Cotton evolution at a glance

Cotton, ‘King of fibre’ is the premier cash crop in India
It is cultivated in tropical and subtropical regions of more than 80 countries of the world.
Cotton belongs to family Malvaceae and genus Gossypium
India is the pioneer country for the cultivation of cotton hybrids on commercial scale. After releasing of Hy.4 developed by Dr.C.T.Patel from 1971 from Main Cotton Research Station, Surat.
Cotton is providing livelihood directly and indirectly to over 60 million people and accounting for about 16 per cent of India’s export earnings.
Play a vital role in agriculture, industry, social and monetary affairs of country’s economy. .
More than 150 cotton hybrids have been released by various State Agricultural Universities and private seed companies.

1. COTTON EVOLUTION :
AT A GLANCE

2. •Introduction
•History and Evolution
•Morphological diversity in cultivated
species
•Case Studies (C.S.)
•Fiber evolution under domestication
•Conclusion
2
Content

3. 3
Introduction
Karpas/Karpasi - Sanskrit
Karposas –Greek, Carbasus- Latin
Cutan – Arbi Cotton – English
Key role in human civilization
Vital role in national economy
White gold
Dominancy over synthetic fibers
Tree of wool
Eight groups of diploid 2n = 26
Subkingdom - Tracheobionta
Superdivision - Spermatophyta
Division - Magnoliophyta
Class - Magnoliopsida
Subclass - Dilleniidae
Order - Malvales
Family - Malvaceae
Kingdom - Plantae
Vascular Plant
Seeded Plant
Flowering Plant
Dicot Plant
Mallow plants
Fig. 1: The Clade tree for the Gossypium spp.
Genus - Gossypium

4. 4
World's major cotton producing countries
Year 2012-13
Source: United States Department of Agriculture, Foreign Agricultural Service
Country Area
(M ha.)
Production
(M bales of
480 lb)
Productivity
(kg/ha)
India 11.70 25.50 475
China 5.28 34.00 1403
United States 3.82 17.01 971
Pakistan 3.00 9.60 697
Brazil 1.00 6.50 1415
Uzbekistan 1.29 4.30 729
Australia 0.45 4.20 2055
Turkmenistan 0.60 1.50 544
Argentina 0.36 0.80 484
Turkey 0.40 2.60 1415
World 34.13 118.95 759

5. India has the unique
distinction of being the
only country in the world
to cultivate all four
cultivable Gossypium
species…•1331555
•1331555
Cotton in India Cotton in India
Year 2012-13
AICCIP Project – Annual Report
Leading States
Maharashtra – Area (41 lakh ha)
Tamilnadu – Productivity (831 kg/ha)
Area (M ha)

11.77
Production
(M bales)
25.61
Productivity
(kg/ha)
486
World Ranking
Area 1
st
Production 2
nd
Productivity 34
th
5
Gujarat - Production (85 lb)

6. 6
The Gossypiae tribe, distinguished from other Malvaceae : The embryo, wood
and seed coat anatomy, and by the presence of the punctae or lysigenous
cavities (“gossypol glands”) that are widely distributed throughout the
plant body
Gossypium : An undivided style, coriacious capsule containing several seeds
per locule, a somatic chromosome number of 26, and the presence of
three foliaceous involucellar bracts subtending each flower
Plant habit: Fire-adapted, herbaceous perennials in northwest Australia to
small trees in southwest Mexico that “escape” the dry season by dropping
their leaves.
Corolla colors: rainbow of mauves and pinks, whites and pale yellows and
even a deep sulphur-yellow
Seed: Nearly glabrous to short, stiff, dense brown hairs that aid in wind-
dispersal to long, fine white fibers that characterize highly improved forms
of the four cultivated species. Seeds that produce fat bodies to facilitate
ant-dispersal
Gossypioides – Kokia represents the example of long-distance salt-water
dispersal in the tribe
DIVERSIFICATION OF THE COTTON TRIBE

7. 7
Fig. 1. The range of morphological diversity exhibited by members of the Gossypium
genus

8. 8
History and Evolution
The oldest Malvacean pollen is from the Eocene (38 – 45 million years before present -
mybp) in South America and Australia and from the Oligocene (25 - 38 mybp) in Africa
It suggests that the Malvaceae originated during the first third of the Tertiary (65-2.6
mya) and that by approximately 30 mybp it had achieved a world-wide distribution
(Seelanan et. al. 1997)
Fig. 2: Phylogenetic relationships in the cotton tribe
(Gossypiae) as inferred from molecular sequence data
The tribe Gossipiae is approximately
20 million years old
The Lebronnecia/Hampea/Thespesia
separated approximately 15 mybp.
Gossypium is inferred to have
branched off from its closest relatives
(Kokia and Gossypioides)
approximately 12.5 mybp
Successful grafts could be made
between Kokia rockii and Gossypioides
kirkii

9. 9
Fig. 3: Evolutionary History of Gossypium, as inferred from multiple molecular
phylogenetic data sets.
Genus Gossypium is differentiated
cytogenetically into eight ‘‘genome
groups’’ (designated ‘‘A’’ through ‘‘G’’,
and ‘‘K’’)
They differ in DNA content and
chromosome size but not in chromosome
numbers
Three lineages of diploid species are
recognized; the African/Arabian, the
Australian and the American

