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The word protein was first coined in 1838 to emphasize the importance of this class of molecules. The word is derived from the Greek word proteios which means “of the first - rank”. Proteins are polymers/macro molecules made up of several amino acids. When there are more than 50 amino acids in a chain, the polypeptide is normally called a protein. Each protein in the cells of living beings has a unique sequence of amino acids that determines its biological function. The proteins are folded into specific defined structures, which are maintained by large number of relatively weak bonds. The three dimensional structure is well defined and suited to it’s specific function.

Lipids are a diverse group of chemical molecules. They are generally insoluble in water but soluble in organic solvents. Lipids include long-chain hydrocarbons, alcohols, aldehydes, fatty acids, and their derivatives, especially, glycerides, phospholipids, glycolipids and sulfolipids. Other compounds like sterols, fatty acid esters of sterols, vitamins A, D, E, and K, carotenoids, and other poly-isoprenoids also are part of the lipids. Oils and fats are mainly triglycerides and neutral molecules. Those in the liquid state at ambient temperatures are called oils while those in the solid state are called fats. Lipids and lipid components have varied uses in the food and non food sectors. Vegetable and animal matter contain a variety of these constituents in different proportions. It is neccessry to evaluate the composition and quality of these constituents from the point of view of their utility.

Carbohydrates are the most abundant biomolecules on earth. They occur in nature as glucose, starch and cellulose etc. Each year, photosynthesis converts more than 100 billion metric tonnes of carbon dioxide and water into starch, cellulose and other plant products. Carbohydrates are polyhydroxy aldehydes or ketones and their derivatives. They provide 4K calories of energy per gram. They promote utilization of lipids and reduce wastage of proteins. They are readily available in roots, tubers, cereal grains, sugarcane and sugar beet.

Organic material especially, seeds, grains, leaves, fruits and nuts contain prominently three groups of compounds. They are carbohydrates, proteins and fats/oils, mostly in that order. They also contain 3-5% minerals and smaller quantities of vitamins and other minor constituents. Cereal grains contain more of carbohydrates while oilseeds and nuts contain more oil. Tree nuts and even oilseeds may contain 30-50% protein while cereal grains contain 5-8% protein only. The starch and sugar contents of oilseeds may be less than 10% while the oil content of cereal grains ranges around 5%. The actual content and the composition of these groups of compounds really account for their quality as well as commercial value.

DNA and RNA are the carriers of genetic information in all the living organisms. The study and analysis of the genetic code can provide information that can be used in clinical diagnostics, drug discovery, genetic engineering and forensic sciences. Hence there is need to understand the techniques in isolation of DNA and RNA followed by their amplification and sequencing.

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte.  Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand  to determine concentration. The volume of titrant reacted is called titre. Volumetric analysis originated in late 18^th-century in France.

Gravimetric analysis describes a set of methods in analytical chemistry for the quantitative determination of an analyte based on the mass of a solid. A simple example is the measurement of solids suspended in a water sample. A known volume of water is filtered, and the collected solids are weighed.
 
In gravimetry, the analyte needs to be first converted to a solid by precipitation with an appropriate reagent. The precipitate can then be collected by filtration, washed, dried to remove traces of moisture from the solution, and weighed. The amount of analyte in the original sample can then be calculated from the mass of the precipitate and its chemical composition.

In some cases, it is easier to remove the analyte by evaporation. The analyte might be collected—perhaps in a cryogenic trap or on some adsorbent material such as activated carbon—and measured directly. Or, the sample can be weighed before and after it is dried; the difference between the two masses gives the mass of analyte lost. This is especially useful in determining the water content of complex materials such as foodstuffs.

Immunoassays rely on the ability of an antibody to recognize and bind a specific macromolecule in what might be a complex mixture of macromolecules. In immunology the particular macromolecule bound by an antibody is referred to as an antigen and the area on an antigen to which the antibody binds is called an epitope.

In some cases an immunoassay may use an antigen to detect for the presence of antibodies, which recognize that antigen, in a solution. In other words, in some immunoassays, the analyte may be an antibody rather than an antigen.

When a metal M is immersed in a solution containing its own ion Mⁿ⁺, then  an electrode potential  develops. The value of  the  electrode potential  is given by the Nernst equation.

