eChapters

Stock or Gillyflower (Matthiola spp.) belongs to family Brassicaceae. It is a hardy annual, biennial and perennial plant, flowering in terminal clusters. Matthiola incana is ornamentally important and grown for various purposes i.e. cut flower, fragrance, pot culture, etc. This species develops a woody base in areas where it grows as a biennial or short-lived perennial, hence the name of stock. Generic name “Matthiola” was given in the honour of “Dr. Pietro Andrea Gregoria Matthiole” (1501-1577), personal physician of Emperor Maximilian of Austria. “Incana” means “hairy or gray-white” in reference to plant leaves. It exists as both single and double forms and is valued for fragrant flowers that can be used as fresh or dried cut flower. They are excellent pot plants for the greenhouse in winter and spring and provide good cut flowers. Flowers are well arranged on a long column and colours are variable from white to rose, crimson, purple, yellow, mauve, pink, etc. The highly fragrant flowers are used as a garnish, especially with sweet deserts. Many old names were given to Matthiola incana including stocks, sea stocks, wallflowers and wall or gillyflowers.

Crossandra belongs to family Acanthaceae. It is also known as Kanakambaram in Tamil or Kanakambara in Kannada and Fire cracker in English because of cracking sound during opening of seed pod. Crossandra is derived from Greek word “krossoi” meaning fringe and “aner” meaning male i.e. fringed anthers. Crossandra is an evergreen shrub and one of the important loose flower used for adornment. The flowers are commonly grown for flower adornment in the form of garlands, venis and gajras. Though it is not fragrant, flowers are very popular because of its attractive bright colour, light weight and good keeping quality. These are used for making garland, either alone or in combination with jasmine flowers. Using crossandra flowers in combination with jasmine is becoming increasingly popular in India, particularly in southern parts, because the jasmine flowers provide colour contrast and the desired fragrance. Crossandra varieties show a remarkable range of colours, varying from orange, pink, red, yellow and double coloured blue-type with white throat.

Jasmine (Jasminum spp.) belongs to the family Oleaceae, order Oleales are climbing, trailing or erect shrubby plants and there are both deciduous and evergreen species. The generic name Jasminum is derived from Arabic word “Jassamine”, “Jasmin” and “Jasminum” (Bailey, 1963). Flowers are white, yellow or rarely reddish. Flowers are used for making garlands and Veni. Jamine oil extracted from the flower is highly valued in perfumery industry. France, The Netherlands, Italy, Belgium, Algeria, Turkey, Morocco and Tunisia are major jasmine oil producing countries (Singh, 2006).

Marigold (Tagetes spp.) an annual flowering plant belongs to family Asteraceae, alternately known as Compositae. The word “marigold” means “Mary’s Gold” and refers to the “Virgin Mary”. However, word “Tagetes” named after the Etruscan God “Tages” who supposedly emerged from the earth as it was being ploughed and was imbued with the power of divination. Cultivated species include Tagetes erecta commonly referred as African marigold and Tagetes patula as French marigold. Marigold commonly propagated by seed and cutting is a leading loose flower of India. Selection of variety is favoured by a higher proportion of double inflorescences.

Cattleya belongs to the family Orchidaceae. It is highly important in floriculture and has been cultivated since the 19^th century. The name “Cattleya” was given in the honour of “Sir William Cattley”. Cattleyas have earned the reputation as the “Queen of Orchids” and are known to the public as the ultimate in floral corsages. While no longer the reigning queen of the orchid floral industry it is difficult not to be impressed by a well-flowered Cattleya. No longer limited to white and various shades of lavender and purple, high quality flowers occur in all colours except true blue and black and in a wide range of plant sizes. They are widely known for their large, showy flowers and were used extensively in hybridization for the cut-flower trade until the 1980s when pot plants became more popular.

Cymbidium is a genus in the orchid family Orchidaceae. It was first described by Olof Swartz in 1799. The name is derived from the Greek word “kumbos”, meaning “hole”, “cavity”. It refers to the form of the base of the lip. The flowers are long-lasting, both on the plant and when cut large attractive and available in a wide range of colours. Smaller plants are now coming into vogue as decorative pot plants. These have smaller flowers but they are as desirable as the standard varieties and often more acceptable in modern homes. The popularity of miniature cymbidium is now spreading from Asia to the worldwide orchid community. These ancient flowers have been treasured in numerous societies for nearly two thousand years. Many orchid lovers are most charmed by its fragrance and form rather than its petite size.

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.

Paphiopedilum is a genus of the orchid subfamily Cypripedioideae  and family Orchidaceae. It is derived from Paphos and ancient Greek word “pedilon” means “slipper”. Paphiopedilums are often called “slipper orchids” because of their unique pouch. The pouch traps insects seeking nectar and to leave again they have to climb up past the staminode, behind which they collect or deposit pollinia. Paphiopedilum has a highly ornamental value being the treasure of Orchidaceae. They are easily grown as houseplants and their care is very similar to African Violets.