10. 10
Table 1. Gossypium Species, their Genomes and Distribution
No. Species Genome Distribution No. Species Genome Distribution
Diploid (2n = 26) 26G. thurberi D
1
America
1G. africanum A Africa 27G. armourianum D
2-1
America
2G. herbaceum (Cult.) A
1
Afghanistan 28G. harknessii D
2-2
America
3G. arboreum (Cult.) A
2
Indo-Burma 29G. klotzschianum D
3-k
America
4G. anomalum B
1
Africa 30G. davidsonii D
3-d
America
5G. triphyllum B
2
Africa 31G. aridum D
4
America
6G. barbosanum B
3
Cape Verede 32G. raimondii D
5
America
7G. capitis-viridis B
4
Cape Verede 33G. gossypioides D
6
America
8G. sturtianum C
1
Australia 34G. lobatum D
7
America
9G. nandewarense C
1-n
Australia 35G. trilobum D
8
America
10G. robinsonii C
2
Australia 36G. laxum D
9
America
11G. australe C
3
Australia 37G. turneri “D” America
12G. pilosum K Australia 38G. stocksii E
1
Arabia
13G. costulatum K Australia 39G. somalense E
2
Arabia
14G. populifolium K Australia 40G. areysianum E
3
Arabia
15G. cunninghamii K Australia 41G. incanum E
4
Arabia
16G. pulchellum K Australia 42G. longicalyx F
1
Africa
17G. nelsonii K Australia 43G. bickii G
1
Australia
18G. enthyle K Australia Allotetraploid (2n = 52)
19G. londonderriense K Australia 44G. hirsutum (Cult.) (AD)
1
America
20G. marchantii K Australia 45G. barbadense (Cult.)(AD)
2
America
21G. exiguum K Australia 46G. tomentosum (AD)
3
Hawai
22G. rotundifolium K Australia 47G. lanceolatum (AD) America
23G. fryxellii K Australia 48G. mustelinum (AD) America
24G. binatum K Australia 49G. darwinii (AD) America
25G. nobile K Australia 50G. caicoense (AD) America
Source: CICR Tech. Bull. No. 5

11. 11
Fig. 4: Genome biogeography of Gossypium
D genome
diploids
C , G & K
genome
diploids
B & F genome
diploids
E genome
diploids
Singh (1999)
Asia
Arizona
Mexico
USA
Galapogos Ilands
sAfrica
nAfrica
NE. Africa
Australia
Hawaii
Peru
Ecuador
11
A genome

12. 122*!
African-Asian Species!& 5
Subgenus : Gossypium
Section : Gossypium
Section : Serrata
Genome ?
Subsection : Gossypium
A genome
Subsection : Pseudopambak
E genome
1 species
7 species
1 species
3 species
2 species
G. anomalum germplasm pool for bacterial blight
resistance
Cytologically unique, and unusual for its ecological
adapatation to mesic environments
Seven species adapted to the extremely arid
habitats of eastern Africa, the south eastern tip of
Arabia, and the Sind in Pakistan
This poorly known species may be distinguished
from other Gossypium species by its serrate leaves
Subsection : longicalyx
F genome
Subsection : Anomala
B genome
An A-genome progenitor served as the female parent
in the hybridization event of allopolyploidization
G. arboreum, G. herbaceum small scale cultivation
Germplasm pool for several agronomically desirable
traits.

13. 13
G. anomalum
G. capitis-viridis
G. triphyllum
G. longicalyx
African-Asian species
13

14. 14!
Australian Species
Subgenus : Sturtia

13 species
3 species
2 species
section : Hibiscoidea
G genome
section : Grandicalyx
K genome
section : Sturtia
C genome
Do not deposit terpernoid aldehydes (“gossypol”) in the
seeds
G. Sturtianum “Sturt’s Desert Rose”, the floral emblem of
the NorthernTerritory
Basal species in the Australian Gossypium lineage
Unusual herbaceous perennials, in the Kimberley region
Thick root- stock from which they resprout following fire
or seasonal drought
Eliosomes on nearly hairless seeds to facilitate ant
dispersal.
This section has the largest genome in the genus
Do not deposit gossypol in the seeds
Possess stiff spreading seed hairs that allow the seed to
“climb” out of the capsule, and are the only species that
are wind dispersed

15. 15
G
1-n
Australia
G. nandenwarense
G. bickii
G. sturtianum
G. australe
Austraian species
15

16. 16' 1!
American Diploid Species!& / 1
'
Subgenus : Houzingenia D
genome
Section : Houzingenia
Subsection : Houzingenia
Subsection : Integrifolia
2 species
2 species
Subsection : Caducibracteolata
Section : Erioxylum
Subsection : Erioxylum
Subsection : Selera
Subsection : Austroamericana
4 species
3 species
1 species
1 species
Large shrubs and small trees
 G. trilobum, source of CMS and restorer factor
Tolerate mild frost via defoliation
Interspecific hybrids are embryo lethal
Calciphiles, found in arid habitats
G. armourianum germplasm pool for bacterial blight
resistance gene
G. harknessii source of CMS and restorer factors.
Unique flowering phenology, At the height of the
dry season, while leafless, the plants flower and
fruit. After the fruit mature the plants remain
dormant until returning the rains stimulate new
vegetative growh.
G. gossypioides the only diploid species that
shows evidence of the original A X D hybridization.
G. raimondi having the genome most similar to the
D-subgenome of allotetraploid, serve as the model
of D genome diploid parent