When a fixed voltage is applied to two electrodes dipping into a solution,a current will flow, depending on the conductivity of the solution. Conductivity measurements do not give information about the nature of the ions in solution. However, they are useful in the quantitative measurement of the ions.

Compounds having one or more asymmetric carbon atoms can rotate the plane of polarized light. Such compounds are called optically active. Measurement   of this property is called polarimetry.
 
The magnitude and direction in which the plane of polarized light is rotated depend on 1.The nature  of the compound, 2. The  concentration of the solution, 3. The path length of light, 4. The solvent, 5. The wave length of light and 
6. The temperature. These variables are related and can be presented in the formula

Mass spectrometry (MS) is a  useful  technique which produces spectra of the masses of the atoms or molecules in a sample.  The spectra are used to determine the elemental or isotopic   details  of a sample. The masses of particles and of molecules, are used to elucidate the chemical structures of molecules, such as peptides and other chemical compounds. Mass spectrometry works by ionizing chemical compounds to generate charged molecules and measuring their mass-to-charge ratios.

A sample, which may be solid, liquid, or gas, is ionized, by bombarding with electrons. This may cause some of the sample’s molecules to break into charged fragments. These ions are then separated according to their mass-to-charge ratio, typically by accelerating them and subjecting them to an electric or magnetic field. Ions of the same mass-to-charge ratio will undergo the same amount of deflection. The ions are detected by a mechanism capable of detecting charged particles, such as an electron multiplier. Results are displayed as spectra of the relative abundance of detected ions as a function of the mass-to-charge ratio. The atoms or molecules in the sample can be identified by correlating known masses to the identified masses or through a characteristic fragmentation pattern.

In 1896, French physicist Becquerel observed that uranium compounds affected a photographic plate that was wrapped inside a black paper. He found that all uranium compounds gave off penetrating rays. He called the production of radiation by uranium compounds “radioactivity”. Madame and Pierre Curie later identified thorium, polonium, and radium as the other radioactive elements.

Nuclear Magnetic Resonance spectroscopy is a powerful and theoretically complex analytical tool. The nuclei of certain isotopes are continuously spinning with an angular momentum, which can give rise to an associated magnetic field.

Inductively coupled plasma atomic emission spectroscopy (ICP-AES) uses an inductively coupled plasma to produce excited atoms and ions that emit electromagnetic radiation at wavelengths characteristic of a particular element. A plasma is a neutral gas containing a good number of positive and negative ions or free electrons. A plasma can only be created. A combustion flame is one example of a plasma. Advantages of ICP-AES are excellent limit of detection and linear dynamic range, multi-element capability, low chemical interference and a stable and reproducible signal. Disadvantages are spectral interferences (many emission lines), high cost and operating expense and the fact that samples typically must be in solution.

Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids, the analyte atoms or ions must be vaporized in a flame or graphite furnace. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels. The analyte concentration is determined from the amount of absorption. Applying the Beer-Lambert law directly in AA spectroscopy is difficult due to variations in the atomization efficiency from the sample matrix, and non-uniformity of concentration and path length of analyte atoms (in graphite furnace of AA). Concentration measurements are usually determined from a working curve after calibrating the instrument with standards of known concentration.

When an element burns in a flame it emits radiation characteristic of its identity. Flame photometry is the determination of an element in solution by measurement of emission of light by atoms of the element in flame. Initial tests for identification of a few elements by flame tests are well known. Na burns with yellow flame, K with lilac flame, Ca, with red flame, Cu, with green flame etc. Emission of characteristic radiation by an element and correlation of emission intensity with the concentration of that element form the basis for flame photometry.

The sample to be analyzed is prepared in solution and sprayed under controlled conditions into a flame. The light from the flame enters a monochromator to isolate the desired region of the spectrum. A photocell and an amplifier measure the intensity of the isolated radiation. After proper calibration of the photometer with solutions of known composition and concentration, it is possible to correlate the intensity of a given spectral line with the unknown concentration of that element. A calibration curve prepared using known concentrations is useful. Internal standards and addition of known concentration of sample to be quantified are more useful.