Vanda is a genus in the orchid belongs to family Orchidaceae. The name Vanda is derived from the Sanskrit name for the species Vanda tessellate. The name Vandas will be used here to cover all vandaceous orchids including Vanda, Ascocentum, Aerides, Renanthera, Rhynchostylis, etc. and hybrids between them. Although there are some vandaceous orchids that originate in mountainous areas most are low-level plants that love warm temperatures. This has contributed much to the work of hybridists producing flowers for the cut flower market. It is one of the five most horticulturally important orchid genera because it has some of the most magnificent flowers to be found in the entire orchid family. It is highly prized in horticulture for its showy, fragrant, long lasting and intensely colourful flowers.

Year                    Milestones
1951    :    First amino acid was sequenced by F. Sanger and H. Tuppy.

1953    :    J.D. Watson and F.H.C. Crick proposed that DNA is a double helix.

1958    :    Discovery of DNA polymerase by Kornberg’s group and DNA replication studies began.

1959    :    Isolation of RNA polymerase.

Wild relatives of cultivated plants constitute a part of crop genepool, which possess genes that have great potential for their utilization in crop improvement programmes. Wild genepools especially those occurring in biotically disturbed habitats are under threat of genetic erosion and require immediate collection to make use of their wider adaptability, tolerance/resistance to disease, insect-pests, yield, quality attributes and other biotic and abiotic traits. The wild relatives of crop plants occur in all the major phytogeographical regions of India as component of different vegetation types and exhibit variable life forms and habitat specificity. High priority demand is towards collection of those that are at the risk of erosion due to habitat disturbance by manmade/natural causes and over-exploitation of species for commercial use.

INTRODUCTION

Heterosis has contributed significantly towards increased crop production and it has become the basis of multibillion dollar agro-businesses in the world (Phillips, 1999). Hybridization is the important way that can create genetic variability and make new options. The F1 population is obtained from the crossing of two homozygous but genetically dissimilar gametes or individuals (purelines in self pollinated crops or inbred lines in cross pollinated crops) that shows increased or decreased vigour over the better or mid parent value. Heterosis is maximum in F1, generation which diminishes gradually in later generations. Hence, production of F₁, hybrid seeds of different flower crops is considered as the extreme focused area in floriculture industry.

Since floricultural and ornamental crops are grown for aesthetic purpose and are non-edible there is likely to be less concern in bio safety issues compared to other food crops. Hence there is considerable potential for developing transgenics in ornamental crops. Advances in transgenic technology provide new opportunities for manipulation of the genome. These will have significant impact on expanding and diversifying the gene pool of crop plants, introducing specific genes and shortening the time required for the production of new varieties or hybrids. Molecular breeding is beneficial to increase the production and quality by creating plants with enhanced resistance to diseases, insects or viruses and increased tolerance to environmental stresses like salinity, temperature or drought. Through this technique genes for shelf life, flower colour and architecture may be directly transferred to develop new varieties that are tailor made to customer preferences. Bioluminescent orchids and blue roses are the significant outcomes of the genetic transformation studies in ornamentals (Swarnapiria, 2009).

INTRODUCTION

The seed (or zygotic seed) is the vehicle that connects one generation to another in much of the plant kingdom. By means of seed, plants are able to transmit their genetic constitution in generations and therefore seeds are the most appropriate means of propagation, storage and dispersal. A synthetic seed or ‘synseed’ is “an encapsulated single somatic embryo”, i.e., a clonal product that can be handled and used as real seed for transport, storage and sowing and that, therefore, would eventually grow either in vitro or ex vitro, into a plantlet through a process of “conversion”. Now a day, artificial seed technology is one of the most important tools to breeders and scientists of plant tissue culture.

INTRODUCTION

Seed is one of the most vital and important inputs for increasing agricultural production. Commercial flower seed production is an international business involving highly specialized growers. Compared with the production of seeds of cereals, pulses oilseed even vegetable seeds, it is done on a relatively small scale. However, a large number of species are being produced under very different cultural conditions. It seems to have great scope for expansion in developing countries like India, especially under northern India climatic zones having favourable growing conditions, skilled and cheap labour.

Plants belonging to the Rhododendron subgenera Pentanthera (deciduous) and Tsutsusi and Azaleastrum (evergreen) are called azaleas. Azalea belongs to family Ericaceae. Azaleas are one of the favourite ornamental plants used by home owners and professional landscapers. They are used as foundation, accent, individual specimen plants, and as mass plantings. Azaleas are good companion plants, working well in designs with many trees, shrubs and ground covers, offering a variety of landscape options. Azaleas can be found in all ranges of colours, from delicately pink-tinged white to strong, bright red, and there are species that has the startling colour of flame. Its bold colour scheme has caused people to carry it far and wide, for use wherever a sudden note in strong hue is appropriate among the milder expressions of the rest of the flowers. The evergreen azalea, Rhododendron simsii  Planch., is one of the most important pot plants in Western Europe and the USA. The breeding history of this vegetatively propagated plant is a relatively short one, and breeding has been focused on flower characters because the public is continually asking for new flower colours and flower types.

