eChapters

Introduction

Agriculture is the back bone of Indian economy. About 18.8 percent (2021-22) of the national income originates from the agriculture sector. Approximately 60 percent of India’s population is directly or indirectly dependent on agriculture for livelihood. A large number of important industries like jute, textiles, edible oils, tobacco, sugar etc. receive the raw materials produced by agriculture sector. India occupies second position in the production of fruits and vegetables in the world after China (National Horticulture Database 2019 2020) It is grown almost in all the states of the country.

Cauliflower (Brassica oleracea L. var. botrytis) like all other Brassicaceae family crops has descended through introgression, mutation, human selection and adaptation from a single wild predecessor Brassica oleracea L. var. sylvestris which is still found growing in western and southern Europe and North Africa. The name cauliflower consists of two Latin words namely ‘caulis’ means cabbage and ‘floris’ means flower. It is grown throughout the country for its highly suppressed ‘prefloral fleshy apical meristem’ called “Curd” which is used as vegetable, soup and for pickling (Choudhury, 2006). Cauliflower is the pride of cole crops because of its good taste, flavour and nutritional value. It contains good amount of vitamins like vitamin A, vitamin C and fair amount of proteins and fibers. The cauliflower is also a good source of minerals like Ca, Mg, P, Fe, Na, and S.

The demographic transition theory is one of the most important population theories which is the best documented by the data and statistics of recent demographic history. In its original form, the demographic transition theory was put forward by W. S. Thompson (1929) and Frank W. Notestein (1945). These scholars based their statements and arguments on the trends in fertility and mortality, being experienced in Europe, North America and Australia.

The theory postulates a particular pattern of demographic change from a high fertility and high mortality to a low fertility and low mortality when a society progresses from a largely rural agrarian and illiterate society to a dominantly urban, industrial, literate and modern society. The three very clearly stated hypotheses involved in the process are:

1. The decline in mortality comes before the decline in fertility.
2. The fertility eventually declines to match mortality and
3. Socio - economic transformation of society takes place simultaneously with its demographic transformation.

In the present – day world, as would true of any point in time, different countries of the world are at different stages of the demographic transition. In the opinion of Trewartha, this is largely due to the dual nature of man. According to him, biologically, man is same everywhere and is engaged in the process of reproduction but culturally man differs from one part of the world to another. It is the cultural diversity of man that gives rise to varying fertility patterns in different areas resulting in different stages of demographic transition.

The demographic transition theory is characterized by conspicuous transition stages. The transition from high birth and death rates to low rates can be divided into stages. In the words of E.G. Dolan, “Demographic transition refers to a population cycle that begins with a fall in the death rate continues with a phase of rapid population growth and concludes with a decline in birth rate”.

Abstract

Population of Rajasthan as per Census 2011 is 68,621,012 persons which is much higher than census 2001 that records 56,507,188. It includes 12 districts of Rajasthan. Western Rajasthan covers about 61% area of the total geographical area and 39.51% population of the total population of the Rajasthan. The growth rate of population is much higher than that of the Rajasthan State. In the census 1981 Western Rajasthan had registered a phenomenal increase of 35.48 per cent over 1971 population. Regional pattern of growth rate in western Rajasthan shows that extreme hot arid region district (Barmer) is on top having 32.55 per cent growth rate whereas Indira Gandhi Canal Region (Ganganagar) district has least population growth of 10.06 per cent only. In 1981, the average urban growth rate had been 54.52 per cent. In 2001, the rural density of population was 83 persons per sq. km.

Experiment - 1
 
Aim: Molecular analysis of putative transformed plants by Polymerase Chain Reaction

The expression of transgenes are not identified at that time but it can be achieved through DNA analysis of that plant. The presence of transgene are generally identified of PCR-based detection followed by gel electrophoresis and comparison with standard samples. The main achievement of PCR-based detection is that it is very sensitive. The Polymerase Chain Reaction (PCR) provides a rapid and sensitive method to amplify a specific gene sequence. 

