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

Flowering plants (Angiosperms) are identified by their morphological characteristics like flower, fruit and seeds that help their taxonomic characterization into different species, genera, families and orders. The floral characters which are used for taxonomic characterization of plants include the type of inflorescences, perianth structure, floral symmetry, arrangement of floral leaves, type of androecium, stamens, gynoecium, carpel, ovule, etc. The type of fruit and seed also play important roles in taxonomic classification. In this chapter we will briefly discuss about various morphological features of flowering plants (in botanical terms) that are useful in taxonomy.

Nomenclature of Plant

Nomenclature of plant is the formal and scientific naming of plants. It is related to but distinct from taxonomy for grouping and classifying plants and provide botanical name.

The scientific/botanical nomenclature started with Species Plantarum by Carolus Linnaeus in 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN).

ICBN and ICN

International Code of Botanical Nomenclature, (ICBN) was adopted by the VIIth International Botanical Congress held in Stockholm, July1950. While the International Code of Nomenclature for algae, fungi, and plants (ICN) was adopted by the XVIIIth International Botanical Congress held in Melbourne, Australia in July 2011.

Introduction

We come across a variety of chemicals every day in a laboratory. While some of them are relatively safer, others are extremely hazardous. Thus, it is very important to know the potential hazards that can be caused by the chemicals present in the laboratory and the safety measures needed to be followed to avoid the hazards. Additionally, we should also be aware of the steps necessary to be taken on such hazardous situations. According to IUPAC, a hazardous chemical mean the chemical which has the potential to cause damage in various ways. In a laboratory, there are chemicals that might be irritant, carcinogen, respiratory fibrogen, systemic poison, asphyxiant, flammable, etc. which have the potential to cause hazard to the workers or environment. Therefore, it is important to use appropriate procedure to reduce the risk and protect the health/safety of laboratory personnel, the public and the environment.

Types of Hazards Associated with Chemicals

Chemical hazards: The hazards caused by chemicals can be broadly classified into three categories.

1. Health hazard: This is also known as toxic effects of chemical. The risk associated with a chemical in laboratory depends on the extent of exposure and the inherent toxicity of the chemical. Many chemical reactions form the product that might be much more toxic than the reacting chemicals. For example, inadvertent mixing of formaldehyde (a common tissue fixative) and hydrogen chloride results in the generation of bis(chloromethyl) ether, a potent human carcinogen. For most of the chemicals, the route of exposure (through skin, eyes, gastrointestinal tract, or respiratory tract) is more important (Figure 17.1) that must be considered during risk assessment.

Introduction

Proper electrical wiring and earthing are crucial for laboratory safety and functionality. A laboratory houses several installations/equipment that demand stable/continuous power supply. Inappropriate or faulty wiring and earthing may lead to significant risks, including electrical shocks, damage to equipment, and even incidence of fire. Therefore, understanding the requirements of electrical wiring and earthing is essential for designing, construction, and maintenance of laboratory. This chapter aims to provide a basic knowledge of electrical wiring and earthing necessary for a laboratory. Importance of earthing in mitigating electrical hazards and ensuring integrity of electrical installations are also described.

Basics of Electrical Wiring

Basic understanding of electrical wiring is necessary for laboratory safety and efficient electrical functioning. The potential difference between two electrical points (negative and positive) is known as Voltage, which drives the flow of electric current. This is measured as volt (V). The rate of flow of electricity in a circuit is known as Current (I), which is measured as ampere (A). Current can be either direct (DC) or alternating (AC). Opposition/resistance experienced in the flow of current in circuit is known as Resistance (R) and it is measured in ohms (Ω). Higher the resistance means lesser the current flows at a given voltage. The rate at which electrical energy is transferred/utilized in an electric circuit is known as Power (P), which is measured in watt (W). The Power can be calculated as the product of voltage and current (P = V × I).

For a researcher, laboratory is another home where he/she spends much time every day. As we take care of cleanliness, safety, and design of our home, we must take care on these aspects of laboratory too. It is the responsibility of the laboratory personnel to ensure cleanliness/safety of the laboratory. Since every laboratory chemical and equipment have the potential to cause harms if not used with appropriate precautions. Hence, as a laboratory user, it is our responsibility to follow the basic safety/biosafety rules and regulations set up by the Principal Investigator of the laboratory, Institutional Biosafety Committee, as well as by other regulatory authorities, if any. We must be aware of the general/personal protective measures, cleanliness and laboratory waste disposal prior to joining a research laboratory. In this chapter we will briefly discuss about personal safety, chemical safety, cleanliness, waste disposal, etc.