Bougainvilleas (Bougainvillea spp.) are tropical and sub tropical plants belonging to Nyctaginaceae family. They are thorny, evergreen and some are fragrant. Bougainvillea is named for “Louis A. de Bougainville”, a French navigator (1729-1811) who discovered the plant in Brazil in 1768. Bougainvillea plant spreading horizontally or hanging downwards as it is climbing upwards, it makes itself at home in almost any situation. It can be grown as a hedge, groomed as a ground cover, pruned as an espalier, trained as a tree or contained in a pot in a variety of shapes. Bougainvillea is ideal for bonsai. Red, violet, orange, yellow or white bracts appear at the ends of new growth.

The  Camellia  is  one  of  our  most  beautiful  and most  appreciated ornamental  plants belonging to the family Theaceae. The genus Camellia was named by Linnaeus after the Jesuit botanist “Georg Joseph Kamel”. Camellias represent gratitude, love and perfection and are a perfect way to tell someone they possess those qualities. The camellia is the state flower of Alabama. Industrial use of Camellia is in the oil industry. Seeds of several species belonging to the sections Oleifera, Paracamellia, Camellia and Furfuracea are used for extracting edible oil, which is used extensively for cooking in China (Ming, 2000, Gao et al., 2005 and Zhang et al., 2007). In China, more than 3 million hectares are used for camellia oil production and nearly 645000 tons of seeds are harvested each year, which yield nearly 164000 tons of edible oil (Ming, 2000 and Gao et al., 2005).

Lagerstroemia indica belongs to family Lythraceae commoly known as Crape myrtle. It it grown well in India for various landscape purposes. It is called Sawani or Shravani (Hindi), Dhayti (Marathi), Chinagoranta (Telugu), Pavalakkurinji (Tamil). Lagerstroemia a long period of striking rainy season flower colour, attractive fall foliage and good drought-tolerance all combine to make a favourite shrub or small tree for either formal or informal landscapes. It is a deciduous, multi stemmed; rounded crown; dense branching and is highly recommended for planting in urban and suburban areas.

Hibiscus a well known member of the family Malvaceae, grows as an evergreen shrub plant. The plant is extensively cultivated as an ornamental plant that bears large flowers on the bushy hedges. These enormous flowers are usually dark red in colour and are not usually fragrant. The huge size and the reddish colour and hues attract humming birds (Kumar and Singh, 2012). The generic name is derived from the Greek word “hibiskos” which was the name Pedanius Dioscorides gave to Althaea officinalis. Hibiscus rosa-sinensis was named by Carolus Linnaeus. The Latin term “rosa-sinensis” literally means “rose of China”, though it is not closely related to the true roses. Member species are often noted for their showy flowers and are commonly known simply as hibiscus, or less widely known as rose mallow. The hibiscus is used as an offering to goddess Kali and Lord Ganesha in Hindu worship. Hibiscus is an important flowering and garden plant. It has various medicinal values (Chopra et al., 1996 and Sayed et al., 2012).

The genus Hydrangea is the best-known member of family Hydrangeaceae tribe Hydrangeae from the Asterid order Cornales. With more than two centuries of horticultural trade, Hydrangea cultivars are among the most popular ornamental shrubs worldwide (McClintock, 1957 and Kardos et al., 2009). Hydrangea (Hortensia) is a very popular ornamental plant for gardens. Hydrangeas occur most often on partly shaded but open slopes, rock edges, cliffs, roadside banks, edges of woods, or in moist open woods. Usually, restricted to the more moist, protected slopes. Recently it is commercialized for the production of cut flowers (Sacco et al., 2012). In India is widely grown in hilly areas.

Ixora is an ornamental plant which is a medium-sized, tropical flowering, evergreen shrub that is used in landscapes. The genus Ixora belongs to the family Rubiaceae. The plants have glossy green leaves which are arranged oppositely along each stem. All Ixoras produce clusters of star-shaped flowers on stem tips or terminal growth. They are grown for their beautiful flowers which bloom in summer in clusters of different shades of red, pink or yellow (De Block, 1998 and Husain and Paul, 1988). The colour of the wild flowers is red or reddish-orange but ornamental varieties may have white, yellow, salmon or pink flowers. It is commonly known as West Indian Jasmine. The other common names of this plant are Jungle Geranium, Flame of the Woods, Jungle Flame, Burning Love, Red Ixora, Ixora, Amor Ardiente, Cruz de Malta, Dola de Coral, Equisosea and Rajana (Griffiths,1994 and Liogier,1997), Rangan, Kheme, Ponna, Chann Tanea, Techi, Pan, Santan, Jarum-Jarum and many more. Members of Ixora prefer acidic soil and are suitable for bonsai (Frommer, 2001). I. coccinea is used extensively for landscaping and is also grown as a potted ornamental (Lakshmanan et al., 1997). Ixora coccinea and Ixora parviflora are generally used as the ornamental plants in gardens and parks.

