ca
2,500 species
Plants in World Commerce
– ca
150 species
Major Economic Importance
– ca
20 species
Crops recently domesticated
–
0 species
Plant Manipulation – the Raw
Material
Flowering Plants
– ca 300,000 species
Plants eaten regularly by people – ca
2,500 species
Plants in World Commerce
– ca
150 species
Major Economic Importance
– ca
20 species
Crops recently domesticated
–
0 species
Crops of Major Economic
Importance
Crops of Major Economic
Importance
Wheat, Rice, Maize (Corn),
and Potatoes – the Big 4
Traditional Methods of Plant
Manipulation
- Selection
- Polyploidy
- Asexual Reproduction (=cloning)
- Inbreeding
Variation and Selection
Keystone of Evolutionary Theory – “Selection of the Fittest”
Natural Selection – wild populations
Variation and Selection
Keystone of Evolutionary Theory – “Selection of the Fittest”
Natural Selection – wild populations
Artificial Selection – when done by people
Variation and Selection
Keystone of Evolutionary Theory – “Selection of the Fittest”
Natural Selection – wild populations
Artificial Selection – when done by people
Note: For selection to work, there must be variation, and it must
be heritable
- mutations (natural and induced)
Variation and Selection
Keystone of Evolutionary Theory – “Selection of the Fittest”
Natural Selection – wild populations
Artificial Selection – when done by people
Note: For selection to work, there must be variation, and it must
be heritable
- mutations (natural and induced)
- geographic variation
Artificial Selection in Cole Crops
Polyploidy
Eukaryotic organisms, typically 2 sets of chromosomes/nucleus
= diploid
Polyploidy
Eukaryotic organisms, typically 2 sets of chromosomes/nucleus
= diploid
Gametes – have one set of chromosomes/nucleus (result of meiosis)
= haploid
Polyploidy
Eukaryotic organisms, typically 2 sets of chromosomes/nucleus
= diploid
Gametes – have one set of chromosomes/nucleus (result of meiosis)
= haploid
Some plants – cells have >2 sets of chromosomes = polyploid
triploid
= 3 sets
Polyploidy
Eukaryotic organisms, typically 2 sets of chromosomes/nucleus
= diploid
Gametes – have one set of chromosomes/nucleus (result of meiosis)
= haploid
Some plants – cells have >2 sets of chromosomes = polyploid
triploid
= 3 sets
tetraploid = 4 sets
Polyploidy
Eukaryotic organisms, typically 2 sets of chromosomes/nucleus
= diploid
Gametes – have one set of chromosomes/nucleus (result of meiosis)
= haploid
Some plants – cells have >2 sets of chromosomes = polyploid
triploid
= 3 sets
tetraploid = 4 sets
pentaploid = 5 sets
hexaploid = 6 sets
etc.
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
“Even” polyploids (4x, 6x, 8x) – often fertile
- organs can be larger, including fruits, seeds
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
“Even” polyploids (4x, 6x, 8x) – often fertile
- organs can be larger, including fruits, seeds
- heterosis fixed
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
“Even” polyploids (4x, 6x, 8x) – often fertile
- organs can be larger, including fruits, seeds
- heterosis fixed
Many crop plants are polyploid – see text, Table 1.1
Coffee, Cotton, Potato, Strawberry, Sugar cane, Tobacco, Wheat
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
“Even” polyploids (4x, 6x, 8x) – often fertile
- organs can be larger, including fruits, seeds
- heterosis fixed
Many crop plants are polyploid – see text, Table 1.1
Coffee, Cotton, Potato, Strawberry, Sugar cane, Tobacco, Wheat
Even some crops that appear to be diploid are ancient polyploids:
Corn, sunflower
Polyploidy continued
“Odd” polyploids (3x, 5x, 7x) – usually sterile
- advantage for seedless fruit
“Even” polyploids (4x, 6x, 8x) – often fertile
- organs can be larger, including fruits, seeds
- heterosis fixed
Many crop plants are polyploid – see text, Table 1.1
Coffee, Cotton, Potato, Strawberry, Sugar cane, Tobacco, Wheat
Even some crops that appear to be diploid are ancient polyploids:
Corn, sunflower “Whole Genome Duplication” - WGD
Hybrid sterility
Polyploidy can overcome hybrid sterility
Inbreeding
Most Plants are Outcrossing – gametes from different individuals
Inbreeding
Most Plants are Outcrossing – gametes from different individuals
Some plants, particularly weeds and crop plants, are inbreeding
- self-fertilization
- self-compatibility
Inbreeding
Most Plants are Outcrossing – gametes from different individuals
Some plants, particularly weeds and crop plants, are inbreeding
- self-fertilization
- self-compatibility
Forced Inbreeding:
- increased homozygosity
- inbreeding depression
Inbreeding
Most Plants are Outcrossing – gametes from different individuals
Some plants, particularly weeds and crop plants, are inbreeding
- self-fertilization
- self-compatibility
Forced Inbreeding:
- increased homozygosity
- inbreeding depression
Crossing between homozygous lines  Heterosis (hybrid vigor)
- uniformity
Inbreeding
Most Plants are Outcrossing – gametes from different individuals
Some plants, particularly weeds and crop plants, are inbreeding
- self-fertilization
- self-compatibility
Forced Inbreeding:
- increased homozygosity
- inbreeding depression
Crossing between homozygous lines  Heterosis (hybrid vigor)
- uniformity
- need to produce new seed each year
Asexual Reproduction
Asexual Reproduction  new plants identical to parent (clones)
Asexual Reproduction
Asexual Reproduction  new plants identical to parent (clones)
Applications of Asexual Reproduction:
- vegetative propagation (cuttings, rhizome pieces etc.)
