eChapters

3.1 Chemistry of greenhouse gases (ghgs)

Greenhouse gases (GHGs) are atmospheric-gases that have capabilities to absorb and radiate-back the infrared (IR) radiation in the earth-atmosphere system (Figure 3.1). In this process the atmospheric-gases absorb and radiate- back IR radiation in lower atmosphere effectively emitting and absorbing heat energy heat energy. They maintain the heat budget of earth-atmosphere and keep our plant warm. If we typically see the chemistry of those gases, the key point is that they should have dipole moments. This is the property which makes them capable to absorb and radiate-back the range of IR radiation. In a molecule when valence-electrons are not equally shared in a bond between the two atoms, a slight positive charge is developed above one atom and a negative charge on the other atom. That charge difference of the different atoms in a molecule generates the dipole moment. For instance, in water vapour (H₂O- vapour), an unequal sharing of electrons and or separation of charge causes dipole moment. In H₂O, the centre has a positive charge at the hydrogen atoms and negative charges are located on the oxygen atom. The magnitude of dipole- charges, vibration and stretching of O-H bond generates certain frequency of the oscillating dipole moment that actually regulates the absorption capacity of IR radiation by H₂O vapour.

Climate change is caused by both natural as well as anthropogenic causes and it has been changing since the inception of earth-atmosphere (Figure 2.1). In a broader sense, anthropogenic activities (human activities) also must be considered as natural one in longer time scale as human and their activities are also a part of natural-ecosystem-functions. Among the natural phenomena, volcanic eruptions and continental drifts significantly affect the earth’s precipitation and temperature. A huge volume of CO₂ is released due to volcanic eruption at a little span of time-period which heated up the earth-atmosphere. Climate variability is primarily governed by rise in sea temperature, movement of warm water from the Western Pacific towards Peru, and El Nino which occurs at an intervals of 3-7 years. Climate variability also influenced the alteration in temperature and precipitation world wide. And persistent climate variability cause long term climate change. Therefore, basically three drivers that causes climate change are, the alteration in the energy of sun received by earth-atmosphere (natural causes), variations of ref lectivity of earth-surface- atmosphere system (natural as well as anthropogenic causes) and fluctuations in the greenhouse effect (natural as well as anthropogenic causes).

1.1 Weather

Firstly, what is weather? Simply, the conditions in the atmosphere above the earth is called weather. It refers to the conditions such as wind, rain and temperature, prevailing at a particular location during periods of hours or days. We often ask “what’s the weather like today”? Any individual can answer to this question as it requires only a short term experience or say exposure to the atmosphere. The TV news forecasters predict weather each day and inform about the temperature, cloudiness, humidity, or possibility of storm in the next few days. Weather is localised, say, it’s a hot and cloudy weather in one part of the country and dry and windy on the other part.

1.1.1 What are the factors that influence weather?

Before we try to understand the factors that influence weather, we must understand what the components that describe a weather conditions are? Is it the rains, or the air temperature or both? The answer to this question is not so easy, and it’s a bit complicated. There are many components that constitute weather. Weather components include rain, cloud cover, sunshine, winds, hail, snow, sleet, storms, thunderstorms, heat waves and many more. These components are sometimes referred as weather parameters or climate elements. Each of these components define weather patterns of a particular area. These components determine the status of local atmospheric conditions. Again, as a basic definition, weather is the state of the atmosphere and majority of weather phenomena occur in the lowest layer of the atmosphere, called as the troposphere. Does it mean that ground conditions such as the topography, water bodies and vegetation of a particular area has nothing to do with it? No, it is not so. The state of the atmosphere is subjected to various processes taking place not only in the atmosphere but also in the ocean, the sea-ice, the vegetation, etc. Weather parameters or the components of weather form a sequence of events, and the influences are far reaching and they do not remain solely in the atmosphere. For example, terrestrial radiation impacts the air temperature, air pressure and humidity. The terrestrial location also influences the cloud formation. The clouds may or may not turn into precipitation depending on the outcome (cloud or rain), which is by and large governed by troposphere. Likewise, a lack of precipitation affects not only weather conditions, but also soil moisture conditions that may result in lowering of water levels (ground water table) in soil. Wind speed and direction are governed by the atmospheric pressure and air temperature. So, all these parameters or components are interrelated and the weather conditions are the outcome of their interactions. Therefore, we can say that, the three main components of weather are temperature, precipitation and solar radiation. These components are influenced by different factors.

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.

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.

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.

The Indian Society for Protected Cultivation (ISPC) has organized a National Seminar on ‘Advances in Protected Cultivation’ at the NASC Complex, DPS Marg, Pusa, New Delhi, on 21 March 2013, with an objective of collection and collation of scientific advances made in protected cultivation in India and dissemination of these among policy-planners, farmers, students, scientists, industry and other stakeholders. In spite of the fact that protected cultivation is in its state of infancy in the country in terms of scientific engagements, more than 120 delegates from distant parts of the country registered for the seminar besides good number of policy-planners, recognized names in agriculture and higher officials from industry particularly corporate associate life members of the society.

In the inaugural session, Dr Brahma Singh, President, ISPC and Chairman, Organizing Committee welcomed the Chief Guest Padama Bhushan, Dr R S Paroda, formerly Secretary and Director-General, Indian Council of Agricultural Research (ICAR), New Delhi and Chairman Haryana Kisan Ayog, Chaudhary Charan Singh Haryana Agricultural University , Hisar ; Guests of Honour Dr M M Pandey, Deputy Director-General (Agricultural Engineering), ICAR and Dr H S Gupta, Director, Indian Agricultural Research Institute, New Delhi, other dignitaries on and off the dais, delegates, press and media. He also highlighted that this seminar intended to review the advances made in protected cultivation in India with a purpose to accelerate the same. He emphasized that protected cultivation offers opportunities to earn more from the limited land, water and other resources. It also enables production of quality products which fetch more prices and pride, besides being a potential practice for provisioning disease-free quality planting material for horticultural crops.