17. American species
G. nandenwarense
G. harknessi
G. thurberi
G. klotzchianum
G. harknessi
17

18. 18
G. aridum G. raimondii
G. gossypoides G. trilobum
American species
18

19. 19
American species
G. lobatum
19

20. 20
Table 2. Characters for Breeding Value found in different Species
No.Characters for Breeding ValueSpecies
I. Donors for Fibre Quality
1Fibre length G. anomalum, G. stocksii, G. raimondii, G. areysianum, G. longicalyx
2
Fibre strength and
elongation
G. stocksii, G. areysianum, G. thurberi, G. anomalum, G. sturtianum,
G. raimondii, G. longicalyx
3Fibre fineness G. anomalum, G. raimondii, G. longicalyx
4Fibre yield G. anomalum, G. sturtianum, G. australe, G. stocksii, G. areysianum
5High ginning G. australe
II. Donors for Resistance to Insect Pests
1Bollworms
G. thurberi, G. anomalum, G. raimondii, G. armourianum, G.
somalense
2Helicoverpa G. somalense
3Jassids G. anomalum, G. raimondii, G. armourianum, G. tomentosum
4Whitefly G. armourianum
5Mites G. anomalum
6Aphids G. davidsonii
III. Donors for Resistance to Diseases
1Bacterial Blight G. anomalum, G. raimondii, G. armourianum
2Verticillium Wilt G. hirsutum race mexicanum var. nervosum, G. harknessii
3Fusarium Wilt G. sturtianum, G. harknessii, G. thurberi
4Nematode G. darwinii
IV. Donors for other Characters
1Cytoplasmic male sterilityG. harknessii, G. aridum, G. trilobum
2Drought resistance
G. aridum, G. darwinii, G. tomentosum, G. stocksii, G. areysianum,
G. anomalum, G. australe, G. harknessii, G. raimondii
3Frost resistance G. thurberi
4
Delayed morphogenesis of
gossypol gland
G. australe, G. bickii
Source: CICR Tech. Bull. No. 5

21. Hutchinson et al. (1947), indicated that allopolyploid cotton first formed in
agricultural times, perhaps within the last six millennia, following
human-mediated intercontinental transfer of a cultivated A-genome
diploid.
Endrizzi et al. (1989) argued for a probable Miocene origin (5–18 mya), based on
thermal stability measurements in inter-specific DNA hybridization
experiments.
Phillips (1963), indicated that polyploid cotton originated “in geologically
recent times, probably since the start of the Pleistocene (0-5 mya).”
According to the hypothesis, hybridization and polyploidization took place
prior to the separation of the parental A- and D-genome lineages,
which subsequently drifted apart as a consequence of plate tectonic
movements. Under this scenario, then, allopolyploids originated prior
to the rifting of the South American and African continents, in the
Cretaceous (65 mya) or perhaps the early Tertiary (2.5-65 mya).
ORIGIN OF THE ALLOPOLYPLOIDS
TIME OF FORMATION
21

22. PARENTAGE OF THE ALLOPOLYPLOIDS
Stephens (1944), compared allometric patterns of leaf development in intergenomic
hybrids and stated that “either (G. klotzschianum, its close relative G. davidsonii, or
G. raimondii) in combination with G. arboreum would produce a hybrid showing
considerable similarity to present-day New World cottons.”
Hutchinson et al. (1945) indicated G. raimondii as the D-genome donor on
comparative analyses of morphological traits in synthetic A x D amphiploids, and
from observations of lint characteristics and vigor of intergenomic hybrids
Fryxell (1965), indicated G. raimondii as the D-genome donor based on observations
of the lint characteristics of diploid and wild polyploid species.
Hutchinson et al. (1947) reported on the basis of multivalent frequencies in
synthetic allopolyploid x D-genome that the G. raimondii as closer to the D-genome
than the other species tested.
Gerstel (1958), studied multivalent frequencies in hexaploids involving both of the
two extant A-genome species (G. arboreum and G. herbaceum ) to argue that G.
herbaceum was more closely related to the A-genome of the natural allopolyploids.
All allopolyploids contain an Old World (A genome) chloroplast genome, indicating
that the seed parent in the initial hybridization event was an African or Asian A-
genome taxon.
Genomes of the only two A-genome species, G. arboreum and G. herbaceum, differ
from the A sub-genome of allopolyploid cotton by three and two reciprocal
chromosomal arm translocations, respectively suggesting that G. herbaceum more
closely resembles the A-genome donor than G. arboreum. 22

23. 23
Fig. 5 - Evolutionary framework of Gossypium allotetraploids
Diploid Ancestor
(6-11 million year ago)
G. raimondiiG. herbaceum
AA
Old World
N=13
(Big chormosomes)
DD
New World
N=13
(Small chormosomes)
Polyploidization
(1-2 million years ago)
AADD
New World Tetraploid
N=26 (13 big + 13 small)
G. mustelinum G. darwaniiG. barbadense
G. tomentosum
G. hirsutum
Endrizzi et al. 1985; Wendel 1989

24. Morphological diversity in cultivated species
Gossypium herbaceum
•Leaf lobes: Less deep with shriveled base
•Squares: Horizontally extended, round or
triangular
•Flowers: Yellow with pigmented base
•Shorter stamens
•Bolls: Round, pointed and smooth surface without
blackspots
•Lint: White, brown or ash colored
24

25. Gossypium arboreum
•Leaves: Okra type or Deep leaf lobes
•Squares: Vertically extended, triangular, less tips
and covers buds and flowers almost completely
•Flowers: Yellow, white or reddish colored
•Longer stamens
•Bolls: Tapering, Black spotted with uneven surface
25

26. Gossypium hirsutum
•Leaves: Larger, heartshaped or triangular with less
deep leaf lobes
•Squares: Vertically extended and heartshaped
•Shorter stamens
•Bolls: Round, pointed and less blackspotted
•Lint: White, brown or dark brown
26

27. Gossypium barbadense
•Leaf lobes: Deep with folded base
•Squares: Vertically as well as horizontally
extended with heart shape and narrow tips
•Longer stamens
•Bolls: Longer, wide at base and pointed at tip
with rough surface and black spots
27

