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Cutaneous muscle

In the cervical region of ox, the cutaneus muscle, cutaneus colli is poorly developed. It is in the form of a narrow strip on the ventral part of the neck. It arises from the ventral median connective tissue strip of the superficial fascia and extends cranially covering the cervical part of the deep fascia. The fibres of this muscle fan out dorsolaterally and form the aponeurosis with the cervical fascia and join the cutaneus facei.

Fascia

The major groups of muscles of the cervical region are covered by the thick superficial layer of fascia. The fascia is abundant and well developed in the cervical region of the ox. The fascia of the neck is in two layers, the superficial and deep. The superficial fascia is attached to the skin, whereas the deep fascia is again in two parts, the superficial and deep parts. The superficial part covers the superficial structures in the neck viz. the trapezius and brachiocephalicus muscles in the dorsolateral aspect and the jugular canal with jugular vein, and the rhomboideus muscles on the ventrolateral aspect of the neck. The superficial parts of the deep layer of cervical fascia of two sides meet at the median line both, dorsally and ventrally. The deep part of the deep fascia is attached to the vertebrae and the longus colli muscle on either side at the median line and covers the trachea, oesophagus, carotid artery etc before joining ventrally.

Site of incision: Make a midventral incision on the neck from larynx up to thoracic inlet then make ventrodorsal incision from both ends of this incision up to mid dorsal aspect of neck region.

Site of incision

Remove the skin flap of pectoral region to expose the pectoral muscles.

Site of incision: Make a transverse incision below the anus between lateral margins of tuber ischia. Then from each end of this incision make an oblique incision caudo-cranially so that these join midventrally each other between the thighs. Remove the triangular flap of skin to expose the region.

Site of incision: Make a straight dorso-ventral incision through skin from the summit of dorsal vertebral spine to the cranioventral aspect of shoulder joint. Extend it up to the cranial margin of shoulder joint, then caudo-ventrally up to caudal most part of elbow joint. Make another ventrodorsal straight incision from caudal most point of elbow joint to the summit of vertebral spine then reflect the skin flap from ventral to dorsal up to mid dorsal line of the body. Remove the facia to expose the various muscles of this region.

Site of incision: Detach the limb from the trunk by cutting various muscles viz; pectoral muscles, serratus ventralis, latissimus dorsi, brachiocephalicus, omotransversarius, trapezius, rhomboideus and long head of triceps.

Site of incision: Remove the abdominal viscera to expose the sublumber region.

Site of incision: Make two incisions at mid-lateral aspect at base of the tail join them dorso-ventrally and reflect the skin caudally up the 4-5 inches.

Site of incision: Make a dorsoventral incision along caudal border of last rib up to mid ventral region of abdomen and another incision along the coxal tuber up to mid ventral region of abdomen. Joins the above two incision mid ventrally and reflect the skin up to mid dorsal aspect of lumber region.

Site of incision: Make a midventral incision on the sternum from cranial to caudal than from both ends of this incision make cranial incisions along the caudal border of shoulder and arm region to mid dorsal aspect of back and along last rib to mid dorsal aspect of back, respectively. Reflect the skin flap from ventral aspect to mid dorsal region of back.

Cutaneous muscle

The cutaneous muscle of the thoracic region is a part of the cutaneous muscle of the trunk. It arises from the interbrachial fascia on the medial surface of the arm and elbow and the lateral aspect of the arm and shoulder. It extends as a broad sheet between the shoulder and arm cranially and the stifle and thigh caudally and then upward to the middle of the dorsum and the tuber coxae.

Fascia of thorax

The fascia of the thoracic region is the caudal continuation of cervical fascia. It is in two layers, the superficial and deep. The superficial fascia is continuous with that of the skin and the cutaneous muscle. The deep fascia forms a well developed sheath for aponeurosis with the longissimus muscle. It is attached medially to the supraspinous ligament and the summits of the spinous processes of the thoracic vertebrae while laterally it is attached to the lateral surface of the ribs. From here it continues ventrolaterally and passes medial to the scapula under the rhomboideus thoracis muscle.

A branch of anatomy that deals with muscles and their accessory structures is called as myology and the body system concerned with myology is called muscular system. The muscular system is composed of specialized cells called muscle fibres because of their shape in the form of fibre or spindle. The plasma of these cells contains myofibrils which are contractile elements that cause contraction of muscles in a definite manner under the influence of a stimulus which is a unique property of muscles. These cells together constitute the distinctive muscular tissue.

