1. The document describes a process for obtaining haploid embryos in wheat through wheat and maize wide hybridization. Key steps include growing maize as a pollen donor, vernalizing and growing wheat plants, emasculating wheat spikes, pollinating with maize pollen, applying a hormone spray, harvesting spikes 16-19 days after pollination, rescuing embryos under sterile conditions, and regenerating embryos on media. The goal is to produce haploid wheat embryos that can be doubled to create homozygous breeding lines more rapidly.
Haploid plant formation can occur through several methods, including anther/pollen culture, ovule culture, and distant hybridization. Anther/pollen culture involves culturing anthers or isolated microspores to induce microspores or pollen to undergo embryogenesis rather than gametogenesis. Success requires triggering a shift from the gametophytic to sporophytic development pathway. Temperature shock, culture medium composition, and donor plant conditions influence response. Haploids can be doubled to create homozygous diploid lines using colchicine, valuable for shortening plant breeding cycles.
The document discusses the process of developing commercial hybrid varieties through inbreeding. It involves three main steps - developing inbred lines through self-pollination over multiple generations, evaluating the inbred lines through tests like top cross testing and single cross evaluation, and producing hybrid seeds by crossing selected inbred lines. The hybrids derived from inbred lines are homogeneous and uniform, performing predictably, which makes them desirable for commercial production. Objections to the dominance hypothesis for heterosis are also addressed, with explanations like linkage and large number of genes governing traits resulting in symmetrical distributions.
Wheat is the second most important winter cereal in India after rice. It contributes approximately 95% of total cereal production. India is the second largest producer of wheat in the world next to China. The major achievements of the Indian wheat program include releasing 373 wheat varieties since 1965, developing advanced production technologies, preventing rust epidemics through improved protection strategies, and strengthening international collaborations for global food security. However, biotic stresses like various rust diseases, insects, and weeds; and abiotic stresses such as drought, heat, and poor soil health pose key constraints. The document discusses issues and strategies regarding wheat improvement, crop protection, resource management, and production targets to ensure food security.
Engineering C4 rice could significantly increase yields, water and nitrogen use efficiencies. C4 photosynthesis concentrates carbon dioxide in mesophyll cells before transferring it to bundle sheath cells for carbon fixation. Replicating this two-cell C4 pathway in rice will require altering leaf anatomy, cell biochemistry and gene regulation, which may take over 15 years of research. Key challenges include developing Kranz anatomy and optimizing C4 enzymes in the right cell types through molecular engineering and breeding approaches.
This document discusses hybrid breeding and its achievements. It describes the objectives, steps, and methods involved in hybrid seed production, including the development of inbred lines, evaluation of inbreds, and production of hybrid seeds. Various types of hybrids are mentioned, such as single cross, double cross, top cross, and population hybrids. The advantages of hybrids include increased yield, uniformity, and vigor. Examples are given of hybrids released in crops using male sterility systems. The document concludes with achievements of hybrids in various crops in India.
This document provides information on groundnut seed production practices and crop management. It discusses the different classes of groundnut seed, including nucleus, breeder, foundation, and certified seed. It outlines seed certification standards and the inspection process. The document also covers technical aspects of groundnut seed production such as soil and climate requirements, field isolation, crop rotation, land preparation, fertilizer use, seed selection and treatment, planting methods, and crop maintenance practices.
Asexuapropagation and clonal propagationPawan Nagar
Some agricultural and horticultural crops such as sugarcane, potato, banana, and citrus propagate asexually through vegetative means rather than sexually from seeds. There are several reasons for this type of asexual reproduction: many of the crops are perennial plants that show reduced flowering and seed set or do not flower at all; propagating asexually avoids inbreeding depression in crops that are cross-pollinated and highly heterozygous; and some species are interspecific hybrids.
The main purpose of these slides is to convey information to the Professors, Lecturers, and Students. These slides contain authentic information about this topic which is mentioned in that.
Haploid plant formation can occur through several methods, including anther/pollen culture, ovule culture, and distant hybridization. Anther/pollen culture involves culturing anthers or isolated microspores to induce microspores or pollen to undergo embryogenesis rather than gametogenesis. Success requires triggering a shift from the gametophytic to sporophytic development pathway. Temperature shock, culture medium composition, and donor plant conditions influence response. Haploids can be doubled to create homozygous diploid lines using colchicine, valuable for shortening plant breeding cycles.
The document discusses the process of developing commercial hybrid varieties through inbreeding. It involves three main steps - developing inbred lines through self-pollination over multiple generations, evaluating the inbred lines through tests like top cross testing and single cross evaluation, and producing hybrid seeds by crossing selected inbred lines. The hybrids derived from inbred lines are homogeneous and uniform, performing predictably, which makes them desirable for commercial production. Objections to the dominance hypothesis for heterosis are also addressed, with explanations like linkage and large number of genes governing traits resulting in symmetrical distributions.
Wheat is the second most important winter cereal in India after rice. It contributes approximately 95% of total cereal production. India is the second largest producer of wheat in the world next to China. The major achievements of the Indian wheat program include releasing 373 wheat varieties since 1965, developing advanced production technologies, preventing rust epidemics through improved protection strategies, and strengthening international collaborations for global food security. However, biotic stresses like various rust diseases, insects, and weeds; and abiotic stresses such as drought, heat, and poor soil health pose key constraints. The document discusses issues and strategies regarding wheat improvement, crop protection, resource management, and production targets to ensure food security.
Engineering C4 rice could significantly increase yields, water and nitrogen use efficiencies. C4 photosynthesis concentrates carbon dioxide in mesophyll cells before transferring it to bundle sheath cells for carbon fixation. Replicating this two-cell C4 pathway in rice will require altering leaf anatomy, cell biochemistry and gene regulation, which may take over 15 years of research. Key challenges include developing Kranz anatomy and optimizing C4 enzymes in the right cell types through molecular engineering and breeding approaches.