Infrared light (800-1500nm) interacts with molecules at the level of atomic vibrations. An infrared spectrum gives valuable information about the molecular structure. It is rarely used for quantitative purposes and hence concentration measurements are not possible. Infrared light detects vibrations characteristic of functional groups. For example the C=O (carbonyl) group absorbs at 1700 cm-1 (wave number). The main region of interest for analytical purposes is from 2.5- 25µm or 4000- 400 cm-1. At wavelengths below 25µm the radiation has sufficient energy to cause changes in the vibrational energy levels of the molecule, and these are accompanied by changes in the rotational energy levels. The pure rotational spectra of molecules occur in the far infra red region (50-1000 µm) and are used for determining molecular properties.

Spectrophotometry measures how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through the sample solution. Chemical compounds normally absorb or transmit light over a certain range of wavelength. Hence spectrophotometry is used to measure the amount of a known chemical substance. It is one of the most useful methods of quantitative analysis in the laboratory and is widely used.

A  colorimeter or spectrophotometer is an instrument that measures the amount of photons (the intensity of light) absorbed after it passes through the sample solution. With the spectrophotometer, the amount of a known chemical substance (concentrations) can also be determined by measuring the intensity of light detected. Depending on the range of wavelength of light source, it can be classified into two different types, namely,1) UV-visible spectrophotometer which uses light over the ultraviolet range (185-400nm) and visible range (400-700nm) of electromagnetic radiation spectrum and 2) IR spectrophotometer which  uses light over the infrared range (700-15000nm) of electromagnetic radiation spectrum.

The mass spectrometry (MS) is not very well suited to the analysis of mixtures of similar substances because of the multiplicity of fragment ions. The gas chromatography (GC), of course,  has no ability to identify compounds on its own. The GC/MS can easily overcome these defects and can identify the components (fractionated by GC). The combined instrument of GC/MS is an unexcelled instrument that can identify the compounds after their  fractionation.

The GC-MS is composed of two major building blocks: the gas chromatograph and the mass spectrometer. The gas chromatograph utilizes a capillary column which depends on the column’s dimensions as well as the stationary phase properties. The difference in the chemical properties between different molecules in a mixture and their relative affinity for the stationary phase of the column will promote separation of the molecules as the sample travels the length of the column. The molecules are retained by the column and then elute (come off) from the column at different times and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately.

High pressure (or performance) liquid chromatography (HPLC) is more versatile than GC since it is not limited to volatile compounds. The choice of mobile and stationary phases is wider. HPLC has high resolving power, separations are speedier, quantifications are more precise and it is in general, more reproducible. Liquid chromatography basically involves separation of components due to differences in the equilibrium distribution of sample components between the mobile (liquid) and stationary phases.

Gas chromatography is one of the most valuable techniques available for organic analysis. It has been applied for the separation, identification and analysis of virtually all volatile compounds. In gas chromatography, the mobile phase is gas. When the stationary phase is liquid , it is called gas liquid chromatography (GLC). If the stationary phase is solid, it is called gas solid chromatography (GSC). The sample is transported through a stationary phase with help of an inert carrier gas, namely the mobile phase. The fractionation of the components in the sample mixture takes place based on the partitioning between the stationary and mobile phases.

When a particle revolves around an axis, a force is developed and acts away from the axis of rotation. This force is called centrifugal force. A particle suspended in a medium takes some time to sediment, which depends upon the size, molecular weight, and viscosity or density of the medium under normal “g” (gravity). To speed up the process of sedimentation, the external field of force is allowed to act on the particle which depends also on the distance of the particle from the axis of rotation in addition to the other factors.

Dialysis
 
The main purpose of dialysis in biological research is the removal of small molecular weight (M.W.) constituents from biological fluids. This is achieved by dialysing the material in a cellulose tubing with a pore size of 40-80 A0 (4-8mm) diameter which allows the passage of compounds with molecular weight less than 10,000. The following is the procedure followed: cut the length of the dialysis tubing depending upon the volume to be processed. Open the sides of the tubing with a flow of distilled water and transfer it to a boiling water bath. Do not allow the tubing to dry as it will distort the pore size. Make a bag by tying a knot at one end of the tubing. Transfer the solution to be dialysed into the bag. Tie another knot at the top of the bag. The bag is then put in a beaker containing the solution against which dialysis is to be carried out. In general, one volume of the desired solution is dialysed against 50-100 volumes of buffer. The total period of dialysis could range from 8-48hr. The efficiency of dialysis could be increased by stirring and changing the dialysate solution at frequent intervals.