Classification of muscles

Based on their morphological and functional characteristics, there are three types of muscles in the body.

Smooth muscle: The muscular tissue in this type of muscles is constituted by masses of spindle shaped cells and they occur mainly in the walls of hollow visceral organs including glands, the vessels, eye ball and hair follicles. These are nonstriated muscles. Contraction in these muscles is weak but sustained and mostly consistent and rhythmic. The action of this muscle is involuntary i.e. not under the will.

Cardiac muscle: The muscle fibres of this muscle are arranged in irregular masses and they form cross striations. The ends of some fibres come in contact with the sides of others forming a kind of syncytium. This is a striated muscle and its action is involuntary. This muscle occurs only in the wall of the heart and the immediate proximal ends of the major blood vessels like aorta, venacava and the pulmonary veins.

Key Points

• The main objective of managing open fractures is to neutralize further damage to the surrounding tissue while executing prompt, stable osteosynthesis and immobilization.

• Discomfort management should be considered because musculoskeletal diseases can cause severe discomfort.

Degenerative Myopathies

It is a degenerative disease of the musculature. Endocrine imbalances (hyperadrenocorticism, hypothyroidism, and hyperthyroidism), hypokalemia in cats, ischemic myonecrosis in recumbent cattle, post-exercise rhabdomyolysis, chemical agents, poisonous plants, and drug-induced degenerative conditions are some of the possible associations with it.

Somites are derived from paraxial mesoderm and they are located lateral to the developing notochord and neural tube. During the third week of gestation in domestic animals, the outlines of somites first become visible and in the fifth week of gestation the somite formation is completed. Somites differentiate into sclerotome, myotome and dermatome. They form skeletal, muscular and dermal elements i.e, vertebral column, muscles and dermis respectively.

The connective tissue, cartilage and bone all differentiate from mesenchyme which arises chiefly from mesodermal somites and lateral layer of somatic mesoderm while connective tissue of alimentary canal and lower respiratory tract is derived from splanchnic mesoderm. Mesenchyme is a spongy meshwork composed of branching cells spaces between which are filled by ground substance. The supporting tissues, connective tissue, cartilage and bone are derivatives of mesenchyme in which ground substance is gelly like, stiff and firm respectively.

Mushrooms are most ancient, best known and greatly admired fleshy macrofungi. Mushrooms are delicacies, much sought after and greatly valued foods. Wild mushrooms are mostly found in forests, tree trunks, pastures, lawns and road side during winter season and appear at surprising speed. Mushroom hunting or gathering is a popular hobby in Western countries. The wild mushrooms may be edible or unpalatable or poisonous. Poisoning by wild mushrooms is common and may be fatal or produce merely mild gastrointestinal disturbance or slight allergic reaction. The term toad stool is popularly reserved for inedible or poisonous mushrooms, but this classification has no scientific basis. This alarming term keeps many people away from these foods. It is important that every mushroom intended for eating be accurately identified. Mushrooms vary in colour, size, shape, growth habit, yielding ability and other characteristics.

STRUCTURE: Mushrooms are the fleshy fungi which constitute a major group of lower plant kingdom. Mushroom is the conspicuous umbrella-shaped fruiting body (sporophore) of certain fungi of the order Agaricales in the class Basidiomycetes but also of some other groups. Popularly, the term mushroom is used to identify the edible sporophores. The edible reproductive part consists of a stem and a cap. Gills found on the underside of the cap, are arranged like spokes in a wheel. The gills bear multiple spores which start new fungi. The sporophore emerges from an extensive underground network of fine thread like white growth known as mycelium. The mushroom, fruit body produced basidiospores at the tip of club like structures, called basidia, which are arranged along the gills of the mushroom. Beneath the mushroom, in the soil, is the mold colony itself, consisting of a mat of intercoiled hyphae, sometimes several feet in diameter. The mushrooms first appear as white tiny ball consisting of short stem (stipe) and a cap (pileus) which begins to open up like an umbrella. The delicate membrane or Veil (velum) enveloping the cap tears off, if allowed to develop fully, and lamellae (gills) radiating from the stalk into the cap become visible. These gills become darkened as the basidiospores (seeds) develop into millions and fall in the ground for starting their life cycle once again for second generation of mushrooms.

