eChapters

1.    Classification of Trees
    
2.    Flowering and Foliage Trees of Indian Gardens
    
3.    Palms and Cycads
    
4.    Coniferous Trees and Deciduous Trees for Temperate Climatic Situations
    
5.    Propagation and Planting of Trees
    
6.    After Care of Trees
        
    Further Reading

1.    Basic Principles
    
2.    Scale and Proportion
    
3.    Balance
    
4.    Rhythm
    
5.    Simplicity
    
6.    Unity
    
7.    Transition
    
8.    Focal Point or Emphasis
    
9.    Elements
    
10.     Variety
    
11.     Grouping
    
12.     Mass
    
13.    Sequence
        
    Further Reading

Appendices
    
I.    Released Varieties/Hybrids in Aromatic Crops from KAU
     P. Skaria Baby, P.P. Joy, Samuel Mathew, Ancy Joseph and Ragina Joseph 
    
IIa.    Released Varieties of Fruit Crops in India
    T. Radha
    
IIb    Released Varieties of Arid Fruits
    S.K. Sharma
    
III.    Released Varieties of Ornamental Plants
    P.K .Valsala Kumari 
    
IVa.    Released Varieties of Coconut
    P. Maheswarappa
    
IVb.    Release Varieties of Cocoa
    P. Maheswarappa
    
IVc.    Released Varieties of Plantation Crops
    P. Maheswarappa
    
Va    Released Varieties of Spices from Kerala Agricultural University (KAU)
    Asha Sankar 
        
Released Varieties of Spice Crops Through All India Coordinated Research Project on Spices
    K. Nirmal Babu
    
Vb    Released Varieties of Spice Crops Through All India Coordinated Research Project on Spices
    K. Nirmal Babu
    
VI    Released Varieties of Vegetables from KAU
    T.R. Gopalakrishnan
    
VII.    Research and Educational Infrastructure in Horticulture in India
    P.G. Sadhan Kumar and S. Nirmala Devi
    
VIII.    Important Websites in Horticulture
    T. Pradeepkumar 
    
VIIIa.    Horticulture Institutes in India
    T. Pradeepkumar 
    
IX.    Vital Statistics on Horticultural Crops
    National Horticulture Board, Gurgaon, Haryana
    
X.    Nutritional Values of Horticultural Crops
        Indian Institute of Nutrition, Hyderabad

Horticultural crops include the fruit crops, vegetables, spices, plantation crops, medicinal plants, aromatic plants, commercial flower crops and ornamental plants.

Knowledge on the methods by which these reproduce is of primary importance from the standpoint of plant breeding. Besides, their annual or perennial nature also decides the methods of breeding to be adopted to get desired improvement.

Two divisions of methods of reproduction commonly recognized are:

1. Asexual i.e. vegetative parts of the plants are utilized to produce new individuals.

2. Sexual i.e. gametic fusion, the resultant zygote develops into seed which is utilized to produce new individual.

This group can be further placed in several sub divisions according to the mode of pollination. They are

a. Naturally self pollinated crop - (e.g. tomato, pepper, brinjal) wherein cross pollination occurs less than 4 % only.

b. Often cross pollinated crop- (e.g. chillies, bhendi) wherein though self pollination is more frequent, cross- pollination may occur so frequently that some methods of preventing cross pollination between varieties and strains of different genotypic constitution must be followed throughout the breeding programme.
Common breeding methods can be applied to the above two groups, however, the parents chosen for breeding under often cross pollinated crop need to be selfed for few generations to select desirable, homozygous lines.

TROPICAL AND SUBTROPICAL FRUITS

2.1 Mango
 

Mango is considered to be an allopolyploid. The chromosome number is 2n =40. The polyembryonic seedlings of cv. Vellaikolumban, earlier reported to be 2n= 80 was later shown to be a diploid. In Canary Island, a putative tetraploid viz Gomera-1 has been identified.

Floral biology

Flower starts opening early in the morning from 4-7 a.m. and maximum flowers open between 9.30-10.30 a.m. and complete 11 a.m. Dehiscence of anthers takes place at 11.30 a.m. and it continues up to 3.45 p.m. The pollen grains are oval, or triangular or oblong. Stigma becomes receptive even 18 hours before flower opening. Mode of pollination is entomophily; nectar is present to attract the insects.