A. Personal Safety

1. Personal Protective Equipment (PPE)

Personal protective equipment (PPE) is special arrangement to protect the worker from specific hazards because of using a hazardous substance. PPE does not reduce or eliminate the hazard, but protects the wearer from exposure to hazardous material. PPE should not be reused or brought outside the laboratory as these might increase the risk of spread hazardous material or contamination. Used PPE must be kept inside the laboratory in a designated waste storage area adjacent to the work area.

Introduction

Several hazardous chemicals, microbes, and techniques like recombinant DNA technology are used for research and development work in research Institutes and universities. Therefore, the researchers, technical, helping and supporting staffs as well as the laboratory outputs must be kept free from contaminations. Thus, biosafety is necessary to prevent unintentional exposure/ release of hazardous chemicals, microbes/pathogens, and toxins to the laboratory staff and environment. Following the biosafety guidelines and ethical considerations are essential to maintain safety standards for the researchers as well as the environment. This chapter deals with various biosafety measures and ethical issues to be strictly followed while working in a research laboratory. The required safety level needs to be determined as per the chemical/biological materials are used in the laboratory to keep the researcher/environment safe for sustainable research and developmental activities.

Biosafety

The term biosafety is used to describe the procedure and policies needed to ensure environmental and personal safety. Biosafety refers to the containment principles, technologies and practices that are implemented to prevent unintentional exposure to pathogens, toxins, or their accidental release into the environment. A fundamental objective of any biosafety program is the containment of potentially harmful chemical/biological agents as precautionary safety measures.

Why Biosafety?

With the increasing number of countries adopting molecular biology tools and techniques in life science research and development activities, especially in the areas of agriculture and medicine, the biosafety issues are gaining importance to ensure biological safety for the public and the environment. Conducting research in safe and sustainable manner is not only a personal requirement but essential collective efforts to ensure biological safety for a clean and safe environment. This requires rules, regulations, monitoring bodies, and awareness among the workers as well as the public. Therefore, biosafety per se is an integral part of laboratory research and requires awareness among the researchers so that biological safety can be well taken care from the grassroot level.

A laboratory is essential for research work in science and development. Most of the research institutes have dedicated laboratories for researchers and students to conduct experiments, perform research work, as well as to provide hands-on learning/training to students. There are certain rules and regulations laid down by the laboratory in-charge which need to be followed strictly for safety purposes. Some of the laboratories keep ‘safety manual’ for researchers to read before entering into the laboratory to conduct experiments. Whenever safety is compromised in a laboratory, there is increase in risk of unwanted incidents in the laboratory. Storing food/beverages in the same refrigerator where laboratory chemicals are kept may lead to disastrous effects on health. This chapter aims to provide instructions in brief on the things to be performed (Do’s) before and after entering onto a laboratory as well as the things never to be done (Don’ts) in a laboratory for the safety reasons.

Good Laboratory Practices (Do’s)

• P Wear apron/labcoat while working in the laboratory.
• P Use gloves/respiratory mask/fumehood while handling toxic/volatile/inflammable chemicals/reagents.
• P Use pippet or pippetor for safety in transfer of solutions.
• P Protect eyes, face and naked parts of the body from UV radiations. Use safety goggles or face mask/apron.
• P Keep your eyes away from Liquid Nitrogen and use cryogloves while handling it.
• P Arrange all the necessary materials/solutions before starting the experiment.
• P Periodically fumigate/ozonize culture and inoculation rooms.
• P Autoclave all contaminated materials before discarding.
• P Pre-treat gel or solution containing Ethidium Bromide (EtBr) before discarding into laboratory waste-disposal bin, and use gloves while handling them.
• P Burn all the transgenic plant materials in an incinerator after taking necessary observations.
• P Make entry in the designated log-book and clean the instrument after using it properly.
• P Switch-off the instrument after use or when not in use.
• P Wash hands with soap and remove the labcoat before leaving/going out of the laboratory7.
• P Ensure that switches for fans/lights, and water taps are off while leaving the laboratory.
• P Follow the biosafety guidelines suggested for handling and disposal of the hazardous chemical.

Introduction

Fruit crops have been cultivated for centuries, both commercially and in amateur gardens, and many species covering a wide range of trees, shrubs, and non-woody perennials.Fruit crop species have certain common characteristics: they are long-lived, usually highly heterozygous, and clonally propagated from an elite mother plant. Fruits are increasingly recognized as an important component of a healthy diet, and consumption of temperate fruit and fruit products, especially juices and dairy derivatives, has risen sharply over the past decade.China is the largest producer of fruit crops with approximately.