28. Singh (1999)
Variability in New world and deshi cotton
28

29. 29
Table 3. Variability in qualitative characters of cultivated species of Gossypium
Plant
parts
G. hirsutum G. barbadense G. arboreum G. herbaceum
Stem
Glandless, red, hairy, short
sympodia, zero branch
pubescent, dwarf
Short branch,
dwarf, glandless,
smooth
Bushy dwarf,
glabrous, green
Short branch,
bushy dwarf
Leaf
Curly, cup, glandless, okra,
super okra, red, pubescent,
hairy, smooth mosaic,
round, yellow veins, fused
veins, nectariless
Wrinkled, rugate,
okra
Crinkled, glabrous,
narrow, broad,
laciniate, sintle lobed,
nectariless, red vein
Curly, crumpled,
hairy, stellate
hairs, glabrous,
red
BractsCaduceus, frego, accessoryFrego Frego type, entire Multibracteole
Flower
Cleistogamy, male sterile,
indehiscent anthers, open
bud, buff pollen, yellow
pollen, cream pollen,
orange yellow pollen, petal
spotted, ghost spotted, club
stigma style, sunken
stigma, nectariless
Cleistogamous,
semigametic,
fertility enhancer,
male sterile,
cream, white
Petalody, pistillate,
sunred spot,
thumbnail red, red
margin, ghost spot,
male sterile, yellow
petal, pale and white
petals, Chinese
yellow petal
Spotless, ghost
spot, male
sterile, yellow
petal, pale
yellow petal,
Chinese yellow
and pale petals
BollsCluster, glandless, hairy
Smooth, cluster,
glandless
Partial dehiscence,
few loculed, fused,
big long, retentive
loculi
Closed, big
Seed Naked, fuzzy, coloured fuzzNaked Tufted, naked Semi fuzzy
Lint
Brown, green, khaki,
lintless
Cream, white
Lentless, short,
sparse, khaki, white,
brown
Coloured,
lintless, hairy
Singh, 1999

30. 30
Cytogenetic Investigations

31. 31
No. Intergenomic Hybrids Univalents Per Cell
1 A X B 2.82
2 A X C 8.50
3 A X D 13.98
4 A X E 17.13
5 B X C 11.17
6 B X D 18.19
7 B X E 22.35
8 C X D 13.10
9 C X E 24.68
10 D X E 25.15
11 D X F 21.60
12 G X C 3.84
C.S.-1: Average univalent frequencies in hybrids of diploid Gossypium spp.
•E genome ancient and closest to the ancestral genome of the Gossypium
•C and D genomes evolved in intermediate age, where D > C
•A and B genomes originated very recently; they are closely related; B > A
•F genome is of more recent origin same as A & B genomes
•C and G genomes are more related
Endrizzi et al. (1985)

32. 32
Chromosome No. G. herbaceum G. arboreum Allotetraploids
1
2
3
4
5
1 2
3 4
5 6
7 8
9 10
1 3
2 4
5 6
7 8
9 10
1 2
3 5
4 6
7 9
8 10


1 4
3
3 6
5
4
7 10
9
8
7 10
9
8
3
2 4
5
61
C.S-2: Chromosome end arrangements for the first five chromosomes of the
A genomes of G. herbaceum, G. arboreum and Allotetraploids
Menzel and Brown (1954)
Texas

33. 33
C.S.-3: Incipient genome differentiation for D genome chromosomes
between G. hirsutum (AD) and G. harknessii (D
2-2
),
G. raimondii (D
5
) and G. lobatum (D
7
)
•Two type of crosses:
1.‘A’ genome monosomes ( G. hirsutum) X Homozygous
translocation lines (G. hirsutum) as Control
2.Homozygous translocation lines (Chromo. # 14, 15, 16, 19 and
20) X harknessii, raimondii and lobatum
•Objectives:
1.Total genome affinity (Genome Affinity Index)
GAI = Mean No. of groups of paired chromosomes
Base chromosome numbers (13)
2.Affinity at specific chromosome regions [Chiasma freq. at
(a) Unbroken arm, (b) Translocated region and (e) Interstitial
region]
Menzel et al. (1978)
Florida

34. Table 4. Summary of chromosome pairing in triploid hybrids and controls in crosses
between A-D homozygous translocation lines and appropriate monosomic lines
TT Line
D
Chromo.
Other Parent
Mean frequency per cell of
Mean pairs D
chiasmate arms per
PMC
GAI
I II III
AZ-7
H6L - H14L
H14 Haplo-H6
D
5 12.1411.99 0.96 25.12 0.996
D
7 13.9311.58 0.63 21.02 0.939
2B-1
H2R - H14R
H14 Haplo-H2
D
5 12.8912.68 0.24 24.72 0.993
D
2 - 2 13.8211.89 0.46 21.86 0.950
D
7 14.4311.86 0.27 20.42 0.933
1040
H4R - H15L
H15 Haplo-H4
D
5 12.4112.24 0.71 24.32 0.996
D
2 - 2 12.4211.34 1.27 22.64 0.970
D
7 14.5511.48 0.49 19.44 0.920
4672
H1R - H16R
H16 Haplo-H1
D
5 11.9911.89 1.06 26.02 0.996
D
7 16.6310.76 0.41 17.30 0.859
E20-7
H3L - H19L
H19 Haplo-H3
D
5 12.7512.89 0.15 25.70 1.003
D
7 14.2111.76 0.34 19.64 0.930
10-5ka
H4L - H19R
H19 Haplo-H4
D
5 12.3512.25 0.72 25.14 0.997
D
2 - 2 13.1411.81 0.70 21.98 0.962
D
7 14.7911.57 0.35 19.70 0.916
4669
H1L – H20R
H20 Haplo-H1
D
5 12.2512.04 0.89 24.95 0.994
D
7 17.0410.41 0.38 16.54 0.830
•The order of relationships found was D
5
> D
2 - 2
> D
7
to D
h 34