The flowering duration is usually of short i.e. 2 to 3 weeks. The mango inflorescence or panicle bears mainly two types of flowers - male and perfect. The number of flowers per panicle varies between 1000 to 6000 depending upon the variety and climatic factors. The percentage of perfect flowers varies between 0.74 per cent in Rumani, 16.41 to 55.7 per cent in Neelum and up to 69.8 per cent in Langra.

3.1 Tomato

Tomato (Lycopersicon esculentum) is an important vegetable crop. Its 2n= 24.

Floral biology

Flowers are borne in small forked racemose cyme. Anthesis starts at 6.30 a.m. and continues up to 11.00 a.m. Anther dehiscence is longitudinal. It occurs 1-2 days after opening of corolla. The stamen sheds its pollen when the style grows up through anther tube, thus self-pollination occurs. When the stigma protrudes above the anther tube, chances of cross pollination through bees increases. The optimum temperature for pollination is around 21°C.

Like many other beautiful plants, Bougainvillea has been chosen as the symbol of a host of countries, regions and municipalities. It is the National Flower of the Caribbean Nation of Granada and the United States territory of Guam. It is also the official flower of several counties in Taiwan and Malaysia. In the United States, Bougainvillea is the floral symbol of three California cities (Camarillo, Laguna Niguel and San Clemente). Bougainvillea spectabilis: Paper Flower; Common name: Bougainvillea; Scientific name: Bougainvillea spp.; Hindi: Baganvilas (Booganbel); Manipuri : Cherei; Bengali : Baganbilash; Marathi: Bougainvillea (Booganvel); Konkani: Bouganvila; Telegu: Bogam Malle (Kagithala Puvvu); Malaysia: Bunga kertas, buganvil, buginvila;  Indonesia: kembang kertas; China: Ye Zi Hua; Spain: Bouganvilla, Aka Buganvilla; Mexico and Philippines: Bugambilia; Honduras: Napoleon; Colombia, Nicaragua, El Salvador, Costa Rica and Panama: Veranera; Colombia, Cuba, Panama, Puerto Rico, Dominican Republic and Venezuela: Trinitaria; Argentina, Bolivia, Brazil, Paraguay and Uruguay: Santa Rita; Northern Peru: Papelillo.

Bougainvillea plants are native of South America from Brazil west to Peru and south to southern Argentina (Chubut Province). A native to coastal Brazil, the bougainvillea was discovered in 1768 in Rio de Janeiro by French naturalist Dr. Philibert Commerçon (also sometimes spelled Commerson). The plant is named after his close friend and ship’s admiral Louis-Antoine de Bougainville, who commanded the ship La Boudeuse that sailed around the world between 1766-1769, and in which Commerçon was a passenger. Twenty years after Commerçon’s discovery, it was first published as ‘Buginvillea’ in Genera Plantarum by A.L. de Jusseau in 1789. The genus was subsequently spelt in several ways until it was finally corrected to ‘Bougainvillea’ in the Index Kewensis in the 1930s. Originally, B. spectabilis and B. glabra were hardly differentiated until the mid 1980s when botanists recognized them to be totally distinct species. Bougainvillea spectabilis Willd., a native of Brazil reported to be found wild in all provinces of that large country (Taillemite 1977, Forzza 2010). The oldest herbarium specimens of Bougainvillea spectabilis Willd. were collected during the brief stop of the Étoile in Rio de Janeiro. Two are kept in the General Herbarium of the Muséum National d’Histoire Naturelle in Paris (P 00169376, images in Monnier et al. 1993 : 176 and Jolinon 2004 : 79; P 00307018), and two in the Jussieu Herbarium conserved in the same institution (PJuss.; IDC 6206, No. 

Bougainvilleas are widely grown in India for multipurpose uses.  There are numerous varieties and cultivars that are important from floriculture point of view. Bougainvillea profusely flowers almost all the year round except in rainy season and very severe winter. It has earned a pride place in the floriculture and landscaping due to its variegated foliage and colourful bracts. Bougainvillea belongs to the family Nyctaginacea and in the tribe Mirabileae. It is the only genus in the monotypic subtribe Bougainvilleineae (Gills 1976, Hammad 2009). The first generic name as Bouginvillea was published by A.L. de Jussieu (1789) in his work ‘Garden Plantarum’. The spelling of the generic name subsequently changed about half a dozen times. Finally as per International Code of Botanical Nomenclature, it was spelt as Bougainvillea as used by Spachs (1841) and published in the Index Kewensis (Suppl. 9 : 1931-1935; c.f. Sharma 1996). Heimerl (1900) recognized 10 species, three of which (B. spectabilis Wild., B. glabra Choisy and B. peruviana Humb. and Bonp.)