• India ranks the second in fruit production.

• India has witnessed increase in horticulture production over the last few years. Significant progress has been made in area expansion resulting in higher production.

• Over the last decade, the area under horticulture grew by 2.6% per annum and annual production increased by 4.8%.

• Production of fruit crops has increased from 50.9 Million Tonnes to 97.35 Million Tonnes since 2004-05 to 2017-18.

• Total production of fruits is highest in case of Andhra Pradesh followed by Maharashtra.

Introduction

• The green revolution of the 1960s and 1970s ended chronic food deficits and while cereals still command the attention of policy makers, fruit production has surged impressively, making India the second largest global producer behind China.

• Annual growth in horticulture has seen fruit production grow at faster rate and constitute the larger segment of agriculture. • No doubt, there has been manifold increase in area, production and productivity but when we compare the productivity of various major fruit crops with other developed countries, our productivity is very low.

• This may be mainly attributed by non-availability of quality planting material and seeds, existence of old unproductive seedling orchards, small and unirrigated land holdings, use of inferior genetic stocks/ varieties/hybrids, poor management and non-adoption of package of practices, high incidence of pest and diseases, heavy pre and post harvest losses and lack of trained human resource.

• To meet increasing demand the productivity per unit area per unit time and per unit investment has to be increased from limited land resources, where production and supply of quality planting material of elite varieties is one such important factor that can bring tremendous improvement in production, productivity and higher economic returns to farmers.

• This may be mainly attributed by non-availability of quality planting material and seeds, existence of old unproductive seedling orchards, small and unirrigated land holdings, use of inferior genetic stocks/ varieties/hybrids, poor management and non-adoption of package of practices, high incidence of pest and diseases, heavy pre and post harvest losses and lack of trained human resource.

Introduction

• At present, horticulture is recognized as a potential sector to enhance agricultural production, improve house hold nutritional security and income generation through diversification and employment, value addition and export.

• Inspite of the enormous success achieved in horticulture sector, several constraints still exist.

• Besides new emerging challenges, poor productivity per unit area continues to be a concern in most of the horticultural crops with climate change impacting the productivity further.

3.1 Role of root stock in fruit crops

• The role of rootstocks and its use in different fruit crops has significant impact on fruit crop production by influencing canopy architecture, nutritional uptake, flowering, yield and fruit quality.

• Besides, it can also confront biotic and abiotic stresses such as soil pathogens, thermal stress, salinity and nutritional stress.

• Due to limited availability of arable land and high market demand for fruit crops, they are frequently cultivated under unfavorable soil and environmental conditions like thermal stress, drought, flooding, salinity and contamination of organic pollutants.

• One way to substantiate or reduce these losses in production would be the use of appropriate rootstocks, which are capable of reducing the effect of external stresses on the scion.

• Rootstocks have a primary role in determining orchard efficiency.

• They are responsible for water and mineral uptake and provide anchorage for the tree.

4.1.1 Vertical row planting pattern

1. Square system: In this system, trees are planted on each comer of a square whatever may be the planting distance. This is the most commonly followed system and is very easy to layout. The central place between four trees may be advantageously used to raise short lived filler trees. This system permits inter cropping and cultivation in two directions.

2. Rectangular system: In this system, trees are planted on each corner of a rectangle. As the distance between any two rows is more than the distance between any two trees in a row, there is no equal distribution of space per tree. The wider alley spaces available between rows of trees permit easy intercultural operations and even the use of mechanical operations.

4.1.2 Alternate row planting pattern

3. Hexagonal system

• In this method, the trees are planted in each comer of an equilateral triangle.

• This way six trees form a hexagon with the seventh tree in the centre.

• Therefore, this system is also called as 'septule' as a seventh tree is accommodated in the centre of hexagon.

• This system provides equal spacing but it is difficult to layout.

• The perpendicular distance between any two adjacent rows is equal to the product of 0.866 x the distance between any two trees.

• This system accommodates 15% more trees than the square system. The limitations of this system are that it is difficult to layout and the cultivation is not so easily done as in the square system.

5.1 Crop modelling

• Crop model

• “Schematic representation of the system’’i.e. a model as defined by De Wit 1970.

• Such a model can be based on statistics applied to a set of experimental data or on physical laws (Guyot, 1997).e.g. Irrigation is able to satisfy a crop’s water needs provided its management relies on the measurement or estimation of evapotranspiration. The manager can either invest in equipment to monitor changes in water content in the soil or fluxes of water into the plant or the atmosphere, or rely on a ‘‘schematic representation of the system’’, i.e. a model.