35. 35
Table 5. Chiasma frequencies at 15 specific positions in 2n – 1 and (AD)
1
D
5

translocation heterozygotes
TT Line
Cyto-type
Chrom-
osome
Chiasma freq. at the following positions
a
(unbroken arm)
b
(translocated
region)
e
(interstitial
region)
Arm
X ma
freq.
Arm
X ma
freq.
Arm
X ma
freq.
2B-1
H2-H14
2n – 1 H14 L 0.9803 R 0.0156 R 0.9294
(AD)
1
D
5 0.9902 0.0032 0.9055
4672
H1-H16
2n – 1 H16 L 1.0000 R 0.9811 R 0.9803
(AD)
1
D
5 0.9816 0.7938 0.8428 *
E20-7
H3-H19
2n – 1 H19 R 0.9782 L 0.0217 L 0.9130
(AD)
1
D
5 0.9444 0.0111 0.9777
10-5ka
H4-H19
2n – 1 H19 L 0.9406 R 0.9809 R 0.6206
(AD)
1
D
5 0.7200 ** 0.8355 ** 0.6355
4669
H1-H20
2n – 1 H20 L 0.9805 R 0.9559 R 0.0259
(AD)
1
D
5 0.9818 0.9745 0.0381
•The differentiation was significant at only 3 positions lower than those of controls
which confirms the previous results of GAI i.e. D
5
> D
2 - 2
> D
7
to D
h

36. 36
Fig. 6 - Model for configurations of marked chromosomes expected in 2(AD)
1

and (AD)
1
D
x
translocation heterozygotes if one of the chromosomes
involved in the translocation is in the D
h
genome and the other in the
A
h
genome

37. 37
C.S.-4: Incipient genome differentiation for A genome chromosomes in
G. hirsutum (AD) and Asiatic diploids
The Study:
•Chiasma frequencies in triploid hybrids of genome constitution
(AD)A involving G. hirsutum (AD), G. herbaceum (A
1
) and G.
arboreum (A
2
)
•Six different translocation lines involving chromosomes 6, 7, 10,
11, 12 and 13 of the A
h
genome were used to mark specific
chromosome regions in hybrids and controls
Objectives:
•Has any divergence in meiotic homology occurred between the
A
h
genome and A
1
or A
2
?
•Differentiation is generalized or localized?
Menzel et al., 1982Florida

38. 38
Table 6. Means and Standard Deviations for the total number of chiasmate II-arm per PMC in
A2N, 2(AD)
1
tt and Tt controls and in (AD)
1
A triploids
Other
Parent
(Species)
Statistic
G. arboreum
(A2)
13 II A2N
G. hirsutum (AD)1
TM-1
Z9-9
6L-10R
1052
7R-11R
1043
7L-12R
2785
10R-11R
6-5M
11R-12L
TM-1
hirsutum
II arms - 25.6925.7725.6225.5625.7525.57
S. D. - 0.590.430.640.800.560.69
A1A
herbaceum
II arms - 25.1724.6524.7425.2725.0725.05
S. D. - 0.911.101.030.931.221.02
A1J
herbaceum
II arms - 24.8924.4724.2624.7725.0825.10
S. D. - 1.051.191.371.090.971.00
A2N
arboreum
II arms 25.35 24.3023.8524.1124.3124.7124.33
S. D. 0.79 1.311.351.481.101.011.31
X
X
X
X
•No significant differences of A genome of G. hirsutum with A genomes of
G. herbaceum or G. arboreum
•Slightly lower frequencies in hybrids as compared to controls  A
h
slightly
differentiated from the A
1
and A
2
genomes
•No localized differences were observed

39. Molecular Investigations
39

40. 40
C.S.-1: Genetic diversity and evolution of Old World Cultivated Cottons as
revealed by Isozyme/Allozyme Analysis
Old world cultivated cotton group
•G. arboreum
•G. herbaceum
Methodology:
•103 accessions of G. arboreum + 31 accessions of G. herbaceum
subjected to isozyme analysis
•20 enzyme systems examined  13 enzyme systems (19 loci with
42 alleles) found polymorphic (Uniqueness of loci as well as
alleles studied)
Wendel et al., 1989Iowa

41. 41
Table 7. Gene frequencies at 19 polymorphic loci in A genome diploid Gossypium
Loci AlleleG. arboreumG. herbaceum Loci AlleleG. arboreumG. herbaceum
1 Ast2-2 0.00 0.03 11 Pgd1-6 0.15 1.00
4 1.00 0.97 8 0.80 0.00
2 Aco1-1 0.00 1.00 9 0.05 0.00
4 1.00 0.00 12 Pgd2-1 1.00 0.00
3 Adh2-4 0.57 0.01 4 0.00 1.00
6 0.43 0.99 13 Pgd3-2 0.00 0.07
4 Arg1-3 0.30 0.93 4 1.00 0.93
4 0.69 0.07 14 Pgm1-4 0.00 1.00
6 0.01 0.00 5 1.00 0.00
5 Enp1-4 0.42 0.93 15 Pgm3-2 0.01 0.00
5 0.58 0.07 4 0.96 0.71
6 Idh1-4 1.00 0.97 6 0.03 0.29
6 0.00 0.03 16 Skd1-4 0.86 1.00
7 Leu1-2 0.02 0.93 6 0.14 0.00
4 0.95 0.07 17 Tpi1-4 0.04 1.00
6 0.03 0.00 5 0.96 0.00
8 Mdh1-4 1.00 0.07 18 Tpi2-4 0.12 0.00
6 0.00 0.93 5 0.88 1.00
9 Mdh5-4 0.91 0.00 19 Tpi4-4 1.00 0.23
6 0.09 1.00 n 0.00 0.77
10 Nad1-1 0.02 1.00
4 0.98 0.00
Out of 19 loci, both are fixed at 3 and nearly fixed at 5 additional loci; Thus, both are
clearly demarcated by isozyme constitution
Out of 42 alleles, 13  G. arboreum, 8  G. herbaceum and 21 shared by both