Global demand for cut flowers is increasing steadily at around 10 per cent per annum. The share of India in this flourishing trade estimate at over US$ 40 billion per annum is negligible at 0.4 per cent. Floriculture include cut flowers, pot plants, cut foliage, seeds, bulbs, tubers, rooted cuttings and dried flowers or leaves. At international cut flower trade, flowers such as rose, carnation, Chrysanthemum, gerberas, gladiolus, gypsophilla, liatris, nerine, orchids, anthurium, tulips and lilies are preferred. Roses, gerberas and carnation are grown in greenhouses. The open field crops are Chrysanthemum, roses, gaillardia, lily, marigold, aster, tuberose etc. In India, floriculture is emerging as an important economic activity, earning foreign exchange. It has become a potential farm income enterprise. The domestic markets for high-quality flowers have been growing at 10- 20 per cent per year for the last few years. India’s flower business is estimated to be worth $ 400 million at retail, and about $ 100 million in international trade. Flower exports are about $ 30 million, constituting mainly of roses and dried flowers. Both Central and State Governments have been more than proactive and have made large investments in this industry in assisting production and marketing.

A large variety of floricultural crops can be produced in protected environment as economic cash crops for the benefit of farmers. Problems associated with floriculture in hills are small, scattered land holdings and sparsely located population. There is a lack of irrigation facilities due to scarce availability of water resources; widespread natural vagaries like drought, hail storms, frost etc. There is a serious gaps in application of advanced floricultural technologies for improving quality and productivity; high pressure on land use for different purposes like cereal crop production, fodder production, etc. due to low per capita land availability; difficulty in technology dissemination due to difficult terrain, hostile climate, poor communication facilities and sparsely located population. Consuming markets within the state are very less which result in dependence upon distant markets of the county. There is a high post-harvest losses due to lack of modern post-harvest management system; very high temperature differentials in production areas and consumer markets; perishable nature of flowers, resulting in high post-harvest losses during transportation; and distant location of production areas from main roads. High cost of marketing, lack of organised system of marketing, lack of bargaining power with individual growers due to small production levels; inadequate availability of market intelligence to farmers resulting in imbalances in distribution of produce in different markets.

Fusarium wilt of carnation caused by Fusarium oxysporum f.spp dianthi causes severe yield losses under protected cultivation. For the management of Fusarium wilt, 27 isolates of Bacillus strains were isolated from the rhizosphere of different crops including carnation. Among various species of Bacillus, Bacillus amyloliquefaciens (BSC7) was identified as a most virulent antagonistic bacterial isolate. Studies on antagonism under Environmentally Controlled Scanning Electron Microscopy (ESEM), depicted the presence of rod shaped bacterial cells with biofilm formation at 44847x. Detection for the presence of antibiotic biosynthetic genes reflected the presence of surfactin, iturin, bacillomycin and fengycin genes. The 24 isolates of Bacillus spp. showed positive reaction for surfactin gene. Nineteen isolates were amplified for Iturin A gene except BS5, BS9, BSC1, BSC2, BSC11, BSD1 and BSD2. Strains of B. subtilis BS1, BS2, BS5, BS6 and BS8 expressed Bacillomycin D gene. The genomic DNA of strains BS1, BS2, BS4, BS6, BS7 BS8, BS11 and BS14 showed positive for Fengycin D gene. The isolate of B. subtilis BS2 showed positive reaction for four genes namely surfactin, iturin, bacillomycin and fengycin.

In vitro screening of Bacillus, B. amyloliquefaciens (BSC7), P. aeruginosa (P1) and T. viride (TV1) showed highest inhibition against F.oxysporum f.sp.dianthi to an extent of 55.95, 55.29 and 81.61 per cent over the control respectively. The antifungal activity of antagonistic B. amyloliquefaciens BSC7 and T. viride TV1 against F.oxysporum f.sp. dianthi was confirmed under ESEM by observing disintegration, lysis and structural abnormalities of the hyphae of the pathogen at the zone of interaction.

H orticultural crops are most important ones incurring huge amount of pesticides in our country. The intensity of esticides on them is highest per unit area. However research on integrated pest management has not matched the progress and problems of plant protection at large and protected cultivation in particular. The USA, UK, Israel and Russia, pioneers in protected cultivation, are able to harvest productivity of up to 500 tonnes/ha of tomato and 200 tonnes/ha each of cucumber and capsicum, while in India up to 300 tonnes/ha of tomato and 100 tonnes/ha each of cucumber and capsicum are obtained, has compared to normal open field where their yield ranges from 40 to 60 and 10 to 20 tonnes/ha in India, respectively.

The sustainability of an agro-ecosystem is represented by its ability to maintain a given level of productivity over time and a given quantitative-qualitative level of environmental resources (Loucks, 1977). The greenhouse is also a form of agro-ecosystem, where unlike other agro-ecosystems, environment has been adapted to crop in order to maximize its productivity. The greenhouse system has to take maximum advantage of natural benefits offered by location in certain latitudes while minimizing the disadvantages (Castilla, 2002). Higher productivity under such protected cultivation is attainable mainly on account of reduced competition, healthy environment, better nutrient management, increased surface area and longer crop duration. However, ideal and stable environment with warm, humid and abundant food under protected conditions provides an excellent platform for pest development often more than open field crops, leading to severe pest situations in greenhouses, as revealed by extensive surveys.

The beginning of protected cultivation in the country has paved the way for export of horticultural produce, especially of flowers to earn valuable foreign exchange. The technology also became handy for quality production of flowers and F₁ hybrid seeds for domestic and export markets. In view of the globalization of international market and tremendous boost that is being given for export of flowers, there has been a spurt in the demand for protected cultivation technology. Low-cost polyhouses are quite popular in the North-East and in the northern plains, flowers are being raised in polyhouses either for capturing the early markets or to improve the quality of seedlings. Several commercial floriculture ventures are coming up in Uttrakhand, Maharashtra, Karnataka and Tamil Nadu to meet the demands of both domestic and export markets. There has been a substantial increase in area under protected cultivation of different flower crops. Though there were initial hitches owing to the cost sharing, farmers of some states have taken maximum benefits of the existing schemes and adopted the technology. Protected cultivation technology is one of the most useful technology inputs which hold promise to transform Indian floriculture and bring in the “Colour Revolution”.

Nearly, 40 countries are involved in protected cultivation of flower and vegetable crops. New production centers are being added constantly, mostly from developing nations. Today, majority of production is from developing countries like Zimbabwe, Morocco, Kenya, Ecuador, Costa Rica, Mexico, Singapore, Malaysia and India. In developed world, USA has an area of about 6,000 ha under greenhouses which are mostly used for floriculture. The Netherland is traditional exporter of greenhouse grown flowers all over the world. Israel, the largest exporter of cut flowers, has wide range of crops under greenhouses. About 1,000 ha area is under protected cultivation. Approximately, 98% of flowers are grown under open field cultivation and hardly 2% under the greenhouse cultivation.