This document discusses hybrid breeding and its achievements. It describes the objectives, steps, and methods involved in hybrid seed production, including the development of inbred lines, evaluation of inbreds, and production of hybrid seeds. Various types of hybrids are mentioned, such as single cross, double cross, top cross, and population hybrids. The advantages of hybrids include increased yield, uniformity, and vigor. Examples are given of hybrids released in crops using male sterility systems. The document concludes with achievements of hybrids in various crops in India.
This document provides information on groundnut seed production practices and crop management. It discusses the different classes of groundnut seed, including nucleus, breeder, foundation, and certified seed. It outlines seed certification standards and the inspection process. The document also covers technical aspects of groundnut seed production such as soil and climate requirements, field isolation, crop rotation, land preparation, fertilizer use, seed selection and treatment, planting methods, and crop maintenance practices.
Asexuapropagation and clonal propagationPawan Nagar
Some agricultural and horticultural crops such as sugarcane, potato, banana, and citrus propagate asexually through vegetative means rather than sexually from seeds. There are several reasons for this type of asexual reproduction: many of the crops are perennial plants that show reduced flowering and seed set or do not flower at all; propagating asexually avoids inbreeding depression in crops that are cross-pollinated and highly heterozygous; and some species are interspecific hybrids.
The main purpose of these slides is to convey information to the Professors, Lecturers, and Students. These slides contain authentic information about this topic which is mentioned in that.
This document discusses methods for improving crop populations through intrapopulation and interpopulation breeding. Intrapopulation improvement involves selecting within a population to increase frequencies of advantageous alleles. Interpopulation improvement utilizes selection between populations and can capture effects of additivity, dominance, and epistasis. Common interpopulation methods include reciprocal recurrent selection using half-sib or full-sib families to select and recombine superior lines between populations. The document also discusses heterotic patterns used in maize breeding and provides examples of tester lines and populations used in different regions and countries.
Seed viability equations and application of nomograohs in storagekartoori sai santhosh
The document discusses the development of seed viability equations over time to better predict seed longevity in storage. Key developments include adopting international gene bank standards, incorporating the effects of temperature, moisture content, and seed quality on longevity, and relating longevity to the glass transition temperature of seeds. The equations have evolved from basic forms involving three or four constants to a single improved equation incorporating constants for species and storage conditions.
1) Apomixis is a form of asexual reproduction that occurs in some plant species and can fix heterosis in hybrids. It allows for the production of seeds that are genetically identical to the parent plant.
2) There are different types of apomixis that occur, including apospory and diplospory. Apomixis is detected by a failure to obtain hybrid plants from crosses and uniform progeny from heterozygous plants.
3) Developing apomictic lines involves transferring genes from wild species, induced mutations, or isolating recombinants from interspecific crosses. Apomixis has advantages like fixing heterosis but also challenges like complex genetics and environmental influences on facult
1. Seed quality control systems were established in Nepal to regulate and improve seed production and distribution.
2. Standards for seed certification were developed for key crops to ensure minimum thresholds for varietal purity, disease resistance, and other quality factors.
3. Both public and private organizations now participate in seed production, processing, and marketing under the oversight of the National Seed Board.
This document discusses mass selection, a method of plant breeding where individual plants are selected based on desirable phenotypes from a mixed population. Seeds from selected plants are then combined to grow the next generation. Mass selection can be used to improve self-pollinating or cross-pollinating crops. It has resulted in improved varieties of crops like bajra, yellow sarson, brown sarson, maize, desi cotton, and castor. While mass selection is simple and applicable to many crops, the improvements may be less than other methods and varieties developed have more genetic variation than pure lines.
This document discusses the development of inbred lines through repeated self-pollination and selection over multiple generations. It describes how inbred lines are developed from variable source populations in both self- and cross-pollinated crops using methods like pedigree selection. Inbred lines are homozygous genotypes that are then used to produce hybrid varieties which benefit from heterosis or hybrid vigor. The document outlines the procedures for inbred line development and some of the early hybrid varieties released for important crops in India.
The document provides information on seed production of bajra (Pennisetum typhoides L) in India. It discusses the introduction and importance of bajra cultivation. It then describes the floral structure and pollination behavior of bajra. The rest of the document outlines the methodology for commercial bajra seed production, including site selection, isolation distances, crop management practices, harvesting, processing and certification standards. The goal is to produce high quality seeds through proper agronomic practices and genetic purity maintenance.
History of plant breeding by dr p vinod (2)Vinod Pawar
1. The document provides an overview of plant breeding, including its definition, history, objectives, and future prospects. It discusses the science of genetics and modern plant breeding techniques.
2. Key developments in the history of plant breeding in India are highlighted, including the establishment of agricultural research institutions and contributions from eminent Indian scientists.
3. The objectives of plant breeding are described, such as higher yield, improved quality, biotic/abiotic resistance, and wider adaptability. Potential applications of new technologies like genetic engineering are also noted.
Mating design is a schematic cross between the groups or strains of plants are made in a plant breeding that is common in agriculture and biological sciences
Analysis of variance in offspring plants results from a mating design
To evaluate the effects of additive, dominance ,and epistasis and heritability value equal to the value of genetic expectations
This document discusses balanced tertiary trisomics (BTT), which are a type of tertiary trisomic plant that can be used for hybrid seed production. Tertiary trisomics have an extra chromosome that is the result of a translocation. BTTs are constructed so that a dominant marker gene linked to the translocation breakpoint is on the extra chromosome. The two normal chromosomes carry recessive alleles. This allows BTTs to be distinguished from diploids for use in hybrid seed production schemes, such as one developed for barley where BTTs are male fertile and function as pollen parents, while diploids are male sterile and function as seed parents. The progeny of BTT selfing can then
This document discusses seed production methods for radish. It begins by noting India's import of radish seeds and the requirements for certified radish seeds in India. It then discusses the following key points in 3 sentences:
1) Radish is a highly cross-pollinated crop in the cruciferous family that is pollinated mainly by honey bees. Selection of true-to-type roots and isolation distances of 1600m for foundation seed and 1000m for certified seed production are required.