The genus Bougainvillea, although having broad range of adaptability along with diverging habitate is not rich in scientific literature. The available literature on description of elemental species and mode of origin and description of different sports (cultivated species) are very poor and all the literarture are not available at one place. On the basis of available literature (Philbert 1789, Humboldt and Bonpland 1808, Fitch 1854, Bailey 1914, Merril 1923, Standley  1931, Heimerl 1934, Hottes 1947, Bor and Raizada 1948, Preston 1950, MacSelf 1951, Sargeant 1951, Van 1951, Crane and Lawrence 1952, Holttum 1955a-d, 1957a,b, Pancho and Bardenas 1959, Marigowada 1961, Sharma 1962, Menninger 1970, Ramcharan et al., 1974, Zadoo et al., 1976, Linnaeus 1789, Swarup and Singh 1995, Willdenow 1798, McDaniells 1981, Rodale et al., 1997, Gordon 2002, Lopez and Galetto, 2002, Fatima et al., 2007, Kent et al., 2007, Kobayashi et al., 2007a,b, Hammad 2009, Lack, 2004, 2012) an attempts has been made to give a short description of elemental species and important role played by Bougainvillea cv. 

As mentioned above, all the present day Bougainvillea cultivars being grown in India are either exotics introduced from abroad (Africa, USA, U.K., South Africa, Australia, Philippines, Sri Lanka, Jamaica, Canary Island, Singapore, Java, West Indis etc) or developed by concentrated efforts of nurserymen, individuals or scientific institutions. Bougainvillea are widely grown in Indian gardens. There are numerous varieties and cultivars that are important from floriculture point of view. Most of the present day varieties have arisen through bud sports, chance crossing and induced mutation. India is one of the major repository of wide range of genotypes of Bougainvillea and is perhaps the foremost among nations which have done appreciable good work on Bougainvillea. The genetic variation in plants is considered to be an unlimited resource. The main aim of germplasm collections are assemblies of genotypes or populations representative of cultivars, genetic stocks, wild species etc. which are maintained in forms such as plants, seeds and tissue cultures. The primitive cultivars and wild relatives of crop plants constitute a pool of genetic diversity.  The  germplasm collection and conservation of plant genetic resources provide the diverse raw materials for immediate or future breeding programme. Activities that relate to the conservation and use of plant genetic resources include : exploration and collection; characterization and evaluation; conservation; assessment of variation and identification of useful genes; and exchange and genetic enhancement. Germplasm are the basic raw materials, which after proper screening can be utilized either for direct commercial exploitation or can be used in breeding programme for developing new and novel varieties.

Bougainvillea can grow in almost all kinds of edaphic conditions except in the water lodged regions. They grow well in the degraded soils (black cotton soils, red soils, crevices of rocks, to some extent in sandy soils, water stress conditions, high and low pH soils). Open sunny location is most suitable for best performance. Full sunshine helps for producing brilliant colours in masses. But young plants must be protected from heat. Kuzmina-Medova (1986) estimated that Bougainvillea require more than 2000 lux light for satisfactory growth. Different floricultural crops are propagated/multiplied by different means like sexual propagation (by seeds), asexual propagation (cuttings, layering, grafting, budding) and micropropagation. Bougainvillea is mostly propagated by vegetative propagation i.e. hard wood cuttings but it can also be propagated by different conventional propagation methods (Watson and Criley 1973, Iredell 1994, Srinivas 1995, Sindhu and Dagar 2015, Rajan et al., 1998, Tavares et al., 1998, Criley 1997, Pertuit 1999, Gilman 1999, Hackett et al., 1972, Schoellhorn and Alvarez 2002, Hamilton and Midcap 2003).

Bougainvillea is relatively pest-free. Worms, aphids, and moths might be an issue. Sometimes it gets attacked by spiders which can be controlled by using miticide and by the fungus Phytophthora which is checked by spraying Blitox (copper oxychloride) (Sharma 1996, Banerji 2010). Although it is normally pest-free plants, but may suffer from worms, snails and aphids. The larvae of some Lepidoptera species also use them as food plants, for example the giant leopard moth (Hypercompe scribonia). Leaf spot disease caused by Cercosporidium bougainvillea has been reported in the U.S.A. (Sobers and Martinez 1966, Sobers and Seymour 1969). When compared to B. spectabilis, B. glabra has been reported to be resistant or only slightly susceptible to the leaf spot disease (Pal and Swarup 1974). Cercosporidium bougainvillea has been reported in Colombo by Pardo-Cardona (1998) and in Indonesia by Kobayashi and Oniki (1994). The disease can be controlled by spraying copper Carbendazim at the rate of 1 g/l at an interval of 10-15 days. Fusarium wilt caused by Fusarium oxysporum in bougainvillea has been reported in Italy (Polizzi et al., 2010). Bacterial leaf spot caused by Pseudomonas andropogonis has been reported in Brunei, Darussalam (Peregrine and Ahmad 1982, Sivapalan and Hamdan 1997) and U.S.A. (Walker 1991, Walker and Hodge 1991). This can be controlled by spraying copper oxychloride at the rate of 3 g/l at intervals of 10-15 days.