42. 42
•Out of 19 polymorphic loci,
G. arboreum and G. herbaceum
are:
Fixed for different alleles at 3 loci
and nearly fixed at 5 additional loci
Based on these isozyme studies
+
Previously documented cytogenetic evidences
•Out of 42 alleles of these 19
loci:
8 unique to G. herbaceum
13 restricted to G. arboreum
21 shared by both
•G. arboreum and G. herbaceum were domesticated independently due to
fixation of large no. of loci and high level of allelic novelty

43. 43
C.S.-2: Restriction site mutations in cpDNA of Old World diploids,
5 Allotetraploids and 10 New World diploids
Old world diploids
•G. herbaceum
•G. arboreum
Allotetraploids
•G. hirsutum
•G. barbadense
•G. tomentosum
•G. mustelinum
•G. darwinii
New world diploids
•G. thurberi
•G. armourianum
•G. harknessii
•G. davidsonii
•G. klotzschianum
•G. aridum
•G. raimondii
•G. gossypioides
•G. trilobum
•G. turneri
Synthetic allotetraploids
and their respective
parents were studied for
cpDNA restriction site
mutations
Out of 78 restriction site mutations
observed:
•38  subsets of D genome diploid
species (Within D genome)
•30  unified Old World and New
World cottons & differentiated D
genome from both of them
Wendel (1989)USA
Confirmation of strict
maternal inheritance of
cpDNA

44. 44
•Hybridization and polyploidization events that led to the evolution of
tetraploid cotton were relatively recent i.e. 1.1 to 1.9 MYA (million years ago)
•Divergence time of 6 to 11 MYA of A and D genomes is supposed from their
respective parental lineages
•Female parent of initial intergenomic hybridization was very similar to
present day G. arboreum and G. herbaceum
Probe used
Dra I (P1, P4)
Dra I (P3)
Hind II (P6-8)
Pal I (P6-8)
Sac II (P1, P4)
Bgl II (S6-8)
Cla I (P4)
Eco RI (S6-8)
Sac I (P10-10)
Sry I (P6-8)
Xba I (P3)
Xba I (P1)
Parsimony tree of Gossypium

45. 45
C.S.-3: Bidirectional interlocus concerted evolution following allopolyploid
speciation of r-DNA
•Reported on r-DNA evolution in 5 Allopolyploids (AD genomes),
species representing their diploid progenitors (A and D genomes)
and one of distantly related species (C genome)
•Sequence data from the internal transcribed spacer regions (ITS1 &
ITS2) and the 5.8S gene
Wendel et al. (1995)Ames

46. 46
•Arrays are homogenous, or nearly so, in all diploids and allopolyploids
•Sequence Parsimony – interlocus concerted evolution has been bidirectional in
allopolyploid species (non-monophyletic) under the evolutionary forces.
•Sequence Evolution occurred subsequent to hybridization and
allopolyploidization
Parsimony (gene) tree of r-DNA ITS
sequences in Gossypium
D genome Clade
A genome Clade
Organismal tree

47. 47
C.S.-4: Analysis of nuclear and chloroplast genes to resolve the
diversification of Cotton genus
Phylogenetic relationship derived using DNA sequences from:
•11 single copy nuclear loci
•Nuclear rDNA
•4 cpDNA loci
Cronn et al. (2002
Iowa

48. 48
Based on the sequence data:
•Separation of Gossypium (as
diploids), Gossypoides kirkii
and Kokia drynaroides
occurred appox. 13.4 MYA
•The D genome of Gossypium
diverged from all other
Cottons approx. 6.8 MYA
•Lineages comprising A, B, E,
F and G genomes share a
common history of 1 MY
•Cotton genome groups
radiated in rapid succession
after formation of the genus
(in 17% of the time since the
separation of Gossypium
from its nearest extant
relatives)
Fig. 7:Maximum likelihood (ML) tree obtained from nuclear synonymous site data (7978 bp) using
a molecular clock constraint and inferences for absolute timing of divergence among diploid
Gossypium lineages.

49. 49
Shorter
genome
L
1
(cM)
a
Longer
genome
L
2
(cM)
a
Percentage
difference
A 532.73 D 563.77 5.8%
Dt 532.40 At 557.89 4.8%
A 134.00 At 203.00 51.5%
D 769.20 Dt 1219.38 58.5%
a
L
1
and L
2
were calculated by summing the genetic distance between each adjacent pair of loci.
b
Calculated as L
1
–L
2
/L
1
, where L
1
= shorter genome length, and L
2
= longer genome length.
Brubaker et al., 1999USA
C.S.-5 : Comparative genetic mapping of allotetraploid cotton and its diploid
progenitors
Comparative RFLP mapping was used to construct genetic maps for the
allotetraploids (AD genome; n = 26) and diploids (A and D genomes; n = 13)
Polyploidization in Gossypium is associated with enhanced
recombination, as genetic lengths for allotetraploid genomes are over
50% greater than those of their diploid counterparts.
Table 8. Genetic length differences among the diploid (A, D) and allotetraploid
(At, Dt) Gossypium mapping populations.