2) There are two common methods for radish seed production - the seed-to-seed (in situ) method and the root-to-seed (transplanting) method, with the latter allowing for
This document discusses different types of plant breeding populations based on their genetic constitution and mode of reproduction. It describes self-pollinated species as homozygous and homogeneous, producing offspring through self-fertilization. Cross-pollinated species are heterozygous and heterogeneous, as random mating produces new gene combinations. Asexually propagated species can be either self- or cross-pollinated, and are generally highly heterozygous with a broad genetic base. Breeding populations are classified as homogeneous, heterogeneous, homozygous, or heterozygous based on genetic similarity and whether they segregate upon self-fertilization.
Triticale is a human-made cereal grain produced by crossing wheat and rye. Some key points:
- Triticale was first produced in 1875 through inter-specific crosses between wheat and rye. Early hybrids were sterile but chromosome doubling led to the development of hexaploid and octoploid triticale varieties.
- Triticale varieties are used as animal feed and forage but have also been used for making chapatis. They are higher in protein and lysine than wheat.
- India has released four triticale varieties, including late maturing variety Triticale (70-2) and dwarf variety Triticale DTS-703 that is moderately resistant to rust
This document discusses the origin and breeding of maize. It provides three main views on the origin of maize: 1) from teosinte, 2) from pod corn through natural mutation, and 3) from a common ancestor of maize, teosinte and tripsacum. The key tool for hybrid maize seed production is detasseling, which is the removal of the male tassel from the female plant, allowing it to be pollinated in a controlled manner. Breeding objectives include increasing yield, pest and disease resistance, protein and oil content. Breeding methods include introduction, mass selection, ear-to-row, hybridization and selection, and population improvement.
This document discusses several hypotheses for heterosis, or hybrid vigor. It summarizes the dominance hypothesis, which proposes that heterosis results from the superiority of dominant alleles over recessive alleles. It also summarizes the overdominance hypothesis, which suggests heterosis occurs when a heterozygote is superior to either homozygous parent due to production of superior hybrid substances or greater buffering capacity. The document also briefly discusses the epistasis hypothesis, which proposes non-allelic interaction between loci can contribute to heterosis, particularly dominance by dominance epistasis.
CIMMYT breeding strategies and methodologies to breed high yielding, yellow r...ICARDA
CIMMYT has developed high-yielding, rust-resistant bread wheat germplasm through strategies that focus on durable resistance. Breeding efforts utilize race-nonspecific adult plant resistance conferred by combinations of minor genes with additive effects. A recent 5-year cycle developed lines with 12% higher yields and improved resistance to yellow rust. Of 728 advanced lines tested, over 40% had high yields and immunity/resistance to yellow rust. Testing also found that over 40% of lines had good resistance to stem rust race Ug99. CIMMYT's strategy is to deploy varieties with near-immune, durable resistance to provide long-term genetic control of rust diseases.
This document discusses plant breeding and heterosis. It defines heterosis as hybrid vigor resulting from mixing parental genetics. Heterosis can be due to Mendelian or non-Mendelian inheritance. It summarizes the history of hybrid varieties in plants and discusses types of heterosis like true and pseudo heterosis. The document also covers causes of heterosis including genetic and physiological causes, and effects of heterosis like increased yields and resistance to stress. Finally, it discusses hybrid varieties in more detail including single-cross, double-cross hybrids and intergeneric hybrids.
this ppt made for molecular basis of heterosis of crop plant and it has also incuded heterosis on basis of estimation and genetics basis of heterosis. but these points are not properly explation becarse this ppt main aim to explain the heterosis on the basis of heterosis. thank you....
The document discusses anther culture and haploid production techniques. It begins by explaining that anther culture can be used to produce haploid plants faster than traditional breeding methods. It then provides details on the history and development of anther culture techniques. The document outlines the basic procedure for anther culture, including plant growth conditions, anther selection, culture medium, and isolation of haploid plants. It discusses factors that influence anther culture success and limitations of the technique. Finally, it provides some examples of commercial varieties developed using anther culture.
This presentation discusses speed breeding techniques that can accelerate plant development for research purposes. Speed breeding uses controlled environments with extended photoperiods to reduce generation times. It allows up to 6 generations per year for some crops like wheat, barley, and chickpeas compared to normal 2-3 generations. Speed breeding has been shown to work in growth chambers, glasshouses, and homemade growth rooms using LED lighting. It reduces time to flowering and maintains seed viability and yields. Speed breeding can help address global food security challenges by accelerating plant breeding and research.
This document discusses methods for producing haploid plants. It begins by defining haploid plants and their significance. It then describes the two main approaches for producing haploids - in vivo and in vitro. For in vivo, it outlines several techniques including androgenesis, gynogenesis, distant hybridization, and chemical/radiation treatments. For in vitro, it focuses on anther culture and microspore culture, providing details on the protocol for anther culture in tobacco including pre-treatment, culture conditions, and factors that influence success rates.
The document discusses the production of double haploid plants through anther and pollen culture techniques. It provides background on the history of double haploid development, the importance of double haploids in plant breeding, and methods used to induce haploids including anther culture, pollen culture, ovary slice culture, and ovule culture. Key factors influencing anther culture success are also reviewed, such as genotype, culture medium, microspore stage, temperature, and donor plant physiology. Advantages and disadvantages of generating double haploid lines are presented.
