Cotton
J. E.(Jed) and Bonnie McClellan
© 2005 California Academy of Sciences
http://calphotos.berkeley.edu
http://www.georgiacottoncommission.org/
Professor Dr. Naheed Zeba
Dept. of Genetics and Plant Breeding
Sher-e-Bangla Agricultural University, Dhaka
Bangladesh
© 2006 Matt Below
http://calphotos.berkeley.edu
Insulation
“The fabric of our
Lives”
• Oils, Balls, Q-tips ™,
Bandages, Tissue,
Paper, Napkins,
Socks, Shirts, Shorts,
Sweaters, Pants,
Coats, Towels, Linen,
Cushions, Drapery,
Upholstery, Rugs,
Carpet, Comforters,
Mattresses,
Insulation, Filtration
Q-tip
Drapery
Upholstery
Gossypium
Phylum Magnoliophyta
Class Magnoliopsida
Order Malvales
Family Malvaceae
Tribe Gossypieae
Lysigenous glands contain
sesquiterpenes (C15H24)
collectively called gossypol
www.algieri-images.co.uk
© 2006 Matt Below
http://calphotos.berkeley.edu
n = 26
Diversity
• Annual, biennial or
perennial
• Herbaceous, short
shrub or small tree
• Primary axis, alternate
• Leaves have varying
texture, shape,
hairiness
• Showy cream, yellow,
red or purple flowers
axilary, terminal or
solitary with typically 5
petals
www.malvaceae.info
www.biologie.uni-hamburg.de
www.invasive.org
Seed Hairs
• Unicellular
outgrowths of the
epidermis of the
seed or seed coat
• Unique
convolutions
(folded or coiled)
and spiral twists
causes the fibers
to cling together
when spun
African-Asian diploids:
G. herbaceum
G. arboreum
New World tetraploids:
G. barbadense
G. hirsutum
• Annualized
• Longer, stronger fiber
• Higher yield, abundant
fiber
• Ease of harvest
• Time of maturity
• Day length neutral
• Disease resistance
• Glandless seed
http://www.classbrain.com
Four Independently Domesticated
Species!!
Modern Mechanized Production
http://entweb.clemson.edu
http://content.answers.com
Modern Cotton Gin Stand
USDA
ITS sequence: Internal Transcribed Spacer sequence refered to as non
functional RNA situated between rRNA on a common precursor transcript.
Wendel and Cronn, 2003
6-11 mya
(million
years
ago)
“Line of Domestication”
www.prosnea.nl
Two parental diploid groups on
opposite sides of the world!
How did Gossypium disperse over such a long
distance? Where humans involved?
When did the divergence of A and D genomes
occur?
And, when did the chance recombination of these
genomes lead to
allopolyploidization?
Cretaceous Hypothesis:
(geologic period and system MYA)
• Based on the observation of global distribution and
impressive morphological variation within the tribe
• Evidence points to progenitor diploid species lines which
are in currently in different hemispheres (any half of the
earth)
• The continents where the progenitors may have
originated have shifted due to the movements of tectonic
plates separating the African and South American
continents
• Rationally suggests that allopolyploidy must be ancient!
Hybridization must have occurred before the splitting of
the supercontinents and therefore can be dated back to
the Cretaceous or early Tertiary
www.public.iastate.edu
http://www.rocksandminerals.com/geotime/geotime.htm
Hypotheses for Recent Origin of
Allopolyploidy in Cotton:
• Agronomically advanced fiber probably only
developed once
• Origin must have involved human transfer of the
A genome cultigen to the New World
• Followed by hybridization of the A genome
cultigen with a New World D genome species
• So…allopolyploid cotton formed during
agricultural times, within the last 6 millennia!
Other proposals:
• Endrezzi et al.
Thermal stability measurements and hybridization
experiments:
– Argue for Miocene origin (5-18 mya)
– Calculations based on an early Cretaceous
divergence of parental diploid groups
• Phillips 1963
Review of cytogenetic evidence
– Argues for mid-Pleistocene
– Two germinal lines of anciently diverging tribes
recently combined to form tetraploids
A Pleistocene Origin
Evolutionary implications of a recent origin
of allopolyploidy:
• Divergence and speciation of Gossypium
tetraploids
• Diploid parentage of the tetraploids
• Biogeography
How can the progenitors have dispersed?
