In the UK, linters are referred to as "cotton wool". Disease emergence is favored by warm temperatures; fungus may be introduced to field through infected seed or by contaminated equipment and human movement. Once the D genome is assembled from all of this raw material, it will undoubtedly assist in the assembly of the AD genomes of cultivated varieties of cotton, but much work remains. Cottonseed hulls can be added to dairy cattle rations for roughage. These curly fibers typically are less than 1⁄8 inch (3.2 mm) long. "[48], During the middle 20th century, employment in cotton farming fell, as machines began to replace laborers and the South's rural labor force dwindled during the World Wars. Introduction • Cotton- King of fibres • Cotton-white gold, one of the most important commercial crops of the world. Transportation Information Service of Germany, Gesamtverband der Deutschen Versicherungswirtschaft e.V. sturtianum - after English explorer Charles Sturt (1795-1869), who first collected the plant. Cotton is of tropical origin but is most successfully cultivated in temperate climates with well-distributed rainfall. The cotton is turned into cloth in Lancashire. A tropical perennial plant, man has hybridized and selected it to grow quickly and tolerate growing conditions outside of tropical areas, where it's grown as an annual crop. hirsutum. [86] The American cotton variety Pima cotton is often compared to Egyptian cotton, as both are used in high quality bed sheets and other cotton products. ), Cotton manufacture was introduced to Europe during the Muslim conquest of the Iberian Peninsula and Sicily. [68] This was 69% of the worldwide total area planted in cotton. (See Vegetable Lamb of Tartary. This has led to an international dispute (see Brazil–United States cotton dispute): On 27 September 2002, Brazil requested consultations with the US regarding prohibited and actionable subsidies provided to US producers, users and/or exporters of upland cotton, as well as legislation, regulations, statutory instruments and amendments thereto providing such subsidies (including export credits), grants, and any other assistance to the US producers, users and exporters of upland cotton. This cotton is used mainly for underwear, stockings, and gloves. Before 1865 the cotton was largely produced through the labor of enslaved African Americans. Women carry harvested cotton to be deseeded in Bukina Faso, Africa. Under natural conditions, the cotton bolls will increase the dispersal of the seeds. Cotton strippers are used in regions where it is too windy to grow picker varieties of cotton, and usually after application of a chemical defoliant or the natural defoliation that occurs after a freeze. The Greeks and the Arabs were not familiar with cotton until the Wars of Alexander the Great, as his contemporary Megasthenes told Seleucus I Nicator of "there being trees on which wool grows" in "Indica". Cotton remains a major export of the United States, with large farms in California, Arizona and the Deep South. People use the bark of the root and seed to make medicine. Insects outbreak favored by a cool, wet spring following a mild winter; cutworms have a wide host range and attack vegetables including asparagus, bean, cabbage and other crucifers, carrot, celery, corn, lettuce, pea, pepper, potato and tomato. The Egyptian government of Viceroy Isma'il took out substantial loans from European bankers and stock exchanges. The cottonseed which remains after the cotton is ginned is used to produce cottonseed oil, which, after refining, can be consumed by humans like any other vegetable oil. The cloth is finally sold back to the kings and landlords of India who got the money to buy this expensive cloth out of the poor peasants of India who worked at seven cents a day. The fibers of this soft and fluffy plant are used to manufacture a variety of fabrics and textiles, ranging from lightweight laces to thick-piled velveteen. There are about 50 Gossypium species, making it the largest genus in the tribe Gossypieae, and new species continue to be discovered. بنیاد دائره المعارف اسلامی, "Ancient Egyptian cotton unveils secrets of domesticated crop evolution", "COTTON TEXTILES AND THE GREAT DIVERGENCE: LANCASHIRE, INDIA AND SHIFTING COMPETITIVE ADVANTAGE, 1600-1850", "Cotton textiles and the great divergence: Lancashire, India and shifting competitive advantage, 1600-1850", "100 Years of Cotton Production, Harvesting, and Ginning Systems", "Cotton Seed Sprouts on the Moon's Far Side in Historic First by China's Chang'e 4", Celebrating the first anniversary of World Cotton Day at the WTO, "Natural drought or human-made water scarcity in Uzbekistan? The captains, officers, sailors of these ships, whose wages must be paid, are English. Recently, Shenzhen IVPS Technology Co., Ltd. and the Dongguan police succeeded in removing an illegal factory hidden in Changan Industrial