This document discusses methods for improving crop populations through intrapopulation and interpopulation breeding. Intrapopulation improvement involves selecting within a population to increase frequencies of advantageous alleles. Interpopulation improvement utilizes selection between populations and can capture effects of additivity, dominance, and epistasis. Common interpopulation methods include reciprocal recurrent selection using half-sib or full-sib families to select and recombine superior lines between populations. The document also discusses heterotic patterns used in maize breeding and provides examples of tester lines and populations used in different regions and countries.
Seed viability equations and application of nomograohs in storagekartoori sai santhosh
The document discusses the development of seed viability equations over time to better predict seed longevity in storage. Key developments include adopting international gene bank standards, incorporating the effects of temperature, moisture content, and seed quality on longevity, and relating longevity to the glass transition temperature of seeds. The equations have evolved from basic forms involving three or four constants to a single improved equation incorporating constants for species and storage conditions.
1) Apomixis is a form of asexual reproduction that occurs in some plant species and can fix heterosis in hybrids. It allows for the production of seeds that are genetically identical to the parent plant.
2) There are different types of apomixis that occur, including apospory and diplospory. Apomixis is detected by a failure to obtain hybrid plants from crosses and uniform progeny from heterozygous plants.
3) Developing apomictic lines involves transferring genes from wild species, induced mutations, or isolating recombinants from interspecific crosses. Apomixis has advantages like fixing heterosis but also challenges like complex genetics and environmental influences on facult
1. Seed quality control systems were established in Nepal to regulate and improve seed production and distribution.
2. Standards for seed certification were developed for key crops to ensure minimum thresholds for varietal purity, disease resistance, and other quality factors.
3. Both public and private organizations now participate in seed production, processing, and marketing under the oversight of the National Seed Board.
This document discusses mass selection, a method of plant breeding where individual plants are selected based on desirable phenotypes from a mixed population. Seeds from selected plants are then combined to grow the next generation. Mass selection can be used to improve self-pollinating or cross-pollinating crops. It has resulted in improved varieties of crops like bajra, yellow sarson, brown sarson, maize, desi cotton, and castor. While mass selection is simple and applicable to many crops, the improvements may be less than other methods and varieties developed have more genetic variation than pure lines.
This document discusses the development of inbred lines through repeated self-pollination and selection over multiple generations. It describes how inbred lines are developed from variable source populations in both self- and cross-pollinated crops using methods like pedigree selection. Inbred lines are homozygous genotypes that are then used to produce hybrid varieties which benefit from heterosis or hybrid vigor. The document outlines the procedures for inbred line development and some of the early hybrid varieties released for important crops in India.
The document provides information on seed production of bajra (Pennisetum typhoides L) in India. It discusses the introduction and importance of bajra cultivation. It then describes the floral structure and pollination behavior of bajra. The rest of the document outlines the methodology for commercial bajra seed production, including site selection, isolation distances, crop management practices, harvesting, processing and certification standards. The goal is to produce high quality seeds through proper agronomic practices and genetic purity maintenance.
History of plant breeding by dr p vinod (2)Vinod Pawar
1. The document provides an overview of plant breeding, including its definition, history, objectives, and future prospects. It discusses the science of genetics and modern plant breeding techniques.
2. Key developments in the history of plant breeding in India are highlighted, including the establishment of agricultural research institutions and contributions from eminent Indian scientists.
3. The objectives of plant breeding are described, such as higher yield, improved quality, biotic/abiotic resistance, and wider adaptability. Potential applications of new technologies like genetic engineering are also noted.
Mating design is a schematic cross between the groups or strains of plants are made in a plant breeding that is common in agriculture and biological sciences
Analysis of variance in offspring plants results from a mating design
To evaluate the effects of additive, dominance ,and epistasis and heritability value equal to the value of genetic expectations
This document discusses balanced tertiary trisomics (BTT), which are a type of tertiary trisomic plant that can be used for hybrid seed production. Tertiary trisomics have an extra chromosome that is the result of a translocation. BTTs are constructed so that a dominant marker gene linked to the translocation breakpoint is on the extra chromosome. The two normal chromosomes carry recessive alleles. This allows BTTs to be distinguished from diploids for use in hybrid seed production schemes, such as one developed for barley where BTTs are male fertile and function as pollen parents, while diploids are male sterile and function as seed parents. The progeny of BTT selfing can then
This document discusses seed production methods for radish. It begins by noting India's import of radish seeds and the requirements for certified radish seeds in India. It then discusses the following key points in 3 sentences:
1) Radish is a highly cross-pollinated crop in the cruciferous family that is pollinated mainly by honey bees. Selection of true-to-type roots and isolation distances of 1600m for foundation seed and 1000m for certified seed production are required.
2) There are two common methods for radish seed production - the seed-to-seed (in situ) method and the root-to-seed (transplanting) method, with the latter allowing for
This document discusses different types of plant breeding populations based on their genetic constitution and mode of reproduction. It describes self-pollinated species as homozygous and homogeneous, producing offspring through self-fertilization. Cross-pollinated species are heterozygous and heterogeneous, as random mating produces new gene combinations. Asexually propagated species can be either self- or cross-pollinated, and are generally highly heterozygous with a broad genetic base. Breeding populations are classified as homogeneous, heterogeneous, homozygous, or heterozygous based on genetic similarity and whether they segregate upon self-fertilization.
Triticale is a human-made cereal grain produced by crossing wheat and rye. Some key points:
- Triticale was first produced in 1875 through inter-specific crosses between wheat and rye. Early hybrids were sterile but chromosome doubling led to the development of hexaploid and octoploid triticale varieties.
- Triticale varieties are used as animal feed and forage but have also been used for making chapatis. They are higher in protein and lysine than wheat.
