eBook Chapters

Portrait of a Chromosome

• Cytogenetics is the study of chromosome abnormalities and associated effects on health or other traits.
• Excess or deficient genetic material can cause syndromes or end prenatal development.
• Chromosomes consist of highly coiled DNA, RNA, histones, and nonhistone proteins.

Telomeres and Centromeres are Essential

Telomeres consist of repeat sequences and protect chromosome tips.

A centromere is a constricted site where spindle fibers attach during cell division.

Centromeres are regions of repeated DNA bound to centromere-associated proteins.

Weaning foods

Introduction

Breast milk is natural and best for the growth and development of newborn babies. Although breast milk is adequate to provide an optimum nutrient till the age of six months but after that it is not sufficient to sustain optimum growth and fulfill their nutritional requirements. Various nutrients are required to supplement milk until child is ready to eat adult meal. This additional food along with the breast milk is referred as “complementary Food”. With adequate amount of complementary feeding breast-feeding continues up to two years of age and beyond so, referred as complementary feeding period.

Appropriate and adequate amount of complementary feeding helps in preventing malnutrition stunting and promoting growth. Introduction of this complementary food is called as weaning.

Weaning is the process of introducing adult food and beverage to the infant to support their growth and development. This is very crucial period in infant’s life. This is a period for diet transition as the nutrition requirements for growth and brain development is quite high. Introduction of various taste and texture promotes biting and chewing skills (Guthrie, 1975). Most six-month age children start eating semisolid foods. Weaning homogenized infant foods play a major role in the nutrition of infants (Martinez, 2004).As infants grow, their nutritional requirements also increase. To keep up this growing demand WHO recommends that infants start eating solid, semi-solid or soft foods at the age of 6 months to ensure sufficient nutrient intake.

Botany :Annual Chrysanthemum is a winter annual that can be grown either as pot plants or in groups as bed plants for various ornamental purposes. There are two types of annual Chyrsanthemums: Chrysanthemum Segetum and C.coronarium. Major varieties of Chrysanthemum segetum L. are Morning Star, Evening Star, Eastern Star, Blanca, Eldorado, Gloria, Isabel, Romeo, and yellow Stone while popular cultivars of C. coronarium L. include Nivea, Oreon, Albo, Golden Crown, Luteum, Tom Thumb Golden Gem, Tom Thumb-Primrose Gem and Tetra Comet. In addition to this, there is another type of annual Chrysanthemum, i.e. C. carinatum. Popular varieties of C. carinatum S. are Merry, Atrococcineum, Burridgeanum, Eclipse, Flammenspiel, John Bright and Northern Star.

Propagation

Annual Chrysanthemums can be propagated by seeds. Their sowing time depends upon climate. It varies in different parts of India. In the Northern plains, winter season annual Chrysanthemums are sown during September–October. The seeds are sown in nursery beds, earthen pots, seed pans or wooden seed trays. The seed compost should consist of one part each of garden soil, coarse sand, farmyard manure and leaf-mould. For preparing the nursery beds, the soil should be dug up thoroughly and sufficient farmyard manure, should be mixed in soil. Raised nursery beds of convenient size (normally 60cm wide and 15cm high) should be prepared. If soil is heavy, some quantity of sand may be added. It is better if the soil of nursery bed or earthen pots is sterilized with 2% formalin. For this, soil is drenched with formalin solution and is covered with polythene sheet for 45hr. Afterwards, the polythene is removed and soil is dried before sowing the seeds.

1. Introduction

Chrysanthemum is commonly known as ‘Guldaoudi’, “Queen of the East”, “Glory of East” or “Autumn Queen”. It is one of the most beautiful and widely cultivated flowers that can be grown for its aesthetic value as well as for its commercial potential. The word chrysanthemum is derived from two Greek words, viz. “Chrysos” means gold and “Anthemon” means ‘flower’ i.e. golden flower. Chrysanthemum is the only crop that offers a great genetic diversity of flower colour, shape, forms, size, easy to propagate, growing habit, longer flowering duration and excellent vase life. Based on the shape of flower heads and floret arrangement of petals it can be used as pot plants for indoors and outdoors decoration as well as exhibition purpose; as cut flowers for flower arrangements, bouquets making and vase decoration; loose flower for making garlands, worshipping purpose and for bedding and garden decoration. Tall cultivars are suitable for background planting in borders and the dwarf and compact can be planted in front rows. 

Chrysomelid beetle : Aulacophora foveicollis : ChrysomelidaeAphids : Macrosiphoniella  sanborni; Myzus  persicae; Brachicaudus  helichrysi; Aphis  gossypi; Aphis fabae; Aulocorthum circumflexum: Aphid

Chrysanthemum   is infested by different species of aphids. Aphids are small, soft bodied insects and their colour varies with species. Both nymphs and adults cluster on the growing stem tips and under surface of leaves. As a result, the plants show loss of vigor, distortion of leaves and flowers, yellowing, premature leaf fall and stunted growth. The damaged plants bear only undersized buds and they remain unopened. Peak damage period is November-December. Secretion of honeydew by the aphids favor development of sooty mould which hinders photosynthesis and the plants become stunted. They are also vectors of virus diseases.