Solvent extraction is mainly used to remove dissolved substances from solutions or soluble material from solids /powders/ solid mixtures. Solvent extraction is explained using distribution law or partition law. The law states that if to a system of two liquid layers made up of two immiscible liquids/ slightly miscible liquids is added a third substance soluble in both layers , then the substance distributes itself between the two layers so that the ratio of concentration in one solvent to the concentration in the second solvent remains constant at a constant temperature.

Gel-filtration chromatography or molecular sieve chromatography is a method based on molecular dimension. The gel consists of beads which are composed of dextran polymer (sephadex, agarose or polyacrylamide gels). The separation depends upon the different abilities of the various sample molecules to enter pores which contain the stationary phase. Very large molecules, which never enter the stationary phase, move through the chromatographic bed fastest. Smaller molecules, which can enter the gel pores, move very slowly through the column, because they spend a proportion of their mobility, time in the stationary phase. Molecules are, therefore eluted in the order of their decreasing molecular size.

This technique is used in the separation of ionised and ionisable compounds.It consists of an insoluble matrix to which charged groups are covalently bound. The charged groups are associated with mobile counter ions. These counter ions can be reversibly exchanged with other ions of the same charge without altering the structure of the matrix.

The ion exchanger is complex and polymeric. The polymer carries an electric charge that is exactly neutralized by the charges on the counter ions. These active ions are cations in a cation exchanger and anions in an anion exchanger. A cation exchanger consists of polymeric anions and active cations whereas anion exchanger consists of polymeric cations and active anions. Amberlite IR 120 and Dowex 50 WX are cation exchangers while Amberlite IRA 400 and Dowex 1X are anion exchangers. Ion exchangers should be insoluble in water and hydrophilic to allow the ions to pass through. It should be chemically stable and should be denser than water when swollen.

Electrophoresis is the migration of particles under the influence of a direct electric current. There are two requirements for this process to be carried out. First the particles to be separated should be charged or at least should accept charge. Proteins, amino acids, nucleotides etc. conform to this requirement. Second, the medium used for separating the compounds also should carry charge. The mobilities of the ions depend on the nature of the electrolyte solution, the concentration and temperature. The cations and anions move in opposite directions with the cations moving towards the anode and the anions towards the cathode.

Kirchner was the first in 1950 to think of thin layers. But it was Egon Stahl in 1958 who was responsible for bringing out standard equipment and related procedures to popularize thin layer chromatography (TLC). TLC is a modified form of column chromatography. Hence it is also called open column chromatography. The adsorbent is spread over a supporting material (glass or plastic sheets) to form a thin layer of adsorbent. As a binder, plaster of Paris or gypsum is added to the adsorbent material like silica gel (hence silica gel TLC). The adsorbent is spread over the plate as a thin layer of 0.25 or 0.5 mm. The adsorbent to water ratio is 1:2. It is initially allowed to air dry, followed by drying in an oven at 110oC for 1-2hr or overnight (activation of TLC plates) after which the plate is ready for thin layer chromatography.

Column chromatography is a separation technique in which the stationary bed is in a tube. The particles of the solid stationary phase or the support coated with a liquid stationary phase may fill the whole inside volume of the tube (packed column) or be concentrated on or along the inside tube wall leaving an open, unrestricted path for the mobile phase through the tube (open tubular column). Differences in rates of movement through the medium are calculated as different retention times of the sample.
 
The separation of compounds in the column chromatography takes place based on the phenomenon of adsorption. Here the substance gets attracted by electrostatic forces to the surface of a unit particle. If the substance is in solution and the particle insoluble in the solvent, then part of the substance is adsorbed and part remains in solution. The ratio between the amount adsorbed and the amount in solution is a constant called adsorption coefficient. The separation takes pace based on the differences in the adsorption coefficients.

Paper chromatography (P.C.) is the easiest to perform and requires simple and ordinary apparatus. It easily provides qualitative information since components of a mixture can be separated based on their mobilities or molecular weights. It also can provide quantitative information if some special attention and calculation procedures are followed. Paper chromatography is a technique that involves placing a small dot or line of sample solution on to a strip of chromatography paper. The paper is placed in a jar containing a shallow layer of solvent and sealed. As the solvent rises through the paper, it meets the sample mixture, which starts to travel up the paper with the solvent. This paper is made of cellulose, a polar substance, and the compounds within the mixture travel farther if they are non-polar. More polar substances bond with the cellulose paper more quickly, and therefore do not travel as far.