Rapid diversification and speciation
• Phylogenetic analyses demonstrate
radiation into 3 lineages (direct descent
from an ancestor; ancestry or pedigree.)
involving 5 tetraploid species
• Supported by low levels of interspecific
divergence in nuclear genes
-Island endemics
must have
originated after
additional
dispersal events
Concerning diploid parentage
Cytogenetic studies indicate G. raimondii as the closest living relative of
D genome parental donor
• Hutchinson et al., 1947
– used 5 D-genome species in crosses with G. hirsutum
or G. barbadense
– Indicated G. raimondii as closer to the D-genome
than other species tested
– Innovative approach involving comparative analysis of
diverse synthetic allohexaploids
• Liu et al., 2001
– G. raimondii is the sister group to clade of all 5
allopolyploid species
A-genome perspectives
• A-genome of allopolyploid cotton is more similar
to the A-genome diploids than the D-genome of
the allopolyploid is to that of the D-genome
diploids!
• G. arboreum and G. herbaceum better models of
the progenitor A-genome diploid than G.
raimondii is of the D-genome diploid
• G. herbaceum more likely the A-genome donor
than G. arboreum
Biogeographical Theories
Theories, based on cytogenetic data, suggested that
polyploidization occurred after a Trans-Atlantic
dispersal of a species similar to G. herbaceum
Wendel and Albert, 1992:
Suggest pre-Pleistocene A-genome radiation into Asia,
followed by trans-Pacific dispersal to the Americas
• Supported by biogeography of D-genome species
• Recent arrival of G. raimondii in Peru
Allopolyploidization of Cotton
Occurred Only Once
• All New World
tetraploid cottons
contain Old World
Cytoplasm
• Must have been one
single seed plant in
the initial hybridization
event
By Evert at http://davesgarden.com
So, how did it get there?
www.ferdinando.org.uk
Transoceanic
Voyages
•Long distance dispersals are
characteristic of Gossypieae
•Important in diversification and
speciation
But How!?
• Seeds of many species of Gossypium are tolerant to long
periods of immersion in salt water
• Capable of germination after many years of immersion
• But, only retain their buoyancy for a couple months
• Stephens, 1966 suggested long distance dispersal
may have been accomplished on naturally floating
debris.
Drapery (cloths used for decorative purposes)
Upholstery ( is the work of providing furniture especially seats, with padding,
springs, and fabric or leather covers.
Insulation – insulation help decrease the flow of heat, and is a sound absorber.
Cotton insulation is one of many types of insulation for home construction use in
United States.
lysigenous: formed by the breaking down of adjoining cells —used especially of some
intercellular spaces.
Sesquiterpenes are a class of terpenes that consist of three isoprene units and have
the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be acyclic or
contain rings, including many unique combinations. Biochemical modifications such as
oxidation or rearrangement produce the related sesquiterpenoids
Internal transcribed spacer (ITS) refers to the spacer DNA situated between the smallsubunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the
corresponding transcribed region in the polycistronic rRNA precursor transcript.
The Paleozoic Era (from the Greek palaios (παλαιός), "old" and zoe (ζωή), "life",
meaning "ancient life") is the earliest of three geologic eras of the Phanerozoic Eon,
spanning from roughly 542 to 251 million years ago.
Fish, arthropods, amphibians and reptiles all evolved during the Paleozoic. Life began in
the ocean but eventually transitioned onto land, and by the late Paleozoic, it was
dominated by various forms of organisms. Great forests of primitive plants covered the
continents, many of which formed the coal beds of Europe and eastern North America.
Towards the end of the era, large, sophisticated reptiles were dominant and the first
modern plants (conifers) appeared.
The Mesozoic Era is an interval of geological time from about 250 million years ago to
about 65 million years ago. It is often referred to as the Age of Reptiles because
reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the
time
The Cenozoic is known as the Age of Mammals, because the extinction of many
groups allowed mammals to greatly diversify.
Early in the Cenozoic the planet was dominated by relatively small fauna, including small
mammals, birds, reptiles, and amphibians.
A cultigen is a plant that has been deliberately altered or selected by humans; it is the
result of artificial selection. These man-made or anthropogenic plants are, for the most
part, plants with commercial value used in horticulture, agriculture or forestry.
The Cretaceous ( , -shəs), derived from the Latin "creta" (chalk), usually abbreviated K
for its German translation Kreide (chalk), is a geologic period and system from circa to
million years (Ma) ago
A cultigen (from the Latin cultus cultivated, and gens - kind) is a plant that
has been deliberately altered or selected
byThe
humans;
it is the(result
of artificial
Pleistocene
) (symbol
PS1) is the geological epoch (particular period of time)
selection
which lasted from about 2,588,000 to 11,700 years ago,
In epidemiology, an infection is said to be endemic in a population when that infection
is constantly maintained at a baseline level in a geographic area without external
inputs.
Biogeography is the study of the distribution of species and ecosystems in geographic
space and through geological time
In physics, buoyancy or upthrust, is an upward force exerted by a fluid that opposes
the weight of an immersed object.
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