Electrophoresis is a method used to separate charged particles from one another based on differences in their migration speed. In the course of electrophoresis, two electrodes (typically made of an inert metal, e.g. platinum) are immersed in two separate buffer chambers. Gel electrophoresis is a technique used to separate molecules based on physical characteristics such as size, shape, or isoelectric point. A gel is composed of agarose or polyacrylamide. Agarose is used for separating DNA fragments in size range of 100bp to 20kb. Polyacrylamide is preferred for smaller DNA fragments. Separation is achieved by moving the negatively charged nucleic acid molecules through agarose matrix with an electric field. Rate of migration of DNA molecules is inversely proportional to their molecular weight. Smaller molecules move faster than larger ones. But conformation of the DNA molecule is also an important factor. Conformations of a DNA plasmid that has not been cut with a restriction enzyme will move with different speeds such as: supercoiled plasmid DNA will move fastest followed by linearised DNA, while open circular DNA will move at the slowest pace. To visualise DNA, gels are stained with ethidium bromide which intercalates in DNA and fluorescse under UV.

Experiment- 1

Aim: Direct DNA delivery to Plant by Particle Bombardment
 
In direct gene transfer method, the foreign gene of interest is delivered into the host plant cell without the help of vector. Klein and Coworkers (1987) evolved a procedure through which the delivery of DNA into cells of intact plant organs or cultured cells is done by a process called Projectile Bombardment. The microprojection (Small and high density particles) are accelerated to high velocity by particle gun apperatus. These particles with very high kinetic energy penetrate the cells and membranes and transmit foreign desired DNA inside of the bombardment cells.

Experiment - 1 
Aim: Mobilization of recombinant Ti plasmid (with gene of interest) from  
(E. coli) to an Agrobacterium tumefaciens strain. 

Principle: Due to ease of cloning and harvesting plasmids, E. coli is most popular for maintenance of plant transformation vectors. Consequently, the plant transformation vector with cloned gene of interest is mobilized to recipient Agrobacterium strain harbouring vir plasmid. Plasmid are closed, circular DNA molecules that are able for autonomous replication with a host cell. 

Experiment - 1

Aim: Isolation of plant genomic DNA through modified CTAB method

Principle: Genomic DNA is extracted from plant material requires cell lysis, inactivation of cellular nucleases and separation of the desired genomic DNA from cellular debris. Ideal lysis method is rigorous enough to disrupt the complex starting material (plant tissue), yet gentle enough to preserve the target nucleic acid. The cetyltrimethylammonium bromide (CTAB) procedure is sufficient for the extraction and purification of DNA from plants and plant derived food stuff.  This is particularly suitable for the elimination of polysaccharides and polyphenolic compounds otherwise affecting the DNA purity and hence quality.

Koch‘s Postulates (Pathogenicity test)

Robert Koch developed the following postulates in 1883 on the basis of which an organism could be attributed to be the cause of a specific disease.

i)Recognition: The suspected organism must be found in every case of disease (Presence of organism in the diseased tissues).

ii)Isolation: The organism must be isolated in pure culture from every case of disease (Isolation in pure form).

iii)Inoculation: The isolated pure culture when introduced into the same species or variety of susceptible host must be capable of reproducing the original disease with its typical symptoms (Pathogenicity).

iv)Re-isolation: The organism must be re-isolated from the artificially infected host and its characteristics must be exactly like those observed in step 2 (This step was added by E.F. Smith).

If all the postulates are proved true, then the isolated pathogen is identified as the actual causal organism responsible for the disease.

Object: Demonstration of leaf anatomy or structure of C₃ and C₄ Plants (demonstration by already prepared slides).

Material required: Already prepared slides of corn and wheat leaves and microscope.

A large population of endocrine cells secrete the same chemical messengers (bio-active animals and regulatory peptides) as do the neurons and therefore these endocrine dells are referred as “Paraneurons”.
However these messengers are not used as neurotransmitters, rather they are released into blood circulation and interstitial fluid as hormones/chemical mediators to act on the target cells in endocrine or paracrine manner. This subset of endocrine cells forms the “Neuroendocrine system” and its synonyms are the “diffuse neuroendocrine system (DNES)”, “APUD (amine precursor uptake and decarboxylation) cell system” and the “regulatory peptide secreting cell system”. The DNES consists of cell populations scattered throughout the body either to form a coherent tissue in some organs (e.g. anterior pituitary, pancreatic islets, adrenal medulla) or to form a diffuse scatter of single cells or group of 2-3 cells within the stroma of the other organs (e.g. C cells of thyroid, intra-epithelial endocrine cells of the gut, airway and urinogenital system, chief cells of parathyroid, glomus cells of carotid body, melanocytes of skin, some cells of pineal gland and placenta, modified cardiac myocytes, hypothalamic neurons synthesizing oxytocin and vasopressin as well as neurons synthesizing releasing factors controlling the secretion of hormones by the adenohyposis etc.). These cells synthesize and store the hormones in their secretion granules as neurosecretory granules which have characteristic ultrastructural morphology.
The cells of the DNES can be identified by: (i) the ultrastructural morphology of the cells and their secretion granules, (ii) the empirical histochemical staining techniques which stain the neurosecretory granules, (iii) the novel current day, immunohistochemical techniques, or more aptly (iv) a combination of