Chromatography is a general technique available for the separation of closely related compounds in a sample. The term chromatography is derived from Greek where chroma means colour and graphein means to write. It is a very useful technique for both qualitative (preparative ) and quantitative (analytical) analyses. The separation is effected by the differential distribution of the components between two immiscible phases, namely, stationary and mobile phases. The various constituents of the mixture travel at different speeds, causing them to separate. The separation is based on differential partitioning (partition coefficient) between the mobile and stationary phases. The stationary phase is a porous medium through which the sample mixture percolates under the influence of a moving solvent (mobile phase).

Analysis of materials or samples is essential to understand their nature and quality. In recent years it has become mandatory to display the composition of food as well as non-food items. This is because of the need for their safety from the point of view of their day to day use. Environmental awareness has further imposed many restrictions on items of wide ranging nature. Analytical information gained from a laboratory is highly useful in knowing the qualitative and quantitative composition of the material.

The hybrid breeding program in pigeonpea is unique and the first among the food legume. The concept of hybrid in this crop was conceived in 1974; and it is based on a small window of natural out-crossing present in the crop. This natural out-crossing in pigeonpea is mediated by a range of flying insects, which forage on large bright colored flowers of the crop in search of nectar and in the process affect the cross-fertilization. In the last 40 years a lot of basic and applied research has been successfully completed and over 50 research papers have been published in national and international journals of repute. A coordinated effort of scientists of different institutions has led to the release of two hybrids, one for central and another for peninsular zone of India.

With the advent of hybrid technology, it is natural to assess its potential benefits at the national level. To meet the domestic requirement of pigeonpea, about 50.000–60,000 metric tons of pigeonpea is imported annually from Myanmar and Africa. In this communication, an attempt has been made to look into the possibility if we can meet the entire domestic needs of pigeonpea through the adoption of hybrid technology. It is a big question but the goal is not impossible. The estimates shown in Table 18 show that if only 2% of total pigeonpea area can be brought under hybrids, the target can be met with ease. This will require seed production in only 700-800 hectares.

To overcome the challenge of popularizing pigeonpea hybrids in the country, it is considered fair enough to compare the hybrid rice with respect to their seed production technology, yield advantages and profitability to the farmers and seed producers. Since both pigeonpea and rice are grouped under self-pollinated crops, this comparison, in the views of authors, may help in encouraging hybrid pigeonpea seed producers and those involved in marketing of hybrid seed.
  
Rice is a highly self-pollinated crop and earlier hybrids were not possible because it was essential that large quantities of hybrid seeds are produced easily and economically. In China, the birth place of hybrid rice, this impossible looking task was accomplished. To launch this program, the Chinese scientists decided to alter the pollination system of rice.

Fig. 25: ICPH 2671 in field

5.1 Seed back up programs

In hybrid breeding program, testing of new hybrid combinations is a continuous process and in most cases, the availability of crossed (hybrid) seed for their annual evaluation of selected hybrids is an important issue. Since, the selection of hybrids for advancement is based on yield data, one year will be required to produce seed for testing in the subsequent season. This means for each cycle of advancement, one valuable season will be consumed in their seed production. To avoid this situation and enhance the testing program at a fast pace, an aggressive hybrid seed production program should be followed. This can be achieved by visually selecting relatively more number of hybrids based on their flowering time, plant vigor, disease resistance, and early pod load about 4-5 weeks before harvesting. During this period, the new seed of the selected hybrids can be produced manually. This operation is facilitated by the perennial nature of pigeonpea plant, which can flower for extended periods of 40-50 days; that allows completion of desired number of pollinations of the target crosses in the same cropping season. One trained person can pollinate about 300 buds in 6-7 hours; and with 20% success, about 150 seeds can be produced. Experience has shown that, with good planning and crop management, this program can be achieved with ease.

