Strategies for Enhancement in Food Production

🎯 Key Points

• Composite fish culture (polyculture) niches: Catla (surface), Rohu (middle), Mrigal/Common carp (bottom feeders) — different feeding zones let multiple species coexist in one pond without competing
• Plant breeding steps in order: germplasm collection → evaluation/selection of parents → hybridisation → selection of superior recombinants → testing/release; emasculation (anther removal) + bagging prevents unwanted self/cross pollination during crosses
• Biofortification examples: Golden Rice = beta-carotene (vitamin A); Protein maize (Opaque-2 gene) = high lysine/tryptophan — engineered to fix specific nutrient deficiencies
• Totipotency (any plant cell can regenerate a whole plant) is the foundation of tissue culture/micropropagation; Somatic hybridisation = protoplast fusion (no sexual crossing needed) — Pomato is the classic potato+tomato example
• SCP (single cell protein): Spirulina grown on wastewater, Methylophilus on methanol — microbial protein source that reduces dependence on conventional agriculture

Animal Husbandry

Animal husbandry covers dairy farming, poultry farming, fish production, beekeeping (apiculture), and sericulture. Key dairy breeds include exotic Friesian and Jersey, and Indian breed Sahiwal (dairy) and Ongole (drought). Poultry breeds include Leghorn and Rhode Island Red. Diseases affecting poultry include Ranikhet, fowl pox, and fowl cholera.

Fish Production

Capture fishery includes marine and inland fishing. Culture fishery (aquaculture/pisciculture) uses composite fish culture (polyculture) with Catla (surface), Rohu (middle), Mrigal (bottom), common carp, silver carp, and grass carp. CIFA and MPEDA are key organizations.

Apiculture and Sericulture

Apis cerana indica (Indian bee) and Apis mellifera (European bee) are used in beekeeping. A colony has a queen, drones, and worker bees. Silk is produced from Bombyx mori (mulberry silkworm). Antheraea assamensis produces muga silk.

Plant Breeding

Steps: germplasm collection, evaluation and selection, hybridization, selection of superior recombinants, testing and commercialization. Emasculation removes anthers from bisexual flowers; bagging prevents contamination. Semi-dwarf wheat varieties (Sonalika, Kalyan Sona) and high-yielding rice (Jaya, Ratna) were developed during the Green Revolution by Norman Borlaug; M.S. Swaminathan led the effort in India.

Biofortification

Golden Rice contains beta-carotene (Vitamin A). Iron-rich beans have 3x more iron. Protein maize (Opaque-2 gene) has high lysine and tryptophan, developed at CIMMYT.

Single Cell Protein (SCP)

Spirulina (cyanobacterium) is grown on waste water and is rich in protein. Methylophilus methylotrophus grows on methanol. SCP reduces pressure on conventional agriculture.

Tissue Culture

Totipotency is the capacity of a plant cell to develop into a complete organism, first demonstrated by F.C. Steward with carrot cells. Explant is the plant part used; callus is the undifferentiated cell mass. Micropropagation enables large-scale clonal propagation. Somatic hybridization involves protoplast fusion using cellulase and pectinase. Pomato (potato + tomato) is a classic example of a somatic hybrid. A cybrid results from fusion of an enucleated protoplast with a whole protoplast.

Mutation Breeding and Polyploidy Breeding

• Mutation breeding: induces mutations using physical (gamma rays, X-rays) or chemical mutagens to create genetic variability, then selects useful mutants; e.g. mung bean variety resistant to yellow mosaic virus and powdery mildew was developed this way
• Polyploidy breeding: induced increase in chromosome number (often using colchicine) can produce larger fruits/seeds; many commercial varieties of fruits and vegetables are polyploids

Disease and Pest Resistance Breeding

• Breeding for biotic stress resistance follows the same broad steps as conventional plant breeding: screening germplasm for resistant sources, hybridisation with high-yield varieties, and selection of resistant recombinants
• Examples: Himgiri (wheat) resistant to leaf and stripe rust, brown rust, and hill bunt; varieties of Brassica resistant to white rust; chilli variety resistant to bacterial blight, mosaic virus, and fruit rot