50. 50126F5
Evolution of Fiber Under Domestication
Pre-adapted A-genome ancestor later
contributed this genome and its
propensity to allotetraploid cotton that
colonized and diversified in the new
world cotton
The origin of spinnable fibers is occurred
once in the history of Gossypium,
following the divergence of the
A- genome and F-genome clades
Fig. 8. Evolution of Fiber Under Domestication
Gossypium spp were independently
domesticated by aboriginal
domesticators about 5000 yrs ago, or
more, and transformed into fiber and
seed oil plants

51. 51
Human selection over 5 millennia transformed
G. hirsutum into;
Rangy high yielding
Perennial shrub with a
poorly synchronized
fruit set
annualize row-crop
with a heavy fruit set
Photoperiod sensitivity photoperiod
insensitivity
Small seeds that
required scarification
for germination in vitro
seeds that germinate
readily upon planting
At the same time, fibers become longer, stronger
and finer
Domestication led a fine-tuning of the reactive oxygen species which thereby
lead up-regulation of signal transduction and hormone signaling genes and
down –regulation of cell wall maturation genes
G. arboreum race indicum: Africa, Asia
G. herbaceum ssp. africanum, southern Africa
G. hirsutum race yucatanense, Yucatan peninsula
G. barbadense, Central coastal Peru
Fig. 9. Evolution of
G. hirsutum fiber
under
Domestication

52. 52
Cultivated G. hirsutum
wild G. hirsutum G. tomentosum
Cultivated G. arboreum
wild G. herbaceum G. raimondii
G. davidsonii G. longicalyx G. anomalum G. sturtianum
Fig. 10. Mature seeds of cultivated and wild tetraploid and diploid species

53. 53
C.S. -6. Gene expression in developing fibres of Upland cotton (G. hirsutum L.)
was massively altered by domestication
 Microarray analysis, followed by clustering
Categorized and compared the expression level of 40,430 genes in
wild and domesticated cotton
Ryan et al., 2010USA
At all time points more genes were up-regulated in TM-1 than in yucatanense
Fig. 11. Genes differentially expressed during fiber development in cotton

54. 54
Add one graff
C.S.-7. Evolution of Spinnable Cotton Fiber Entailed Prolonged Development
and a Novel Metabolism
Microarray analysis with 22,000 genes
Gene expression profiling
Fig. 12. Summary of the Number of Genes Differentially Expressed between
Adjacent Time-Points during Fiber Development (FDR < 0.05); G. logicalyx
(F genome), G. herbaceum (A genome)
Hovav et al., 2008USA

55. 55
Fig. 13. An Evolutionary and Development Model Describing Processes That Lead to
the Formation of Spinnable fiber
At the beginning of fiber development in F-genome fibers, many genes involved with
stress-response processes were highly upregulated
A-genomes fibers was accompanied by novel expression of genes that assist in
regulating H
2
O
2
and other ROS levels Hovav et al., 2008

56. 56
1027 - A LF
G. arboreum G. hirsutum
G. herbaceum
Am. Nect. less
Gaorani - 6
BC to G. hirsutum
Deviraj
170 – Co – 2
(1951)
Biurbon Cotton was the first G. hirsutum type tried out in the state – Year
1797
Renewd effort- Year 1810, East India Company – Year 1838
CO - 2 Red Arboreum
BC to G. hirsutum
BC-263-1 BC-22
BC to BC 22
Gujarat 67
(1963)
CO - 2 G. tomentosum
BC to CO2
Cotom Indor-2
CTI 421
KW 66 2096
SRT 3087
G.Cot 12
(Khapati)
(1974)
G. Cot. Hy. 4
(1971)
Devitej
134 – Co – 2
(1952)
G.Cot 100
(1974)
Stabilized
G. Cot. Hy. 6
(1980)
G.Cot 10 (SRT 1)
(1974)
Surat Dwarf
G. Cot. Hy. 10 hh (1995)
G. Cot. Hy. 12 hh(2006)
Dharwar
American 2.6.5
G. Cot. Hy. 8
(1989)
G. Cot. Hy. 6 BG II hh (2012)
G. Cot. Hy. 8 BG II hh(2012)
Other Hybrids
Bt cotton Hybrids
Success of Allotetraploid Cotton in Gujarat
G. Cot. Hy. 102 hb(2002)
GTHH-49 BG II hh(2013)
G. Cot. Hy. 12 BG II hh (2013)

57. 57
Variety Year of ReleaseArea of Cultivation
Wagad 8* 1930 Wagad Area
Vijay* 1943 Middle Guj.
Kalyan* 1947 North Guj.
Pratap 1947 Mathio tract
Vijalpa* 1952 South Guj.
Digvijay* 1956 Middle Guj.
Sanjay 1958 Mathio tract
V 797* 1966 Wagad Area
Sujay* 1971 Middle Guj.
G. Cot 101 1977 Budded cotton for Adivasi area
G. Cot 11* 1979 South & Middle Guj.
G. Cot 13* 1981 Wagad Area
G. Cot 15* 1989 Mathio tract
G. Cot 17* 1995 Middle Guj.
G. Cot 19* 1997 Mathio tract
G. Cot 21* 1998 Part of Wagad Area
G. Cot 23* 2002 Gujarat State
Hybrids
DH 7 1985 Gujarat State
DH 9 1988 Gujarat State, M.P.
G. Cot. MDH 11 2002 Gujarat State
Table 9. Diploid Cotton Varieties Released from the Gujarat
* G. herbaceum