- India has released four triticale varieties, including late maturing variety Triticale (70-2) and dwarf variety Triticale DTS-703 that is moderately resistant to rust
This document discusses the origin and breeding of maize. It provides three main views on the origin of maize: 1) from teosinte, 2) from pod corn through natural mutation, and 3) from a common ancestor of maize, teosinte and tripsacum. The key tool for hybrid maize seed production is detasseling, which is the removal of the male tassel from the female plant, allowing it to be pollinated in a controlled manner. Breeding objectives include increasing yield, pest and disease resistance, protein and oil content. Breeding methods include introduction, mass selection, ear-to-row, hybridization and selection, and population improvement.
This document discusses several hypotheses for heterosis, or hybrid vigor. It summarizes the dominance hypothesis, which proposes that heterosis results from the superiority of dominant alleles over recessive alleles. It also summarizes the overdominance hypothesis, which suggests heterosis occurs when a heterozygote is superior to either homozygous parent due to production of superior hybrid substances or greater buffering capacity. The document also briefly discusses the epistasis hypothesis, which proposes non-allelic interaction between loci can contribute to heterosis, particularly dominance by dominance epistasis.
CIMMYT breeding strategies and methodologies to breed high yielding, yellow r...ICARDA
CIMMYT has developed high-yielding, rust-resistant bread wheat germplasm through strategies that focus on durable resistance. Breeding efforts utilize race-nonspecific adult plant resistance conferred by combinations of minor genes with additive effects. A recent 5-year cycle developed lines with 12% higher yields and improved resistance to yellow rust. Of 728 advanced lines tested, over 40% had high yields and immunity/resistance to yellow rust. Testing also found that over 40% of lines had good resistance to stem rust race Ug99. CIMMYT's strategy is to deploy varieties with near-immune, durable resistance to provide long-term genetic control of rust diseases.
This document discusses plant breeding and heterosis. It defines heterosis as hybrid vigor resulting from mixing parental genetics. Heterosis can be due to Mendelian or non-Mendelian inheritance. It summarizes the history of hybrid varieties in plants and discusses types of heterosis like true and pseudo heterosis. The document also covers causes of heterosis including genetic and physiological causes, and effects of heterosis like increased yields and resistance to stress. Finally, it discusses hybrid varieties in more detail including single-cross, double-cross hybrids and intergeneric hybrids.
this ppt made for molecular basis of heterosis of crop plant and it has also incuded heterosis on basis of estimation and genetics basis of heterosis. but these points are not properly explation becarse this ppt main aim to explain the heterosis on the basis of heterosis. thank you....
The document discusses anther culture and haploid production techniques. It begins by explaining that anther culture can be used to produce haploid plants faster than traditional breeding methods. It then provides details on the history and development of anther culture techniques. The document outlines the basic procedure for anther culture, including plant growth conditions, anther selection, culture medium, and isolation of haploid plants. It discusses factors that influence anther culture success and limitations of the technique. Finally, it provides some examples of commercial varieties developed using anther culture.
This presentation discusses speed breeding techniques that can accelerate plant development for research purposes. Speed breeding uses controlled environments with extended photoperiods to reduce generation times. It allows up to 6 generations per year for some crops like wheat, barley, and chickpeas compared to normal 2-3 generations. Speed breeding has been shown to work in growth chambers, glasshouses, and homemade growth rooms using LED lighting. It reduces time to flowering and maintains seed viability and yields. Speed breeding can help address global food security challenges by accelerating plant breeding and research.
This document discusses methods for producing haploid plants. It begins by defining haploid plants and their significance. It then describes the two main approaches for producing haploids - in vivo and in vitro. For in vivo, it outlines several techniques including androgenesis, gynogenesis, distant hybridization, and chemical/radiation treatments. For in vitro, it focuses on anther culture and microspore culture, providing details on the protocol for anther culture in tobacco including pre-treatment, culture conditions, and factors that influence success rates.
The document discusses the production of double haploid plants through anther and pollen culture techniques. It provides background on the history of double haploid development, the importance of double haploids in plant breeding, and methods used to induce haploids including anther culture, pollen culture, ovary slice culture, and ovule culture. Key factors influencing anther culture success are also reviewed, such as genotype, culture medium, microspore stage, temperature, and donor plant physiology. Advantages and disadvantages of generating double haploid lines are presented.
8. In vitro production of haploids.pptxBekeleAlemayo
Haploid plants contain only one set of chromosomes (n) rather than the normal two sets (2n). They can be produced through anther/microspore culture or ovary/ovule culture. Anther/microspore culture involves culturing isolated anthers or microspores on nutrient media, which can develop into haploid plants through embryogenesis or organogenesis. Ovary/ovule culture involves culturing isolated ovaries or ovules to produce haploid plants. Haploids are valuable in plant breeding as they allow for rapid development of homozygous lines and recessive traits, shortening the time needed for plant improvement programs.
This document discusses anther and pollen culture techniques. It provides a brief history of the development of these techniques from the 1950s onward. It then describes the process of anther culture, where anthers are cultured in nutrient medium to produce haploid callus or embryos. Pollen or microspore culture involves isolating pollen grains from anthers and culturing them. The goal is to produce haploid embryos or callus that can develop into haploid plantlets. Key factors that influence success include the genotype, microspore stage, culture medium, temperature, and physiological status of the donor plant. Anther culture has applications in mutation studies, plant breeding, and secondary metabolite production.
This document summarizes a study on using colchicine pretreatment of maize anthers to induce doubled haploids. Two maize genotypes were used as donors for anther culture. Anthers were pretreated with different concentrations of colchicine for various durations before culture. Results showed increased embryogenic structure formation with 100 mg/L colchicine in one genotype and 300 mg/L in the other. Both genotypes produced doubled haploid plantlets when anthers were pretreated with 250 mg/L colchicine for 6 days. The study demonstrates the use of colchicine pretreatment to improve chromosome doubling rates in anther culture of maize.
