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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.

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.

Mutation breeding is a method that uses physical radiation or chemical means to induce genetic variation in plants to develop new crop varieties. Mutation can be defined as a sudden heritable change in the character of an organism which is not due to either segregation or recombination. Mutation is the source of most genetic variation and the motor of evolution. It is a natural process, which occurs spontaneously and slowly over generations in plants, animals and all living beings. It involves alteration of their DNA, leading to the development of changes within the organism. Mutation may be sped up through the treatment of physical or chemical mutagens to achieve alteration in characteristics that are useful for the development of new variety of a plant species.
Spontaneous mutations
Spontaneous mutations are the net result of all that can go wrong with DNA during the life cycle of an organism (Glickman et al., 1986). Thus, the types and amounts of spontaneous mutations produced are the resultant of all the cellular processes that are mutagenic and those that are anti-mutagenic. Spontaneous mutations occur naturally without any apparent cause however, there are two possible sources of origin of these mutations.

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.

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.

Mycobacteria are slender rods of varying lengths that sometimes show branching filamentous form resembling ‘fungal mycelium’. Hence, the name mycobacteria, meaning fungus like bacteria.
Although cytochemically gram positiive, the Mycobacteria do not take up the dyes of the gram stain because the cell walls are rich in lipids – Mycolic acid. Once a dye has been taken up by the cells they are not easily decolourised, even by acid-alcohol. Mycobacteria are therefore called as acid-fast bacilli. The genus includes animal and human pathogens as well as saprophytic members often referred to as atypical, anonymous, opportunistic, tuberculoid and MOTT (Mycobacteria other than typical tubercle) bacilli. Clasification of Mycobacteria (Tubercle Bacilli)
I. Slowly growing Mycobacteria
• Mycobacterium tuberculosis causes human tuberculosis in human and dogs.
• Mycobacterium bovis causes bovine tuberculosis in many animal species and also cause tuberculosis in human
• Mycobacterium africanum causes human tuberculosis.
• The human type (Mycobacterium tuberculosis) is primarily a pathogen for man. But can cause disease in cattle, pigs, dogs, monkeys, parrots and other species. The bovine type (Mycobacterium bovis) is a common cause of disease in domestic animal particularly cattle, pigs, cat, dogs and horse. The avian type (Mycobacterium avium) is primarily a pathogen for birds. But can cause disease in cattle, sheep, goat and pigs.

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.

    Q.1.    How many species of Mycoplasma are responsible for causing mastitis?
    Ans.    At least seven species like Mycoplasma bovis, Mycoplasma Canadensis, Mycoplasma bovigenitalium, Mycoplasma alkalensis, Mycoplasma capricolium, Mycoplasma californicum, Mycoplasma disper and Ureaplasma sp. are responsible for causing mastitis

    Q.2.    Which herds are more prone to such type of mastitis?
    Ans.    The herds where milking hygiene is very poor and when the cows are imported from other farms or from public sale yards.

    Q.3.    Which organs act as common habitat of the Mycoplasma organisms?

The name Mycoplasma is originated from the Greek word mykes (fungus) and plasma (formed). It was first used by Albert Bernhard Frank, a German Biologist in 1889. He thought it was a fungus. An older name for Mycoplasma was Pleuropneumonia-Like Organisms (PPLO), referring to organisms similar to the causative agent of contagious bovine pleuropneumonia (CBPP). It was later found that the fungus-like growth pattern of M. mycoides is unique to that species. It was first isolated in 1898 by Edmond Nocard and E. Roux from bovine lungs. Whereas, Mycoplasma pneumoniae was considered as a virus previously. Eaton and his co-workers cultured the causative agent of human primary atypical pneumonia (PAP) or "walking pneumonia." It was known as "Eaton's agent." In the early 1960s, Leonard Hayflick, in Philadelphia, was first to isolate and cultivate the causative agent of primary atypical pneumonia and identified the agent as a Mycoplasma and named it Mycoplasma pneumoniae.

The mycoplasmas are microorganisms in the class Mollicutes. Of the nine genera in this class, five contain species of veterinary interest. The genus Mycoplasma, in which there are about 100 species, contains most of the animal pathogens. The first mycoplasma identified in 1890 was Mycoplasma mycoides subspecies mycoides, the cause of contagious bovine pleuropneumonia. Similar types of mycoplasmas which were subsequently identified were called pleuropneumonia- like organisms (PPLO).
Mycoplasmas, the smallest prokaryotic cells capable of self-replication, are pleomorphic organisms ranging from spherical (0.3 to 0.9 pm in diameter) to filamentous (up to 1.0 μm long). Because they cannot synthesize peptidoglycan or its precursors, they do not possess rigid cell walls but have flexible, triplelayged outer membranes.
Their flexibility allows them to pass through bacterial membrane filters of pore size 0.22 to 0.45 μm. Mycoplasmas are susceptible to desiccation, heat, detergents and disinfectants. However, they are resistant to antibiotics such as penicillin which interfere with the synthesis of bacterial cell walls. Based on 5s rRNA sequence analyses, the mycoplasmas have been shown to be linked phylogenetically to Gram-positive bacteria such as Clostridium species which have low guanine-cytosine content in their DNA. They require enriched media for growth, characteristically forming umbonate micro-colonies
when illuminated obliquely and microcolonies with a ‘fried egg’ dppearance in transmitted light. The dense central zone is due to extension of the microcolony into the agar. Mycoplasmas, which have relatively small genomes (approximately 800 genes) are fastidious in their growth requirements.
Most mycoplasmas are facultative anaerobes and some grow optimally in an atmosphere of 5 to 10% CO2. Nonpathogenic anaerobic mycoplasmas are found in the rumens of sheep and cattle. The genera Mycoplasma and Ureaplasma contain animal pathogens.