Nerium (Nerium oleander L.) belongs to family Apocynaceae is a Mediterranean evergreen shrub characteristic of watercourses, gravely places and damp slopes (Portis et al., 2004 and Herrera, 1991). The first Oleanders came to subtropical Galveston in 1841. Joseph Osterman, a prominent merchant, brought them from Jamaica. After distributing these oleanders, these new plants were growing throughout the city. Later as early as 1908, an editorial in the Galveston Tribune observed that the oleander was emblematic of Galveston. In 1910, The Galveston Daily News also reported that Galveston was known throughout the world as “The Oleander City” and in 1916, an article named it one of the most beautiful cities in the South. It is widely grown as an ornamental in warm temperate and subtropical regions, due to its abundant and long-lasting flowering and moderate hardiness. It is used for screens, hedging along highways, planting along beaches and in urban areas as, by removing suckers and leaving just a few stems, it can also be formed into very attractive small trees (Portis et al., 2004). Nerium oleander is among the most toxic of all ornamental plants. More than fifty toxins have been isolated, including cardiac glycosides, general cell toxins and the strychnine-like compound rosagenin. The ancient city of Volubilis in Morocco took its name from the old Latin name for the flower.

Rhododendron belongs to family Ericaceae. The word “Rhododendron” is derived from the ancient Greek word “rhódon” which means rose and “déndron” which means tree. This genus is characterized by shrubs and small to (rarely) large trees. The smallest species grow up to 10–100 cm tall and the largest Rhododendron giganteum is reported to grow over 30 m tall. They are noted for their clusters of large flowers. The alpine species have small flowers and small leaves and tropical species grow as epiphytes. The colour of the rhododendron flower is available in nearly every colour of the rainbow including various shades of blue, yellow, pink white, red, orange and purple. Rhododendron flower from January through August, depending on the location and the climate.

Ageratum is a winter season annual that is grown for its beautiful flowers. It belongs to family Asteraceae. The word “Ageratum” is derived from the Greek words “ageras” meaning non-aging referring to the longevity of the whole plant. Ageratum houstonianum (flossflower, bluemink, blueweed, pussy foot, Mexican paintbrush) syn. Ageratum mexicanum Hort. is a cool-season annual plant often grown as bedding in gardens. Ageratum houstonianum is from Mexico and is named after William Houston (1695-1733), a Scottish physician who collected the first ageratum plants. The flowers are blue in colour (sometimes white, pink, or purple). The ray flowers are threadlike leading to the common name and are used for flower arrangements and potted ageratum plants are used for beautification of the surroundings. Growing ageratum is very easy under suitable climatic conditions. The genus Ageratum consists of some ornamental species, but only a few species have been phytochemically investigated (Burkill, 1985). A. houtsonianum contains essential oil the main constituents were precocene I (23.34%), precocene II (43.99%) and beta -caryophyllene (9.18%) (Menut et al., 1993 and Shahi et al., 1996).

Impatiens balsamina (Balsam, Garden Balsam or Rose Balsam or Gulmehndi) is a species of Impatiens widely cultivated as an ornamental plant in landscaping belongs to the family Balsaminaceae. It is a qualitative short-day plant, propagated by seed and is one of the popular species of North India. It is called kamantigue in the Philippines. This species of Kamantigue are used in teas. In many English speaking countries they are known as “Touch me not”, possibly due to the ripe seed pods explosively bursting when touched. Different parts of the plant are used to treat disease and skin afflictions such as the leaves, seeds, and stems. It is also edible if cooked. Juice from balsam leaves treats warts and also snakebite, while the flower can be applied to burns to cool the skin. Impatiens balsamina L. has been used as indigenous medicine in Asia for the treatment of rheumatism, fractures, and fingernail inflammation. In Korean folk medicine Impatiens (‘Bong Seon Wha Dae’) has been used to cure constipation and acute gastritis by meat. There are mainly four forms of I. balsamina namely red, purples, white and pink.

Cosmos is a flowering plant belongs to family Asteraceae. Cosmos bipinnatus is ornamentally important species grown for garden display. The word cosmos is derived from the Greek word “kosmos”, which means a balanced universe or order, harmony and often referred to as Mexican Aster. The species name is from the Latin “bipinnatus” meaning “twice-pinnate” The botanical epithet is from the Latin “pinnatus” meaning “with leaflets arranged in opposite pairs”. Cosmos flowers are produced in a capitulum. Modern varieties come with single or double flowers, picotee edges, and even furled petals in the variety Seashells. Ornamental uses of cosmos include cut flowers and as border annual in the gardens. It is a very popular flower for summer bedding. Cosmos has a pleasant aroma and attracts butterflies to the garden. Essential oil extracted from leaves of cosmos. The major constituent of C. bipinnatus contained 15-17% beta-elemene, 15-17% beta-caryophyllene, 10-21% germacrene D and 12-15% bicyclogermacrene (Menut et al., 2000).