The production of haploid plants exploiting the totipotency of microspore.
Androgenesis is the in vitro development of haploid plants originating from totipotent pollen grains through a series of cell division and differentiation.
Anther culture is a technique where anthers are excised from flower buds and cultured on nutrient media. This can produce haploid plantlets through either organogenesis or embryogenesis. The first report of haploid tissue from anther culture was in 1966 in Datura pollen grains. Haploids are useful for plant breeding as they contain only one allele per gene, revealing recessive traits, eliminating lethal genes, and allowing for efficient production of homozygous plants. The protocol involves sterilizing tobacco flower buds, removing anthers, and culturing them on nutrient media. After 3-4 weeks, haploid plantlets emerge from the cultured anthers. Haploids have applications in basic research, mutation studies
Much faster rates of growth can be induced in vitro than by traditional means.
Multiplication of plants which are very difficult to propagate by cuttings or other traditional methods.
Production of large numbers of genetically identical clones in a short time
Seeds can be germinated with no risk of damping off/ predation.
Under certain conditions, plant material can be stored in vitro for considerable periods of time with little or no maintenance
Tissue culture techniques are used for virus eradication, genetic manipulation, somatic hybridization and other procedures that benefit propagation, crop improvement, and basic research.
By means of tissue culture it is possible to produce pathogen free plantlets by mass multiplication in a very limited amount of area from a very small sterile part of a mother plant. This method is also used to produce/ multiply plants that are to be transported across national border and so for their faster multiplication.But the establishment of a tissue culturing unit needs huge financial investments, skilled labors/technicians and required areas for its establishment are major constraints. Plant tissues grow and multiply in the labs only when there is an uncompetitive, growing condition with uninterrupted supply of nutrients.
Medium:
It contains all the elements that contribute the required nutrients that aid to the growth of the tissues; it is in liquid state or semi-solid in nature. The tissues are grown on the media. It consists of 95% of water, major and minor nutrients, plant growth hormones, vitamins, sugar rich compounds and chelating agents.
Totipotency:
It is the ability of a tissue or an organ of a plant to produce the whole plant, under the optional laboratory conditions and this is called as Totipotency. This is the baseline over which plant tissue culture relies upon.
Callus Culture:
When the cells divide into an undifferentiated mass it is called as callus. Any part of a plant can be used to produce the calli. It may be a stem, leaf, meristem or any other part. It is used to produce variations among the plantlets.
Suspension culture:
The callus produced from the explants are grown on nutrient solutions (that are semi solid) for a period of time and they are induced to produce plants with new traits.
Embryo Culture:
The method of culturing mature and immature embryos in media is called embryo culture. By this method, it is possible to produce plants from dormant seeds and seeds with metabolites that inhibit germination. This method is very important in crop improvement programs.
Somatic Embryogenesis:
When the plants are grown on nutrient media, calli are formed. When these calli are subjected to growth in cytokinin medium, somatic embryos are formed. They are circular, elongated,
Single cell culture
• As stated earlier, cells derived from a single cell through mitosis constitute a clone and the process of obtaining clones is called cloning (asexual progeny of a single individual make up.
This document provides instructions for mass producing two types of biological control agents: the Helicoverpa armigera Nuclear Polyhedrosis Virus (HaNPV) and the entomopathogenic nematode Neoplectana spp. (DD-136).
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Wide hybridization (Wheat x Maize)
1. Name- Patil Kulbhushan Savindra
PID.- 12020442
Department of Genetics and plant
Breeding
Topic- Wheat X Maize Wide Hybridization For Obtaining
Haploid Embryos
Assignment - I
Dr. Sanjeet Singh
Lovely Professional University
2. 1. Introduction
• Wheat is the staple food of millions of people. It is also an important part of the daily
diet of many millions more. There has been a tremendous increase in wheat
production in our country since the times of the Green Revolution.
• However, at present, the wheat production has almost reached a plateau and another
breakthrough is required in order to meet the ever-increasing food demand of the
nation.
• The genetic up gradation of wheat through conventional breeding approaches require
longer time there is a need to assist these methods following certain biotechnological
tools so as to shorten the breeding cycle and Doubled Haploidy (DH) breeding is one
such tool which has been widely used in breeding programs (Sunega et al, 1994).
Amongst the available techniques for the development of haploids and doubled
haploids in wheat, chromosome elimination approach following wheat x maize
system is one of the most efficient approach (Laurie and Bennett, 1988).
3. • The use of doubled haploid (DH) plants has revolutionized modern plant breeding
and genetic mapping studies in many important cereals and fruit crops.
• DH technology fixes rare alleles and may play an important role in evaluation of
genetic diversity. Thus, doubled haploid technology is useful in plant improvement
for gene transfer and production of breeding lines.
• Doubled haploids are homozygous plants developed by androgenesis (microspore
and anther culture), gynogenesis (ovary and ovule culture), and wide hybridization.
• In wheat, the wide hybridization method is the most effective for producing
doubled haploids(Niu et al, 2014).
• The method of crossing between species of the same or different genera is called
wide hybridization.
• Wide hybridization has been becoming popular in wheat since late 1970s which
has been described in several literatures.
4. • Haploid production through wide hybridization is considered gynogenesis because
the haploid developed from this procedure contain the maternal haploid genome.
• The haploid production through wide hybridization was first discovered in crosses
between barely and bulbous barely.
• In 1986 Laurie and Bennett established the wide hybridization system between
wheat and maize. He reported that wheat ovules were fertilized by maize pollen
and the haploid wheat embryos were produced through the elimination of maize
chromosomes.
• The efficiency of haploid induction in common wheat is usually higher than durum
wheat using wide hybridization with maize.
