SAN ASSIGNMENT ON COTTON SPECIES

Submitted by:Santosh pathak

IAAS , Lamjung Campus

WEL-COME

INTRODUCTION:

Cotton, the king of fibers, usually referred as white gold is soft, fluffy staple fiber that grows in a ball, or protective capsule, around the seed of cotton plants of the genus Gossypium.

The plant is shrub native to tropical and subtropical regions around the world, including the Americas, Africa ,and India.

The greatest diversity of wild cotton species is found in Mexico, followed by Australia and Africa.

Cotton was independently domesticated in old and new world

Current estimates for world production are about 25 million tons annually, accounting for 2.5% of the world’s arable land.

China is the world’s largest producer of the cotton, but most of this is used domestically and India rank first in area (1, 10, 00,000 ha).

The United State has been the largest exporter for many years .some important cotton growing country are India , USA, China ,Brazil , Egypt ,Pakistan, Greece ,etc.

In Nepal it is mostly cultivated in western parts of the country like in Banke, Bardiya, Kailali, Dang, and kanchanpur..In 2003/04 its total production is 12.5 in 15.5 ha ,2009 59 tons in 100ha and in 2010 area and the production of seed cotton is 121ha and 109 tons (a/c to FAO).

Long cotton fiber are spur into thread for textile, toweling, Paper, Banknotes, surgical sutures, rope, and Sheets.

Short cotton fibers or linter, provide cellulose used for dynamites, sausageskin,lino,cellophane,rayon,photographic film, nail polish, solid fuel rockets, chewing gums etc.

crushed cotton seed yields a useful vegetable oil and the meal from crushed seeds is used for a cattle feed ,fish bait and organic fertilizer.

SPECIES OF COTTON

The genus Gossypium which belong to the family malvaceae and the tribe Gossypieae, it is the leading fiber crop in the world.

Although the genus has approximately 50 species, including 45 diploids and five allotetraploids

Only four of them are cultivated for their spinable fiber, including two diploid(2n = 29 = 26): G. arboreum .L (A2A2) and G. herbaceum L. (A1A1), and two tetraploid (2n = 49 = 52): G. hirsutum L. (AD1AD1) and G. barbadense L. (AD2AD2)

. The remaining 46 species are distributed throughout the tropics and subtropics of the world in wild form.

The wild species of Gossypium are important source of useful traits such as special and superior fiber properties.

cytoplasmic male sterility, resistance to biotic and abiotic stress etc. which can be introgressed into the cultivated germplam in breeding programmes

.It has become a necessity to develop basic germplam materials enriched with rare useful genes from wild species through introgression. Among 46 wild species few wild species are listed below;

G.africanum G.amomalum G.triphyllum G.capitis viridis G.sturtianum G.nandedewarense G.aridum etc

According to the classification of Hutchinson (1947) the following four cultivated species contain almost all the varieties of the cotton.

Gossypium herbaceum (n=13) Gossypium arboreum(n=13) Gossypium hirsutum (n=26) Gossypium barbadense(n=26)   G. arboreum and G. herbaceum

are desi cotton whereas G .hirsutum and G. barbadense are American cotton.

 

Gossypium herbaceum Gossypium herbaceum, called

Levant cotton, height of 1.5 to 2m.

It is a species of cotton native to the semi-arid region of sub-Saharan Africa and Arabia where it still grows in the wild as a perennial shrub.

It was first cultivated in western Sudan from there it spread to India, before being introduce to Egypt

Its blooming period is late spring/early summer.

Genome : A1 Ploidy level : 2n=26

Morphological features ; Annual hard stems and branches round,

faintly striated, bent slightly at the joints, sparsely hairy.

Leaves leathery, prominently reticulate, deeply cordate, less than half cut into 5-7 broad ovate rotund, suddenly acute or apiculate lobes, below distinctly pilose, especially along the veins.

Bracteoles large, green coloured, broadly ovate rotund obtuse, only very slightly united at the bottom, but profoundly cordate, gashed across the top into 7-9 fairly long teeth.

Flowers not very large, yellow with purple claws and rotating to right; calyx large, loose, undulate, and with large glands.

Capsule small, round, pitted with 3-4 valves, seeds large, angled beaked, coated with grey fuzz and harsh grayish-white wool.

Some varieties: G 67, K-7, kalyan, Sanjay etc.   Characters of breeding value: Disease, insects

and drought resistance.   Key character for identification;Bushy annual. Bracteoles flaring widely from the flower bud,

usually broader than long, upper margin usually serrated into 6-8 teeth.

Capsule small, round with 3-4 locules. Races of G. herbaceum: Persicum,

Kuljianum, Acerifolium and Wightianum.

Gossypium arboreum Gossypium arboreum ,commonly

called as tree cotton is a species of cotton native to India ,Pakistan and other regions of the world .

There is the evidence of its cultivation as long ago as the Harappa civilization of the Indus valley for the production of cotton textile.

The shrub was included in Linnaeus’ species planetarium published in 1753.

  Genome: A2,   Ploidy level : 2n=26   Distribution : Indo-Burma, China

and Arab  

Morphological features : A perennial, usually 6 to 10 feet in height, having

long trailing thin branches, stems and more especially the young branches, petioles, peduncles and bracteoles of a deep glossy purple color

Apeculiarity sometimes even possessed by the young leaves, especially on the under surface.