1. Introduction

Mushrooms represent a highly specialized group of fungi, mostly basidiomycetes, with production of fruiting bodies bearing the spores for continued propogation. The fruiting bodies vary greatly in shape, size, color, texture, structure and aroma (Rajarathnam et al., 1998). They are endowed with the unique ability to biodegrade cellulosic wastes, including lignin, and biotransform into edible fruiting bodies (Rajarathnam et al., 1992, 1998, Rajarathnam and Zakia Bano, 1990). Their chemistry is also varied comprising characteristic polysaccharides, phenolics, proteins, amino acids, peptides, lectins, fatty acids, minerals, and so on (Rajarathnam et al., 1998). The wide spectrum of compounds have endowed the mushroom species with a spectrum of biofunctional activities of medicinal importance and accordingly their role in human health are implicated through studies on chemical, cell culture and animal feeding experiments. Vast literature available on this subject is condensed for presentation here.
Fifty nine medicinal species are reported from Diaoluoshan Nature Reserve in Hainan Province, China (Li et al., 2003). A health food made from luminescent mushrooms (Mycena chlorophos) is described. The luminescent parts that emit light in the carpophore of the mushrooms are dried without thermal decomposition and pulverized (Sugimoto, 2006). Consideration is given to the health promoting properties of 3 types of Asian fungi, namely, shiitake (Lentinus edodes), reishi (Ganoderma lucidum) and maitake (Grifola frondosa). Properties considered include beneficial components (e.g polysaccharides, vitamins, amino acids) and effects on the immune system (Anon, 1997). Auricularia auricula (kikurage or tree-ear) and Tremella fuciformis (shirokikurage or white jelly-leaf) are widely used in Chinese cuisine. Chemical structures of some of the polysaccharides from A. auricula and T. fuciformis, in relation to their medicinal and nutritional effects are described (Misaki and Kakuta, 1995).

1. INTRODUCTION

Mushrooms are edible fungi of commercial importance and their cultivation has emerged as a promising agro-based land-independent enterprise. There are about 20 varieties of mushrooms being cultivated throughout the world for food. In India, only white button mushroom (Agaricus bisporus J.E. Lange Imbach), oyster mushroom (Pleurotus spp. [Fr.] P. Kumm) and paddy straw mushroom (Volvariella volvacea [Bul.] Singer) are grown commercially. Of these, white button mushroom contributes ~90% of the total production. Mushrooms have been recognized as an alternate source of good quality protein and produce the highest quantity of protein per unit area from agro-wastes. Besides, they provide potentiality for generating employment, improving economic status of growers, help in checking pollution and earn foreign exchange.

Out of the total production about 45% of mushrooms produced are consumed in the fresh form while the other 55% are processed, with 5% in dehydrated form and 50% in canned form. This is because their shelf-life in the fresh form is very short and hence mushrooms are traded in the world market mostly in the processed form. Fruiting bodies (reproductive phase) of Agaricus are appreciated not only for texture and flavour but also for their chemical and nutritional characteristics.

Sciarid(mushroom flies): Bradysia paupera, Lycoriella auripila: Sciaridae

The larvae feed on the mycelial attachments and restrict the growth of the spawn. The maggots also feed on the developing mushrooms or pinheads and thus cause loss in yield. They also bore the developing mushrooms and render them hollow.

1.1. Mushroom

Fruiting body of fungus appears above ground and contains spores.

Fungi are network of fine microscopic threads collectively known as mycelium.

Fungi are the part of the plant kingdom and don’t contain chlorophyll and root system.

Mushroom comes under sub division Basidiomycotina, order – Agaricales.

Melons (Cucumis melo) are annuals with climbing, creeping or trailing vines of length up to three meters. The desert types quench thirst and add to the nutrient content of main diet. The non-desert types are used as vegetables. Muskmelon (Cucumis melo., 2n=2x=24) encompasses the netted, salmon -flesh cantaloupe, the smooth – skinned green fleshed ‘Honey Dew’, the wrinkled, white – fleshed, ‘Golden Beauty’ and several other dessert melons in USA.

Origin: Not known with certainty but, 40 or more wild species of Cucumis are found to occur in the tropics and subtropics of Africa. Wild species of Cucumis occur in Africa and it is likely that it originated in African continent. It does not appear to have been known to the ancient Egyptians, not to the Greeks and seemed to have reached Europe towards the decline of Roman Empire. Although melon was introduced into Asia at a comparatively later date there are undoubtedly well developed secondary centers of origin of C. melo in India, China and then Southern USSR. In India Oriental pickling melon (C. melo var conomon) and snap melon (C. melo var momordica) are unique and have considerable variability in Western Ghats of India. They are popular desert and preserving melons cultivated in Warm humid tropical condition of South India. It is also considered that China as primary center of origin and Indo-Burma as secondary center of origin. It has been introduced to Europe and from Europe to the USA by the early travelers. At present muskmelon is being cultivated throughout the world under tropical and subtropical climatic conditions. Polymorphism in leaf, flower, fruit shape and colour (Kirkbride, 1993), allowed the classification of horticulturally important melons into seven groups.

