eChapters

Introduction

Test of pollen viability (extent of pollen viability) is important in pollination experiments to ensure fertility/seed setting. It is also important in monitoring state of pollens during storage in ecological/ taxonomic studies as well as during research on pollen biochemistry, genetics, stigma interactions, and incompatibility studies. Pollen viability refers to the ability of pollen to accomplish post-pollination events to achieve fertilization. Pollen viability test has gained importance particularly in plant breeding and hybrid seed production experiments/ practices. In this chapter, you will be acquainted with the basics of pollen viability test. However, for more professional knowledge on the topic readers are suggested to refer specialized books.

Pollen Viability Test

It is important to know the extent of viability of pollens used in pollination experiment, in finding fertility of a plant of interest, to monitor state of pollen on storage, in ecological/taxonomic studies, as well as in research on biochemistry, genetics, stigma interaction, incompatibility assay, etc. of pollen. Several pollen viability tests have been developed time-to-time. It is recommended to initially use different tests for a given pollen type to find out the most appropriate method that provides reliable result on pollen viability. It is important to note that every procedure requires standardization of protocol according to the sample used. Following different tests are used for assessing pollen viability.

1. In-vitro Pollen Germination Test

It is a simple, speedy, and quantitative test for assessing pollen viability. In this method, a collection/sample of pollen is germinated in vitro and observed under microscope. The percentage of germinating pollens (producing pollen tube) after appropriate treatment and a given period of time is determined. The percentage provides an index of viability of the pollen sample.

Introduction

Seed is a living entity (mature ovule) consisting of a tiny plant in embryonic stage along with the stored food protected by an outer layer known as seed coat. Seed is an important biological input in agriculture, which is economically important for successful crop husbandry. Cotyledons serve as the source of nutrients (proteins, carbohydrates, and oils) that not only nurture the plant at the early developmental (seedling) stages of plant but also the vegetarian (heterotroph) organisms. Being one of the important inputs in agriculture, viability of seed needs to be assessed to know the germination percentage of seeds used to raise a crop. Since viability of seeds may deteriorate on storage depending on the storage conditions. Therefore, often it becomes important to test viability/germinability and vigour of seeds before being used for raising a crop or conducting an experiment. In this chapter, we briefly discuss about the different methods which can be used for testing the viability of seeds.

Seed Viability

Seed viability can be defined as the capability of the seed to germinate and produce a normal seedling within a specified period. In other words, seed viability indicates how many seeds in a lot are alive and could develop into plants under appropriate field conditions. It is very important that most of the stored seeds are capable of germinating when sown in a field. They must possess higher viability at the beginning of storage and maintain it over the storage. A seed with high initial viability survives longer in storage; however, the viability deteriorates slowly at first and then rapidly as the storage prolongs. It is important to know the duration of storage after which a considerable decline in viability occurs under given storage conditions so that to take necessary action to revive the seeds. Excessive deterioration in vianility of seeds may lead to loss of the seed/material/ germplasm.

This chapter introduces social forestry as an approach that connects forest development and management with community needs, rural livelihoods, environmental improvement, and social participation. It examines the major components of social forestry and the role of community participation in forest management. The chapter also discusses ecological impacts, biodiversity, rural economic development, gender and social equity, legal frameworks, participatory forestry experiences, and emerging technological opportunities. By examining both social and ecological dimensions, the chapter highlights the importance of inclusive participation and community-based approaches in achieving sustainable forest management.

Floriculture has become very important industry as a result of science based techniques and steady supply of improved plant materials. One of the major constraints of floriculture industry is non availability of large scale quality planting materials. Conventional methods of propagation can not meet the increasing demand of propagating materials. Micropropagation is perhaps the most widely used biotechnology tool for large scale propagation of floricultural crops. This economic proposition has led to intensive practical research to evolve tissue culture techniques for mass propagation and production of virus-free plant material.  Since most of the ornamental crops are highly heterozygous, their seed progeny is not true-to-type. Conventionally in these plants vegetative reproduction method is followed to produce genetically identical plants at commercial scale. But the main constrain of this method is that only a limited number of plants can be raised in a year from a single mother plant and often fail to meet the market demand. Therefore, most of the modern floriculturists follow the micropropagation technique for rapid multiplication of ornamental plants.