Bougainvilleas is a multipurpose plant due to the variation in habit, growth and colour pattern of different cultivars and are grown as pot plants, standard, hedges, bush, climber, bonsai, landscape, as an espalier, factory gardens, institutional gardens, municipal gardens, terrace garden, wind curtain, topiary, pergola and various other multipurpose. Bougainvillea in an urban landscape trained as a “standard”. It is used as an accent plant, a specimen plant, in hanging baskets, in containers, and for bonsai. Bougainvillea is used to decorate all public, home gardens, play ground and office corridor. About 300 cultivars (150 of which were bred in India) have been derived from 4 species, viz. Bougainvillea peruviana, B. glabra, B. X buttiana and B. spectabilis,through hybridization and natural or induced mutation. Indian-raised cultivars are listed in categories for growing as climbers, bushes, hedges, standards and pot plants and are also grouped under bract colour  (Nagpal 1990, Singh 1990, Singh et al. 2015, Sharma et al. 2015, Kumar et al. 2007, Mathur 2000, 2001, 2007, 2015, Richard and Erin 2002, Simon 2005). It is tolerant to a number of adverse conditions like dry soil, saline soil, pollution etc. Bougainvilleas are sprawling climbers and shrubs. They naturally bloom in the spring and seem to bloom harder in drier years. It is very good plant for desert gardens. It can be used as vines, shaped into bushes, into ground cover. Most suitable for landscaping.  Bougainvillea plants can grow easily on walls. Internode length has a strong influence on bougainvillea growth habit and characteristics in the landscape. They are pollution and drought tolerant and very ideal for landscaping of industrial region as well as for road dividers. They are very hardy plants and specially suitable for growing in rocky and arid areas where other ornamental floweing plants do not  easily thrive well (Fig. 10).

While much has been written about the taxonomy of wild plants, the cultivated plants have always been looked at with suspicion by taxonomists. There might have feeling that cultivated plants are not natural and therefore fall outside the orbit of a taxonomist. It may be that taxonomy of cultivated plants is more difficult due to their extensive distribution needing wide sampling, rampant hybridization and high mutation rate, leading to diversity in their variation patterns. One of the principal advantages of the study of cultivated plants is that more often we know their genetic-evolutionary race history, together with its reasons and diversity. There is, therefore, a need to take up, what may be called as Hortorium Taxonomy, i.e. taxonomy of the cultivated plants so as to put the subject on a proper footing as a prelude to writing a ‘Flora of the Cultivated Plants of India’. The related wild species together with the elemental, basal or parental species of a cultivated species should be classified according to the rule of the International Code of Nomenclature for Cultivated plants based on the cultivar concept. A cultivar is not to be confused with a botanical variety.

Early reports are always path finders for future research. Earlier studies at CSIR-NBRI on characterization of bougainvillea is so important that it should be highlighted for researchers. Horto-taxonomical description of the leading Bougainvillea species/cultivars have been prepared according to their affinities to the species and hybrid seedlings (Sharma 1986a,b, 1996, Srinivas 1995, Khoshoo 1971a,b, Zadoo et al., 1975a, Jayanthi 1999). 
Abraham Kavoor : Bougainvillea x buttiana, tall, vigorous growth, young branches greenish-coppery, leaf blade ovate, green; thorn long, straight; bracts ovate, yellow-orange.
Abhimanyu : B. peruviana, bud sport of ‘Arjuna’, medium, drooping; branch greenish-coppery; leaves variegated, leaf elliptic, green; thorn long, straight, bracts elliptic, red-purple.
Aida : B. spectabilis, hybrid seedling of B. spectabilis (Lancaster 1940, Calcutta), tall, growth vigorous, young stem greenish coppery, tomentose, leaf blade ovate, base acute, apex acute to acuminate, coppery, old dark green, puberulent, thorn straight, bract young carmine changing to rose madder, elliptic, apex obtuse, profuse blooming, ideal as shrub, and pot culture.