• In very simple terms we can define a crop model as “a well-thought out plan of activities to grow the desired crop to get maximum possible yields of high-quality produce with the given resources. It can be a mental or a written exercise (a “schematic representation of the system”) that a farmer or a farm manager prepares for a crop or for an individual crop”.

• In other words, we can also say that a model is “an attempt to describe a certain process or system through the use of a simplified representation, preferably a quantitative mathematical expression, that focuses on a relatively a few key variables that control the process or system”.

• It is clear that in finalizing a crop model we have to assume some mean or standard values (based on the past record, experience, expert judgment, etc.) of the variables which we may not be taking explicitly in our model.

6.1 Scenario in precision farming

• India’s population is around 1366 million by 2020 which requires food grain production of 350 million tones.

• Considering the current food grain production levels, India needs to raise food grain production levels by not less than 4.00 per cent per year. As the availability of land has decreased, application of fertilizers and pesticides become necessary to increase food production.Indiscriminate use of inputs coupled with improper management practices over a long period has resulted in decline in soil productivity.

• Agriculture production system is outcome of interaction of various agro inputs. Therefore, judicious management of these inputs is necessary for the sustainability of these inputs.

• In our agriculture systems, spatial variability over the landscape is ignored and fertilizers, herbicide, pesticides, fungicides etc. are applied at uniform rate over the whole field.

• It has been recognized that crops and soils are not uniform within a given field. The management of in-field variability in soil fertility and crop conditions for improving crop production and minimizing the environmental impact is the crux of precision farming.

• Definitions • It is defined as the application of technologies and principles to manage spatial and temporal variability associated with all aspects of agricultural production (Pierce and Nowak, 1999).

• It is an integrated information and production-based farming system that is designed to increase long term, site specific and whole farm production efficiency, productivity and profitability while minimizing unintended impacts on environment.

Introduction

• India is the second largest producer of fruits in the world after China

• India is rich in fruit diversity starting from tropical, subtropical to temperate region.

• Some of the fruits like Guava, pomegranate, lemon, mandarin etc., if left without any treatment, give several light harvests of the variable quantities and qualities from the various flowering flushes throughout the year.

• Some of the fruit crops bloom throughout the year without any resting period and produces two or three crops (bahar) in a year but yield and quality is not so good in all crop harvest. So, it is very essential to understand the flowering and fruiting behavior of crops and which bahar will give good crop with considering all the factors associated with a particular bahar.

7.1 What is crop regulation?

• Crop regulation means to force the tree for its rest and to produce blossom and fruits during any one of two or three flushes”

• Crops in which flowering is continuous throughout the year; economic yield cannot be achieved in any of the season.

• Therefore, by analyzing market demand flowering can be forced in particular one season, which gives the economic yield.

• Through various techniques like cultural practices and chemical treatments, trees are thrown to rest prior to flowering and then practices are done to trigger flowering.

• Thus, crop regulation is a method to regulate flowering by altering natural tendency of the tree by artificial means.

8.1 What is stress?

• Physics:Mechanical force per unit area applied to an object.

• Biology:Stress is any adverse environmental factor or condition that affects normal metabolic or physiological processes. It may be :

• Biotic stress (living) • Abiotic stress (non-living) 8.2 Abiotic stress

• Abiotic stress is defined as:“The negative impact of non-living factors on the living organisms in a specific environment”

• Only 10% of the world arable land may be categorized as free from stress.

8.2.1 Type of abiotic stress

8.2.1.1 Temperature stress

• Temperature is one of the most important components of climate. It plays vital role in the production of horticultural crops.

• The different activities of plant like growth and development, respiration, photosynthesis, transpiration, uptake of nutrients and water and reproduction (Such as pollen viability, blossom fertilization fruit set etc.), carbohydrate and growth regulators balance, rate of maturation and senescence, and quality, yield and shelf life of the edible products.

• The above function of the plant should be well when the temperature at the optimum range.During high temperature plant does not perform proper functions of growth, where in low temperature physiological activities of the plant are stopped.

Introduction

• Successful horticultural production is not possible without sufficient moisture regimes and for that, the appropriate techniques should be adopted.

• In the total cultivated land of India, 75 % of land contributed as a rainfed area or dry land area in which 60% with semi-arid and 19.3 % of area with arid zone.

• The irrigation facilities are covered only 38 % of the total cultivated land of the country.

• The moisture is always the limiting factor in arid area.