Zone, Dongguan, which specializes in the manufacture and sale of counterfeit SMOK brand atomizers and atomizing coils.A … Typically the infected leaves retain their green color or green yellow color. Secondary wall, is consists of concentric layers of cellulose it is also called the S2 layer, that constitute the main portion of the cotton fiber. Under severe conditions leaf and flower drop may occur. British and French traders invested heavily in cotton plantations. Defoliatores include the fall armyworm, Spodoptera frugiperda. The cottonseed meal that is left generally is fed to ruminant livestock; the gossypol remaining in the meal is toxic to monogastric animals. [68], Cotton has been genetically modified for resistance to glyphosate a broad-spectrum herbicide discovered by Monsanto which also sells some of the Bt cotton seeds to farmers. This was the usual word for cotton in medieval Arabic. This plant can be weedy or invasive according to the authoritative sources noted below.This plant may be known by one or more common names in different places, and some … Cotton No. The symptoms are mainly seen in the lower canopy. dated to as early as 5500 BC, but this date has been challenged. The largest exporters of raw cotton are the United States, with sales of $4.9 billion, and Africa, with sales of $2.1 billion. variegated cutworm (Peridroma saucia) adult, Variegated cutworm (Peridroma saucia) larvae. eastern cottonwood. Cotton linters are fine, silky fibers which adhere to the seeds of the cotton plant after ginning. The target spot is confused with leaf spot caused by Cercospora spp. [21] Between the 12th and 14th centuries, dual-roller gins appeared in India and China. There are four commercially grown species of cotton, all domesticated in antiquity: Hybrid varieties are also cultivated. A less technical use of the term "cotton wool", in the UK and Ireland, is for the refined product known as "absorbent cotton" (or, often, just "cotton") in U.S. usage: fluffy cotton in sheets or balls used for medical, cosmetic, protective packaging, and many other practical purposes. Learn more about your crops in our library, Learn about ways to keep your crops healthy. Cottonwood, several fast-growing trees of North America, members of the genus Populus, in the family Salicaceae, with triangular, toothed leaves and cottony seeds. [4]The two New World cotton species account for the vast majority of modern cotton production, but the two Old World species were widely used before the 1900s. Cotton botanical aspects 1. "Tetraploid" means that its nucleus has two separate genomes, called A and D. The consortium agreed to first sequence the D-genome wild relative of cultivated cotton (G. raimondii, a Central American species) because it is small and has few repetitive elements. It is commonly used to make … Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus Gossypium in the mallow family Malvaceae. Small soft bodied insects on underside of leaves and/or stems of plant; usually green or yellow in color, but may be pink, brown, red or black depending on species and host plant; if aphid infestation is heavy it may cause leaves to yellow and/or distorted, necrotic spots on leaves and/or stunted shoots; aphids secrete a sticky, sugary substance called honeydew which encourages the growth of sooty mold on the plants. Production capacity in Britain and the United States was improved by the invention of the modern cotton gin by the American Eli Whitney in 1793. This is only possible in former British colonies and Mozambique; former French colonies continue to maintain tight monopolies, inherited from their former colonialist masters, on cotton purchases at low fixed prices.[96]. Although Whitney patented his own design for a cotton gin, he manufactured a prior design from Henry Odgen Holmes, for which Holmes filed a patent in 1796. These later types of reads will be instrumental in assembling an initial draft of the D genome. [28] India had a 25% share of the global textile trade in the early 18th century. USBG Plant Location: Conservatory. The advent of the Industrial Revolution in Britain provided a great boost to cotton manufacture, as textiles emerged as Britain's leading export. Insect can go through 3–5 generations a year. Sucking pests include the cotton stainer, Dysdercus suturellus and the tarnish plant bug, Lygus lineolaris. [66][67] The International Service for the Acquisition of Agri-biotech Applications (ISAAA) said that, worldwide, GM cotton was planted on an area of 25 million hectares in 2011. Species. [88] Not all products bearing the Pima name are made with the finest cotton: American-grown ELS Pima cotton is trademarked as Supima cotton. John Chardin, a French traveler of the 17th century who visited Safavid Persia, spoke approvingly of the vast cotton farms of Persia. It now is … It is filled with living protoplast during the growth period. These are popular for