The document discusses doubled haploid technology for line development in maize. It describes the history of maize doubled haploids and the different types and techniques used, including in vitro and in vivo methods. The key steps of doubled haploid production are outlined, beginning with the selection of individuals for haploid induction, induction of haploids, identification of haploids, chromosome doubling in haploids, and seed production from the D0 nursery. Advantages and applications of doubled haploids in plant breeding are also mentioned.
This document summarizes a seminar on doubled haploids (DH). It defines a DH as an individual with a doubled set of chromosomes from a haploid cell. It discusses the history of DH development, including early work in the 1920s. It also covers methods for producing haploids, identifying haploids, doubling chromosomes, and applications of DHs in plant breeding like QTL mapping, backcrossing, hybrid sorting, and cultivar development. DHs allow fixing of traits in one or two generations, faster development of pure lines and cultivars compared to conventional methods.
Heterotic group โis a group of related or unrelated genotypes from the same or different populations, which display similar combining ability and heterotic response when crossed with genotypes from other genetically distinct germplasm groups.โ
Definitions, variety production release and notification in india and pakistsudha2555
ย
1. The document discusses concepts related to variety release and seed production systems in India and other countries like Pakistan. It defines key terms and describes procedures for variety testing, release, and notification.
2. Variety testing in India involves evaluation through station trials, multilocation trials, national trials, and on-farm trials over several years before potential release. Superior varieties identified through this process may be recommended for release.
3. Release and notification involves recommendation by variety release committees at the state and national level, followed by an official notification from the Government of India allowing commercial seed production.
Genetic Enhancement- Need for Genetic EnhancementKK CHANDEL
ย
Journey From Wild to Domestication; Genetic Enhancement- Need for Genetic Enhancement; Genetic Enhancement in Pre Mendelian Era and 21st Century; Genetic Enhancement and Plant Breeding; Reasons For Failure in Genetic Enhancement; Sources of Genes/ Traits- Novel Genes For Quality
Reverse Breeding: a tool to create homozygous plants from the heterozygous po...Sanjay Kumar
ย
This document provides an overview of reverse breeding, a novel plant breeding technique to directly produce homozygous parental lines from any heterozygous plant. It discusses how reverse breeding uses RNA interference to suppress meiotic recombination and produce doubled haploids from gametes, generating homozygous parental lines. The document summarizes a case study applying this to Arabidopsis thaliana and discusses applications like reconstructing hybrids, breeding at the chromosome level, and implications for food safety. Limitations and future research directions are also outlined.
Reverse breeding is a novel plant breeding technique that allows the development of parental lines directly from any superior heterozygous plant. It involves suppressing meiotic recombination to produce gametes with whole parental chromosome sets, followed by doubling of haploids to generate parental lines. Two case studies demonstrate using RNAi to silence meiotic genes in Arabidopsis thaliana, producing parental lines that reconstitute the original hybrid when crossed. A second technique, marker-assisted reverse breeding, uses high-density SNP genotyping instead of gene silencing to select maize lines similar to original parents within one year. Reverse breeding techniques accelerate breeding and facilitate hybrid improvement without prior knowledge of parental lines.
Population breeding in self pollinated cropsDarshana Ajith
ย
The document describes Diallel Selective Mating (DSM), a population improvement approach involving parental diallel crosses, F1 diallel crosses, and selective mating series. DSM aims to accumulate desirable alleles, broaden the genetic base, and develop new cultivars through recurrent selection and intermating in segregating generations. It allows for introduction of new germplasm and isolation of pure lines at various stages of the breeding program. While effective for some autogamous crops, DSM requires a large number of crosses and is labor intensive.
This document summarizes a seminar on doubled haploids (DH). It defines a DH as an individual with a doubled set of chromosomes from a haploid cell. It discusses the history of DH development, including early work in the 1920s. It also covers methods for producing haploids, identifying haploids, doubling chromosomes, and applications of DHs in plant breeding like QTL mapping, backcrossing, hybrid sorting, and cultivar development. DHs allow fixing of traits in one or two generations, faster development of pure lines and cultivars compared to conventional methods.