Melon or muskmelon (Cucumis melo L., 2n = 2x = 24, family Cucurbitaceae, mostly andromonoecious, cross-pollinated as well as self-pollinated) has latest global production close to 30 million tons where top ten producing countries are China (16.0 million tons), Turkey (1.8 million tons), Iran (1.6 million tons), Egypt (1.1 million tons), India (1.0 million tons), Kazakhstan (0.9 million tons), USA (0.8 million tons), Spain (0.7 million tons), Italy (0.6 million tons), Guatemala (0.6 million tons). India produced 1.2 million tons melons from 54000 ha acreage during 2017-18 giving a productivity of 22 tons/ha (MAFW, 2018).

US melons encompass the netted, salmon-flesh cantaloupe; the smooth-skinned green fleshed ‘Honey Dew’, the wrinkled-skinned, white-fleshed ‘Golden Beauty’ and several other dessert melons. Other forms with different fruit characters (white-fleshed, green-fleshed, having striped thin skin and juicy) are commonly found in India and in Orient as indigenous land-race cultivars. These are getting displaced by the cultivar types as cantaloupe, Madhuras and Galia due to their long shelf life.

Melon is mainly cultivated for the consumption of the fruits which can be harvested immature; in this case, the fruit is not sweet and can be eaten raw, cooked or pickled. In most cases, the fruit is harvested at maturity with high sugar content (mainly sucrose). Fruit is mainly eaten raw; marginal uses are cubes canned in syrup, in “fruits confits”, candies, ice-creams, biscuits and also in cosmetics. Locally, seeds can also be consumed (Pitrat, 2008).

Melons are annual plants that have up to three meters of climbing, creeping, or trailing vines. Several of them are consumed as dessert fruits while a few varieties/types are used for vegetable purposes. Generally, the fruits of commercial varieties are sweet, juicy, delicious with good nutritional and medicinal properties and a daily intake of 120-150 g can help in weight loss, better eye and skin health (Shivapriya et al., 2021).

Currently, muskmelon is being cultivated throughout the world, especially under tropical and subtropical climatic conditions. In India, muskmelon is grown in 54,000 ha with a production of 1.23 million tons (NHB, 2018). The estimated national seed requirement per year is about 27 tons with a value of about Rs. 27 crores. The crop is cultivated mainly in rabi season (November to February sowings), thus limiting its availability in the market during summer. Rarely, melons are cultivated for the off-season market, and those fetch a premium price. The total value of muskmelon fruits in the domestic market is estimated as Rs.1231 crores.

The initial symptom of Alternaria brassiciola appears as small, dark colored spots which enlarge rapidly to form circular lesions. Under humid conditions a bluish velvety fungal growth is seen in the centre of these spots. Spots caused by Alternaria brassicae are almost similar to those produce by Alternaria brassicicola but are comparatively smaller and lighter in colour. When many spots are formed on the leaves, the leaves turn yellow and dry prematurely. Formation of pods and seeds are adversely affected.

Introduction

Agriculture is the foundation of India’s economy, as it provides food to people, feed to cattle, raw materials to primary and secondary industries, contributes upto 19 percent of GDP and employs 54.6 percent of the workforce (Kirti and Prasad, 2016). Due to diverse soil and climate conditions, vast varieties of crops such as cereals, pulses, spices , millets, oilseeds, flowers and fruits are being grown in India. Among these crops grown, India is among the leading producers of pulses, cereals and spices in the world (Mishra et al., 2021). India is the fourth largest oilseed economy in the world. Among oilseeds, there are nine crops that are the primary sources of oils in the country, out of which seven are edible oils (soybean, rapeseed-mustard , groundnut, sunflower, sesame, niger and safflower) and two are non-edible (linseed and castor).

To isolate a streptomycin resistant mutant of E.coli by Direct selection using Gradient Plate Method.

Introduction

Zylbalskii devised this technique.

A mutation is any change in the nucleotide sequence of DNA. These changes are heritable. Although most mutations are harmful to the organism, a small percentage is beneficial under certain environmental conditions. Mutation can occur during chromosome duplication and they may be spontaneous of they may be induced by mutagenic agent. In this experiment, we select for a mutation causing streptomycin resistance in E. coli. Resistant mutants will be detected directly using thy gradient plate method.