baby clothes and diapers; natural cotton products are known to be both sustainable and hypoallergenic. The gin that Whitney manufactured (the Holmes design) reduced the hours down to just a dozen or so per bale. Nylon, the first fiber synthesized entirely from petrochemicals, was introduced as a sewing thread by DuPont in 1936, followed by DuPont's acrylic in 1944. This mechanised production was concentrated in new cotton mills, which slowly expanded till by the beginning of the 1770s seven thousand bales of cotton were imported annually, and pressure was put on Parliament, by the new mill owners, to remove the prohibition on the production and sale of pure cotton cloth, as they could easily compete with anything the EIC could import. This, coupled with the emergence of American cotton as a superior type (due to the longer, stronger fibers of the two domesticated native American species, Gossypium hirsutum and Gossypium barbadense), encouraged British traders to purchase cotton from plantations in the United States and in the Caribbean. By the 1840s, India was no longer capable of supplying the vast quantities of cotton fibers needed by mechanized British factories, while shipping bulky, low-price cotton from India to Britain was time-consuming and expensive. After the fiber has attained its maximum diameter, new layers of cellulose are added to form the secondary wall. [42][39][43] India served as both a significant supplier of raw goods to British manufacturers and a large captive market for British manufactured goods. Cargill also purchases cotton in Africa for export. Cotton is bought and sold by investors and price speculators as a tradable commodity on 2 different commodity exchanges in the United States of America. Average Size at Maturity: Moderate growing; reaches 1½ ft. tall, 3 ft. wide. common cottonwood. The impacted weavers, spinners, dyers, shepherds and farmers objected and the calico question became one of the major issues of National politics between the 1680s and the 1730s. As there was no punishment for continuing to sell cotton cloth, smuggling of the popular material became commonplace. Small, circular brown lesions on cotyledons and seedling leaves which expand and develop a concentric pattern; necrotic areas coalesce and often have a purple margin; centers of lesions may dry out and drop form the plant creating a "shot-hole" appearance on the leaves. Cotton is an enormously important commodity throughout the world. malvacearum. For the first time in western Sudan, and later in India, Egypt, China and Pakistan. This public relations effort gave them some recognition for sequencing the cotton genome. Braconid wasp parasitizing beet armyworm larva. So I look up cotton's scientific name, Gossypium (Go-sippy-um)—sounds like you're telling a toddler to take a drink—and the photos reveal why people would want to grow it even if they don't have a long enough season to get a little cotton; the blooms are beautiful; a lot like hibiscus. The name is deceiving, though, because the plant is neither lavender nor cotton. Noting its similarities to wool, people in the region could only imagine that cotton must be produced by plant-borne sheep. Since cotton is somewhat salt and drought tolerant, this makes it an attractive crop for arid and semiarid regions. Also, it is thought to interfere with the menstrual cycle by restricting the release of certain hormones.[84]. The spinning wheel, introduced to Europe circa 1350, improved the speed of cotton spinning. 2. At temperatures below 0 °C (32 °F), rotting of wet cotton stops. Egypt under Muhammad Ali in the early 19th century had the fifth most productive cotton industry in the world, in terms of the number of spindles per capita. By the mid-19th century, "King Cotton" had become the backbone of the southern American economy. [17] Fabric name: Cotton Fabric also known as: Pima cotton, Egyptian cotton, Supima cotton Fabric composition: Organic fibers from the seeds of the cotton plant Fabric possible thread count variations: 100, 200, 300, 600, up to 2,000 Fabric breathability: Very breathable Moisture-wicking abilities: High Heat retention … In the days of the Soviet Union, the Aral Sea was tapped for agricultural irrigation, largely of cotton, and now salination is widespread. The name of the genus is derived from the Arabicword goz, which refer… [1] Cotton was independently domesticated in the Old and New Worlds. The major cotton producing countries are USA, China, India, Pakistan, Uzbekistan, Turkey, Brazil, Greece, Argentina and Egypt. In order to compete with India, Britain invested in labour-saving technical progress, while implementing protectionist policies such as bans and tariffs to restrict Indian imports. There would be no way to untangle the mess of AD sequences without comparing them to their diploid counterparts. A temperature range of 25 to 35 °C (77 to 95 °F) is the optimal range