Orchids are known for their exquisite beauty and trade in global floriculture business. The Netherlands is pioneer in roduction and ex ort of tem erate orchid while Thailand and Hawaii are the world leader in tropical orchids, respectively. Recently, Malaysia, Singapore, Thailand and Sri Lanka are catching the international market. The orchid industry is expanding in terms of magnitude in some of the major orchid-producing nations. The global orchid market has passed $ 1 Billion mark in 2010. The leading orchid producing countries in 2010 are:

Country Production ($ million) Japan 280 USA 170 Taiwan 130 China 70 Brazil 60 UK 45 Thailand 35 Italy 30 New Zealand 20 Source: Orchid News The world consumption of orchids (potted plants) is valued more than $ 500 million (2000). The Dominican Republic, Costa Rica and India have recently begun to produce orchids for export. Commercial production of orchids has increased dramatically through the world in the past quarter century. The most common genera sold in Japan from 1993 to 2002 were Phalaenopsis (30%), Nobile type Dendrobium (20%), Oncidium (20%), Cymbidium (15%) and Cattleya (10%). The potted orchids sold through Dutch flower auctions increased from 50, 0000 to 18 million pots.

India is the second largest producer of vegetable crops with a total production of 146.5 million tonnes (2010-11). More than 60 vegetable crops belonging to, Solanacious, Cucurbitaceous, Leguminous, Cruciferous (cole crops), root crops and leafy vegetables are grown in tropical, subtropical and temperate regions. The demand of vegetables will be 225 million tonnes by 2020 and 350 million tonnes by 2030. A larger quantity of quality seed of vegetable crops will be required in order to achieve the demands of vegetables. The limiting factors which reduce seed yield under open field condition are biotic and abiotic stresses, requirement of isolation distance and generation system of seed multiplication etc. These problems can be effectively managed when we go for seed production under protected structures.

Protected cultivation was introduced in India during 1985 but its progress is slow during the last 25 years due to lack of suitable varieties and hybrids for protected cultivation. Presently, area under polyhouse in India is 2000 ha, therefore, knowledge of polyhouse vegetable production technology of tomato and cucumber with intervention of drip irrigation and fertigation along with suitable varieties will be quite effective for enhancing their productivity. Therefore, it is imperative to develop hybrid seed and production of suitable varieties/hybrids at affordable prices to small and marginal farmers to achieve the targeted production potential of vegetable crops. Keeping in view some genotypes were isolated and pure line and hybrid breeding programme were adopted for improvement of these genotypes. After three years of multilocational testing at tarai, midhills and higher hills under polyhouse condition, four genotypes were identified and released. They are: Pant Parthenocarpic Cucumber 2 (1,755 q/ha) and Pant Parthenocarpic Cucumber 3 (1,605 q/ha) of cucumber and Pant Polyhouse Hybrid Tomato 1 (1,616 q/ha) with average fruit weight of 130-140 g and Pant Polyhouse Tomato 2 (1,291 q/ha) of tomato with single fruit weight 100-105 g. These genotypes were released by Uttarakhand State Variety Release Committee during May 2011 for commercial cultivation.

Kerala has a tropical humid weather characterised by high rainfall and humidity. The intense rainfall during June-September is a limiting factor for vegetable cultivation. High cost of labour, rapid urbanisation, small size of holdings and quality conscious consumers are some of the factors favouring protected cultivation in Kerala. Rain shelters and modified naturally-ventilated polyhouses are recommended structures for protected cultivation of vegetables. The important vegetables grown are cucumber, yard long bean, Capsicum, okra, tomato, cabbage, cauliflower and leafy vegetables. The conventional saw-toothed structure has been modified to suit Kerala weather by making variation in height and improving the roof and side ventilation so that temperature variation inside the structure is only 1°C compared to the ambient. The Kerala Agricultural University has also developed an ad-hoc package for protected cultivation of vegetables, considering the soil and weather parameters and is providing necessary technical support to growers and extension officers. The technology for large-scale production of virus-free vegetable transplants in pro-trays has also been standardized. There is a growing demand for quality, disease-free seedlings and technology can be scaled up into a profitable agri-entreprenurial model. Open field precision farming through fertigation and mulching is profitable compared to conventional system of cultivation. Besides maximising water-and nutrient-use efficiency of the crop, this technology offers scope for mechanisation in vegetable cultivation saving human labour requirement by almost 50%. Rain shelters are useful for year-round production of vegetables in homestead for small growers.

Floriculture industry comprises of cultivation and trade of cut and loose flowers, potted plants, foliage and bedding plants, and dried flowers under open field as well as protected conditions. Globally, more than 145 countries are involved in cultivation of floricultural crops. Though the art of growing flowers is not new to India, protected cultivation is relatively new in India. Enormous genetic diversity, varied agroclimatic conditions, versatile human resources offer India a unique scope for diversification into new avenues which have not been explored to a greater extent. India also has a strong dry flower industry, which contributes a major share to the overall trade. Other segments like fillers, potted plants, seeds and planting material, turf grass industry and value-added products also contribute a share in overall growth of floriculture industry.

Cut flower production is a growing business in most of the Asian countries. Technology for production is well-known and it has been utilized to the maximum in many countries. As a consequence, cut flowers are commercially produced in larger quantities in these countries, resulting in surplus quantity during normal periods of blooming. On the other hand, such prices are much higher during the periods of needs such as certain special occasions, or off-season.

In spite of considerable progress achieved during the last four decades in vegetable production in India, average productivity of vegetable crops is still low as compared to national and world level, indicating the scope to enhance their yield potential of quality produce. This is because of an appealing gap between potential yield and actual yield. In many vegetables, yield realized is even lesser than 50 % of potential yield. Sometime, farmers growing vegetable crops during main season do not get back their cost of cultivation. The prices of the same vegetable produce is very high during off-season. Several biotic and abiotic stresses are major factors responsible for low productivity and poor quality in different vegetable crops under open field cultivation, especifically in rainy and post-rainy seasons. The increasing demand of off-season high quality vegetables in various markets of big cities has called the attention of vegetable growers for diversification from traditional techniques of vegetable cultivation to modern systems of cultivation.