• So, conservation of soil moisture or water management is the most important task for arid fruit production.

• Out of total cultivated area of Horticultural production, l lakh ha is under arid or semi-arid.

• In arid area, some fruit crops with specials features are adapted for their production. So, in this area, the soil moisture conservation or the water harvesting techniques is the prime important tools for crop production with best management systems.

10.1 What is nutrient management?

• Nutrient management is an important component in orchard management for high efficiency and high fruit quality. Fruit trees are perennial woody plants which can store nutrients and then release them for growth.

• Therefore, the nutrient uptake of fruit trees includes the total nutrients of the fruits, leaves, new branches, and time increments of storage. Nutrient uptake is different under different yield levels. For example, the N uptake of apple trees was 100–120, 110– 130,120–140, and 130 150kg/ha under yield levels of 30, 45, 60, and 75t/ha, respectively.

• Basal fertilization is considered to be important for high-quality fruit production by providing nutrients for tree growth and also improving soil structure which promotes better root development. It is usually recommended and immediately applied during the dormant season up to autumn, after fruit harvest.

• Top dressing applications are usually chemical fertilizers which are applied two to four times before bud break or prior to or after blooming and at the fruit enlargement stage, depending on the requirements of each type of fruit tree.

• Using this INM method, the total nutrient demand is calculated according to target fruit yield level and NPK fertilizers are recommended based on soil fertility index (High, Moderate, and Low soil fertility) and nutrient demand with different stages. For moderate apply trees, most of N fertilizer is applied in autumn after picking to add N storage and renew tree vigor, and most of the P fertilizer is applied in spring with flowing stage to improve flower bud quality, and most of the K fertilizer is applied in summer fruiting period to improve fruit quality. Management of high yielding fruits using suitable pruning, and irrigation, are combined in this INM

11.1 Quality

• Quality of fruit or any other commodity is combination of attributes, properties or characteristics like appearance, texture, flavor and nutritive value that determine their value to the consumer.

• Keeping quality is also an important quality attributes in all fruits.

• Quality parameters • Appearance (size, shape, color and freedom from defects)

• Texture (firmness and juiciness)

• Flavors (swetness, sourness, bitterness, astringency, aroma and off f lavour)

• Nutritional (vitamins and minerals)

• Quality management Quality management is a method of ensuring the effectiveness of all the factors those implemented to improve and maintain the quality in acceptance form at consumer’s level.

11.2 Pre-harvest management of quality

11.2.1 Genotype and rootstock management

Abnormal milk: It is milk that is not smooth and homogenous but is flaky, ropy, stringy, slimy, watery, discoloured or bad flavoured (Plate 1 & 2).

Abrassive peeler: It is equipment comprising a rotating drum lined with carborandum (an abrasive material) in which certain vegetables like potato and ginger are tumbled and exposed to the abrasive action of the carborandum lining, thereby facilitating separation of peel from the vegetables (Plate 3).

Absinthe: It is green liqueur which is flavored with wormwood, anise, and other aromatic herbs (Plate 4). Its commercial production is banned in ma ny countries for health concerns.

Absolute alcohol: It is water free alcohol. It contains atleast 99 per cent pure alcohol by weight and obtained by digesting rectified spirit over quicklime and redistilling the same.

Absolute density: It is the ratio of weight of certain volume of a substance at 1oC to that of weight of same volume of water at 4oC.

Absolute humidity: Absolute humidity is defined as kg of water vapour per kg of dry air at a given temperature and pressure. Absolute humidity is the mass of water vapour divided by the mass of dry air in a certain volume of air at a specific temperature. The warmer air absorbs more water than cooler one. Absolute humidity is the measure of water vapour or moisture in the air, regardless of temperature.

Absolute pressure: It is equal to atmospheric pressure minus vacuum pressure (Plate 5).

Absolute zero: It is a theoretical temperature characterized by complete absence of heat and motion and equivalent to exactly -273.15°C or -459.67°F (Plate 6).

B.T.U.: It stands for British thermal unit. The heat required to raise the temperature of one pond of the water through 1oF is called BTU (Plate 82).

Baby back ribs: Meaty pork ribs cut from the lower back rib section.

Bacitracin: A polypeptide antibiotic isolated from a bacillus (Bacillus subtilis or B. licheniformis) and usually used against gram-positive bacteria.

Back Bacon / Canadian bacon: Bacon cut from the loin that has little fat and is cut into round or oblong slices.

Backward feed evaporator: In this evaporator, fresh feed enters the last and the coldest effect and continues on until the concentrated product leaves the first effect (Plate 83).