The tissue system

A group of tissues performing a similar function irrespective of its position in the plant body is called a tissue system. In 1875, Sachs recognized three tissue systems in the plants.

a) Epidermal tissue system

b) Vascular tissue system

c) Fundamental tissue system.

a) Epidermal tissue system

Epidermal tissue system is the outermost covering of plants. It consists of epidermis, stomata and epidermal outgrowths. Epidermis is generally composed of single layer of parenchymatous cells compactly arranged without intercellular spaces. But it is interrupted by stomata. In leaves, some specialized cells which surround the stomata are called the guard cells. Chloroplasts are present only in the guard cells of the epidermis. Other epidermal cells usually do not have chloroplasts. The outer wall of epidermis is usually covered by cuticle. Stoma is a minute pore surrounded by two guard cells. The stomata occur mainly in the epidermis of leaves. In some plants such as sugarcane, the guard cells are bounded by some special cells. They are distinct from other epidermal cells. These cells are called subsidiary or accessory cells. Trichomes and root hairs are some epidermal outgrowths. The unicellular or multicellular appendages that originate from the epidermal cells are called trichomes. Trichomes may be branched or unbranched. Rhizodermis has two types of epidermal cells - long cells and short cells. The short cells are called trichoblasts. Root hairs are produced from these trichoblasts.

Efficient horticultural production depends greatly on appropriate tools, implements, and timely cultural operations. This chapter introduces the major equipment used for land preparation, planting, weeding, pruning, propagation, irrigation, harvesting, and routine crop management. It emphasizes correct tool selection according to crop, operation, plant structure, and working conditions. Digging tools, secateurs, loppers, pruning saws, grafting knives, and other specialized implements are discussed along with principles of maintenance, sharpening, sterilization, and safe handling. The chapter also explains important cultural operations that influence crop establishment and productivity. Proper use of tools improves precision, reduces labour, prevents plant injury, and increases operational efficiency in horticultural systems.

ABSTRACT

Chamba and Kangra districts of Himachal Pradesh are abode to vast natural diversity. The people of the area had developed varied traditionl approaches to live with the nature so that natural resources can be protected for their sustained use. The present paper enumerates some of the ecofriendly life styles, agroforestry systems and water use practices being adopted by the farmers of the region.

Horticultural plants are grown for their diversified produce like fruits, vegetables, flowers, aromatic (essential oils) or medicinal components, spices (oleoresins), etc. if these plants are allowed to grow naturally, they will grow wild with very less potential yield. Therefore, it is essential to train and prune these plants not only to develop the proper framework in manageable shape but also to improve the potential yield in terms of quality and quantity.

Once the sapling is planted, it is essential to maintain the proper framework by cutting certain branches as well as some parts of branches. In the initial period, it is essential to maintain well distribution of flower or fruit bearing parts growing in four directions. Once the plant achieves proper framework after a certain period; then also some of the plant parts, namely branches or certain portions of branches, are removed to achieve potential yield.

Horticultral plants are grown for their produce like fruit, vegetable, flower, medicinal, aromatic, spices etc. Therefore, these plants should be managed in such a way that human desires for the purpose of growing them are fully satisfied in terms of quality and quantity of produce. This demands direct manipulation of plant growth itself or plant environment through various inputs. In manipulation of plant development, training and pruning are important for which our knowledge about plant development and its phenology has to be complete. These practices are important in fruit crops.

Training: Physical techniques that control the shape, size and direction of plant growth are known as training or in other words training in effect is orientation of plant in space through techniques like tying, fastening, staking, supporting over a trellis or pergola in a certain fashion or pruning of some parts.

Ethylene is a primary plant hormone involved in the senescence of plant tissues including flowers and leaves. In carnation, inhibition of the synthesis or action of ethylene delays the onset of senescence symptoms and lengthens the vase life of flowers. Leaves of cut chrysanthemum of some cultivars frequently become yellow, sometimes prior to onset of flower senescence, in response to exogenous ethylene. Generation of transgenic plants with suppressed production or action of ethylene is an excellent way to lengthen the longevity of these ornamental plants. This paper reviews our studies on generation and characterization of carnations with reduced ethylene production and chrysanthemum with reduced sensitivity to ethylene.

Ethylene is a primary plant hormone involved in the senescence of cut flowers of many ornamentals such as carnation, sweetpea and delphinium. It is produced on a large amount at a later stage of flower senescence. The increased ethylene production accelerates withering and dropping of petals. Inhibition of synthesis or action of ethylene delays the onset of senescence symptoms and extends the vase life of flowers.

ABSTRACT

Survey and research trial conducted for the selection of promising tree based farming system in Paonta valley region of H.P. have been summarized in the manuscript. Tree based farming innovations with intercropping, their planting technology and geometry around field/ farm, pure plantation , block plantation of trees grown with agricultural/fruit crops for better productivity per unit of land have been suggested for improving socio-economic condition of the regional farmers.