Chrysanthemum (chrysos =golden; anthos = flower) is a popular flower crop of commercial importance known as the “Queen of the East”. It ranks next only to rose among flower crops in the world.

Chrysanthemum (Dendranthema spp.) belongs to family Compositae (Asteraceae). It was named by Carolus Linnaeus from the Greek prefix “chrys” means golden and “anthemon” means flower. Chrysanthemum morifolium is the modern florists chrysanthemum, which evolved as a result of endless variation and hybridization from C. sinensis, C. indicum and C. ornatum (Bailey, 1963). This group is also distinguished as C. hortorum. The name of C. morifolium Ramat has been changed to Dendranthema grandiflora Tzvelev (Anderson, 1987, Heywood and Humphries, 1977). Chrysanthemums are mainly herbaceous perennial and bear flowers in capitula. Chrysanthemum perennates in nature by means of stolons and is readily propagated through basal stem cuttings. It ranks second next to roses in importance among the cut flower crops in the world.

Chrysanthemum (Dendranthema spp.) belongs to family Compositae (Asteraceae). It was named by Carolus Linnaeus from the Greek prefix “chrys” means golden and “anthemon” means flower. Chrysanthemum morifolium is the modern florists chrysanthemum, which evolved as a result of endless variation and hybridization from C. sinensis, C. indicum and C. ornatum (Bailey, 1963). This group is also distinguished as C. hortorum. The name of C. morifolium Ramat has been changed to Dendranthema grandiflora Tzvelev (Anderson, 1987, Heywood and Humphries, 1977). Chrysanthemums are mainly herbaceous perennial and bear flowers in capitula. Chrysanthemum perennates in nature by means of stolons and is readily propagated through basal stem cuttings. It ranks second next to roses in importance among the cut flower crops in the world.

ORIGIN AND DISTRIBUTION

Chrysanthemum is originated in northern hemisphere (Europe and Asia). However, some workers reported that China is the native place of chrysanthemum (Carter, 1980). Most of the species in the lineage of present day cultivars are from China.

Chrysanthemum was first cultivated in China as a flowering herb and is described in writing as early as 15^th century B.C. As herb, it was believed to have the power of life. In 18^th century, they appeared in Japan as the crest and official seal of the Emperor. Japan also has a national chrysanthemum day, which is called the Festival of Happiness. In the western world, they are introduced in England, Japan, France and U.S. have developed a wide range of colours, shapes and sizes of flowers. Since the chrysanthemum was first introduced in the U.S. during colonial times, its popularity has grown such that mums now reign as undisputed ‘Queen of the Fall Flowers’. The Netherlands is the foremost importer of chrysanthemum cut flowers and is the centers for re-export to other parts of the world. In India, chrysanthemum is successfully grown under protected as well as open conditions in different states.

INTRODUCTION

The chrysanthemum is one of the most beautiful and perhaps the oldest flowering plant, commercially grown in different parts of the world. It is commonly known as Queen of East, Autumn Queen and Guldaudi. It is im ortant both as cut flower and as potted plant in the international market. In Dutch cut flower auction, chrysanthemum ranks second after rose. It is preferred practically due to vast range of shapes and sizes of flowers, brilliance of colour tones, long lasting floret life, diversity of height and growth habit of the plant, exceptionally hardy nature, relative ease to grow all the year round and versatility of use.

It is one of the most important traditional flowers of India mainly used as a potted plant, loose flower, cut flower and as border plant in the garden. Chrysanthemum cinerariifolium inflorescences are of considerable importance in the manufacture of pyrethrin insecticides. The leaves of Chrysanthemum balsamita become leathery on drying and can be used as bookmarks. Fresh young customary leaves can be used in salads and to add a balsam flavour in beer, soups and bread. Now programmed blooming of chrysanthemum all the year around is possible by environmental manipulations.

Chrysanthemum (Chrysanthemum morifolium) is a popular flowering plant grown for its magnificent flowers in wide range of colour. There are various size of flowers like mini, small and large. Forms of the flowers also vary from ball shape to spider type. In ornamental gardening, Chrysanthemum is used as bedding as well as pot plant. Cut-flowers are also very popular for vase decoration and commercially important. Flowers of the small-flowered cultivars are also used as loose flowers for making garland and floral ornaments.

Classification

There is huge diversity in the form and types of Chrysanthemum. Therefore, one has to know the various types of flowers, growth habit and their use in the gardens.

Abstract: Chrysanthemum, commonly known as Queen of East, is perhaps oldest flowering plant, commercially grown in different parts of the world in a wide range of floricultural product including potted plants, cut flowers and garden plant. Vast range of shapes and sizes of flowers, brilliance of colour tones, long lasting bloom, ease of production and cultivation all the year round, range of plant habits from pot mums to tall shrub, hardy nature, and versatility of use make this a versatile floriculture crop, wide range of polyploidy level (diploid to decaploid) is found in different cultivars and are almost exclusively asexually propagated. The crop arises from multiple species, its allopolyploid nature has complicated progress in crop development due to inbreeding depression, genetic load and aneuploidy. Precise genetic information and trait heritability has been established for this crop; plant breeding continues to produce new variants for commercial production. Currently, numerous varieties have been developed through complex interspecific crosses among elemental species, open pollination, indiscriminate Intervarietal hybridization, spontaneous and induced mutation, selection, and management of chimera. Number of traits targeted for genetic intervention have been presented and discussed. Crop idiotypes for product classes prescribe numerous traits for incorpotion by flower breeders and geneticists including compact framework to withstand bloom for pot mums, long lasting bloom colour with enhanced shelf life for cut flower and sweet scented blooms with extended blooming season for garland use.