58. 58
Table 10. Tetraploid Cotton Varieties and hybrids Released from the Gujarat
Variety Year of ReleaseArea of Cultivation
Deviraj (170-Co.2) 1951 Whole Guj.
Devitej (134-Co-2-M) 1952 Middle Guj.
G 67 1963 South & Middle Guj.
G. Cot 10 1974 Whole Gujarat
G. Cot 100 1974 South Guj.
G. Cot 12 1981 Wagad area
G. Cot 16 1995 Middle Guj.
G. Cot 18 2001 Saurashtra region
G. Cot 20 2010 Gujarat State
GJ. Cot 101 2013 Gujarat State
G. Cot Hy. 4 1970 Guj., A.P., Karnataka, Maharashtra
G. Cot Hy. 6 1980 Guj., Maharashtra ., A.P.,
G. Cot Hy. 8 1989 Gujarat State
G. Cot Hy. 10 1995 Gujarat State
G. Cot Hy. 102 (HxB) 2002 Gujarat State
G. Cot Hy. 12 2006 Gujarat State
G. Cot Hy. 6 BG II 2012 Gujarat State
G. Cot Hy. 8 BG II 2012 Gujarat State
G. Cot Hy. 12 BG II 2013 Gujarat State
GTH-49 BG-II 2013 Gujarat State

59. Fig.14:Current Cotton evolutionary Progress in IndiaFig.14:Current Cotton evolutionary Progress in India
New Insecticides
LRA 5166, NHH 44
2012
59

60. Name Event Genes Year of approval
Bollgard I MON 531 cry1Ac 2002
Bollgard II MON 15985 cry1Ac and cry2Ab 2006
Event 1 Event 1 Truncated cry1Ac 2006
GFM Cry1A GFM C cry1Ab+cry1Ac 2006
DharwadEvent Dharwad Event Truncated cry1Ac 2008
9124 Metahelix cry1C 2009
Bt cotton events approved for cultivation in India
Event name Event number Company/institution Genes
Event 1 + Event 24 Event 1 + Event 24 JK Agri cry1Ac and cry1EC
Widestrike Event 3006-210-23 Dow Agro cry1Ac and cry1F
+Event 281-24-236
Roundup Ready MON 15985 + Monsanto cry1Ac,cry2Ab, CP4EPSPS
Flex Bt MON 88913
TwinLink® Cotton GHB119 Bayer Crop Sci. (cry2Ae/PAT) &
T304-40 (cry1Ab/PAT) cry1Ab,
cry2Ac and bar
GHB614 Zmepsps
Source: http://www.igmoris.nic.in/field_trials.asp.
Bt cotton events currently undergoing field tests in India
60

61. 6135
Conclusion
•Cotton distinguished from other Malvaceae species by having the
gossypol glands.
•Gossypium and their nearest relatives (Gossypoides and Kokia)
diverged from their common ancestors about 13.4 MYA.
•Divergence of A and D genomes from their parental lineages
occurred about 6 to 8 MYA.
•Allotetraploid cottons evolved approximately 1.1 to 1.9 MYA as a
result of hybridization between their diploid ancestors followed
by polyploidization events.
•The maternal parent (progenitor) involved in the evolution of
allotetraploids was ‘A’ genome donor (i.e. similar to the present
day old world cottons), also confirmed through mitochondrial and
diploid genome.
Cont…

62. •Origin of the spinable fiber occurred once in the history of
Gossypium in A genome; these traits and major fiber
quality related traits from the D genome were later
contributed to allotetraploid cotton.
•Domestication has made fiber longer, stronger and finer.
•Great variability exits in the genus which has been
successfully exploited by introgression breeding. These
introgressions led to considerable improvement in
productivity, fiber quality and biotic and abiotic stress
resistance.
Cont…
62

64. 64

65. 65
Future Prospects
•Understanding the relationships among species and their
evolutionary development will continue to provide insights into the
biology of cotton which in turn will increase the effectiveness of
improvement efforts.
•The wild species of cotton, consequently, represent an ample
genetic repository for exploitation. Although these wild species
remain a largely untapped genetic resource, examples abound of
their productive inclusion in breeding programs.
•Sequenced cotton genomes will ultimately stimulate fundamental
research on genome evolution.
•Transgenic cottons have been proven as one of the successful crops
for large scale cultivation. Thus, the fate of the transgenic cottons
should be further considered from the evolution point of view.
•The genes can be incorporated from the wild species to cultivated
cottons by Cisgenic approach, especially for fiber quality as well as
pests and disease resistance.

66. 66
C.S.-3: Analysis of DNA polymorphism in G. hirsutum,
G. herbaceum and G. raimondii by RFLPs
Homologous and homoeologous probes:
•Mapped PstI-genomic probes from A, D and AD genomes
•Screened cDNA NotI-genomic probes from G. hirsutum
Genomic DNA from all three genomes were digested using EcoRI
Reinisch et al. (1994)
Table 8. Hybridization of homologous and homeologous cotton DNA probes to
EcoRI-digested genomic DNA from A, D and AD genome cottons
Source of DNA probe
Number of restriction fragments hybridizing to
genomic DNA from different genomes
Source of genomic DNA
A D AD Total
A genome PstI fragments 157 155 187 499
D genome PstI fragments 178 161 232 571
AD genome PstI fragments 149 126 226 501
AD genome cDNAs 167 154 262 583
Total 651 596 907 2154
Average per DNA probe 2.96 2.71 4.12 ---
Iowa