ABSTRACT

In agroforestry and forestry sectors, little efforts have been made for tree improvement research in India. Planting of genetically poor quality of seedlings/propagules is one of the major reasons of low level impact of agroforestry systems in Indian Agriculture. Most of the agroforestry tree species have not been even gone through simple selection for superior types (plus trees). Exploration, collection and conservation of germplasm of woody agroforestry species, selection for fast growing trees, clonal propagation, seed orchards and other advances in tree breeding are still in fancy stage. At present, all the woody agroforestry species are propagated through collected seeds and/or propagules by unskilled labourers. It is well known that through tree breeding and establishment of seed orchards of improved genotypes, significant achievements towards the improvement of productivity of economic tree products is possible as happened in agricultural crops in India and industrial trees in USA and Europe. Even by small efforts of tree improvement, productivity of economic tree products can be raised by 20-30 per cent. In this paper breeding methodology, limitations, status and strategy of various agroforestry species has been discussed in special reference to Leucaena leucocephala (Subabul), Prosopis cinereria (Khejri), Azadirachta indica (Neem), Populus spp., Dalbergia sissoo (Shisham), Acacia nilotica (Desi babul), Eucalyptus spp. Casuarina equisetifolia (Casuarina), Albizia lebbek (Desi siris) and Jatropha curcus (Ratanjot).

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/ or animals interact. Interaction literally means influence or mutual or reciprocal action. So component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole. In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/ or animals interact. Interaction literally means influence or mutual or reciprocal action. So, component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

The success of an agroforestry system relies heavily on exploitation of the component interactions. In an ideal relationship, production of trees as well as crops or grasses in combination could be comparable to their sole performance. Agroforestry could be even more advantageous if the production of associated components is increased due to influence of trees. This is possible because trees are capable of improving productivity of soil in many ways. A large number of trees are known to fix nitrogen symbiotically. Nevertheless, instances of crop inhibition in association of trees are not uncommon. Such inhibitions are primarily caused by shade effect as well as competition for below-ground resources such as nutrients and water. In some cases, inhibitory effect may also result from allelochemicals secreted by some of the tree species.

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/or animals interact. Interaction literally means influence or mutual or reciprocal action. So component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

The success of an agroforestry system relies heavily on exploitation of the component interactions. In an ideal relationship, production of trees as well as crops or grasses in combination could be comparable to their sole performance. Agroforestry could be even more advantageous if the production of associated components is increased due to influence of trees. This is possible because trees are capable of improving productivity of soil in many ways. A large number of trees are known to fix nitrogen symbiotically. Nevertheless, instances of crop inhibition in association of trees are not uncommon. Such inhibitions are primarily caused by shade effect as well as competition for below-ground resources such as nutrients and water. In some cases inhibitory effect may also result from allelochemicals secreted by some of the tree species.

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/ or animals interact. Interaction literally means influence or mutual or reciprocal action. So, component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

INTRODUCTION

Promoting agroforestry is a major opportunity to deal with problems related to land-use and CO2-induced global warming (Albrecht and Kandji 2003). As per recent projections, the area of the world under agroforestry will increase substantially in the near future. Undoubtedly, this will have a great impact on the flux and long-term storage of carbon in the terrestrial biosphere (Dixon 1995). Several studies have shown that inclusion of trees in the agricultural landscapes often improves the productivity of systems while providing opportunities to create carbon sinks (Winjum et al. 1992; Dixon et al. 1993; Krankina and Dixon 1994; Dixon 1995). The amount of carbon sequestered largely depends on the structure and function of agroforestry systems - which to a great extent, are determined by environmental and socio-economic factors. Other factors influencing carbon storage in agroforestry systems include tree species and management system. The significance of agroforestry with regards to carbon sequestration and other CO2 mitigating effects is being widely recognized. There are sound reasons to believe that agroforestry can contribute significantly to carbon sequestration. It is important that research attention is focused on this aspect of agroforestry systems (Nair and Nair 2002).

This chapter introduces tree improvement approaches aimed at developing forest species with enhanced resistance to biotic and abiotic stresses. It examines the challenges posed by climate change and discusses conventional and modern tree breeding techniques. The chapter further explores climate-smart tree improvement, resistance to pests and diseases, and tolerance to environmental stresses such as drought, heat, salinity, and other changing climatic conditions. By integrating breeding strategies with modern technologies and climate-resilience objectives, the chapter emphasizes the development of improved forest trees capable of maintaining growth, productivity, survival, and ecosystem functions under changing environmental conditions.

1. Tree improvement consists of_____________ and_____________. (Silviculture and tree breading)
2. Variation within the local progenies is due to_____________. (Environment)
3. Larger units of similar vegetation are referred as_____________. (Biome)
4. _____________ is the only gaseous hormone. (Ethylene)
5. More genetic gain can be achieved in the_____________ seed orchard. (Clonal)
6. _____________ is known as father of genetics. (Mendel)
7. Pure line theory was proposed by_____________. (Johannsen)
8. Self-incompatibility hampers the development of_____________. (Inbreds)
9. Progeny having both parent identities is known as_____________. (Fullsib)