Introduction

The chrysanthemum is one of the most beautiful and perhaps the oldest flowering plant. It is commercially grown in different parts of the world. Chrysanthemum is commonly known as Guldaudi. In Dutch cut flower auction, chrysanthemum ranks second after rose. It is preferred practically due to vast range of shapes and sizes of flowers, brilliance of colour tones, long lasting floret life, diversity of height and growth habit of the plant, exceptionally hardy nature, relative ease to grow all the year round and versatility of use.

It is one of the most important traditional flowers of India mainly used as a potted plant, loose flower, cut flower and as border plant in the garden. Chrysanthemum cinerariifolium inflorescences are of considerable importance in the manufacture of pyrethrin insecticides.

Chrysanthemum takes its name derived from the Greek word chryos meaning gold and anthos meaning a flower, as many species have yellow flower heads. The genus Chrysanthemum belongs to family Asteraceae. It is herbaceous perennial plant. The genus comprises some 200 species of annuals, perennials and shrubs from northern temperate zone (chiefly Europe and Asia), whereas some researchers claim it was originated only from China. Though botanists have retained only the annual species under the genus Chrysanthemum (Beckett, 1983; Dole and Wilkins, 1999).

Annual chrysanthemums which are propagated through seeds. Annual chrysanthemum comprise ofthree species viz, Chrysanthemum segtum (corn marigold), Chrysanthemum carinatum (tricoloured chrysanthemum) and Chrysanthemum coronarium (crown daisy or garland chrysanthemum). The crown daisy or garland chrysanthemum (C. coronarium) is a native from Southern Europe, branching annual with finely cut foliage reaching a height up to a metre, size of flowers varies from 2.5 to 4 cm and colour is usually in shades of yellow and white with cream zone at the center (Vishnu Swarup, 1967).

Importance and Uses

Chrysanthemum is the number one dollar earning flower in the United States and cultivars suitable for growing throughout the year have been evolved there. The members of National Chrysanthemum Society run into thousands in several countries. It ranks second (next to rose) in the international cut flower trade. In India, it occupies a place of pride both as a commercial flower, garden plant, pot plant and as a popular exhibition flower.

Large number of chrysanthemum cultivars which exhibit wide variation for characters like growth habit, size, colour and shape of blooms makes chrysanthemum suitable for varied purpose. Its erect and tall growing cultivars are suitable for background planting in borders and as cut- flowers. The dwarf and compact growing ones are suitable for front row planting or pot culture. The decorative and fluffy bloomed small flowered cultivars are ideal for preparation of garland and hair decoration. The extra large- bloomed cultivars are prized for their exhibition value. Certain species like Chrysanthemum cinerariifolium and Chrysanthemum coccineum are cultivated as sources of pyrethrum, a natural insecticide.

ABSTRACT

We report here the occurrence of chrysoberyl bearing gem pegmatitesof Southern India. The Pan-African Chrysoberyl mineralization is associated with intrusive event of grey pegmatites within granulite facies parametamorphic aluminous khondalites. Lithological and structural controls of chrysoberyl mineralization are discussed. The chrysoberyl occurrences in southern India, southern Madagascar and Sri Lanka provide strong evidence for India-Sri Lanka-Madagascar juxtaposition in the East Gondwana assembly with the Achankovil Shear Zone of Southern India one side extending into Ranotsara Shear Zone in Southern Madagascar and other side into southern tip of Sri Lanka.

CINCHON, a place where the Countess Ann, a wife of the 4^th Count of CINCHON lived. She was cured by tertian fever in 1638 by the use of cinchona bark. Its virtues were made known to Europe in 1640. The botanists identified it in 1717. This drug shows the pathway for the establishment of homoeopathy.

The key word in the prescribing of China is 'debility' or weakness caused by excessive loss of blood or other fluids from the body, through nursing or salivation or excessive and bloody leucorrhoea, menstruation or long-continuing diarrhoea or through profuse pus formation or after an attack of influenza. There may be haemorrhages from the wounds, the lungs, the bowels or from the nose, a sudden depletion leading to fainting, loss of sight, ringing in the ears or to an over all weakness of the body. China acts as a marvelous remedy in such cases. The dose should be frequently repeated in 200 potency.

4.1. Origin and distribution

• Originated in the central hills of Sri Lanka and Malabar Coast.

• Distributed in tropical and subtropical regions of North America, Central America, South America, Asia, Oceania

• Cultivated in Sri Lanka, Malagasy Republic and Seychelles.

• In India, it is grown in one or two locations in Kerala

4.2. Economic importance

• Commercial products are

? Quills: Scraped peel of inner bark of mature cinnamon shoots, joined together with overlapping tubes, hollow of which has been filled with smaller pieces of cinnamon peels.

? Quillings: Broken pieces and splits of all grades of cinnamon quills.