1. Introduction
Bioremediation is an environmentally friendly process that uses numerousdifferent microbes (e.g., fungi & bacteria), green plants, or combinations
of them to weaken and detoxify dangerous pollutants in a sequential orsuccessional manner. The pollutant composites are converted by biologicalorganisms through a response that takes place as part of their metabolicprocesses. They convert poisonous pollutants into carbon dioxide (CO2) andwater (H2O), microbial biomass, and other products that are less poisonous.The organic wastes are biologically degraded under controlled, harmless, andsafe condition into inoffensive products below the admissible limits establishedby supervisory authorities.

Mycorrhizal symbiosis is the most prevalent and important mutualistic association in plant kingdom. ‘Mycorrhiza’- the word means fungus - root, this association was reported by A.B.Frank in the year 1885. Nearly 95% of plant species form this mycorrhizal association. This serves as critical linkage between plant roots and soil and characterized by the movement of plant produced carbon to fungus and fungal acquired nutrients to plants. Through its hyphae this fungus absorbs the available P from soil and transports directly to root cortex. Mycorrhizal associations vary widely in structure and function. There are seven types of mycorrhizae (Table 1). These are endo (arbuscular), ecto, ectendo, arbutoid, monotropoid, ericoid, and orchidaceous mycorrhizae. Among them, endomycorrhizae and ectomycorrhizae are the most abundant and widespread

Mycorrhizae denote the symbiotic associations between plant roots and fungal mycelia. Literally it means fungal root. In 1840, Vittandini proposed that ‘tree rootlets are nourished by certain fungal mycelia which mantle them’. The first illustrations of mycorrhiza were published in the same year by Robert Hartig. However, in 1885 A.B. Frank coined the term “mykorrhizen” to the mutualistic symbiotic fungal association of roots (‘mykos’ fungus ‘rhizen’ roots). He characterized the sheath-forming fungi on tree as ‘ectotropisch’ (ectotrophic) and those without such compact sheath as ‘endotropisch’ (endotrophic). Fossil records reveal that mycorrhizae are as old as terrestrial plants.

The term ‘mycorrhizae’ was coined more than a century ago (Frank 1885) describing that the roots of most plants are colonized by fungi and transformed into fungus roots organ. Mycorrhizae result from a mutualistic symbiosis between plant roots and certain fungi. Roots of most flowering plants live in mutual symbiosis with mycorrhizae which bio-tropically colonise the root cortex and extra-metricial mycelia help the plant to obtain plant nutrients from soil (Barea, 1991).

These fungi are ubiquitous in soil and are found in the roots of many Angiosperms, Gymnosperms, Pteridophytes and Thallophytes (Mosse et al., 1981). The mycorrhizal fungi perform the function of root hairs. The fungus takes carbohydrates from the plant and in turn supplies the plants with nutrients, hormones and protects it from root pathogens. The dependency of fungal species on host plant ranges from obligate to facultative (Brundrett, 2002; Read and Perez-Moreno, 2003). The mycorrhizal plants have greater tolerance to toxic heavy metal, nigh soil temperature, soil salinity, unfavourable soil pH and to transplantation shocks.

They play an important role in increasing plant growth and nutrients uptake (Bagyaraj, 1992, VasanthaKrishna and Bagyaraj 1993). These fungi can be used to promote biotechnologically developed plant in soil (Varma and Schuepp 1994).

INTRODUCTION

The fine feeder roots of many vascular plants are invaded by specific nonpathogenic fungi forming a distinct morphological unit known as mycorrhiza (In Greek, Mykes mean mushroom or fungus, rhiza mean root). Physiologically mycorrhiza represents a case of symbiosis.

The term mycorrhizae were coined by a German botanist Albert Bernard Frank in 1885 which literally mean “fungus-roots”.  Mycorrhizal fungi form a symbiotic association with agricultural and horticultural crops in addition to certain tropical tree species.
Mycorrhizal fungi are broadly classified in to two groups:
1) Ectomycorrhizae  
2) Endomycorrhizae.