Principle

Microbiologist developed a highly efficient method for isolation of antibiotic resistant mutant. The gradient is said as gradient of antibiotic formed on an agar plate. A gene imparting resistant toward an antibiotic is present in plasmid or chromosome. The occurrence of mutant with different level of streptomycin resistant involves mutation of gene with unequal potential. This means that under certain cells degree of mutation is more while few shows less mutation. Some cells show intermediate resistant while others show completes resistant. The resistant in cell against streptomycin of this type, while in case of penicillin resistant increases step arise & so resistant mutant of high concentration of penicillin cannot be isolated/ obtained. While it is possible with streptomycin obtaining high resistance to penicillin stepwise & so this stepwise increase in resistance involves mutation of gene with equal potential. This theory of mutation through multi step procedure. The gene direct the organism to produce an enzyme, which inactivates an antibiotic & thus resistance to antibiotic, is observed in case of cells. Resistance of antibiotic is a plasmid-mediated resistance.

To isolate a streptomycin resistant mutant of E.coli by Indirect selection using Replica Plate Method.

Introduction

J. Lederberg & his wife E. M. Lederberg devised this technique in 1952.

U.V. light coming from the sun emits strong radiation to extent the antibacterial effect in the microbial population. However it has a very short penetration power, UV light is used as a mutagenic agent & was used by Beedle & Tatum to obtain biochemical mutation. The mutation rate is only once in 10^-9 cells per population. Then hence using mutagens like UV light by 10 to 1000 folds will increase this mutation rate.

In isolation of the mutant using UV light the dose of UV light is measured by its units/nm² organisms. The time selected for the mutation is calculated on the basis of 0.1 to 1% survival & a suitable biochemical character is used to evaluate the mutation.

A detailed treatment on the concepts of mutagenic effectiveness and efficiency was given by Konzak et al. (1965). They proposed the term “effectiveness” as a measure of gene mutations in relation to the dose and “efficiency” as an estimate of the mutation rate in relation to other biological effects induced, such as lethality, injury or sterility. To obtain high efficiency, the mutagenic effect must greatly surpass other effects in the cell, such as chromosomal aberrations, and toxic effects which generally lead to damage

Mutations are sudden heritable changes in characteristic of the organism, that is other than due to recombination (Swaminathan, 1983). Mutations occur naturally as spontaneous mutations and induced as spontaneous mutations and induced artificially by treating the biological materials with physical and chemical agents (mutagens). Experimental mutagenesis is effective method to enlarge genetically controlled variation, considerably within a short time.

Darwin’s theory of evolution explains that “variation is the mainspring of evolution”. The extent of genetic variability available in the breeding population and the selection techniques determine the efficiency of any breeding programme. In classical plant breeding programme, variation is generated by hybridization and selections are made from the resulting segregating generations. Induced mutagenesis can supplement hybridization or replace as a source of variability. Thus, mutation provides the raw material for crop evolution (Mahadeva and Randerson, 1982) and it provides the fundamental variability required for crop improvement by breeding (Konzak, 1984).

MUTATION BREEDING

Mutation refers to sudden heritable change in phenotype of an organism or permanent change in the number, kind and sequence of nucleotides in genetic material, while individuals showing these changes are known as mutants. Mutation was first discovered by Wright in 1791 in male lamb which had short legs. Hugo de vries coined the term mutation. In crop improvement the breeders are always look for wide range of variability and stabilization of desirable traits. Mutation breeding is very useful in inducing new variability, which is an essential requirement of any plant breeding programme. The modern day cultivars are the resultants of various breeding techniques like selection, hybridization, tissue culture and mutagenesis including some biotechnological tools. Novelty in commercial traits like colour, size, shape, length, post harvest life of flowers etc. are always valued and preferred by consumers. Mutation breeding by exposing planting material with irradiation has play vital role in inducing novelty in a number of flower crops.

MUTATION BREEDING

Mutation refers to sudden heritable change in phenotype of an organism or permanent change in the number, kind and sequence of nucleotides in genetic material, while individuals showing these changes are known as mutants. Mutation was first discovered by Wright in 1791 in male lamb which had short legs. Hugo de vries coined the term mutation. In crop improvement the breeders are always look for wide range of variability and stabilization of desirable traits. Mutation breeding is very useful in inducing new variability, which is an essential requirement of any plant breeding programme. The modern day cultivars are the resultants of various breeding techniques like selection, hybridization, tissue culture and mutagenesis including some biotechnological tools. Novelty in commercial traits like colour, size, shape, length, post harvest life of flowers etc. are always valued and preferred by consumers. Mutation breeding by exposing planting material with irradiation has play vital role in inducing novelty in a number of flower crops.