Cinnamon butterfly: Chilasa clytia clytia : Papilionidae

Larvae defoliate plants. The larvae are pests on many crop plants and weeds and are common in the plains. The larvae are jet black at hatching. They develop a series of broad white patches. The adult is a common butterfly rich velvety brown, and spotted with white dots. The hind wings have arrow shaped streaks and crescent shaped spots.

Insects, belonging to the phyllum-arthropoda, have an open circulatory system. An open circulatory system is that in which blood bathes the organs rather internal organs directly in the haemocoel, the coelom of the insects, which actually is not a true coelom. Almost entire haemocoel of insects is formed from the epineural sinus. The haemocoel is divided into the perineural sinus and perivisceral sinus by the dorsal and ventral diaphragm respectively. The characteristic of insects is the presence of dorsal vessel, which comprises of anterior aorta and a posterior heart and is the only conducting tube present in insects. The blood of insects mostly does not perform gaseous exchange, therefore it does not contain haemoglobin, and blood in insects is called the haemolymph, which is red-coloured. So in order to study the circulatory system of insects, the major focus must be on the dorsal vessel, which has been described as follows, along with its accessory structures.

Embryologically, the circulatory system is the first organ system to develop in the living animals. The form and function of this system vary considerably among the animals and are shaped by a variety of environmental factors i.e. phenotypic plasticity. Oxygen (O₂) acquisition and carbon dioxide (CO2) elimination occur simultaneously at the gill site of fish and shrimp. The gases are transported around the body by the circulation of the blood.

3.1. Circulatory System of Fishes

In fishes, heart is simply a muscular enlargement and modification of a part of the main blood vessels, lying between the hepatic capillaries and the gills. Fishes have a closed circulatory system with a heart that pumps blood in a single loop throughout the body. From the heart, blood goes to the gill capillary bed. Then via the systemic capillaries it returns back to the heart. Usually the gills account for approximately 30% of the total resistance to blood flow, the rest being in the visceral and somatic vasculature. Tuna requires more O₂ and the gill area is large with gill resistance up to 57%.

The circulatory system includes the heart, blood and lymph vessels, blood, lymph, cerebrospinal and tissue fluids. Circulation of blood in the body is important for the transport of nutrients to all parts of the body and for the transport of gases and waste products. In fact most of the functions of blood could not have been possible, if there were no circulation of blood.

In order to constantly circulate the blood to all parts of the body and back, the body needs the services of an efficient pump. The pump or heart is based on the ability of muscle to contract or shorten. The blood is carried in a system of elastic tubes of pipes (arteries, capillaries and veins). The circulation of blood in the domestic animals or mammals is referred to as closed circulation because the blood returns to the heart without leaving this system of tubes.

The heartbeat frequency or pulse rate is usually given as the number of heart beats per minute. The heart rate increases several times during exercise or thermal stress. The average pulse rate of various domestic animals is given in Table 1.

It may be defined as a chronic condition of the liver in which there is an increase of the connective tissue, a decrease in its size, and a degeneration of the parenchyma.

Alcohol is the most common cause of the cirrhosis of liver. Alcohol reaches the liver through blood stream. Other causes may include improperly prepared foods, poisonous substances, drugs like arsenic, phosphorus, the infectious diseases like syphilis and obstruction of the bile ducts.

Cirrhosis of the liver produced by alcohol abuse is known as portal cirrhosis where as cirrhosis caused by some obstruction such as a stone in the common duct or some narrowing of the bile duct leading from the liver to the small intestine is called as Biliary cirrhosis.

The economics of migration has drawn attention of many economists and social scientists over the years. Decision making in migration has certain inherent complexities as it takes into account the characteristics of both areas of origin and areas of destinations. Similarly it involves the status of agricultural productivity and efficiency, extant of urban informal sector along with various other amenities available in the destination urban areas. The subject of rural-urban migration and its inter-linkage with urban informal market and agricultural productivity have received considerable attention in theoretical framework as well as in empirical research. Among these vast literatures, the study has reviewed some of them and made a synoptic assessment on these issues in general. Moreover an attempt has been made to review the existing literature on rural-urban migration in West Bengal.

2.1 Migration Decision Making

Migration decision can be two types: individual decision making and family decision making. These two sets of migration decision involve distinctly different sets of factors. Stark (1991) has rightly pointed out that “….the family, should not be treated as if it were an individual”. So there are differences between individual migration decision and family migration decision. Migration decision depends on a host of factors, some are economic, some are demographic and some are sociological in nature. However, individual and family migration decisions are determined by two distinctly different sets of factors.

This chapter describes about the review of relevant researches related to the present study. This also helps in developing conceptual framework and selecting proper methodology for the study. Although studies have been conducted on different aspects of conservation agriculture in past, but a few reviews were available on social ecology and perceptional change of the farmers in managing critical inputs to agriculture like water, nutrient and soil organic carbon, and ecosystem as a whole. So, reviews having a little indirect bearings are also included in this section. In accordance with the subject of the proposed study, the review of literature has been presented under the following sub-heads:

In any scientific investigation and research, a comprehensive review of literature is very essential. Its main function, apart from determining the work done before concerning the problem area i.e., area of investigation, to provide an insight into the methods and procedures and create a basis for interpretation of findings. As direct references of all the items are not in abundance, certain specific references along with some indirect references have been incorporated in this chapter for the purpose of meaningful use. In the present study, reviews of literature have been summarized in the following table

3.1. Origin and distribution

• Originated from Sri Lanka.