- grafting
Naming of Plants
Scientific Hierarchy of Classification (See Table 1.5, page 35)
Kingdom
Division
Class
Order
Family
Genus
Species
Phyta
“plants”
Anthophyta
“flowering plants”
Magnoliopsida“dicots”
Fabales
“bean order”
Fabaceae
“bean family”
Phaseolus*
“beans”
P. vulgaris*
“common bean”
*Name written in Latin
Species Names – Binomial
Nomenclature
Prior to Linnaeus – use of Phrase Names
Species Names – Binomial
Nomenclature
Prior to Linnaeus – use of Phrase Names
Linnaeus – each species called by genus
name + species epithet = binomial
Species Names – Binomial
Nomenclature
Prior to Linnaeus – use of Phrase Names
Linnaeus – each species called by genus
name + species epithet = binomial
Species – only category that is thought to
be discrete, objective
Species Names – Binomial
Nomenclature
Prior to Linnaeus – use of Phrase Names
Linnaeus – each species called by genus
name + species epithet = binomial
Species – only category that is thought to
be discrete, objective
Species name – consists of genus + species
epithet, written in Latin
Principles of Botanical Names
1. Publication – name must be properly published according to
rules of International Code of Botanical Nomenclature
Principles of Botanical Names
1. Publication – name must be properly published according to
rules of International Code of Botanical Nomenclature
2. Type method – each name is associated with a physical
plant specimen (= type specimen)
Principles of Botanical Names
1. Publication – name must be properly published according to
rules of International Code of Botanical Nomenclature
2. Type method – each name is associated with a physical
plant specimen (= type specimen)
3. Priority – Oldest properly published name is correct one
Example – Rule of Priority leads to
Change in Plant Name
Wyethia trilobata
Example – Rule of Priority leads to
Change in Plant Name
Wyethia trilobata
 Complaya trilobata
Complaya – published in 1991
Example – Rule of Priority leads to
Change in Plant Name
Wyethia trilobata
 Complaya trilobata
 Thelechitonia trilobata
Complaya – published in 1991
Thelechitonia – published in 1954
Example – Rule of Priority leads to
Change in Plant Name
Wyethia trilobata
 Complaya trilobata
 Thelechitonia trilobata
 Sphagneticola trilobata
Complaya – published in 1991
Thelechitonia – published in 1954
Sphagneticola – published in 1900
Example – Change in Circumscription of Genus leads to changes in plant names
Chrysanthemum s.l. (ca 100 species)
“Ox-eye Daisy”
“Mums”
Example – Change in Circumscription of Genus leads to changes in plant names
Chrysanthemum s.s. (3 species)
Leucanthemum
Dendranthemum
Categories within Species
Variation also occurs within species, in some cases it is significant
enough to be recognized by scientists:
1. Wild species – varieties or subspecies. Both names are written
in Latin and follow similar rules as for species names
Used to designate geographic races or morphologically distinct
populations adapted to particular local ecological conditions
Cultivar Names
2. Variation within cultivated plants
- “variety” – widely (and still) used
- cultivar (cultivated variety)
Used to denote an assemblage of cultivated plants that is
clearly distinguished by some character(s) and that following
reproduction retains its distinguishing character(s)
Cultivar name is written in any language except for Latin
Cultivar name can be combined with a generic, specific, or
common name:
Citrullus cv. Crimson Sweet;
watermelon cv. Crimson Sweet;
Citrullus lanatus cv. Crimson Sweet
A Rose by Any Other Name …?
Cannabis sativa and the law
Most Botanists:
Cannabis has 1 species, C. sativa
A Rose by Any Other Name …?
Cannabis sativa and the law
Most Botanists:
Cannabis has 1 species, C. sativa
Some botanists recognize 3 species:
C. sativa (hemp, cultivated for rope)
C. ruderalis (wild form, weed)
C. indica (high THC-form)
A Rose by Any Other Name …?
Cannabis sativa and the law
Most Botanists:
Cannabis has 1 species, C. sativa
Some botanists recognize 3 species:
C. sativa (hemp, cultivated for rope)
C. ruderalis (wild form, weed)
C. indica (high THC-form)
Laws: originally proscribe marijuana (C. sativa)  argument that
defendant not literally breaking law
A Rose by Any Other Name …?
Cannabis sativa and the law
Most Botanists:
Cannabis has 1 species, C. sativa
Some botanists recognize 3 species:
C. sativa (hemp, cultivated for rope)
C. ruderalis (wild form, weed)
C. indica (high THC-form)
Laws: originally proscribe marijuana (C. sativa)  argument that
defendant not literally breaking law
Eventual resolution: looked past botanical “semantics” – illegal
regardless of what it is called by scientists
Tuesday Lecture – Origins of
Agriculture
Read: Chapter 2