TYPES OF MUTATION

Based on occurrence

(1)Spontaneous mutation: Occur spontaneously in nature and not present in sufficiently high frequency and spectrum.

(2)Induced mutation: Artificially produced by the treatment of various mutagenic agents and present in sufficiently high frequency and spectrum

The discovery of mutagenic effects of X-rays on the fruit fly (Drosophila) by H. Muller in 1927 and by L. J. Stadler in barley and maize in 1928 paved the way for researchers to experiment with its effects on various organisms. In 1928, H. Stubbe showed the use of mutagenesis in producing mutants in crop plants like tomato, soybean and others. The first commercial mutant was produced in tobacco in 1934. Reports by B. Sigurbjornsson and A. Micke mentioned 77 cultivars that were developed through mutagenesis prior to 1995. In 1995, this number was 484. This number has since been significantly increased covering a large number of crops, namely, corn, wheat, pea, chrysanthemum, poinsettia, dahlia, citrus, apple, peach and the modified traits include plant maturity, winter hardiness, lodging resistance, protein and lysine content and numerous ornamental mutants. By the end of 20th century, the number of mutant varieties rose to 2252 covering a range of crops like cereals, oilseeds, pulses, vegetables, fruits, fibres, and ornamentals. Majority of these mutants were released as direct mutants and the rest as a result of cross breeding with the mutants. Most of the mutant varieties have come as a result of using physical mutagens (X-rays, gamma rays, thermal and fast neutrons) with gamma rays alone accounting for more than 60% of the mutant varieties. By 2017, nearly 3250 mutant varieties belonging to 175 plant species have been developed and released where China, Japan, India, Russia, the Netherlands, Germany and USA are the leading countries. India with 345 commercialized mutants stands third after China (810 mutants) and Japan (481 mutants). Thus mutation breeding is a significant contributor to the development and release of commercial cultivars in several crops and for several traits.

Mutations are sudden and heritable changes in the genetic material. They can result in deletion, inversion and translocation of certain portions in the chromosomes, which can result in the changed expression of a trait due to the interaction of alleles within or without the locus, sometimes the effects revert back or can be heritable.

Most of the fruit crops are highly heterozygous. However, heterozygosity is one of the advantages when it comes to mutation. In highly heterozygous crops wherein there is a need for improvement in a single trait, mutations have been of great use. One of main limitations is use of vegetative material, which due to the unlikelyhood of uniform penetration and distribution of mutagenic agent can result in chimera. Although hybridization and selection have made a fair dent in the improvement of fruit crops, mutation is one of the methods that can be relied upon to develop pre-breeding lines and to bring about change in the quantitavie traits. Another very important fact is that there are crops like grapes wherein a lot of spontaneous mutants have become established varieties viz., Sonaka and Saritha to quote a few. Some of the existing varieites wherein one or two traits need to be improved, mutation would greatly help in this in comparatively short time. In some of the crops like sapota, wherein the conventional breeding would take long time, mutation can be resorted to both for inducing variability in the germplasm as well as for trait improvement. It is also to be noted here that mutation breeding can be a good supplement for conventional breeding, more so with the emergence of tissue culture propagation, which often throws up spontaneous mutants. Mutation as a methodology can also be tried in some fruit crop spp where there is no disease resistance source within. It can also be adopted in cases where there is a need to break linkages.

Vegetables are cheaper source of carbohydrates, proteins, minerals, vitamins and dietary fibers, and hence, assume a place of very great importance in the diet of individuals. All kinds of vegetable are grown almost universally. India occupies the prime position in the production of vegetable crops and is the second largest producer of vegetables in the world. The area and production of vegetables in India have been increasing during the post-green revolution period, and the country is heading towards another revolution in the form of Golden Revolution. However, there is an utmost requirement for genetic improvement of vegetable crops in terms of productivity, qualitative characters and resistance to biotic and abiotic stresses. For any genetic improvement programme, the presence of genetic variation is pre-requisite and mutation is the ultimate source of this heritable variation.