Protected cultivation of vegetable crops offers best choice for diversification. Production of crops under protected conditions has great potential in augmenting production and quality of vegetables, in main and off-season, maximizing water and nutrient-use efficiency under varied agroclimatic conditions. This technology has great potential especially in peri-urban areas, since it can be profitably used for growing high- value vegetables like tomato, cheery tomato, coloured Capsicum and parthenocarpic cucumbers, and healthy and virus-free seedlings in agri-entrepreneurial models.

Tomato varieties produced 50% in plastic house cover more than what they produce in open air (Diez et al., 1985). Nevertheless this production increase is not, by itself the reason for the use of protected cultivation which requires higher expenses. The key factor is the cost increase of final product obtained during off-season, which created an interesting margin in spite of high production costs. The effect of cost of seed in total cost is negligible, which permitted the use of hybrid seed. The new hybrids have brought about production increases which can be calculated to be over 50% more than what the greenhouse varieties produced with the cost of hybrid seed giving an effect on total production costs of only 6-7%. So that under these circumstances, production increase associated with hybrids is certainly very advantageous, apart form other benefits to be derived from hybrids.

R aising of healthy vegetable seedlings is most important aspect in vegetable production, because, up to a large extent it determines the productivity and profitability. Nursery raising under open field conditions suffers by a number of biotic and abiotic factors like, continuous rains, too low and too high temperatures, disease and insect-pest etc. For the early establishment in the field and to reduce the cost of production, vegetable seedlings are being raised in plug trays under controlled conditions round the year. Under this system, each transplant grows in an individual cell to reduce the competition among transplants and maintain the uniformity. Plug transplants establish better in field because roots are not damaged in pulling, transplants often result in better stands, and their growth can be controlled more easily through fertility and water management. With the passage of time, a lot of advances have been made in this direction and a number machines have been developed like media sterilizer, media mixer, plug trays filling, seed sowing machine, growth chamber etc. by which the raising of seedlings under controlled environment becomes easier and labour intensive.

The growth is insulated to allow for heating or cooling according to specific germination needs of the seed. This technique reduces fluctuations in temperature and moisture that can occur in an open house. The growth chambers are usually an insulated room in which temperature and relative humidity can be maintained at a precise level. Air circulation is important to ensure uniform temperature and humidity throughout the chamber. Grafting in vegetables is a recent practice to control soil-borne diseases and nematodes, for both field and greenhouse grown crops. In addition, grafted vegetables can produce higher yields and have improved tolerance to environmental stresses, soil salinity and low soil temperatures which is only possible under protected conditions. Thus under present scenario, raising of seedlings under controlled environment offers opportunity to go for commercial nursery with different machines.

In India, risk-prone, high altitude area constitutes the easternmost trans-Himalayan part of Ladakh and Zanskar range (Jammu and Kashmir) and some parts of Lahoul Spiti (Himachal Pradesh). Truly described as cold desert with low population density, Ladakh constitutes the easternmost trans-Himalayan part of Jammu and Kashmir in India, comprising two districts, Leh and Kargil, bordering Pakistan and China (Fig. 1).

Greenhouse essentially functions based on solar energy to control environment for protecting cultivation from adverse condition. Computer simulation and mathematical modeling are important tools for determining the energy efficient design as well as predicting the overall system performance. The greenhouse climate may be used for crop drying, distillation, biogas plant heating, space conditioning, and aquaculture. Thus, any required configuration of greenhouse can be thermally modeled for predicting and optimizing the performance. The solar energy based greenhouse modeling are useful in evaluation of various applications like greenhouse heating, greenhouse cooling, greenhouse drying and aquaculture greenhouse. Greenhouse clubbed with ground air collector increase in plant and ambient temperature of 5–7°C during night in winter. Whereas, using evaporative cooling pad with greenhouse reduces the ambient temperature of 4–5°C during midday summer. A greenhouse can be very well used for large-scale crop drying, while not in use for cultivation. Some other applications such as covered crop drying and aquaculture are also discussed.

P rotected cultivation technology envisages immense promise, especially for high-value crops against various biotic and abiotic stresses. The climatic parameters stress conditions like unusually low and high temperature, humidity, solar radiation, wind velocity comes under abiotic stresses. The present climate change scenario dealing with various biotic and abiotic stress conditions poses serious threat to agricultural production throughout the world. It is estimated that due to one-degree rise in temperature during rabi season, wheat production declines by 4-5 million tonnes in India. Similarly due to prevailing low temperature and frost like conditions, especially in Northern India, several million tonnes of horticultural crops like tomato, brinjal etc. got wasted every year. Protected cultivation technology deals with following types of protected structures :

Growing population, rapid urbanization and changing climate have created a global challenge to meet the food and nutritional needs. In India, rapid urbanization is not only taking place in larger cities, but satellite towns are competing for food, water, transportation and above all adding to pollution of the environment. As warming of the climate gathers alarming pace, posing a danger to agriculture, greenhouse cultivation is the only answer to save crops of flowers and vegetables. The yield under polyhouse cultivation can be achieved to the level of 5-8 times as compared to open field cultivation.

PROTECTED STRUCTURES

Protected cultivation is unique and specialized form of agriculture. Protected or greenhouse cultivation of vegetables is one of the means for clean vegetable production in peri-urban areas. The protected cultivation facilitates year-round production of high- quality produce with minimum labour and irrigation water, and almost wards off pest problem. In peri-urban regions, where climate prevents or does not favour year-round production of crops in open field, vegetable production can be taken up in protected environment. Use of protected structure for cultivation of crops as a commercial venture is a recent phenomenon, especially in the tropical areas.