• Cultivated throughout tropics.

• Presently maj or producers - China, Vietnam, Indonesia, Argentina, Taiwan, Sri Lanka, Brazil, Madagascar and India.

3.2. Economic importance

• Two types of citronella oil: Java citronella oil obtained from Cymbopogon winterianus which is superior.

• Another is Ceylon citronella oil which is obtained from Cymbopogon nardus inferior type oil.

• Citronella oil - essential oil containing citronellal, geranial and hydroxy citronellal and high value perfumery bases obtained on steam distillation of citronella grass.

• Used for perfuming soaps, detergents, cosmetics, agarbattis and for making mosquito repellent creams.

Introduction

Citrus is one of the most important fruit crops in the world. Citrus fruits are grown in the tropical and subtropical regions of the world. Some of the important countries where these fruits are grown include USA, Brazil, Spain, Israel, South Africa, Australia, China, India, Mexico and Morocco. Citriculture as a garden industry dates back to less than one hundred years. Indian citrus industry is the third fruit industry after mango and banana. The important groups of crops in citrus are sweet oranges, mandarins, limes, lemons, grapefruits and pummelo (Singh, 2001). Total world citrus production is about 115525.2 thousand tonnes, whereas in India, the production of citrus fruits is 8267.2 thousand tonnes (Anonymous 2012). The most important commercial Citrus species grown in India are the mandarin (Citrus reticulata Blanco), followed by sweet orange (Citrus sinensis Osbeck) and acid lime (Citrus aurantifolia Swingle). The main cultivars in the mandarin group are the Nagpur mandarin, Coorg mandarin, Khasi mandarin, Hill mandarin and the Kinnow mandarin. Maharashtra, Karnataka, Andhra Pradesh and Punjab are the major citrus producing states, while in Haryana, Uttar Pradesh, Madhya Pradesh, West Bengal, Tamil Nadu, Gujarat and Bihar, the fruit is grown to a limited extent. In Rajasthan new plantation of citrus are coming up very well and the main cultivars are Nagpur and Kinnow mandarins.

Cultivation of citrus holds promise in arid irrigated tracts. The major citrus fruits under cultivation in arid regions are acid lime , lemon, Kinnow, Mandarin hybrid, sweet orange and grapefruit .Acid lime and kinnow are widely grown. Citrus fruit are grown  through out country for its  nutritive and medicinal value (Chadha, 2001) . Citrus is world’s leading fruit crop. In India, it is cultivated in the states of Maharashtra, A.P., Punjab, Rajasthan, H.P., U.P., M.P., Karnataka, T.N., J&K., Odisha, Gujarat, Assam, & Sikkim, For obtaining quality plant material, propagation is an important aspect. Citrus is largely propagated   by budding except kagzi lime which is raised from seeds because of occurrence of polyembryony and sweet lime which is  commercially  propagated by stem cuttings. Kagzi lime and lemon can also be propagated by layering. In case of citrus the availability of proper plant material is very much essential.

SUMMARY

Citrus is third most important fruit crop in India after banana and mango. Citrus crops have occupied an area of 8.43 lakh ha with total production of 75.7 lakh tons and the productivity of 9.9 tons/ha in India. Such a quantum of citrus production contributes 13 per cent of total fruit production demonstrating the significance of citrus in horticultural research and development in India. Rootstocks are known to have profound effect on the vigour, precocity, productivity, internal quality, and longevity of the scion varieties grafted on them. They are also known to influence the susceptibility of trees to various diseases and insects. Furthermore, it is recognized that optimum performances depends on the proper selection of rootstocks for a given set of growing conditions. The most commonly and widely used citrus rootstocks in India are Rough lemon, Cleopatra and Pectinifera. Rough lemon (Jatti Khatti) is the most important and widely used rootstock in the country for most of the scions followed by Kharna Khatta being more popular in Uttar Pradesh. While the problem of rootstock selection is important in all major fruit crops, it is of even greater importance in citrus due to tristeza virus disease now present in many areas of the world. It is also possible that citrus decline in India may be due partly to stionic incompatibilities. This chapter deals with problems and prospects of rootstocks in citrus in India, particularly related to horticultural aspects, insect-pests, diseases, nematodes, physiological disorders, post harvest quality, aspects related to tissue culture and rootstock breeding.

The research work carried out throughout citrus growing countries of the world including India showed utility of different rootstocks for citrus plants, which varies greatly with scion variety and agro-climatic condition. A wide range of citrus rootstocks are available, each having desirable attributes. The success of a rootstock is determined by its tolerance to prevailing conditions of soil, climate and diseases. Citrus plants are unusual in that many species and cultivars including the commercial rootstocks reproduce true to type from seed. Commercial citrus rootstocks are usually highly polyembryonic but there can be 1-40 zygotic seedlings in the seedbed.