Mutation technique that holds promise of generating a much wider desirable variability than classical breeding has been refined. Out of 2275 mutant varieties worldwide in all crops, as many as 66 mutants are in vegetables. In terms of percentage, China, India, USSR, The Netherlands, The United States of America and Japan account for 26.8, 11.5, 9.3, 7.8, 5.7 and 5.3%, respectively of mutagen varieties in all crops. Such varieties are 3% in case of vegetables. After mutation treatment by a mutagen to a specific plant, DNA alterations (deletion, duplication, inversion, translocation, or transposition of larger DNA fragments, or simple basic pair changes) occur and lead to the DNA sequence change. Hence, new characteristics of that plant are established. In fact, induced mutations supply us with many new plant lines, which may be used as primary materials for crop breeding. Hence, mutation breeding seems to be an effective and ultimate option to improve vegetable crops in the shortest possible time. A large number of new promising varieties in different crops, including vegetables, have successfully been developed worldwide using various mutagens (Chopra, 2005).

22.1 Introduction

Mutations are sudden heritable changes in the genotype of an organism. De Vries (1900) for the first time used the term mutation (mutare in Latin means ‘to change’) for the appearance of new types in evening primrose (Oenothera) plant. In 1901 he put forth the idea of producing mutations artificially for use in crop improvement. Alberto Pirovano (1922) was first to use X-rays and ultraviolet rays for inducing mutations in plants, but his work remained unknown. So, Muller (1927) became the first known to induce mutation in Drosophila fly using X-rays. Though Stadler (1928) had started working simultaneously on barley and maize and induced mutations, he was late in reporting mutation due to longer life cycle of these plants compared to Drosophila. Mutation may be gene mutation (the result of change in the nuclear gene or plasma gene) or chromosomal mutation (change in chromosome number, structure or chromosomal aberrations of various types).

Since genetic variability is essential for any crop improvement programme, the creation and management of genetic variability becomes central to crop breeding. Experimentally induced mutations provide an important source of variability. An advantage of such created variability is that the starting point can be an agronomically accepted cultivar rather than a genetic stock of no direct commercial value with many undesirable attributes. It should, however, be realized that none of the imposed treatments in a plant system has so far been able to direct a specific change. As a result, following mutagenic treatments, a mixed bag of induced variants is found and many of these may not be of any value. Also, many events take place concurrently in a treated cell to produce variation at several loci within a genome. Because of these reasons it will be unrealistic to expect miracles out of a mutation breeding programme. The desired results can be achieved only when the objectives are clearly defined and the experiments are specifically designed to achieve those objectives. When a mutant of the required type is obtained, we only reach the step of identification of a desired recombinant in a conventional breeding programme and all the succeeding steps of evaluation of the mutant are in no way different from those in the conventional breeding procedures.

Refers to entire operation of the induction and isolation of mutants.

Term mutation was introduced by Hugo de vries in 1900 in connection with sudden heritable changes observed by him in Oenothera.

Mutagenesis is the process whereby sudden heritable changes occur in the genetic information of an organism not caused by genetic segregation or genetic recombination, but induced by chemical, physical or biological agents.

Mutations were first identified by Hugo de Vries in the late nineteenth century, while experimenting on the ‘rediscovery’ of Mendel’s laws of inheritance. He coined the term ‘mutation’. Radiation-induced mutations as a tool for generating novel genetic variability in plants, advanced as a field after the discovery of the mutagenic action of X-rays demonstrated in maize, barley and wheat by Stadler. The discovery of X-rays by Rontgen in 1895 led to the application of X-rays for inducing mutations in fruit fly by Muller (1927). Mutation is of two types

A. Define/Explain the followings

1. Mutation: Sudden heritable change in the phenotype of an individual.

2. Macro-mutations: Mutations with distinct morphological changes in the phenotype are called macro-mutations. Such mutations are found in qualitative character and, therefore, are also called oligogenic mutations.

Mutation is defined as a sudden heritable change in gene or in chromosome structure. The process of hereditary change is termed mutation and the individuals affected by the change are called mutants. Besides recombinations, mutations are the cause of genetic variation from which every breeding activity proceeds. By means of mutations, the multiplicity of the types of a population is not only increased by one genotype, but also by large number of further new genotypes due to possibility of subsequent recombinations of mutant with the existing genotypes.