Greenhouse refers to a structure which provide relatively better environment for plant growth. The goal is to create congenial temperature and relative humidity in desired range. The greenhouse covered with polythene sheet, also called as polyhouse, has polythene sheet (UV stabilized 200 micron LDPE sheet) as covering over a relatively rigid frame (made of GI pipes, angle iron, boomboo or wooden) which entraps the solar energy to increase the temperature and provide light for plant propagation. A normal greenhouse has four basic components: 1) frame made from rigid material like GI pipes, wood or bamboo; 2) glazing material, which is transparent to provide enough light for plant propagation; 3) climate control system, which may be natural ventilation or forced ventilation using fans with or without cooling pads, shading nets, pigment painting, etc. and 4) plant growing medium (soil or artificial media like cocopeats) with needful arrangement for supplying inputs (water, fertilizers, pesticides, etc.). The design of greenhouse involves structural design of frame with enough climate control mechanism. It mainly depends on shape, size, material of frame, local climatic conditions, wind pressure, and desired height from crop production point of view. Fabrication of greenhouse should be such that it provides enough structural stability with wind pressure and other factors, perfect joints, anchoring of polythene, and minimum hindrances in crop production practices.

Protected structures such as cloches, low tunnels, greenhouses, livestock housing, aquaculture facilities and phytotrones provide varying degrees of climate control for agricultural production. While cloches and low tunnels provide only passive modification of the growing environment, all other protected structures have the possibility of active and precise growing environment control.

GREENHOUSE TECHNOLOGY

Greenhouse technology permits the management of both biotic and abiotic stresses related to plant growth to maximize the productivity and quality. Resultantly, profitability per unit area per unit time increases by two to three orders of magnitude as compared to open field cultivation. Introduction of greenhouse technology in India for commercial production is only about three decades old, whereas it is more than two centuries old in USA, UK, Holland, France, Italy, etc.

A greenhouse is a framed or inflated structure covered with a transparent or translucent material where plant environment could be, at least partially controlled and which is large enough to permit a person to enter and carry out cultural operations. A greenhouse is called a glasshouse, when covered with glass, and plastic house when plastic is the glazing material. Materials of construction and cropping activities are also used to identify greenhouses. In addition to the growing facility, a commercial greenhouse complex has a head house, an input storage and a sales area. All these components are so arranged that unwanted movements of man and material are obviated.The greenhouse complex should have adequate wind breaks on the upstream side of the wind direction to provide protection against heavy winds.

Protected cultivation of vegetable crops refers to creation of favourable environmental conditions around vegetable plants, offsetting or minimizing the detrimental effects of prevailing or expected to prevail abiotic and biotic factors. In open fields, vegetables face several abiotic and biotic stresses, resulting in lower or poor or no yield. This condition is altered by using different protected structures for cultivation and/or nursery production. Vegetables which are transplanted using seedlings should be produced by raising seedlings under protected conditions. Protected conditions ensure production of healthy seedlings. The use of healthy seedlings ensures better and higher production of vegetables both under protected conditions and open field conditions. Nursery grown in nursery trays can be transported long distances and can wait till field is ready or human resources is available for transplanting. Structures are ideal for production of plug plants/transplants in different sizes of portable trays.

Since ancient times, agriculture is an outdoor or open field production of crops. Open field production is climate and weather dependent. In fact, growth and development of crops under a particular set of climate parameters defines geographical location, productivity and production period of different crops. The magnitude of impact of climate and weather on agricultural productivity and quality of produce is appreciated by farmers and the scientific community, including horticulturists. Abiotic and biotic factors govern crop production potential and quality of products. Among the major constraints in production of horticultural crops are temperature (hot or cold), sunlight duration and quality, water deficiencies or excesses, atmospheric moisture (relative humidity), weeds, deficiency of nutrients, heavy winds, carbon dioxide and host of diseases and insect pests. There are ecological optima for obtaining production potential of each of the crops. Deviation from these conditions results in yield losses partially and sometimes totally. However, near optimal climatic conditions could be created by controlling the climate with the help of greenhouse using

The article is the Inaugural address delivered by Dr. R.S. Paroda at Indian Society for Protected Cultivation (ISPC-registered in March 2012), New Delhi on 21 March 2013 in a seminar ‘‘Advances on Protected Cultivation’’ at NASC, Complex, Pusa, New Delhi different protected structures/methods/devices and such cultivation under controlled environmental conditions is termed as as protected cultivation.

Introduction

Rose, acclaimed as the “Queen of Flowers”, is one of the most popular cut flowers in the global floriculture trade. Popularly referred to as ‘Dutch rose’ in the international market, cut rose occupies a prominent place among the cut flowers owing to its exquisite form, size and attractive colours. Apart from cut flower it is used for making various value added products such as rose oil, rose water, garland, gulkhand, rose attar etc and also in landscaping as pot plant and garden plant. The present day rose (Rosa hybrida) combines all desirable qualities such as, productivity, attractiveness of buds, a variety of colours and forms of the typical species of Rosa.

The major cut rose producing countries of the world are the Netherlands, Colombia, Kenya, Israel, Italy, United States, and Japan. In India, roses are mostly grown under cover (poly house) in Nasik, Pune, Hosur, Kalimpong, Darjeeling, Bangalore, Solan, Palampur, Shimla, Srinagar, Delhi, Ludhiana and Calcutta. The roses grown for export should be popular varieties of that region and maintain high quality standards with respect to bud size and stem length and should have lush green leaves and be free of pests and diseases. These high quality standards can be achieved and maintained only when grown inside poly house or greenhouse, which gives protection against inclement weather conditions and pests and diseases.

Introduction

Flowers speak millions of unspoken words. Presenting a bouquet and making arrangements with flowers in most of the drawing rooms, offices, hotels and hospitals have become the style of the day in the fast – moving modern world where there is hardly any time for exchange of sweet memories. Since time immemorial, the importance of such a delicate creation of nature has always been appreciated. Tamil Nadu ranks first among the flower producing states of India, contributing 25% of the country’s flower production with an area of 31, 970 ha under flowers. Of this, around 700 ha are under protected cut flower cultivation. In Nilgiri district alone, it has an area of around 70 ha under protected cut flower production which is inclusive of around 11.2 ha of lilium.

The genus Lilium (Lilium spp.) is a herbaceous flowering plant normally grown from bulbs, about 110 species world over belongs to lily family Liliaceae. It is native of the northern temperate regions. The species in this genus are the true lilies while the other plants with lily in the common name are related to the other groups of plants. Lilies are usually erect leafy stemmed herbs. The majority of species form tunicless scaly underground bulbs from which they produce flowers. The large flowers have three petals along with three sepals, look like petals.