Dendrobium is a huge genus of orchids. It was established by Olof Swartz in 1799. The name is from the Greek word “Dendron” means “tree” and “bios” means “life”; it means “one who lives on trees”, or essentially, “epiphyte”. The truly spectacular genus Dendrobium contains the largest diversity of horticulturally interesting specimens. More than 1,000 natural species make dendrobium the second-largest orchid genus. Dendrobiums are among the most commonly encountered orchids in the retail trade. Flowers are very long-lasting both on the plant and once cut, looking fresh for up to three weeks or more. Faded flowers on the bottom of the stem can be removed to encourage upper buds to open. Dendrobiums are sturdy orchids that can add a focal point to any room.

ORIGIN AND DISTRIBUTION

Dendrobiums are originally from Southeast Asia. The geographic distribution is from India through China, Japan, Malaysia, Philippines and the islands of the South Pacific with the largest diversity in New Guinea. Dendrobium species are either epiphytic or occasionally lithophytic. They have adapted to a wide variety of habitats from the high altitudes in the Himalayan mountains to lowland tropical forests and even to the dry climate of the Australian desert.

Dendrobium is a huge genus of orchids. It was established by Olof Swartz in 1799. The name is from the Greek word “Dendron” means “tree” and “bios” means “life”; it means “one who lives on trees”, or essentially, “epiphyte”. The truly spectacular genus Dendrobium contains the largest diversity of horticulturally interesting specimens. More than 1,000 natural species make dendrobium the second-largest orchid genus. Dendrobiums are among the most commonly encountered orchids in the retail trade. Flowers are very long-lasting both on the plant and once cut, looking fresh for up to three weeks or more. Faded flowers on the bottom of the stem can be removed to encourage upper buds to open. Dendrobiums are sturdy orchids that can add a focal point to any room.

Dengue is a mosquito-borne viral disease and considered to be a major health problem globally. It is also called break-bone fever, dandy fever, denguero bouquet fever, giraffe fever, Polka fever and 5 days or 7 days fever. There are two important manifestations, namely dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) which are responsible for heavy morbidity and mortality every year causing serious concern to health. It is an important disease caused by an arbovirus worldwide especially in the tropical and subtropical regions. The severity of the disease can be judged from simple statistics that over 40 per cent (2.5 billion) of the world's population in 100 countries continue to live under threat of contracting dengue infection. Annually, dengue virus infections are responsible for up to 100 million cases of dengue fever and more than 500,000 cases of haemorrhagic fever. Besides, every year the disease forces nearly 500,000 people to hospitalization of which 90% are children and causing 24,000 deaths. Mostly these deaths are due to lack of early diagnosis of dengue virus infection. In DHF case fatality rate generally exceeds 20 per cent in a non-endemic population and it can be reduced to less than 1 per cent with the aid of modern supportive therapy based on early diagnosis of the type of viral infection.

Dengue fever (DF) is an acute febrile viral disease characterized by headaches, bone or joint and muscular pains, rash and leucopenia as symptoms. Dengue haemorrhagic fever (DHF) is characterized by four major clinical manifestations: high fever, haemorrhagic phenomena, 73 often with hepatomegaly and in severe cases, signs of circulatory failure. Such patients may develop hypovolaemic shock resulting from plasma leakage. This is called dengue shock syndrome (DSS) and can be fatal.

The year 2001 witnessed unprecedented global dengue epidemic activity in the American hemisphere, the Pacific Islands and continental Asia. During 2002, more than 30 Latin American countries reported over 1 million DF cases with large number of DHF cases. This has been followed by extensive epidemics of DHF in several parts of India during 2003.