The bougainvillea varieties reported from India have been mentioned above. The exact origin of all the varieties are not available. Breeders, sometimes, do not disclose the origin of varieties. An attempt has been made to trace out the mode of origin of different varieties as per available information (Anonymous 1981, Sindhu 2015, Sindhu and Swaroop 2015, Singh 1999, Singh et al., 1999, Nirody 1932, Sharma 1961, 1962, 1963, 1964, 1968, Sharma 1969, Pancho 1963, 1967, Marigowda 1957, Pancho and Elisco 1959, Pancho and Capinpin 1961, Pancho et al., 1961). Information available is not complete in most cases. Following abbreviations have been used – Hybrid Seedling (HS), Bud Sport (BS), Induced Mutant (IM) :

Characterization of Germplasm / Hybrids, Varietal identification, mutants etc.

Accurate identification of plants is desired for patent protection of plant varieties. Accurate characterization is also necessary to trace out the parents of new varieties. Use of present day molecular markers in addition to the classical methods provides more positive identification of new cultivars. RAPD and other molecular techniques have been used in a variety of plant materials for such studies (Sneath and Sokal 1973, Saitou and Nei 1987, Demeke et al., 1992, Selvam and Rajasekaran  1993, 1994, Dubouzet, et al., 1997, 1998, Hallden, et al., 1994, Hu and Quiros 1991, Jain et al., 1994, Matsumoto and Fukui 1996, Williams et al., 1990, Wolff et al., 1995). RAPD technique has been used in the genus Bougainvillea. It is often difficult to distinguish both mutants and hybrids and sports having a common progenitor, or progenitors themselves. Therefore, the industry needs a DNA-based fingerprinting technique to distinguish mutants or cultivars reliably. Reports are available on investigation about the molecular systematics and genetic differences for better understanding of varietal relationships in bougainvillea (Chatterjee et al., 2007, Kumar et al., 2006, Kumar et al., 2014, Hammad 2009, Pavan Kumar et al., 2015). 

Cytogenetics helps in solving intricate problems of evolution of economic plants and their relationship with relevant wild ancestors. Ornamental plants provide very interesting material for evolutionary studies. Such a study would reveal the nature of the evolutionary steps and clarify the changes that the breeding system and chromosomes underwent. The genetic and cytogenetic reasons for the diversity in ornamentals would also be unraveled. Such a study also helps to chalk out a meaningful breeding methodology for genetic improvement. A systematic programme of genetics and plant breeding of ornamental plants was started at CSIR-NBRI. The objectives of the programme were both basic or creative (experimental analysis of the causes of variation and evolution) and applied or productive (experimental synthesis of new and novel variation with better putative parents). Evaluation of colchiploids of ornamentals with different genetic systems was being carried out at CSIR-NBRI, with a view to explore the possibility of their introduction in floriculture trade. Superiority of polyploid cultivars, in general, has been the main factor, which has induced gardeners to raise artificial tetraploids. Most of the garden forms are of hybrid origin, raised over a number of years and named differently by different workers and nurserymen. More often than not, there is no authentic record of their ancestory and they show a great deal of morphological and cytological polymorphism (Khoshoo 1968, 1990, Datta and Banerji (1995). 

For crop improvement and more specifically to develop new varieties a number of plant breeding methods are available. CSIR-NBRI from very beginning selected all available techniques and standardized their practical application for all ornamental crops. All crop specific basic information was collected/generated for successful application of techniques for development of new varieties by creating genetic variability. Ornamental plant species fall into two main categories. In the first group the plants that are capable of sexual reproduction, but are commercially propagated vegetatively. The second group of plant species are the apomicts. In obligate apomicts hybridization fails to generate any variability. For development of new variety creation of genetic variability is pre-requisite. Breeder should have all up-to-date knowledge about all the available techniques and their merits and demerits for improvement and development of new varieties.

Considering the economic importance of chlorophyll variegation in floriculture trade attempt was made for cytological, anatomical and biochemical analysis of chlorophyll variegated mutants for better and clear understanding of origin of chlorophyll variegation (Kirk and Tilney-Bassett 1967, Datta et al. 1995). Following chlorophyll variegated mutants and their respective original varieties were analysed –

‘Los Banos Beauty’ (LBB) : Original double bracted Bougainvillea with green leaf.