for mold development. In general, these conditions are met within the seasonally dry tropics and subtropics in the Northern and Southern hemispheres, but a large proportion of the cotton grown today is cultivated in areas with less rainfall that obtain the water from irrigation. or Alternaria spp. The plant is a shrub native to tropical and subtropical regions around the world, including the Americas, Africa, Egypt and India. It is different in structure from both the primary wall and the remainder of the secondary wall. Botanical Colors provides natural dyes to natural dyers and fashion brands that are sustainable, environmentally friendly and support farming communities. Botanical name: Synonyms: Family: Common name: Abelia chinensis : Caprifoliaceae: Chinese Abelia: Abelia triflora : Caprifoliaceae: Himalayan Abelia: Abelia X grandiflora During the American slavery period, cotton root bark was used in folk remedies as an abortifacient, that is, to induce a miscarriage. The export of textiles was one of the sources of wealth for Meroë. While cotton fibers occur naturally in colors of white, brown, pink and green, fears of contaminating the genetics of white cotton have led many cotton-growing locations to ban the growing of colored cotton varieties. [16], Cotton (Gossypium herbaceum Linnaeus) may have been domesticated 5000 BCE in eastern Sudan near the Middle Nile Basin region, where cotton cloth was being produced. Initially the appearance of small chocolate brown spots which later enlarge to become circular to irregular spot with target markings. Due to the US Department of Agriculture's highly successful Boll Weevil Eradication Program (BWEP), this pest has been eliminated from cotton in most of the United States. Fairly uniform in width, 12–20 micrometers; English people buy Indian cotton in the field, picked by Indian labor at seven cents a day, through an optional monopoly. The name "Egyptian cotton" is broadly associated high quality cottons and is often an LS or (less often) an ELS cotton. Populus deltoides ssp. Plant Botanical Name: Gossypium tomentosum. This made India the country with the largest area of GM cotton in the world. [103], In addition to concerns over subsidies, the cotton industries of some countries are criticized for employing child labor and damaging workers' health by exposure to pesticides used in production. It has the following parts.[111]. Gossypium is a genus of flowering plants in the tribe Gossypieae of the mallow family, Malvaceae, from which cotton is harvested. [citation needed]. Cotton production recovered in the 1970s, but crashed to pre-1960 levels in the early 1990s. Subordinate Taxa. The Indian Mahatma Gandhi described the process: In the United States, growing Southern cotton generated significant wealth and capital for the antebellum South, as well as raw material for Northern textile industries. Later, the invention of the James Hargreaves' spinning jenny in 1764, Richard Arkwright's spinning frame in 1769 and Samuel Crompton's spinning mule in 1775 enabled British spinners to produce cotton yarn at much higher rates. [65] They concluded that the GM cotton effectively controlled bollworm. Neither area has a significant domestic textile industry, textile manufacturing having moved to developing nations in Eastern and South Asia such as India and China. Also known as Hawaiian cotton, Gossypium tomentosum was once extremely common to the dry and rocky coastal areas of the Hawaiian islands. [21] Another innovation, the incorporation of the crank handle in the cotton gin, first appeared in India some time during the late Delhi Sultanate or the early Mughal Empire. While dryland (non-irrigated) cotton is successfully grown in this region, consistent yields are only produced with heavy reliance on irrigation water drawn from the Ogallala Aquifer. Links will be auto-linked. The finished product is sent back to India at European shipping rates, once again on British ships. The fiber is almost pure cellulose. Legal Status. Historically, in North America, one of the most economically destructive pests in cotton production has been the boll weevil. [47], Cotton remained a key crop in the Southern economy after slavery ended in 1865. Seeing the East India Company and their textile importation as a threat to domestic textile businesses, Parliament passed the 1700 Calico Act, blocking the importation of cotton cloth. [30] The most important center of cotton production was the Bengal Subah province, particularly around its capital city of Dhaka. Rio Grande cottonwood. latifolium (Murray) Roberty; Gossypium hirsutum var. The fibrils are deposited at 70 to 80-degree angles to the fiber axis, reversing angle at points along the length of the fiber. The fiber is almost pure cellulose. [95] The future of these subsidies is uncertain and has led to anticipatory expansion of cotton brokers' operations in Africa. Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus Gossypium in the mallow family Malvaceae. The cotton textile industry was responsible for a large part of the empire's international trade. Ensminger, Audrey H. and Konlande, James E. This page was last edited on 8 February 2021, at 22:10. [39], India's cotton-processing sector changed during EIC expansion in India in the late 18th and early 19th centuries. Because Herodotus had written in his Histories, Book III, 106, that in India trees grew in the wild producing wool, it was assumed that the plant was a tree, rather than a shrub. [68] A long-term study on the economic impacts of Bt cotton in India, published in the Journal PNAS in 2012, showed that Bt cotton has increased yields, profits, and living standards of smallholder farmers. [72] On 17 October 2018, the USDA deregulated GE low-gossypol cotton. Gossypium hirsutum; Preferred Common Name. Pima cotton is sometimes called "American Egyptian" because it uses the same types of plants and similar growing conditions in low-lying areas of the southern United States. The area of the United States known as the South Plains is the largest contiguous cotton-growing region in the world. Don't confuse cotton with cottonseed extract (gossypol). Beet armyworm (Spodoptera exigua) adult moth, Early instar beet armyworm (Spodoptera exigua) feeding under leaf surface, Beet armyworm, Spodoptera exigua, on a cotton leaf. In the United States, the state of Texas led in total production as of 2004,[99] while the state of California had the highest yield per acre.[100]. [56][57], Cotton can also be cultivated to have colors other than the yellowish off-white typical of modern commercial cotton fibers. Cotton continues to be picked by hand in developing countries[79] and in Xinjiang, China, by forced labor. Monogram & Name Necklaces Beaded Necklaces Chains ... Downy Cotton Plants*Cotton Branch Vellum Sticker Pack*20 Pcs Cotton Plant Washi Stickers*Botany Inspiration *Journal Collage Supply Scrappybird. The Lancashire Cotton Famine prompted the main purchasers of cotton, Britain and France, to turn to Egyptian cotton. The total international trade is estimated to be $12 billion. Eastern cottonwood (P. deltoides), nearly 30 metres (100 feet) tall, has thick glossy leaves. Wages; profits; all these are spent in England. The word "cotton" has Arabic origins, derived from the Arabic word قطن (qutn or qutun). It consists of fibrils aligned at 40 to 70-degree angles to the fiber axis in an open netting type of pattern. A major constraint to the development of IPM for H. armigera, particularly on cotton, has been the need to deal with a complex of pests where control needs may be irreconcilable, as for example in the characteristics of the cotton plant which can either be unfavourable to H. armigera or to jassid pests in terms of leaf hairiness, … The fiber is most often spun into yarn or thread and used to make a soft, breathable textile. Several early instar beet armyworm larvae feeding in the under side of a cotton leaf. Wilting of cotyledons and seedling leaves; cotyledons become chlorotic at the edges and then necrotic; older plants exhibit symptoms of wilting and leaf chlorosis; wilting is usually gradual but may be pronounced after heavy summer rain; if infection is severe plants become stunted and may be killed; vascular system of infected plants becomes discolored and can be seen by cutting the stem. The Mughals introduced agrarian reforms such as a new revenue system that was biased in favour of higher value cash crops such as cotton and indigo, providing state incentives to grow cash crops, in addition to rising market demand. [24], During the late medieval period, cotton became known as an imported fiber in northern Europe, without any knowledge of how it was derived, other than that it was a plant. Because G. arboreum is a tropical and subtropical plant, cotton agriculture did not spread outside the Indian … Plants stressed by drought, nutrient deficiency and other pests are more susceptible to the disease; fungus spreads rapidly in dense canopies, especially during periods of warm, wet weather. Winding layer, is the first layer of secondary thickening it is also called the S1 layer . A significant cotton disease is Xanthomonas citri subsp. Disease emergence is favored by cool, wet weather. The total cotton area in India was 12.1 million hectares in 2011, so GM cotton was grown on 88% of the cotton area. Symptoms of Asochyta blight on cotton foliage. This cotton is shipped on British ships, a three-week journey across the Indian Ocean, down the Red Sea, across the Mediterranean, through Gibraltar, across the Bay of Biscay and the Atlantic Ocean to London. The EIC embraced the demand, particularly for calico, by expanding its factories in Asia and producing and importing cloth in bulk, creating competition for domestic woollen and linen textile producers. Botanical Name: Linum usitatissimum L. Family: Linaceae . Around the 4th century BC, the cultivation of cotton and the knowledge of its spinning and weaving in Meroë reached a high level. As the Artisan produced textiles were no longer competitive with those produced Industrially, and Europe preferring the cheaper slave produced, long staple American, and Egyptian cottons, for its own materials. A 2006 study done by Cornell researchers, the Center for Chinese Agricultural Policy and the Chinese Academy of Science on Bt cotton farming in China found that after seven years these secondary pests that were normally controlled by pesticide had increased, necessitating the use of pesticides at similar levels to non-Bt cotton and causing less profit for farmers because of the extra expense of GM seeds. Like pima cotton, Egyptian is an extra-long staple cotton, making it equally exceptional in softness, vibrancy, and performance. 9211 1.4.4.1 Cottonseed (all varieties) Gossypium spp. About 62% of the GM cotton grown from 1996 to 2011 was insect resistant, 24% stacked product and 14% herbicide resistant. [22], The earliest clear illustrations of the spinning wheel come from the Islamic world in the eleventh century. [52] Planting time in spring in the Northern hemisphere varies from the beginning of February to the beginning of June. They even share a scientific name! It will cause severe loss if pathogen infect at flowering stage. [64] However, a 2009 study by the Chinese Academy of Sciences, Stanford University and Rutgers University refuted this. Under most definitions, organic products do not use transgenic Bt cotton which contains a bacterial gene that codes for a plant-produced protein that is toxic to a number of pests aespecially the bollworms. This mechanical device was, in some areas, driven by water power. While many fabrics are made completely of cotton, some materials blend cotton with other fibers, including rayon and synthetic fibers such as polyester. The cotton industry relies heavily on chemicals, such as fertilizers, insecticides and herbicides, although a very small number of farmers are moving toward an organic model of production. Cotton is also known as a thirsty crop; on average, globally, cotton requires 8000-10000 liters of water for one kilogram of cotton, and in dry areas, it may require even more such as in some areas of India, it may need 22500 liters also.[59][60]. The exemption of raw cotton from the prohibition initially saw 2 thousand bales of cotton imported annually, to become the basis of a new indigenous industry, initially producing Fustian for the domestic market, though more importantly triggering the development of a series of mechanised spinning and weaving technologies, to process the material. However, scientists have silenced the gene that produces the toxin, making it a potential food crop. [34], It was reported that, with an Indian cotton gin, which is half machine and half tool, one man and one woman could clean 28 pounds of cotton per day. The secondary pests were mostly miridae (plant bugs) whose increase was related to local temperature and rainfall and only continued to increase in half the villages studied. Egyptian Cotton. But this spot is surrounded by reddish to purplish margin. Cotton consists of the epidermal trichomes of the seeds of Gossypium herbaceum Linn and other species of Gossypium of the family Malvaceae. The English East India Company (EIC) introduced the British to cheap calico and chintz cloth on the restoration of the monarchy in the 1660s. [78] Organic cotton products are now available for purchase at limited locations. (GDV), Berlin, History of Egypt under the Muhammad Ali dynasty, Textile manufacture during the Industrial Revolution, International Service for the Acquisition of Agri-biotech Applications, Learn how and when to remove this template message, Diplomacy of the American Civil War#Cotton and the British economy, Centre national de ressources textuelles et lexicales, French National Centre for Scientific Research, "Genetic diversity and population structure of Gossypium arboreum L. collected in China", Encyclopaedia Islamica Foundation. [70] The subsequent introduction of a second variety of GM cotton led to increases in GM cotton production until 95% of the Australian cotton crop was GM in 2009[71] making Australia the country with the fifth largest GM cotton crop in the world. Long staple (LS cotton) is cotton of a longer fibre length and therefore of higher quality, while Extra-long staple cotton (ELS cotton) has longer fibre length still and of even higher quality. [91], Cotton lisle, or fil d'Ecosse cotton, is a finely-spun, tightly twisted type of cotton that is noted for being strong and durable. Without knowing the diploid genomes, the euchromatic DNA sequences of AD genomes would co-assemble, and their repetitive elements would assemble independently into A and D sequences respectively.