4.1. Flower and flowering in pigeonpea

Growth habit: Primarily, there are two major growth types in pigeonpea. These are determinate and non-determinate. The determinate growth in the pigeonpea plants is characterized by flowers in bunches at the top of the canopy (Fig 17a). In this case the epical growing points are transformed in to reproductive buds and bunches of flowers appear on the top of the canopy. Such cultivars are not popular as the management of insects such as Helicoverpa and Maruca becomes very difficult. Most of the cultivated types belong to another growth category called as non-determinate. In such genotypes the apical growing points remain vegetative and the plants keep growing under favorable conditions and it results in tall canopy with many spreading or compact branches. The inflorescence in this case emerges from the axil of secondary and tertiary branches (Fig 17b); and hang sideways. These types show less susceptibility to insects due to non-clustering nature of flowers.

3.1. Natural cross-pollination

Breeding procedures in any plant species of economic importance are guided by its reproductive system particularly, pollination mechanism. In the cereal crops such as maize, pearl millet etc., where cross-pollination is facilitated by wind, the breeders have developed schemes for commercial exploitation of dominance and epistatic genetic variation through hybrid and population breeding. In contrast in self-pollinated crops, the efforts are always made to exploit additive genetic variation primarily through pedigree and mass selection.
 
In pulses, self-pollination is a rule and pigeonpea is no exception. However under field conditions, occurrence of hybrid plants in the populations is not uncommon; and it happens due to some degree of natural out-crossing that took place in the preceding generation. This type of partial natural out-crossing in pigeonpea is affected by a variety of insects (Fig 10) which forage on its large flowers to collect the nectar. These minor incidences of out-crossing are the primary source of varietal deterioration. Recently, the pigeonpea breeders converted this constraint into an opportunity for genetic enhancement of yield through exploitation of hybrid vigor and developing commercial hybrids.

Male sterility is a situation where the male reproductive parts of a plant are either absent, aborted, or non-functional; and therefore, they fail to participate in the process of natural sexual reproduction. This situation generally arises due to some developmental defect that occurs at any stage of microsporogenesis (process of development or release of pollen grains) in the plants. Since male sterility is the manifestation of abnormal growth and development and can occur at any point of time, the action of genes controlling male sterility is also be variable and inconsistent across the genotypes. Based on the type of malfunctioning of androecium, the male sterility systems have been classified as structural (absence or deformity of anthers), sporogenous (defective microsporogenesis), and functional (failure of mature pollen to germinate). In addition, on the basis of genetic control mechanism of the male sterility, it has also been classified as genetic, cytoplasmic, and cytoplasmic nuclear (or genetic) male sterility. With respect to utilization of male sterility in crop breeding, it is essential that individuals with altered male fertility keep their female fertility intact. The fertilization of such plants takes place with pollen grains from other plant that is transferred with the help of external agencies such as wind, insects, or human beings.

Pigeonpea (Cajanus cajan L. Millsp.) is crowned as poor man’s crop which provides much needed protein to farming families with least inputs. It is a versatile plant species which can grow successfully in a range of soil types, temperatures and photoperiods. Its deep root system enables it to overcome intermittent drought and other stresses. In India, the crop is grown annually on about 4.04 m ha (FAO, 2012) and the major pigeonpea growing states are Maharashtra, Andhra Pradesh, Karnataka, Madhya Pradesh, Uttar Pradesh, Bihar and Gujarat (Table 1). The high protein pigeonpea dal (decorticated dry splits) is widely consumed across the country in various cuisines. The annual national production of pigeonpea is about 2.56 m tones. This produce, however, is not sufficient to feed the ever growing population of the country, and hence, necessitates huge (500,000 tons) imports of this pulse. In spite of its importance in food security and sincere research efforts, its national productivity could never cross the bar of 800 kg/ha (Fig 1) since independence. Since last 50 years, ICAR has been very seriously pursuing the issue of genetic enhancement with huge investments and some out-standing pure line varieties with about 10% more grains over the best local varieties were developed.

The English walnut (Juglans regia) is a native of Western and Central Asia. The nut was the food of the royalty and was introduced by the Greeks in Rome, where it became Juglans, a name derived from Jovis and glans, meaning Jupiter’s Acorn or the ‘Nut of the Gods’. The English walnut tree, also known as the Common, Persian or Royal walnut tree, is an ancient tree with many uses, most notably for its use as timber and for the walnut fruit. The common walnut tree has been used as a food, beauty aid, medicine and natural health supplement. In China the tree is used horticulturally in classical garden design.