Introduction

Alstroemeria also known as the lily of the Incas, Peruvian lily or Inca lily, has been grown mainly as a cut flower crop. Recently, it has become popular as a garden flower and also as a potted flowering plant. The plants produce beautiful large inflorescence in many different colours viz. lavender, orange, yellow to dark yellow, white, pink, red, purple and bi-colors. Flowers are characterized by black dots at the base of the petals and throats. The cut flowers have a long post harvest life, up-to two weeks. These valuable characteristics have made Alstroemeria one of the top cut flowers at the Dutch Flower Auction Centers. The plants produce high yield and possess an ever blooming habit after flower initiation has occurred but in general most cultivars flower best during spring and early summer. The straight, un-branched shoots emerge from underground rhizomes which also produce enlarged storage roots. It is gaining popularity in Indian flower market due to long stem flowers and prolonged vase life. Recently flower growers have shown great interest about its production as a cut flower crop.

Introduction

Gerbera is one of the most important commercial flowering crops growing in the world as a cut flower as well as garden decoration, which belongs to family compositae and native in South Africa and Asiatic region. Presently, its demand and utility are rising up continuously in India both in urban as well as rural areas throughout the year. Peoples prefer this flower, because of its unparallel diversity in colour and long vase life; whereas farmers took this crop in relation to high margin of profit and long post harvest life over some others flower. Now, people are showing their keen interest towards use of this flower in their daily life and for celebrating a colorful festival. As per report of NHB (2014), total crop area is 820 hactors, where flower marketed of 3.96 and 17.84 MT of loose and cut flowers respectively. The prime producing states in India for gerbera flower production are Karnataka, Maharastra, Assam, Uttrakhand, Telangana, Tamilnadu and West Bengal. There are some constrains identified in gerbera cultivation under protected situation, like initial investment is too much, protocol of the technology is very much restricted, regular supervision is an essential and all local festivals regulates quantity of consumption etc. However, before adopting this technology for implementation as taking part of business, users should upgrade their knowledge by seeing and believing at different production centers. Details about latest technology are summarized under mentioned, which may be helpful to the students and farmers to some extent for ready references.

Abstract

Natural sunlight is the cheapest source available, but for horticulture it is not always attainable in sufficient quantities. Therefore, the use of artificial light has become very common in order to increase production and quality. Under artificial lighting technologies, LED lighting is one of the technology that can help in producing crops and flowers in a more effective and sustainable way around the world. The benefits of LEDs are that the spectrum and intensity can be selected and adjusted, the energy efficiency is higher than most conventional light sources and their small size, durability, long lifetime, cool emitting temperature, and the option to select specific wavelengths for a targeted plant response make LEDs more suitable for plant-based uses than many other light sources. These advantages, coupled with new developments in wavelength availability, light output, and energy conversion efficiency, can bring about a revolution in horticultural lighting. Light quality plays a major role in the appearance and productivity of ornamental and food specialty crop species. Far-red light, for example, is important for stimulating flowering of long-day plants (Deitzer et al., 1979; Downs, 1956) as well as for promoting internode elongation (Morgan and Smith, 1979). Blue light is important for phototropism (Blaauw and Blaauw-Jansen, 1970), for stomatal opening (Schwartz and Zeiger, 1984), and for inhibiting seedling growth on emergence of seedlings from a growth medium (Downs, 1956). The interactions are complex and continue to be unraveled at the molecular level (Devlin et al., 2007), but much of our understanding of these responses comes from studies with narrow-waveband lighting sources, in which LEDs provide obvious advantages. Thus, one potential role of LEDs in horticulture could be to enhance desired characteristics for specific crops. The artificial LED lightings increase the possibility of year-round production of ornamental plants, which will subsequently increase the income of growers related to ornamental industry. Light-emitting diodes pave the way for a better understanding of the interaction between light and pests, diseases, natural enemies and plants, as they make possible the use of very narrow wavelengths. LEDs as an option for reducing the use of growth retardants and obtaining better product quality in ornamental pot plants. Production of secondary metabolites increase with higher blue light ratio. Secondary metabolites production are increased and act against Reactive Oxygen Species (ROS) and pathogens, precondition the plant for environmental changes so they can cope with stress more efficiently.

India is blessed with wide range of diverse agro climatic conditions, making it an appropriate place for vegetable cultivation, resulting in increasing vegetable production from has increased from 63.8 MT in 1993 to 168.5 million tonnes in 2015-16 and productivity from 12.6 MT/ha to 17.8 MT/ha (www.indiastat.com). Although the production has increased but still the technology used and practices followed is predominantly traditional resulting in low productivity and inconsistent quality and quantity of produce supplies to various markets in the country. The per capita consumption of vegetables in India is very low against WHO standards and FAO recommendation (135 g/day <180 g/day (WHO standards) < 300 g/ day capita (FAO recommendation).

Introduction

India is a land of diverse agro climatic zones and each of these zones offer a great potential for cultivation of wide range of crops across all seasons. Vegetables form major and important part of our dietary requirements, which are widely grown in the rural and peri-urban areas. Hi-tech horticulture including protected cultivation of high value and exotic vegetables has been on the increase, targeting high end domestic and export market. Of late, due to the population pressure, fragmentation of land holdings and urbanization has led to decline in cultivable area, more so in urban and peri-urban areas. Production of vegetables under protected cultivation system results in effective use of the land resources, besides being able to increase the production of quality vegetables both for the export and domestic markets by offsetting biotic and abiotic stresses to a great extent that otherwise is prevalent in open cultivation. Under protected cultivation, vegetables are widely grown due to higher productivity and economic feasibility.

Introduction

‘Protected cultivation’ is a method of cultivation of plants or crops in artificial environment (Polyhouse/ Greenhouse/Glasshouse) to protect the plants or crops from the natural calamities viz. wind, hailstorm, excessive radiation, temperature extremes, insect-pests and diseases. For matching ever growing needs of human population in the country, it has become imperative to provide the not just cereals but also fruits, vegetables, flowers and other horticultural products to fulfill their requirements. In the present scenario of perpetual demand of horticultural produce in order to increase their production round the year and shrinking landholdings drastically, protected cultivation is the best alternative and drugery- less approach for using land and other resources more effeciently.Protected cultivation comprised of selection of crop and media, climate control,marketing, post harvest technology, plant protection and irrigation/ fertigation.