Citrus fruits are originated in the tropical and sub tropical regions of South East Asia, particularly in India and China. North East India is the native place of many citrus species. Citrus fruit has been cultivated in an ever-widening area since ancient times. Although oranges are the major fruit in the citrus fruits accounting for about 70 per cent of citrus output, the group also includes small citrus fruits (such as tangerines, mandarins, clementines and satsumas), lemons, limes and grapefruits. Citrus fruits are consumed as fresh fruit or utilized for preparing processed citrus products. Approximately one third of total citrus production is utilized for processing. India ranks sixth in the production of citrus fruits in the world. In India, it is primarily grown in Maharashtra, Andhra Pradesh, Punjab, Karnataka, Uttaranchal, Bihar, Orissa, Assam and Gujarat. Citrus fruits have several beneficial health and nutritive properties. They are rich in Vitamin C and folic acid, as well as a good source of fiber. In addition they contain potassium, calcium, folate, thiamine, niacin, vitamin B6, phosphorus, magnesium and copper.

Citrus butterfly: Papilio demoleus, P. polytes : Papilionidae

The pest is distributed all over the world and has a host range that includes citrus and other rutaceae plants like Aegle marmelos. Adult has the head and thorax black with a creamy-yellow coloration on the underside of the abdomen. Wings are dull black, orna-mented with yellow markings and a distinct red patch on the hind wing. The underside is orange and yellow coloured and can be seen when it flirts for honey collection or just before egg laying. The Antenna is black and clubbed.

Genus : Citrus
Species : Sinensis aurantium, limon, medica grandis L. paradisi Macf. reticulata Blanco
Family : Rutaceae
Chromosome No. : 2n = 18

Citrus is one of the most important and popular fruit of the world which is widely cultivated in almost all of the tropical and subtropical parts of the world. Amongst the subtropical fruits in respect of average it occupies the third position. In India too it is next to mango and banana in commercial perpective. Citrus fruits on account of extensive adaptability are successfully cultivated in tropical, subtropical and even in the marginal temperate regions where the condition are somewhat favourable with its attractive appearance (foliage) distinct flavour and above all its excellent fruit quantity, citrus is liked by one and all. Fruits are not only refreshing and delicious but are also very rich in vitamin C and is good source of A and B, with fruit sugar acids, minerals like Ca, P, Fe. They are essential and play significant role in health promoting constituents in human diet, significance of citrus fruits in diet is very well established. Limes and lemons

Origin and history: Citrus is the leading fruit crop in the world. In India, citrus ranks second in area sharing 12.8% of the total area under fruit crops with 9.6% share in production. Under citrus group, mandarins are the most important, occupying 50% of the total area under citrus followed by sweet orange and limes. Citrus fruits are grown mainly in Maharashtra, Andhra Pradesh, Punjab, Karnataka and North-Eastern region. 

1.    Nagpur mandarin was introduced in India in 1894 by Shriji Raja Bhosle. 

2.    Kinnow can be grown in high density planting by using the cultivar  Troyer Citrange'  as a root stock by spacing the plants at 1.8 x 1.8 m2. 

3.    Classification of citrus was given by Tanaka and Swingle. 

4.    Grape fruit is also known as Forbidden fruit, Breakfast food.

Genus Citrus (Citrus spp.) belongs to family Rutaceae and subfamily Aurantioedae. Citrus fruits are cultivated over a wide range of agroclimatic conditions because of their ability to adapt to different situations. Citrus is considered to be one of the most remunerative fruit crops in India, having a lasting niche in the international trade and world finance. Most of the Citrus species are believed to be native to tropical and subtropical regions of southeast Asia, particularly, northeastern India and the region between China and India (Ghosh, 2007). Trees belonging to genus Citrus are comparatively small in size (other perennial fruit crops) and evergreen in nature that are grown in tropical, subtropical and even mild temperate climates. Citrus fruits are nonclimacteric so they do not ripen further once removed from the trees. So it is important that they are picked at the right stage of maturity.

Citrus is one of the most important fruit crops of the world. The most important commercial citrus fruits in India is mandarin oranges followed by sweet oranges, lemons and acid limes. Citrus fruits are used for fresh fruit juices, processing into squashes, marmalades and its essential oils from peel are widely used in flavouring, perfumery and cosmetic industry. The citrus peel is one of the important sources for manufacture of pectin.

It is believed that most of the species under the genus citrus are native to tropical and subtropical regions of South-East Asia, particularly India, China and in the region between these two countries. The north-eastern region of India is considered as one of the natural homes for few species of citrus. The other major citrus producing countries of the world are Brazil, USA, India, China,Mexico, Spain, Egypt, Italy, Indonesia and Trukey.

Sweet Orange (Cirus sinensis Osbeck) or Mosambi

Sweet orange is one of the most widely favored citrus fruit of of the world. Its scientific name is Citurs sinensis Osbeck. The sweet oranges are generally round to oval in shape; tight skinned with solid central core. The skin is yellow to orange in colour, smooth and pulp is yellow to orange or reddish. The segments are tightly attached to one another. The commercially important varieties are Malta (Blood Red), Mosambi and Satgudi. Other exotic varieties like Valencia, Washington Navel of USA and Shamouti of Isreal.