Heterotic group โis a group of related or unrelated genotypes from the same or different populations, which display similar combining ability and heterotic response when crossed with genotypes from other genetically distinct germplasm groups.โ
Definitions, variety production release and notification in india and pakistsudha2555
ย
1. The document discusses concepts related to variety release and seed production systems in India and other countries like Pakistan. It defines key terms and describes procedures for variety testing, release, and notification.
2. Variety testing in India involves evaluation through station trials, multilocation trials, national trials, and on-farm trials over several years before potential release. Superior varieties identified through this process may be recommended for release.
3. Release and notification involves recommendation by variety release committees at the state and national level, followed by an official notification from the Government of India allowing commercial seed production.
Genetic Enhancement- Need for Genetic EnhancementKK CHANDEL
ย
Journey From Wild to Domestication; Genetic Enhancement- Need for Genetic Enhancement; Genetic Enhancement in Pre Mendelian Era and 21st Century; Genetic Enhancement and Plant Breeding; Reasons For Failure in Genetic Enhancement; Sources of Genes/ Traits- Novel Genes For Quality
Reverse Breeding: a tool to create homozygous plants from the heterozygous po...Sanjay Kumar
ย
This document provides an overview of reverse breeding, a novel plant breeding technique to directly produce homozygous parental lines from any heterozygous plant. It discusses how reverse breeding uses RNA interference to suppress meiotic recombination and produce doubled haploids from gametes, generating homozygous parental lines. The document summarizes a case study applying this to Arabidopsis thaliana and discusses applications like reconstructing hybrids, breeding at the chromosome level, and implications for food safety. Limitations and future research directions are also outlined.
Reverse breeding is a novel plant breeding technique that allows the development of parental lines directly from any superior heterozygous plant. It involves suppressing meiotic recombination to produce gametes with whole parental chromosome sets, followed by doubling of haploids to generate parental lines. Two case studies demonstrate using RNAi to silence meiotic genes in Arabidopsis thaliana, producing parental lines that reconstitute the original hybrid when crossed. A second technique, marker-assisted reverse breeding, uses high-density SNP genotyping instead of gene silencing to select maize lines similar to original parents within one year. Reverse breeding techniques accelerate breeding and facilitate hybrid improvement without prior knowledge of parental lines.
Population breeding in self pollinated cropsDarshana Ajith
ย
The document describes Diallel Selective Mating (DSM), a population improvement approach involving parental diallel crosses, F1 diallel crosses, and selective mating series. DSM aims to accumulate desirable alleles, broaden the genetic base, and develop new cultivars through recurrent selection and intermating in segregating generations. It allows for introduction of new germplasm and isolation of pure lines at various stages of the breeding program. While effective for some autogamous crops, DSM requires a large number of crosses and is labor intensive.
This document summarizes methods for producing haploid and doubled haploid plants for plant breeding programs. It discusses dihaploid production through halving tetraploid chromosome numbers. It also describes protocols for in vitro haploid production through unfertilized ovule/ovary culture and isolated microspore culture, including donor plant growth, explant collection and sterilization, culture medium, induction methods, and embryo regeneration. The goal is to accelerate the production of homozygous lines for more efficient plant breeding.
Breeding methods in cross pollinated crops with major emphasis on population ...Vinod Pawar
ย
This document summarizes a doctoral seminar presentation on breeding methods in cross-pollinated crops with an emphasis on population improvement. The presentation covered topics like introduction, breeding methods, population improvement, and a case study. Some key breeding methods discussed include mass selection, progeny testing, recurrent selection, hybrids, and synthetics/composites. The document provides details on backcross breeding methods for both transferring dominant and recessive genes, including the steps involved in multiple generations of backcrossing and selection.
Hybridization between individuals from different species belonging to the same genus or two different genera, is termed as distant hybridization or wide hybridization, and such crosses are known as distant crosses or wide crosses.