• High ploidy level and the D genome of common wheat may play an important
role in DH production.
5. 2. Objectives
1. To speed the process of breeding and production of breeding lines.
2. To identify the population development in crop improvement, genetic
manipulation, plant genome and gene mapping.
3. Factors affecting efficiency of DH production in wide
hybridization
1. The position of spikelet in the flower and time for pollination.
2. Temperature, light intensity and photoperiod during the plant growth period.
3. The type and concentration of plant growth regulators applied after pollination.
4. The biochemical elements added to the rescue media.
5. The concentration of colchicine used for chromosome doubling and the plant
growth stage, duration and temperature when the colchicine is applied.
6. 4. Material required for obtaining haploid embryos / DH laboratory-
1. Wheat seeds ( F1, F2 or other generations) and maize genotypes.
2. Glassine bags, surgical scissors, forceps, scalpels, and stapler.
3. Laboratory glassware's.
4. Refrigerator, laminar flow cabinet, distilled water unit, autoclave, pH meter, digital
balance with four-digit precision, stirrer with hot plate and aluminum foil.
5. Hydrochloric acid (1 N HCL) and sodium hydroxide (1 and 10 N NaOH) solutions.
6. Sodium hypochlorite (bleach) and cheesecloth.
7. Alcohol burner or germinator™ 500.
8. 2,4-D solution for spray.
9. MS media.
10. Colchicine stock solution (5%)
7. 5. Procedure for obtaining haploid embryos-
Maize
Planting and
Management
Wheat
vernalization
, planting
and
management
Emasculatio
n and
Pollination
Hormone
Spray
Embryo
Rescue
Regeneration
of embryos
Vernalization
of Haploid
Plantlets for
Winter
Wheat
Colchicine
Treatment
8. 5.1 Maize Planting and Management-
1. Maize was planted 3 weeks before transplanting vernalized wheat seedlings and
is then planted every week to ensure a continuous supply of pollen. At every
planting time, seven to ten pots were planted with three seeds in each pot.
2. Pots were watered as needed and were fertilized weekly with a fertilizer solution.
3. Maize plants should be healthy in order to get viable pollen and should be
monitored from time to time for diseases and pests.
9. 5.2 Wheat vernalization, planting and management-
1. F1 plants obtained from crossing between desired parents are used as female
parents for the wide hybridization. The plants should be healthy without
incidence of diseases or pests.
2. Winter wheat needs 8 weeks of vernalization whereas spring wheat seeds may be
planted directly in pots.
3. As soon as vernalization is over, wheat seedlings are transplanted two seedlings
per one gallon pot.
4. Watering is done on alternate days or if the soil appears dry.
5. Staggered planting of wheat seedlings by 7–10 days may be an option to spread
the workload and reduce the need for large amounts of maize pollen on any
single day.
10. 5.3 (a) Emasculation
1. Selection of the correct developmental stage of the wheat floret is very important.
2. A floret approximately 2/3 of the way up the spike should be checked to determine if
the spike is ready for emasculation.
3. Each wheat floret contains three anthers along with a pistil and the process of
removing three anthers form each floret is called emasculation.
4. If the anthers are starting to change from a dark green color to a light green color and
the stigma is fluffy, the spike can be emasculated.
5. Starting at the bottom of the spike, emasculation is done by removal of the central
florets of each spikelet leaving only the two lateral florets.
6. Anthers are then removed using a forceps from the lateral florets in a systematic
pattern from the bottom to the top of the spike.
7. Once emasculation is complete, the spike is bagged with a glassine bag that is
properly labeled with the name of the cross and the day of emasculation.
12. 5.3 (b) Pollination
1. Anthers are collected from maize plants when the anthers are starting to emerge,
being very careful not to disturb the other anthers as the pollen will be lost.
2. Anthers from multiple maize plants are collected at the same time and placed in
a petri dish.
3. The glassine bags are removed from the emasculated wheat spikes 1 day after
emasculation, or when the stigma has a feathery appearance.
4. The pollen is then brushed onto each stigma on the emasculated spikes using a
small paint brush; the pollen should flow easily from the anther to the
emasculated florets. Once the entire spike is pollinated, the date of pollination is
recorded on the glassine bag and the bag is replaced over the spike.
14. 5.4 Hormone Spray
1. The day after pollination the spikes should be sprayed with 2,4-D (Sigma)
solution (0.5 mg/L ).
2. Wedzony and Van Lammeren in 1996 demonstrated that 2,4-D increased the
number of the pollen tubes that reached the micropyle and multiplied the number
of sperm cells in the pollen tube, thus increasing successful intergenric
fertilization.
3. The hormone treatment is applied by spraying the solution on the spike using a
small aerosol sprayer bottle. The hormone treatment should be done within 24–
48 hrs. after pollination.
4. After hormone treatment, the glassine bags are replaced and secured with a
stapler.
15. 5.5 Embryo Rescue
1. From 16 to 19 days after pollination, spikes are cut off leaving approximately 20 cm
of stem with the spike; spikes with stems are placed in a container of double
distilled water.
2. The caryopses (hybrid seeds) are removed carefully with forceps.
3. The culture of the embryos should be done under sterile conditions in a laminar
hood.
4. Embryos should be rescued within 7 days after collecting the spikes. The spikes are
kept at 4 C until embryos are rescued.
5. The caryopses are surface sterilized with 70% alcohol for 1 min. The ethanol is
drained and the seeds are covered with a 60% sodium hypochlorite (bleach) solution
for 10 min with 2 or 3 drops of Tween 20.
16. 6. The bleach solution is poured off and seeds are rinsed five times with sterilized double
distilled water. Seeds are transferred into sterile petri dishes and then dissected
carefully.