Dairy and Poultry Management

• Dairy farm management: requires high-yielding, disease-free cattle with good housing, regular cleaning, and balanced fodder; cross-breeding exotic breeds (high yield) with indigenous breeds (disease resistance) combines beneficial traits
• Poultry farm management: involves selecting disease-free, suitable breeds, proper housing and feeding, and maintaining hygiene; broilers are raised for meat (need vitamin A and K rich feed), layers for eggs
• Common poultry diseases (Ranikhet, fowl pox, fowl cholera) are managed through vaccination and biosecurity

Animal Breeding: Inbreeding and Outbreeding

• Inbreeding: the mating of more closely related individuals within the same breed for 4-6 generations; it increases homozygosity, and so is used to evolve a pureline, to accumulate superior genes and to eliminate less desirable ones. Continued inbreeding, however, usually reduces fertility and productivity, an effect called inbreeding depression; mating the selected superior animals with unrelated superior animals of the same breed helps overcome it
• Out-crossing: the mating of animals of the same breed that have no common ancestors on either side for 4-6 generations; the offspring is called an out-cross, and this is the best breeding method for animals that are below average in productivity, and for overcoming inbreeding depression
• Cross-breeding: superior males of one breed are mated with superior females of another breed, combining the desirable qualities of both; e.g. Hisardale is a new breed of sheep developed by crossing Bikaneri ewes with Marino rams
• Interspecific hybridisation: the males and females of two different, related species are mated so that the progeny may combine desirable features of both parents; e.g. the mule is produced from a female horse (mare) and a male donkey

Artificial Insemination and MOET

• Artificial insemination (AI): semen collected from a chosen superior male is injected into the reproductive tract of the selected female; the semen may be used immediately or frozen and transported to where the female is kept, helping to overcome several problems of normal mating and allowing one superior bull to sire a very large number of offspring
• Although AI raises the success rate of desirable matings, the conception rate using AI alone is sometimes low, so additional technologies such as MOET are used to improve it further
• Multiple Ovulation Embryo Transfer (MOET): a cow is administered hormones (with FSH-like activity) to induce follicular maturation and super-ovulation — producing 6-8 eggs instead of the usual one per cycle; the animal is either mated or artificially inseminated, and the early embryos (at the 8-32 cell stages) are recovered non-surgically and transferred to surrogate mothers
• Since the genetic (donor) mother is freed for another round of super-ovulation, MOET greatly accelerates herd improvement; the technology has been applied to cattle, sheep, rabbits, buffaloes and mares

Bee-keeping: Requirements and Economic Value

• Bee-keeping (apiculture) is the rearing and management of honeybees on a large scale for the production of honey and other products; it can be practised wherever there are sufficient bee pastures (flowering plants) and requires relatively little investment
• Requirements for successful bee-keeping include a knowledge of the nature and habits of bees, the selection of a suitable location for the hives, the catching and hiving of swarms, and the management of beehives during the different seasons
• Products of value include honey, a highly nutritious food, and beeswax, which is used in the preparation of cosmetics and polishes among many other industrial products
• The greatest importance of bee-keeping lies in the pollination of crops: keeping beehives in fields of crops such as sunflower, Brassica, apple and pear during flowering raises pollination efficiency, improving both the crop yield and the honey yield

🚀 NEET Advanced Edge

Why composite fish culture works without strict species separation: Catla feeds at the surface, Rohu in the middle, and Mrigal/common carp at the bottom — by occupying different feeding niches in the SAME water body, the species avoid direct competition for food, allowing total fish yield per pond to exceed what any single species could achieve alone (a direct application of the niche-differentiation concept from ecology).

Why emasculation AND bagging are both necessary, not just one: Emasculation (removing anthers) prevents the flower from self-pollinating with its OWN pollen, but bagging is still required afterward to prevent unwanted FOREIGN pollen (carried by wind or insects) from contaminating the cross before the breeder deliberately applies the desired pollen — skipping bagging defeats the purpose of a controlled cross.

Worked reasoning: A cybrid is produced by fusing an enucleated protoplast (cytoplasm only, no nucleus) of species A with a whole protoplast of species B. What does the resulting cell's nuclear genome match, and why is this technique useful? Answer: The nuclear genome matches species B (since species A contributed no nucleus); this technique is useful for transferring CYTOPLASMIC traits (e.g. cytoplasmic male sterility, chloroplast/mitochondrial genes) from species A into species B without altering the recipient's nuclear genetic background.