In India, states like Karnataka, Andra Pradesh, Maharashtra and Tamil Nadu are the best suited for protected cultivation of horticultural crops due to their pleasent climatic conditions. Apart from these states, Himachal Pradesh, Uttar Pradesh, Jammu and Kashmir, West Bengal, Delhi and Jharkhand are also fore runners in adopting protected cultivation. Protected cultivation is a key for sustainable production in the country due to its various ecological regions viz., Western Himalayan region, North eastern Himalayas, Eastern Plateau hill regions, Central Plateau hill regions, Western Plateau hill regions, Southern Plateau hill zone, East coast hill zone, West coast hill regions and Gujarat hill regions (Gupta et al., 2003). Control of light through polycover has become a significant part of horticulture technology because quality, intensity and duration of light is involved in many physiological processes of the plants. A plastic film or fibre glass covering over a green house acts like selective radiation filter which allows solar radiation to pass through but traps radiation emitted by the plants inside the greenhouse which is known as ‘Greenhouse effect’. Carbon dioxide released by the plants at night also trapped, this raises the level of CO₂ there by enhances the photosynthetic activity (Ahmed, 1996).

Abstract: Zinnia, multipurpose ornamental annual is noted for its garden performance. The uses of zinnias range from dwarf cultivars used for containers, borders or edging, bedding to tall cultivars used for cut flowers. Breeders and seed companies successfully introduced hybrid cultivars in the mid 20^th century. Some modes of inheritance of floral doubleness, floral colour, male sterility, self incompatibility, leaf morphology, disease resistance have been discussed/ clarified; research succeed in interspecific hybridization, polyploidy, mutation breeding and seed production are presented. Somaclonal variation for generating mutants has created new horizons in zinnia breeding. Important traits for both production and landscape use include flower colour and bloom time, plant habit and form, seed germination, disease and virus susceptibility.

Keywords: Breeding, cytology, inheritance, polyploidy, F₁ hybrids, seed production.

Abstract: Water lily, bulbous ornamental, constitute element of aquatic gardens. A variety of flower colour, flower forms, modes of reproduction and leaf sizes exist in Nymphaea. This species is a complex hybrid group. A wide range of polyploidy (including aneuploidy, trisomy, polysomaty), polymorphism and heterozygosity exists within the cultivars of water lily. Genetic information and trait heritability is almost unknown for this crop. Breeders have created synthetic water lily hybrids. Low fecundity, limited fertility, reproductive barriers, low seed set, relatively low elemental (founding) species among elite germplasm often pose significant challenges to flower breeders. Breeding objectives with high priority include tolerance to drought, year round flowering and lower seed tannins. Future breeding and genetic studies are needed to further transform this crop.

Keywords: Nymphaea, correlation, sterility, interspecific hybridization polyploidy.

Abstract: Verbena, popular annual is suitable for landscapes, hanging baskets and ground cover as bedding type. Due to seed propagation and out crossing, progeny can segregate widely for traits due to heterozygosity. Important traits for landscape use include flower colour and extended bloom time, large and highly showy flowers, plant architecture (matting habit), environmental adaptation to stressful condition (heat tolerance) and disease resistance. Genetic information and trait heritability is almost unknown for this crop. The use of interspecific hybridization, polyploid, breeding for disease resistance and mutation breeding are presented. Tissue banks and genetic evolutionary race history have been maintained. Transgenic plants have been developed.

Keywords: Phylogeny, breeding, F₁ hybrids, transgenic.

Abstract: Tulip (Tulipa) is ornamental bulbous plant cultivated for cut flower, potted plant, garden plant and for landscaping. Species from different sections display complementary agronomic characteristics. The main goals of breeding are introgression of resistance against diseases, short forcing period, flower longevity, new flower colours and flower shapes. Long juvenile phase, slow rate of propagation, long breeding phase, slow rate of propagation, long breeding cycle, knowledge of mode of inheritance, reproductive and germination barriers pose significant challenges to breeders. The use of molecular cytogenetic tools, methods to overcome crossing barriers, polyploidization, biotechnological tools and marker assisted breeding are discussed.

Keywords: Geophyte, monocot, genomic analysis, interspecific hybridization, intergenomic recombination, gene transfer, forcing, tulipa.

Abstract: Tuberose, native of Mexico, occupies prominent position due to long spikes of fragrant flowers, potential in perfume industry and nearly year round growth in tropical and sub-tropical climate. Flowers are used for artistic garlands, floral ornamentals, bouquets and cut flowers for table decoration. Flowers remain fresh pretty long time and stand long distance transportation. Lack of genetic diversity in flower type, size, colour, self incompatibility, sterility, low seed set and limited information on genetics of characters pose significant challenges to breeders. Breeding objectives with high priority include dwarf plant type, novel colours, attractive forms for pot culture/ bedding purpose intense fragrance and high essential oil content. Only two white flowered cvs. Single and Double types are cultivated for commercial production. Salient breeding achievements through planned hybridization and mutation breeding are discussed.

Keywords: Polianthes, cultivars, interspecific/ intervarietal hybridization, transgressive segregants, gamma rays.

Abstract: Limoniums, popularly called as statice/ Sea lavender are morphologically diverse and admired for their ornamental value. Perennial annual statice is widely cultivated worldwide for both, garden decoration and indoor decoration. This chapter includes a short overview of the taxonomic and reproductive behaviour of the genus. Majority of the species are triploids and reproduce apomictically. Limoniums exhibit incompatibility linked with pollen and stigma dimorphism, heterostyly and biparental inbreeding and species cross compatibility leading to genetic variability. Many F₁ hybrids are available for commercialization as potted lines. Use of tissue culture, molecular markers, embryo rescue, cryopreservation, super compact transgenic clones has been discussed. No genetic information and trait heritability has been established for this crop. Traits of interest to flower breeders for crop transformation include: plant architecture, panicle length, number of branches per panicle, novel colours of both calyx and corolla, high number of flowers per stem, environmental adaptation to stressful conditions, etc.

Keywords: F₁ cultivars, interspecific hybridization, polyploidization, self incompatibility, potted plants.