Leaves of a thick and leathery consistence, gland dotted, sub-glabrous or having short, abortively stillate hairs on the blade, especially more under surface, and a few younger spreading hairs on the petiole and young shoots.

Blade of the leaf mostly five to seven lobed. Flowers yellow with purplish red petal spot. The

flower are set on short pedicel(i.e. flower stalk).

The corolla is pale yellow in color some time with purple center and occasionally entirely purple.

The staminal tubes bear the anther and are 1.5 to 2cm in length.

The fruit is a three to four celled capsule .it is ovoid and oblong in shape and glabrous(i.e. hairless)

The seed within are globular and are covered in long white cotton.

  Some varieties: Shyamali, Western-1, D46-2-1,231-R etc.  Characters of breeding value: Disease, insects and drought

resistance.  Key character for identification: Bracteoles closely

investing the flower bud, entire or with 3-4 coarse teeth near the apex, longer than broad. Capsule round to tapering with 3-4 loculi.

Races of Arboreum : Soudanense, Sinense, Burmanicum, Cernuum, Bengalense and Indicum 

Gossypium hirsutum   Gossypium hirsutum, known as upland cotton or

Mexican cotton is the most widely planted species of the cotton ,constituting worldwide some 90% of all production for this species;

it is native to Central America and possibly Mexico. G.hirustum include number of varieties or cross bred cultivar with varying fiber lengths and tolerance to a number of growing condition.

Highly adoptable cultivar like Laxmi and Gujarat 67 also belongs to this species.

The longer length varieties are called 'long staple upland" and the shorter length varieties are referred to as“ short staple upland“ the long staple varieties are mostly cultivated in commercial production.

Genome : (AD)1 Ploidy level : 2n=52 Distribution : America

Morphological features ; Annual shrub of 1 to 1.5 m tall,

stem tip green to pigmented, glabrous to densely hairy.

Leaf broad to very narrow, nectaries present, pedicel large variable, bracteole size large but variable, serrations few to several.

Corolla yellow, petal spot usually absent.

Bolls is rounded, 3to 5locular with 5 to 7 seeds per locules.

Seed bear copious lint and a thick Fuzz.

Anther color greenish to yellow

Stigma generally none protruding. Boll round, oval or elongated large.

Locules 3-5, generally smooth, tip blunt, lint white, cream, brown, green etc.

Characters of breeding value : Fiber yield, length, strength, fineness and

Elongation, resistance to Verticillium wilts absent. Some Varieties: 320F, H14, Indore-1, laxmi,

Krishna, Narbada.   Key character for identification : Flower yellow

and petal spot usually a   Races of G.hirustum : Latifolium, Punctatum,

Morilli, Richmondii, Palmeri, Marie Galente, and Yucatenense

 

Gossypium barbadense Gossypium barbadense, also known

as extra-long staple cotton as it is generally has a staple of at least 13/8" or longer.

It is tropical frost sensitive perennial plant that produce yellow flower and has black seed.

it grows as a small bushy tree and yield cotton with unusually long, silky fibers. To grow, it requires full sun and high humidity and rainfall.

This plant contain the chemical gossypol, which reduces its susceptibility to insect and fungal damage .

The leaves of G. barbadense are used to treat hypertension and delayed irregular menstruation.

it contributes about 8% of total cotton production.

  Genome : (AD)2   Ploidy level : 2n=52   Distribution: America

Morphological features : A shrub, 1.5 to 2 m tall, broad leaves, slightly

hairy or deeply coated with long grey hair, with deep 3-5 lobes.

Nectaries present, stem weak, pedicel 1.0 cm. long, bracteole size 3.0-3.5 cm, fused at base, serrations 8-13 in number

. Corolla yellow, size 4.5-5.5 cm, petal spot present, anther yellow, pollen yellow, stigma protruding, boll elongated, locules 3, slightly pitted, tip pointed, lint white

Bolls are large and round and bold 5 to 8 seeds per locules.

Seeds are bald with no Fuzz  Some Varieties: Sujata, Varlaxmi, Andrew

etc. . Characters of breeding value : Fiber

fineness Key character for identification: Petal

spot present deeply pitted pointedbolls. Races of G.barbadense: Brasiliense

The lint length of Gossypium arobreum and Gossypium herbaceum is less than about 22mm and are short staple cotton.

While list length of Gossypium hirsutum is 25 to 30 mm and are classified as medium to long staple cotton. There are distinct races within species based on the geographical distribution.

It is supposed that the present day cultivated arobreum are derived from this perennial race. The race Cernuum is suited to high rainfall region of Assam and Bangladesh

. It has produced comilla cotton. The Sinense race has provided the commercial cultivar of china Korea and Japan.

The race bangalense has provided the annuals with high ginning, coarse cotton of Punjab and Sindh regions of Pakistan, Uttar Pradesh.

The important races of G. herbaceum included Persicum and Africana which has spread to Iran, Afghanistan and apart of Africa.

In upland cotton G. hirsutum race Marie galnte is large perennial shrubs or small tree. Highly photo periodic and spread over Caribbean island, panama, and northern Brazil. The race Punctatum of upland cotton is found in Gulf of Mexico.

THANK-YOU