Introduction

My journey into the heart of wildlife conservation began in the unassuming classrooms of KendriyaVidyalaya, where my curiosity for the natural world was nurtured by dedicated teachers and an enriching curriculum. My dreams took f light when I studied stories of Mahadevi Verma in my school days where she was taking care of wild animals in her home. Fuelled by my determination, I pursued my education in Veterinary College, Hebbal, Bangalore from 2006 to 2011. To increase my knowledge and help the wild animals in better way, I did master in Veterinary Microbiology from Veterinary College, Hebbal, Bangalore during 2012-2014, research was conducted in “Salmonellosis in Wild Animals” and PG diploma course in wild animal disease management from TANVAS, Chennai in 2016 research was on “Oral Microflora of Snakes”. Pursing higher studies gave direction to help wild animal, also gave me abilities to write research paper which will help the communities.

Etiology

The condition is characterized by formation of granuloma to pyogranulomatous dermatitis with paniculitis. The causative organism is normally present in the macrophage which may be Mycobacterium tuberculosis, M? bovis and M? microti.

Etiology

Genus Mycobacterium contains many pathogenic species that can cause disease in birds (M. avium, M. tuberculosis, M. genavenes, M. gordonae). Within M. avium, organisms are divided into four sub species. M. avium sp avium, M.avium sp silvaticum, M. avium sp homnissuis and M. avium sp paratuberculosis. Mycobacterium avium sp avium - has wide host spectrum; poultry, pigeons, raptors, ratites and wild birds. M. genavense- affects Psittacines and passarines. M. tuberculosis- psittacines and other cage birds, and wild birds in captivity. M.bovis- Psittacines and others.

Under natural conditions, M. avium sp avium does not cause severe disease in mammals except in rabbit and pig. Majority of mycobacteriosis in pigs is by M. avium sp avium. In cattle and other mammal infection by M. avium remain localized and is known to give positive reaction to mammalian tuberculin. The disease in caged and wild birds in captivity is common with M. tuberculosis, because of its close contact with humans. Tuberculosis is a serious problem in zoological gardens. M. avium is being isolated in increasing number of immunocompromized human patients.

In 1882, Robert Koch first isolated the organism, stained with alkaline methylene blue and vesuvin as counter stain and proved its etiologic relationship with Tuberculosis.  Ehrlich first developed acid fast stain in 1882 and used for better staining of the bacteria which was adopted by Robert Koch. Later this staining technique was modified by Ziehl-Neelsen, accordingly it is now a day known as Z-N staining. In 1890, Koch prepared a glycerine broth extract of the tubercle bacillus, known as ‘tuberculin’.

      He tried to prepare it as a curative agent; however, it was used later in diagnosis. In 1895, Johne and Frothingham described the first case of paratuberculosis in cattle, later known as ‘Johne’s disease’. Although, the causative agent was first isolated by Twort and Ingram in 1910.

            In India, bovine Tuberculosis was reported from several states since 1959 (Dhanda and Lal, 1959). Whereas bovine paratuberculosis was first reported by Nanda and Singh (1940) in Hissar, Haryana.

Introduction

Avian mycoplasmosis is caused by several pathogenic mycoplasma of which mycoplasmosis due to Mycoplasma gallisepticum (Mg), Mycoplasma synoviae (MS) and Mycoplasma meleagridis are important. The mycoplasma are group of bacteria that lack cell wall due to which the shape of bacteria is pleomorphic. Due to lack of cell wal, mycoplasma are resistant to those drug which act on cell wall and includes Penicillin and its derivatives. Mycoplasma primarily affects respiratory system and joints in birds and respiratory and urogenital system in humans. The avian mycoplasma are mainly transmitted by vertical route (egg transmission), but can also transmitted by horizontal route. Mycoplasma gallisepticum (Mg) causes chronic respiratory disease (CRD) in chicken, turkeys and game birds. Mycoplasma synoviae (Ms) causes infectious synovitis in chicken and turkeys whereas Mycoplasma meleagridis cause disease in turkey. The Mg and Ms belongs to class of Mollicutes (Molecutis: soft tissue), order Mycoplasmatales and family Mycoplasmataceae. The CRD caused by Mg affects respiratory system and air sac in presence of other respiratory pathogen/ stress or immunosuppression. Clinically, CRD affected birds show respiratory rales, gasping, nasal discharge, and rhinitis with mortality due to complication with other respiratory viral pathogens or E. coli infection. The Ms has affinity for tendon and ligaments of joint causing severe lameness due to tenosynovitis with mild lesions in respiratory system and air sac. The Ms affected birds show lameness, breast blister and increased culling of male breeder birds. The Mg and Ms causes significant losses in poultry industry due to decreased egg production, condemnation and downgrading of carcass and decreased hatchability. Mycoplasma meleagridis in turkey associated with air sacculitis and drop in egg production.