Strawberries one of the best fruits of the world are native to North America. Strawberry fruits are aggregates made up of several small fruits, each with one seed called an achene. The flesh of the strawberry is actually an enlarged receptacle, non-reproductive material. The word strawberry comes from the old English streawberige, most likely because the plant sends out runners which could be linked to pieces of straw. The name Strawberry was also derived from the berries that are “strewn” about on the plants, and “strewn berry” eventually became “Strawberry”. Strawberry is a delicious fruit taken fresh in several ways. It also makes excellent ice cream and jam on account of its rich aroma. 

Sapota or sapodilla popularly known as Chiku is native to tropical America where it is mainly grown for its chickle, “the gutta parcha” extracted from its latex from stems. It is used as a base material in chewing gum and in some other industrial uses. However, in India it is cultivated for its delicious sweet fruits. The fruit is fleshy berry, variable in shape, size and weight. The skin is thin, rusty brown somewhat scurfy looking like Irish potato, and the pulp soft, melting, crumbling with a sandy or granular texture with 1–5 hard black seeds. The fruit has an exceptionally sweet malty flavour. 

Raspberries are grown for the fresh fruit market and for commercial processing. There are many species of raspberry but the name originally referred with the red fruit to the European species Rubus idaeus. The English name comes from an old English term “raspis”, which refers to the slightly hairy or “rasping” surface of the fruit. The raspberry can be of any colour from orange, pink, red, purple to black. Rubus albescens also known as Mysore raspberry is native to India. It is also called Snowpeaks, Ceylon or Hill raspberry. 

Pomegranate commonly known as ‘anar’ is an ancient favourite table fruit of tropical and sub-tropical regions of the world.  The pomegranate tree is native from Iran to the Himalayas in northern India and has been cultivated since ancient times throughout the Mediterranean region of Asia, Africa and Europe. The word pomegranate comes from the Latin “Pomum granatum” which means “apple of many seeds.” The Romans called it the Punic apple. Ancient Romans not only enjoyed the succulent flesh of this fruit but due to the high amount of tannic acid in the skins, they also used the skins in the process of tanning leather. Perhaps due to the fruit’s princely blossom crown, it has gained distinction as a royal fruit. “Pomum granatum” or seeded apple was the name which was known in the middle ages. The French named their hand-tossed explosive a grenade after the seed-scattering properties of the pomegranate fruit.

A plum or gage is a stone fruit tree in the genus Prunus. The European plum is thought to have been discovered around two thousand years ago, originating in the area near the Caspian Sea, while Japanese plums actually originated in China. However, they derived their name from the country where much of their cultivation and development have occurred. Mature plum fruit may have a dusty-white coating that gives them a glaucous appearance and is easily rubbed off. This is an epicuticular wax coating and is known as “wax bloom”. Plum fruit tastes sweet and/or tart; the skin may be particularly tart. It is juicy and can be eaten fresh or used in jam-making or other recipes. Plum juice can be fermented into plum wine; when distilled, this produces a brandy known as Slivovitz or Rakia in Eastern Europe. Dried plums (or prunes) are also sweet and juicy and contain several antioxidants. 

Pineapple is the second most popular tropical fruit next to bananas. It is also known as Piña, Nanas and Ananas. Native to South America, it was named for its resemblance to a pine cone but it is neither a pine nor an apple. When Christopher Columbus made his second voyage to the Caribbean’s in 1493, he and his crew ate the unusual fruit they found there. They thought the fruit looked like a pine cone, so they dubbed it the “Pine of the Indies.” When they introduced it to the English later on, they added the word “apple” because they thought it should be associated with another delicious fruit that people enjoyed. Thus, the name “pineapple” came into existence. In their natural form, every variety of pineapple has a rough, diamond-pattern skin. Their tastes vary slightly, though they all basically have the same juicy, tart taste. 

Japanese persimmons were introduced into the United States from Japan by Admiral Perry who discovered the fruit growing on the coast of Southern Japan in 1851. It is regarded as the national fruit of Japan and several improved cultivars have been developed there. It is the one of the easiest tree fruits to grow in the home landscape and also the most beautiful especially in fall when the foliage turns to brilliant colours and huge orange fruits hang from the tree like ornaments.