Citrus is a major fruit crop grown all over the tropical and subtropical region of the world. Maximum citrus species are native of tropical and subtropical regions of South East Asia specially India, China in the area between these two countries. It is mainly cultivated in China, Brazil, India, USA, Mexico, Spain and Egypt in the world. China is the leading producer country in the world followed by Brazil, India and USA. India is the third largest citrus producer which has 4.8 per cent of the world’s total citrus production.

Citrus crop includes lime, lemon, sweet orange, mandarin orange, Kamala orange, grapefruit, malta and pomelo etc. The disease which attacks one species of citrus mostly attacks other species also.

The prime objective of any plant breeder is to develop high yielding varieties and make the quantity of quality seed of those varieties to farmers for commercial cultivation to realize the benefits of superior varieties. This necessitates, the production of seed of improved varieties in large scale in order to make them available to farmers without losing their genetic purity. Seed production is a continuous process. The seed of improved varieties are produced in several stages, each class producing a special class of seed. The various classes of improved seeds are recognized in order to facilitate seed production and to ensure continuous supply of quality seed. A seed production programme for the production of quality seed has different classes of seeds viz; nucleus seed, breeder seed, foundation seed, registered seed and certified seed. The Association of Official Seed Certifying Agencies (AOSCA) has defined these seed classes as follows:

1. Nucleus Seed

Basic or nucleus seed is the original seed of a released and notified variety. Nucleus seed is multiplied by single plant progeny system, using the concept of maintenance breeding, where purity of the original parental stock is maintained. It is available in very limited quantities and taken from the individual plant of a variety for purification. It is directly under the controlled of concerned crop breeder. This seed has hundred percent genetic and physical purity. Breeder seed is multiplied out of this material and about 500-1000 plants are kept for continued multiplication of nucleus seed.There is no need of any type of tag on nucleus seed but concerned breeder issue a certificate for purity.

3.1 Introduction

Genetics deals with genes and cytogenetics with chromosomes that harbour genes. On the other hand, plant breeding strives to upgrade the genotypes of crop plants. So, the plant breeding methods should be based on genetic principles. Dear students, you should have clear understanding of genetics in broad sense so that you can appreciate the applicability of breeding methods. As I have already pointed out that you have been taught the course ‘Principles of Genetics and Cytogenetics’ in the first semester, only a brief discussion is followed for your review and better understanding.

3.2 Character

When we call ‘character’ or ‘trait’ in genetics, we mean any morphological, anatomical, biochemical or behavioural feature of an organism. For instance, flower colour, blooming period, leaf size, size of guard cells in stomata, vitamin C content, disease resistance etc. A single gene or a number of genes may govern the development of a character and, often it is influenced by the environment. Characters may be qualitative or quantitative.

6.1 Introduction

Plant breeding is the indispensible component of elevating production and productivity of spices by evolving high yielding and/or with good quality type. Thereby, the practice of identification and selection of desirable traits and introgression of those characters in a single plant is being done since the beginning of organized agricultural activities by humankind. The act of plant breeding was reshaped and got a momentum with a scientific basis after the discovery and rather rediscovery of Mendel’s laws. Worldwide, humankind could enjoy the direct benefits of methodical plant breeding during green revolution. Manipulation of genetic architecture for creating variation in the population and successive selection is the basic of all kinds of crop breeding. But the process of creation of variability and selection differs from crop to crop depending on their mode of reproduction. It is comparatively easier to get a new homogeneous population in self pollinating plants. Therefore, segregating generations are handled differently in these two categories of self and cross pollinated crops.

4.1. Agricultural production economics

An applied science, wherein principles of choice are applied to use of land, labour, capital and management in farming.

Explains conditions under which profit and output can be maximized and cost and use of physical inputs can be minimized.

Synonyms : Hog eholera, European swine fever

It is an acute highly infectious viral septicaemia of swine of all ages characterized by rapid and sudden onset, high morbidity and mortality and generalized  haemorrhages. A chronic course  followed by recovery after treatment has been reported in older pigs and appearance of new born pigs with congenital defects.

Etiology : The etiological agent causing hog cholera is a linear  single stranded positive sense RNA virus under the genus Pestivirus and family Flaviviridae. The virions are spherical, 40-50 nm in diameter  and consist of a tightly adherent lipid bilayer envelope covered with glycoprotein peplomers surrounding an icosahedral capsid of 28-35 nm in diameter. The genome is 12 kb in length with 5’end capped but  3’end  not  polyadenylated. The genes for structural proteins are located at 5’ end of genome. The virus replicates in the cytoplasm and matures within cytoplasmic vesicles. Though there is only one antigenic type of the virus, a number of strains of variable virulence and antigenicity has been reported. The causative agent was first thought to be a gram negative bacterium named Salmonella cholera suis. Later, it was confirmed that the disease is caused by a  virus.

History on Classification of Herbicides

Copper sulphate (CuSO₄) was the earliest inorganic salt used as selective herbicide for controlling dicot weeds in cereal crops during 1896 in France, Germany, and USA. Sulphuric acid (H₂SO₄) was used as herbicide in cereals during 1909. In selective killing action depends on the fact that it runs off the leaves of the cereals and scorches rough surfaces of certain seeds. Sodium chlorate (NaClO₃) under the name mort-herbs is used in France for killing deep rooted perennials. Another non-selective herbicide, ammonium sulphamate (NH₄SO₃NH₂) was introduced in 1945 as ammate for the control of woody plants. Organic herbicides are more effective and selective.