Impatiens is the most popular bedding plant grown worldwide. The genus Impatiens is estimated to contain about 850 species (Grey-Wilson, 1980b). The majority is native to tropical and subtropical regions of India and Africa. The popularity of Impatiens walleriana is mainly due to its propensity for producing large numbers of flowers under low light intensity (Simmonds, 1980). Due to the high economic value and consumer demand for bedding impatiens, there has been a concerted effort by plant breeders to release a wide range of cultivars having different flower colours and distinctive foliage. Previously known as I. sultanior, I. holstii, it has several common names including “Busy Lizzie” and “Patience Plant”. It is one of two important groups of Impatiens in the horticulture industry with the New Guinea Impatiens (Impatiens hawkeri) group being the other. Despite being Impatiens walleriana is one of the most important bedding plants in the world, information on I. walleriana relatively scarce. Impatiens walleriana continues to lead as one of the three most important bedding plants worldwide. It is available as both seed and vegetative products. The history of its development, marketing success, wide adaptability, a large palette of flower colours and forms and unparalleled garden performance as a bedding plant for shade are described as an aid for continued crop development with breeding lessons for other flowering crops.

Pansy belongs to the family Violaceae, genus Viola and species tricolor. Pansy also known as butterfly flower, cat face. Pansies are annuals or short-lived perennials, grow 15-30 cm tall and have heart-shaped leaves at the base and oblong leaves growing from the stems. The pansy is quite durable and a “flower for all seasons”. The fragrant and edible blooms are desirable in gardens. Pansy popularity increases possible due to its ease of growing. Whether grown from seed or bedding plants, pansies are relatively disease and pest free blooming prolifically for the gardener’s enjoyment.

Petunias (Petunia spp.) are annual or perennial plants belonging to Solanaceae family. The common kinds are rather weedy in habit, but their great profusion of bloom under all conditions makes them useful and popular.  They are small herbs grown for their showy, often fragrant flower. The geographic distribution includes temperate and subtropical regions of Argentina, Uruguay, Paraguay, Bolivia and Brazil, with a centre of diversity in Southern Brazil. For longer flowering season they may be grown in bed borders, edgings, rock garden, window boxes, hanging baskets and pots. Petunia is considered to be the first cultivated bedding plant and has remained as a commercially important ornamental crop since the early days of horticulture and is one of the favourite genera for developing new varieties. Apart from its significance as an ornamental crop, petunia has proved to be one of the most excellent model crops for studies on gene regulation and genome structure, since the system combines innumerable and excellent technical features with a broad range of research possibilities.

Phlox is a perennial and annual flowering plant belongs to family Polemoniaceae. “Phlox” is a Greek word meaning “flame” and was most likely named thusly due to its bright and vivid colours. Phlox originally came from North America and was available in England by the early 1800s. It quickly grew in popularity and today it is still found growing wild in gardens across the world. Among perennials, Phlox paniculata, Phlox divariecata, Phlox glaberrima are earliest species to be cultivated and reached to England and France from Virginia (USA) in the early 18th century. Among annuals, Phlox drummondii is commonly grown in India. Annual phlox is propagated by seeds, whereas, cutting is used as propagating material for perennial species. Phlox is grown in the garden as bedding and border plant for its dramatic, fragrant, showy and long blooming flowers. The colour range includes white, rose, pink, purple, lavender, violet, pale blue, bright red and magenta. Some flowers are bicoloured.

Salvia belongs to family Lamiaceae. The genus Salvia comprises about 900 species which are grown for their ornamental flowers since they make excellent and showy borders in gardens. One of the species most commonly grown is Salvia splendens is a tender herbaceous perennial, but grown in India as winter season annual flowering plant. It bears racemes of bright scarlet flowers of large size. It has ability to grow under partial shade condition. It is commonly grown as bedding plant due to varying colours mostly scarlet, purple, orange, lavender and yellow and long lasting flowers. The word salvia was derived from Latin word ‘Salvare’ meaning ‘to heal or to be safe and unharmed’ (Blumenthal et al., 2000 and Kamatou et al., 2008) later it was translated in French as “sauge” or “sage” and in old English “Sawge” (Kamatou et al., 2008).