7. Dissection can be achieved in one of the following two ways-
a. From the embryo end, hold the caryopsis with the forceps, and cut the brush
end of the caryopsis using a scalpel. Tilt the open end of the caryopsis toward the
microscope with the forceps. The embryo is a small white or translucent structure within
the caryopsis. Since there is no solid endosperm present, it should be fairly easy to see if
there is an embryo present.
b. To open the caryopsis is to steady the caryopsis with forceps or scalpel and use
another set of forceps to grab the seed coat 2/3 of the way from the embryo end and pull
back exposing the embryo.
17. Harvesting pollinated and hormone
treated wheat heads after 16 days
Embryo rescue under stereo microscope
Removal of hybrid seeds from wheat-
maize hybrid heads
Sterilization of wheat- maize hybrid seeds
18. 5.6 Regeneration of embryos
1. After excision, the embryos are placed in ½ strength Murashige–Skoog (MS) or
B5 basal medium.
2. The concentration of sucrose supplemented in the media is the major element
affecting the germination of the rescued embryos.
3. The embryos are placed in a dark incubator at 23 C for 1–2 weeks.
4. Once good roots and shoots form, the small plantlets are transferred to a lighted
incubator at 23 C . The lighted incubator is maintained using a 16 h day and 8 h
night photoperiod.
5. Sometimes very small embryos are rescued and these embryos do not grow in
normal hormone-free media. Those small embryos are placed in hormone media
fortified with kinetin and phenyl acetic acid (PAA).
19. Regeneration of rescued embryos in dark
incubator
Regenerated plants with well- developed
roots and shoots in a lighted incubator
20. 5.7 Vernalization of haploid plantlets for winter wheat
1. Once the regenerated plants show good root and shoot development in the tubes
we place them in a refrigerated chamber at 4 C for 8 weeks.
2. We transfer haploid plants to potting soil in flat trays after 8 weeks and treat them
with colchicine solution when plants become healthy.
3. Vernalized plants are planted into a soil medium with good nutrition in a flat
having 48–96 cells.
4. Once plants reach the 5–6 leaf stage, we remove them from the soil and wash the
roots to remove the soil. The roots are then trimmed to about 1 cm in length prior
to dipping into the colchicine solution.
21. 5.8 Colchicine Treatment
1. We treat the plants with colchicine after vernalization for winter wheat.
2. Colchicine is an alkaloid obtained from Colchicum species.
3. Colchicine disrupts mitosis by inhibiting formation of spindle fibers and
disturbing normal polar chromosomal migration, resulting in chromosome
doubling (Jensen 1974).
4. Treatment is done at the 5–6 leaf stage. Colchicine treatment is done under a
fume hood and plants are given overnight treatment (14–15 h) under dark.
5. The optimal colchicine treatment should have a high rate of embryo germination
and a high plant survival rate, with a high rate of chromosome doubling.
6. Roots of rinsed plants are kept in tap water for 2–3 h before planting them into
pots or soil beds.
22. Planting chromosome- doubled plants
in a soil bed in the greenhouse
Wheat spike with seeds in chromosome
doubled plants
23. 6. Chromosome elimination????
• Chromosome elimination is a powerful tool in the production of haploid plants. It
is achieved by conducting wide interspecific crosses.
• Ho and Kasha who first used this technology and discovered that certain
chromosomes carry genetic elements that account for genetic stability in
interspecific crosses.
• Various theories have been proposed to explain the mechanism of Chromosome
elimination could be caused by the difference in timing of mitotic processes
(Gupta 1969), the genomic balance (Kasha and Kao 1970) and the failure of the
chromosome to initiate or to complete either congregation at metaphase or
migration to the poles at anaphase (Bennett et al., 1976).
24. • Ho and Kasha developed chromosome elimination by emasculating Hordeum
vulgare and pollinated it with Hordeum bulbosum.
• After pollination, the formation of embryos occurred with approximately 68.5%
being haploid and a few diploid hybrids and aneuploids.
• In hybrid embryos between wheat and maize, the maize chromosome to be
eliminated were peripherally located on the metaphase plates and lagged behind
the what chromosomes at anaphase (Laurie and Bennett 1989).
25. 7.References
• Barclay, I.R. 1975. High frequencies of haploid production in wheat (Triticum
aestivum) by chromosome elimination. Nature (London) 256: 410-411.
• Bennet, M. D., Barclay, I. R. and Finch, R. A. 1976. The time rate and
mechanism of chromosome elimination in Hordeum hybrids. Chromosoma 54,
175-200.
• Blakslee, A. F., Belling, J. F. M. and Berger, A. D. 1922. A haploid mutant in the
jimson weed Datura stramonium. Science 55: 646.
• Chaudhary, H. K., Singh, S. and Sethi, G. S. 2002. Interactive influence of wheat
and maize genotypes on haploid induction in winter x spring wheat hybrids.
Journal of Genetics & Breeding 56: 259-266.
• Matzk, F and Mahn, A. 1994. Improved techniques for haploid production in
wheat using chromosome elimination. Plant Breeding 113:125-129.
26. • Suenaga, K. 1994. Doubled haploid system using the intergeneric crosses
between wheat (Triticum aestivum) and maize (Zea mays). Bulletin of National
Institute of Agrobiological resources 9: 83-139.
• Laurie, D.A. and Bennet, M.D. 1988. The production of haploid wheat plants
from wheat x maize crosses. Theoretical and Applied Genetics 76: 393-397.
• Chaudhary H.K., Sethi G.S., Singh S., Pratap A. & Sharma S. (2005). Efficient
haploid induction in wheat by using pollen of Imperata cylindrica. Plant Breeding
124(1): 96-98.
• Yamamoto, M. & Mukai, Y. (1989).Application of fluorescence in situ
hybridization to molecular cytogenetics of wheat. Wheat Inf. Serv. 69:30-32.