Classification of Herbicides

Classification of herbicides is modified periodically as and when new herbicides are developed. Herbicides are classiûed based on their method of use (soil and foliage applied), mode of action (systemic or translocated and non-systemic or contact herbicide) and chemical key structure (aliphatic-aromatic, dinitrophenal, etc. Some herbicide molecules contain more than one classifying key structure and they are put into the group most likely to be contributing activity.

Any approved herbicide is known by three names: common name, chemical name and trade name. Common name of herbicide is a technically accepted abbreviation of its chemical name. Chemical name reads out its full molecular structure. Trade names refer to their formulations offered by the chemical companies for the consumers.

The modern breeds of chicken have known to be descended from the wild jungle fowl. India, Nepal, Bangladesh, Myanmar, Thailand, Sri Lanka and Malaysia are the homeland to these jungle fowls. There are four known species of jungle fowl viz. Gallus gallus (Red jungle fowl), Gallus lafayetti (Ceylon jungle fowl), Gallus sonnerati (Grey jungle fowl) and Gallus varius (Java jungle fowl). The domestic breeds of chicken/fowl have originated from Gallus gallus.

CMTs can be classified on the basis of morphologic features, tissue of origin (epithelial, myoepithelial or mesenchymal tissue) or prognosis. The World Health Organization (WHO) classification of canine and feline mammary tumors has categorized CMT into three major categories i) malignant, ii) benign and iii) unclassified tumors. On the basis of histological characteristics, the mammary tumors have been classified into fibroadenomas, adenomas, solid carcinomas (with transformed epithelial cells), tubular adenocarcinomas (with tubule like arrangements), papillary adenocarcinomas (having papillary like projections), anaplastic carcinomas (with highly pleomorphic cells), sarcomas (involvement of connective tissue) and malignant tumors (Fig. 2). Fibroadenomas and adenomas are the types of benign mammary tumors the former contains some connective tissues component in between, and carcinomas, adenocarcinomas and sarcomas come under malignant tumors.

Classifications and Nomenclature

Plants can be classified according to the following criteria: (1) botanical, (2) descriptive and (3) agricultural. Botanical classification is based on the morphological characteristics of plants as well as on their anatomy, physiology and DNA sequences. Descriptive classification is based on the environmental adaptation, growth habit and other observable features. In agriculture, plants can be broadly classified as either useful or useless. Those which are useful are called crops while those which are not useful are called weeds.

A common, well-defined system of crop classification is important in crop science and agriculture. Grouping of plants following established systems will simplify plant collection initiatives, research and breeding specialized development efforts. Having standardized botanical names will also facilitate efficient communication, dissemination and retrieval of scientific information. Additionally, the grouping of crops will indicate that these crops may have similar uses, adaptation, growth habits and methods of culture. Classifying crops by family is likewise important in intergeneric grafting. To students of crop science, a list of crops under the various agricultural classifications will be a useful reference in crop names and identification and as a review guide. To the farm manager himself, the same list will offer innumerable benefits in finding alternative crops for specific uses.

Despite these advantages, however, classifications of crops in agriculture vary from place to place and from one country to another due to differences in the primary usage of certain crops, intensity of care, extent of cultivation and other criteria under consideration. It is not uncommon to find crops having two or more classifications, used simultaneously, alternatively or sequentially. FAO(2010) in its report entitled “Crops Statistics - Concepts, Definitions and Classifications”, expressed its difficulty in the collection and presentation of statistical data due to differences in the concepts, definitions, coverage and classifications” of crops which are grown in different countries.

Taxonomy (biological systematics) is the branch of science which deals with classification of units or individuals on the basis of similarities and differences. The classification, nomenclature, and identification are three interrelated components of bacterial taxonomy (Cowan, 1965).

Classification: Classification is the arrangement of bacteria into groups (taxa) based on the similarities of certain characteristics. Presently 11,000 bacterial species is classified. At the current rate of 600 bacterial species / year it is estimated to take 1000 years to classify all the bacteria!

Nomenclature: It is the assignment of specific names to the taxonomic groups following the regulations mentioned in ‘International Code of Nomenclature of Bacteria’ (Euzeby, 1997). International committee on systematic bacteriology (International committee on systematics of prokaryotes, ICSP) standardizes the code. The committee is helped by a number of taxonomic subcommittees on different groups of bacteria. The Code can be amended by the Judicial Commission. The Code contains general considerations, principles, rules and recommendations on the naming of prokaryotes (bacteria) up to the rank of ‘Class’.

Abstract

Classification of the hundreds of possible dryers is essential to the logical selection of appropriate dryer for a given application. Diverse criteria for classification as well as selection of dryers are presented and discussed briefly. The advantages and limitations of different dryer types must be taken into consideration. Initial capital cost is often the key deciding criterion in industrial dryer selection. This is not a good strategy as the user must pay for the operating costs over a long period of life of the dryer. In general several different dryer types are suitable for a given product. Careful selection is essential for cost-effective operation of the dryer.