Zinnia is a very important summer annual belongs to family Compositae. Zinnia was named for the man who wrote the first scientific description of the flower, “Dr. Johann Gottfried Zinn” a German Professor of medicine, but it was the late 19th century that plant breeders started to pay any attention to this plant. Zinnia is a half hardy plant. They are popular for bedding however, cut flowers of zinnia remain fresh for several days. They are easy to grow from seeds. Collection of open pollinated seeds is in common practice in India. Non-uniformity of bloom with respect to colour, flower shape and size, height of the plants and excessive etiolation of the plants result into poor sale of zinnias.

Begonia is a perennial flowering plant belongs to family Begoniaceae. Begonia has rich colour and beautiful form of flowers. It is free flowering and striking foliage with free growth. The name Begonia is given by Franciscan monk Charles Plumier a plant which he found during his journey from Haiti to island Martinique. He dedicated this plant to “Michel Begon” the man who had the direct manmade over the expeditions. Begonia is easy to propagate and grown from seeds and vegetative means particularly cuttings. It is a popular flowering potted plant grown in containers and hanging baskets including tuberous, semperflorens, Rex, Elatior, Loraine and gracilis. Modern commercially cultivated begonias are mostly hybrids between wild types from all over the world.

Cactus (Opuntia ficus-indica), commonly known as prickly pear, belongs to the family Cactaceae. In local parlence, cactus is called nagphani or danda thohar. In Tamil Nadu, it is commonly known as chapathi balli. The word “cactus” derived through Latin from the ancient Greek kaktos, a name used by Theophrastus for a spiny plant (Johnson et al., 1972) which may have been the Cynara cardunculus (Sonnante et al., 2007). It is a storehouse of virtues that have been commercially unexploited so far in India. In addition, certain genera, such as Optuntia and Nopalea have economically useful plant parts. Different parts of the cactus can be used as fruit and vegetable for human consumption, fodder for cattle, and raw material for various industries to prepare plywood, soap, dyes, adhesives and glue, pharmaceutical products for treating blood sugar and various other disorders, and cosmetics such as shampoo, cream, and body lotions, etc. (Barbera et al., 1995 and  Pimienta, 1994). Similarly, the tender young pads of Optunia and Nopalea species, known as nopalitos, are extensively used as a fresh green vegetable in Mexico and Texas. Even its seeds can be used as flavouring agents. Use of cactus pear as a waterproof paint for homes is also reported.

Dahlia (Dahlia spp.) syn. Georgina belongs to family Compositae (Asteraceae). Dahlia was named after “Professor Andreas Dahl”, a Swedish pupil of Linnaeus and author of Observations Botanicae. In India, dahlia is grown as potted plant and landscape uses but it is a poor crop as commercial flower due to shorter commercial life and its potentialities have not been exploited so far. Therefore, there is need to originate more and more new quality cultivars. Dahlias are half-hardy perennials with tuberous roots. Stems are mostly erect, branched, glabrous or scabrous. The leaves 1-3 pinnate, with slightly serrated margin are produced opposite at each node on the stem. They bear flowers on a long, stiff stems well above the foliage. Ray florets are neutral or pinnate and disc florets perfect.

Geranium (Pelargonium spp.) belongs to the family Geraniaceae. The name Pelargonium was introduced by Johannes Burman a Dutch Botanist in 1738, from the Greek word “Pelargos” means stork because the seed head looks like a stork’s beak.  Due to their long and beak-shaped fruits, they are also known by the name of cranesbills. Geraniums are popular flowering plants and grown as decorative pot plants for indoor and outdoor. There is a world demand for the rose geranium essential oil of Pelargonium species which contains geraniol, linalool and citronellol, substitutes for the expensive attar of roses in the perfume trade. Pelargonium species was known for their medicinal value by the earliest indigenous people (Swanepoel, 2009).

Orchids belong to family Orchidaceae, the largest family of the flowering plants. The term ‘orchid’ has its origin from the Greek word, “orchid” meaning “testicle”, referring to the paired underground tubers of terrestrial orchids. There are several generas in orchids, which are popular for their separate importance as cut flower, pot plant, medicinal properties, flavour extraction, etc. The fascinating flowers exhibit an incredible range of shape, size and colour, long life of flowers on plant and an amazingly long keeping quality, which no other plant can claim.

Poinsettia (Euphorbia pulcherrima) is one of the most popular ornamental pot plants belonging to the family Euphorbiaceae. The botanical name Euphorbia pulcherrima means very beautiful. Euphorbia pulcherrima the name originally given by German botanist Karl Ludwig Wilenow was changed to “Poinsettia” in honour of “Mr. Poinsett” in 1836 by William Prescott. Poinsettia is a short-day, non-food and non-feed vegetatively propagated ornamental plant. Poinsettias are fascinating winter blooming small shrubs or trees which can grow anywhere from about 0.6 to 5 m tall. The coloured bracts of poinsettia plants are actually leaves. Colours of the bracts can be red, pink, orange, white or marbled. These coloured bracts are caused by photo-periodism. Poinsettias have also been called the lobster flower and the flame-leaf flower due to the red colour. California is the top U.S. Poinsettia-producing state.