Dengue fever (DF) is caused by ingestion of viraemic blood containing dengue virus by mosquitoes of Aedes sp. followed by passage to a second human host. An extrinsic incubation period is required before the virus appears in the saliva of the transmitting female Aedes mosquitoes. After the bite, there is an incubation period of 3 to 14 days (average 4 to 7 days) followed by the onset of fever and nonspecific signs and symptoms (frontal headache, retro-orbital pain, body aches, nausea and vomiting, joint pains, weakness and rash). The febrile phase is self limiting and may last for 2 to 10 days followed by remission of fever in most cases. Laboratory abnormalities include neutropenia followed by a lymphocytosis and thrombocytopenia.

Introduction

The various reactions of nitrogen (N₂) cycle, transform one form of the element to another. Mineralization liberates nitrogen in inorganic form, immobilization converts its back to an unavailable state, while nitrification changes the nitrogen from a reduced to oxidized state. Certain transformations of nitrogen lead to a net loss of element from the soil through volatilization. For the purpose of crop production, nitrogen volatilization has a deleterious influence because it depletes part of soils reserve of an essential nutrient. The sequence of steps that results in gaseous loss is called denitrification. So denitrification refers to the reduction of nitrates and nitrites to gaseous nitrogen products, principally di-nitrogen and nitrous oxide, coupled to energy production through oxidative phosphorylation.

10.1 Introduction

Biomass fuels are a potential source of renewable energy. One of the major barriers to their widespread use is that biomass has a lower energy content than traditional fossils fuels, which means that more fuel is required to get the same amount of energy. When combined — low energy content with low density -the volume of biomass handled increases enormously. Compaction or densification is one way to increase the energy density and overcome handling difficulties.

Densification means compaction of loose material or to increase density of loose biomass so that its volumetric efficiency can be increased. Densification essentially involves two parts; the compaction under pressure of loose material to reduce its volume and to agglomerate the material so that the product remains in the compressed state. The resulting solid may be a briquette, a pellet and a cube. It will be briquettes if roughly, it has a diameter greater than 30 mm. Smaller sizes are normally termed pellets though the distinction is arbitrary. The process of producing pellets is also different from the typical briquetting processes. The densified product can be developed in the cubical shapes as well.

If the material is compacted with low to moderate pressure (0.2-5 MPa), then the space between particles is reduced. Further, increasing the pressure will, at a certain stage particular to each material, collapse the cell walls of the cellulose constituent, thus approaching the physical, or dry mass and more, density of the material. The pressure required to achieve such high densities are typically 100 MPa plus. This process of compaction is entirely depending on to the pressure exerted on the material and its physical characteristics including its moisture content.

3.1. Determination of Bulk Density of Soil

3.1.1. Determination of Bulk Density of an Undisturbed Soil

Bulk density of soil is expressed as the ratio of the mass (weight) of soil particle to their total volume including the pore space between the soil particles. Alternately, it is the weight of unit volume of dry soil. It is usually expressed in the unit of gram per cubic centimeter (g/cc) or mega gram per cubic meter (Mg/m³). In fine textured soil bulk density varies from 1.00 to 1.60 g/cc, whereas in coarse textured soil from 1.20 to 1.80 g/cc.

3.1 Determination of Bulk Density of Soil

3.1.1 Determination of Bulk Density of an undisturbed Soil

Bulk density of soil is expressed as the ratio of the mass (weight) of soil particle to their total volume including the pore space between the soil particles. Alternately, it is the weight of unit volume of dry soil. It is usually expressed in the unit of gram per cubic centimeter (g/cc) or mega gram per cubic meter (Mg/m³). In fine textured soil bulk density varies from 1.00 to 1.60 g/cc, whereas in coarse textured soil from 1.20 to 1.80 g/cc.

Overview of Inland Fisheries Status

In Thailand, inland capture fisheries are carried out mainly in rivers, lakes, swamps and reservoirs. These fisheries are an important source of animal protein for the rural people. Since 2005, production from inland capture fisheries has increased by almost 13 percent. Gillnets, longlines, hook-and-line, scoop nets, cast nets, and lift nets are some of the fishing gears being used. Among these fishing gears, gillnets are the most popular and efficient, particularly in swamps and reservoirs. Thai silver barb, snakehead, walking catfish, local carps, and Nile tilapia are caught. Nile tilapia, hybrid catfish, silver barb, snakeskin gourami, giant river prawn, striped catfish and striped snake-head contributed 95 percent in quantity and 92 percent in value in fresh water aquaculture.