Abstract: Snapdragon, a decorative ornamental, is used as model plant for genetic and biochemical study. These are popular flowering potted plants, bedding plants and cut flowers around the world due to their flowering floriferousness, wide range in flower colour, size, and shape with numerous phenotypes (Tall Giant/ Grandiflora, Super Giant, Dwarf, Semi-dwarf, Miniature, etc.) series (Butterfly, Rocket Hybrid, Sweet Heart, Pixie, etc.) and cultivars available in market. Hybrid seed production transformed the crop; continued domestication by flower breeders produced a wide range of flower colours and flower patterns. The increasing knowledge of the inheritance of traits and molecular genetics techniques are valuable tools aiding modern snapdragon breeders. Snapdragons are of the few floriculture crops which have genetic evolutionary race history, precise elucidation of taxonomic relationships between taxa, genomic maps, and advanced molecular genetics. In particular elucidation of the genes involved in control of floral development and in anthocyanin biosynthesis pathway has enabled precision in the creation of new flower colours or modification of floral symmetry and expression.

Keywords: Antirrhinum, taxonomy, flower shape, structural genes, molecular biology.

Abstract: Ornamental salvia, native to Brazil is cultivated as bedding plant in the world. Many species have horticultural, commercial and medicinal values. Continued breeding and improvement of salvia is focused on disease resistance, new flower colours, seed oil content and abiotic stress tolerance. Interspecific hybridization is hampered by genomic differences, heterostyly, self incompatibility and low seed set. Breeders have created polyploid cultivars and mutants which have high ornamental value. Continued use of these and other modern techniques will ensure creation of new phenotypes for the market.

Keywords: Salvia, polyploidization, male sterility, inheritance, seed production.

Abstract: Rose is a popular cut flower and flowering garden plant. Fragrance, wide colour range, plant forms and wide adaptability make it a versatile floriculture crop. The diagnostic traits of the different classes are described with reference to their potential commercial value. Increasing genetic information and trait heritability has been established for this crop and molecular genetic techniques are valuable tools aiding modern rose breeders, cultivars are almost exclusively asexually propagated. A gametophytic self incompatibility is found within this species. Numerous cultivars developed through hybridization and mutation techniques are discussed. Rose breeding efforts have been focused on miniature forms, floral fragrance, recurrent blooming, diverse colours, thornlessness, potential rootstocks, mutilple disease, pest resistance and winter hardiness. Transgenic research is highlighted. The journey of rose is endless and rose breeding may continue forever.

Keywords: Rose, intervarietal hybridization, mutation, inheritance, self incompatibility, rootstock, seed production, genetic transformation.

Abstract: Calendulas, popularly known as pot marigold, are admired for their ornamental value. The leaves, seeds and flowers are source of oil, pigments, dye, flavonoids, and ingredient in cosmetics, human, and animal medicines and dietary composition. Currently, there are intraspecific hybrids in the market. Traits of interest to flower breeders for crop transformation include plant architecture, flowering, flower colour and size, large and bold seed with high oil, pest and virus resistance.

Keywords: Calendula, intraspecific hybridization, mutation, molecular marker.

Abstract: Phlox, garden annual, is used as an ideal crop for cytogenetical study. The modern cultivars are grown for ground cover in beds, borders, rock gardens or as edging in landscaping. Phlox taxa serve as a model for speciation through hybridization and contribute to domestication of wild species through interspecific hybridization which revitalized the crop. Limited fertility, reproductive barriers, germination challenges, low seed set often pose significant challenges to breeders. The increasing knowledge of the inheritance of traits and molecular genetic techniques are valuable tools aiding modern phlox breeders. Breeding objectives with high priority include dwarf stature, novel forms, winter hardiness and disease resistance.

Abstract: Petunias, popular bedding plants, with variety of forms, sizes and shapes are employed for landscape planning, garden designs and container gardening. The numerous phenotypes viz., Grandifloras, Multifloras, Millifloras, Waves, Hedgifloras, etc. are complex hybrids. The outstanding marketable series of P. x hybrida have been developed for upright, spreading and semi-trailing to trailing habits. The leaf colour ranges from light to dark green and also variegated types. Flower colours with charming shades and patterns, picotte, star and pronounced venation of darker colours are available on world market. Petunias are strictly cross pollinated and progeny can segregate widely for traits due to heterozygosity. Increasing knowledge of the inheritance of traits and molecular genetics techniques are valuable tools aiding modern breeders. Numerous genes have been identified in the genus with some sequenced genes being used to create transformants with modified plant morphology, floral structure development, floral scent, and flower shelf life. Genes involved in the flavonoid biosynthesis pathway has enabled precision in the creation of flower colours or modification of pigment production and expression. An exploitation of sterility and incompatibility for production of F₁ hybrid seeds is discusses in detail.

Abstract: Periwinkles are popular seed propagated bedding plants with numerous hybrid varieties and series (First Kiss, Garden leader Splash, etc.) and cultivars available on world market and accepted by landscapers. A continued domestication by flower breeders produced a wide range of flower colours and flower patterns. The breeding objectives with high priority include alkaloid content, plant organs rich in pharmaceutical compounds, blooming potted plants with long display life, novel flower shapes/ form. Research focused on genetics of characters, genetic divergence, intervarietal/ interspecific hybridization and seed production has been discussed.

Abstract: Viola or garden pansy, commonly known as sweet violet or king of annuals, are widely cultivated worldwide for landscape planting, garden design and container gardening. Today, numerous OP varieties, F₁ hybrids (Europa, Toto, Wasa), F₂ strains, series (Waterford, heat tolerant S series) and cultivars introduced by seed companies are available on the world market. Pansy breeding efforts have been focused on F₁ hybrid seed production, heat tolerance, flower colour, flower size and form, double flowers, earliness, disease resistance, floriferous nature and interspecific hybridization. Increasing knowledge of the inheritance of traits and molecular genetics techniques are valuable tools aiding modern pansy breeders. Research is needed to exploit heterosis for productivity and gene transformation to create new genetic variability.

Abstract: Orchids, one of the largest commodities in international cut flowers and ornamental plant market, in which genera Cymbidium, Dendrobium, Phalaenopsis, and Vanda are most traded. Orchids occupy prime position among ornamental plants of the modern world. Both warm and cool temperature cultivars are grown in vitro germinated seeds or clones. Breeders have created polyploid cultivars (amphidiploids, triploids) which have greater flower number/raceme, large flowers and other valuable traits. Numerous genes have been identified in the genus with some sequenced genes being used to create genetic transformants. Genome breeding and wide crosses are routinely used to create new genetic variability. Future crop ideotypes are proposed to continue transformation of this crop during the next millennium.