Lotus belongs to the Nelumbonaceae family and the genus Nelumbo. There are two species in this genus; Nelumbo nucifera Gaertn. distributed in Asia and Oceania, and Nelumbo lutea distributed in North and South America (Qichao and Xingyan, 2005). Although, the species nucifera is the most important (commercially and culturally), it is critical to describe the American species, evaluate its horticultural value and its potential as a source of genetic diversity. The American species, represented by Nelumbo lutea (Syn. N. pentapetala or Nelumbium luteum) is known as American Lotus, Water-chinquapin and Yellow Lotus (Sayre, 2004) and is native to the eastern and central portions of the US ranging from Maine to Wisconsin and in the south from Florida to Texas. It is one of the most spectacular and graceful aquatics among all the native plants of India. N. indica are found all over India and extend as far as Kashmir to Kanyakumari exhibiting enormous thermoplasticity and phenotypic diversity with a large number of racial variants with different shapes, sizes and colours. First Indian fossilised record of N. nucifera has been reported from the Pleistocene epoch of Kashmir. The presence of Nelumbo in the Tertiary period of Assam is reported on the basis of impressions of leaves and rhizomes found in the collection from Eocene bed near Damalgiri. These records confirm the evidence in support of the view that N. nucifera is indigenous to India.

Clematis is member of the Ranunculaceae family which also known as buttercup family. This cosmopolitan genus comprises climbing lianas, small shrubs and erect sub-shrubs distributed predominantly in the temperate zone of both hemispheres but with some species distributed in tropical areas (Tamura, 1995, Johnson, 1997, Grey-Wilson, 2000 and Wang and Li, 2005). The word clematis is taken from Greek as in “klema” meaning “a vine branch”. Most species are known as Clematis in English while some are also known as Traveller’s joy, Leather flower, Vase vine and Virgin’s bower the last three being names used for North American species (Chawla et al., 2012).

Sweet pea (Lathyrus odoratus) is the only species in the genus Lathyrus and family Fabaceae which is widely cultivated as an ornamental plant. Lathyrus comes from the Greek word “Lathyros” in which the prefix “la” means “very” and suffix “thyros” means “passionate”. The “Odoratus” is derived from Latin word which means “fragrant” (Fernald, 1950). It is mainly grown for its beautiful flower colour forms. It is an annual climbing plant growing to a height of 1-2 m with the support of a terminal tendril which twines around the plants and helps to climb. The illness caused by the ingestion of sweet pea is known as odoratism or sweet pea lathyrism. Sweet pea was used to verify Mendel’s work with the garden pea (Pisum sativum L.) in the early 1900s (Bateson, 1902). The genetical phenomenon of linkage was first demonstrated in the sweet pea. It is used prominently as a model organism to study flower development due to its large, colourful and fragrant flowers. The essential oils extracted from the sweet pea can be used in perfume blends.

Abstract

The strenuous field trekking, inaccessibility, perception of geology only within the visibility range of the eyes etc. have remained matters of major constraints in the past in field based geological mapping. The remote sensing technology not only eradicated these but also provided lot many newer vistas in the field of geology. In addition, the application of such unique technology has brought out a hierarchy of newer concepts in the field of geology. The paper narrates the newer knowledge gathered on the geology of South India in the post remote sensing Era.

Abstract

The study area falls in the southern part of the Indian Peninsular comprising hard crystalline rocks of Archaeozoic and Proterozoic Era. In the present study, the GIS based 3D visualizations of gravity, magnetic, resistivity and topographic datasets were made and therefrom the basement lineaments, shallow subsurface lineaments and surface lineaments/faults were interpreted. These lineaments were classified as category-1 i.e. exclusively surface lineaments, category-2 i.e. surface lineaments having connectivity with shallow subsurface lineaments and category-3 i.e. surface lineaments having connectivity with shallow subsurface lineaments and basement lineaments. These three classified lineaments were analyzed in conjunction with known mineral occurrences and historical seismicity of the study area in GIS environment. The study revealed that the category-3 NNE-SSW to NE-SW lineaments have greater control over the mineral occurrences and the N-S, NNE-SSW and NE-SW faults/lineaments control the seismicities in the study area.

Abstract

The emergence of Remote Sensing and GIS technologies has substantially eased the problems of groundwater targeting in hard rock aquifer systems. Proper utilization of these can provide more vital information in managing such scarce resource. In this context, a new technique of GIS based visualization of groundwater levels of different periods (1985- 1990 -1995) was attempted for a part of Western Ghats hill-plain region of Tamil Nadu and various groundwater features viz: ridges, valleys, domes and basins were interpreted. The integration of such groundwater features of different periods and their analysis with structural features provided some newer information on geosystem processes and their interface dynamics with hydrosystems, from which, certain strategies were suggested for better groundwater management in hard rock areas.

Abstract

The Pudukkottai district located in the southeastern tip of Tamil Nadu, India provides a complex geological setting with three litho-tectonic blocks membered by the hard Crystalline rocks of Archaeozoic-Proterozoic Era in the west,Mio-Pliocene Sandstone/Cuddalore Sandstone in the centre and Quaternary sediments in the east. While the western and central blocks are separated by a well-defined NNE-SSW trending fault, the central Mio-Pliocene Sandstone block is cut into two parts by a N-S fault with western static block and the eastern uplifted counterpart. Besides the above, the various drainage anomalies viz; Annular, Deflected and Eyed drainages and compressed meanders interpreted using the raw and digitally enhanced satellite multispectral data show that the N-S oriented faults with oscillations from NNW-SSE to NNE-SSW, NE-SW and E-W orientations are tectonically active in the area. The integration of these active faults with known geothermal springs and the maxima axes drawn from the contours deducted from the temperature of groundwater measured during the predawn hours from the wells revealed that the N-S and NE-SW faults are the probable locales for geothermal resources in the study area. Thus the study demonstrates a newer methodology for locating the geothermal prospects.

Abstract

Sabatayn basin is one of the two mature basins producing oil and gas in Yemen. Due to the recent decline in oil production, the exploration activities have been extensively concentrated mainly on these two basins (Sabatayn and Sayun-Masilah). So, this present study has been conducted to evaluate the exploration potential of the remaining trap areas within these mature basins. Fractured basement of reservoir becomes very attractive exploration target in Yemen recently, after the recent discoveries of basement fractured oil fields. As the evaluation of basement traps needs time and fund, to reduce the same, this research study uses a new technique which was devised with the help of Geoinformatics by analyzing the surface and subsurface lineaments effectively. In this study, a satellite image Enhanced Thematic Mapper (ETM+7) based analysis was conducted for extracting surface lineaments, and for the subsurface lineaments, the basement lineaments were extracted from seismic, magnetic and gravity data. An orientation analysis of these surface and subsurface linear features was performed to detect the basic structural grains of the study area. The correlation between these structural grains and subsurface oil and gas traps was performed to understand the connectivity to the reservoirs. This paper discusses in detail about the same and the importance of using surface and subsurface lineament analysis for delineating hydrocarbon reservoirs in the study area.

Abstract

The Mesozoic sediments contribute around 54% of the oil and 44% of the gas reserves of the world (Bois et al. 1982). Indian Mesozoic basins occupy an area of about 400 x 103 sq. km and are characterized as frontier basins under category II - IV. These basins are mostly overlain by the Deccan Traps of Late Cretaceous age and are least explored. Deccan Syneclise is one of the largest Mesozoic basins in India, covering an area of ~ 273 x 103 sq. km. Geophysical studies have inferred hidden sub-trappean Mesozoic sediments with thickness up to 2.5 km. It is considered that requisite heat generation due to Deccan Trap volcanism soon after the Cretaceous sedimentation may have acted as a catalyst in hydrocarbon generation. Surface geochemical prospecting surveys along with carbon isotopic studies have been used to assess hydrocarbon generation potential of this part of the basin. The area adjoining Nandurbar beneath Narmada-Tapti region of Deccan Syneclise was selected for geochemical studies where geophysical studies have shown considerable sediment thickness. Surface geochemical studies indicate the generation of light gaseous hydrocarbons, C1 and SC2+ in the range of 3 to 1187 ppb and 1 to 1449 ppb, respectively. The carbon isotopic signatures of selected soil gas samples dC13 CH4 in the range of - 24 to -39.4‰ PDB) suggest thermogenic origin

Abstract

The state of Tamil Nadu has a low easterly gradient slope and there are number of rivers, big and small originate from the west flow towards east south easterly and confluence the Bay of Bengal. These were grouped into seventeen major and minor river basins, the Cauvery being the largest basin and the river is also a near perennial river. These river basins receive rainfall both from the southwest and northeast monsoons. The state has over 40,000 surface water bodies and number of major dams and reservoirs. Even then, since the rainfall of the north east monsoon, the major source of water source to these basins, occurs in short span of few days with high rainfall, neither adequate storage is there to store them nor the recharge possibility is available, thus all leading to flooding and wastage. The 40,000 and odd water bodies are heavily silted and polluted too. The paper provides an over view of all these, basin wise, and in addition, strongly advocates intra state river linkage and improvised irrigation management as the best option to save the state from its water deficiency.

Abstract

The Tamil Nadu is one of the leading states in groundwater development. Since the surface water resources have been fully exploited for irrigation, the groundwater is massively mined for agriculture, domestic and industrial purposes. The paper provides a synthesis of whole groundwater related issues including basin wise groundwater conditions, the aquifer types, geogenic water quality and quality deterioration due to anthropogenic activities, need for recharge, the utility of Remote Sensing & GIS etc. The paper has come out with set of recommendations as the concluding remarks.