This document discusses the production of inbred lines and hybrid varieties. It describes various methods for producing inbred lines, including inbreeding through self-pollination over multiple generations, and producing haploid plants through anther culture or colchicine treatment. Inbred lines are evaluated through phenotypic and topcross testing before being improved through various breeding methods. Hybrid varieties are produced by crossing two inbred lines and exhibit heterosis. Advantages of hybrids include increased uniformity and yield, while disadvantages include the need to purchase new seed annually. The document outlines achievements and future prospects of hybrid crop development.
Double haploids are produced by doubling the chromosomes of haploid cells. Haploid cells have half the number of chromosomes as the original organism due to meiosis. A doubled haploid would have the full chromosome number and be homozygous. There are two main methods to produce haploids - anther/pollen culture (androgenesis) and ovary/ovule culture (gynogenesis). The haploids can then be doubled using chemicals like colchicine to produce doubled haploids. Doubled haploids have benefits for plant breeding as they are fully homozygous in the first generation, allowing for faster breeding cycles.
Breeding techniques in self pollinated crops presentationDev Hingra
ย
1. Plant breeding techniques for self-pollinated crops include plant introduction, pure line selection, mass selection, pedigree method, bulk method, backcross method, and mutation breeding.
2. Pure line selection involves selecting individual plants, evaluating their progeny, and conducting yield trials to develop uniform varieties. Mass selection composites seed from selected plants for future planting.
3. Plant introduction is an oldest method that can introduce entirely new crop species or superior varieties from other regions. It provides germplasm for breeding programs.
BREEDING METHODS FOR ASEXUALLY PROPAGATED SPECIES Naveen Kumar
ย
This document discusses breeding methods for asexually propagated plant species. It describes two main modes of reproduction - asexual and sexual reproduction. Asexual reproduction, which includes vegetative propagation methods like rhizomes, tubers, bulbs and modified stems/roots, is common in species that cannot or do not flower and sexually reproduce. Methods to develop new varieties in asexually propagated crops include clonal selection, clonal hybridization, and inducing mutations. Clonal selection involves selecting superior clones from a mixed population, while clonal hybridization crosses two desirable clones and selects progeny with superior traits. These methods have been used successfully to develop new varieties of crops like potato, sugarcane, banana and citrus.
1. Inbred lines are developed through repeated self-pollination or inbreeding of plants over multiple generations to produce genotypes that are homozygous and genetically uniform.
2. The pedigree method is most commonly used to develop maize inbred lines, involving self-pollination over 6-7 generations with selection of desirable plants each generation.
3. Doubled haploid lines can also be used, in which haploid cells are induced and then chromosome doubled to instantly produce completely homozygous lines.
This document discusses speed breeding, a technique to accelerate crop breeding cycles. Traditional breeding can take many years to develop new varieties while meeting future food demands poses challenges. Speed breeding uses controlled environmental conditions like extended photoperiod and supplemental lighting to complete multiple generations in a year. Case studies show this approach led wheat and barley to flower in half the time and generated 5 soybean generations per year. Speed breeding holds potential to rapidly develop climate-resilient varieties on a smaller scale while combining with genomics and other innovations.
Heterosis breeding-Classical and molecular concepts Rahul Chourasia
ย
This document discusses heterosis (hybrid vigor) in plants. It begins by defining heterosis as superior performance of F1 hybrid plants compared to their parental inbred lines. It then discusses several historical concepts and models that have been proposed to explain the genetic basis of heterosis, including dominance, overdominance, epistasis, and molecular mechanisms involving gene expression, small RNAs, and epigenetics. It also discusses using QTL mapping to identify genomic regions contributing to heterosis. The document concludes with several case studies, including one on delayed flowering times in tomato plants that are heterozygous for the sft mutant gene.
Clone is a group of genetically identical plants derived from a single individual through vegetative propagation. Clones are true to type of the mother plant and are immortal, identical in genotype, and homogeneous. However, clones can experience decreased vigor and loss of productivity over time due to mutations, viruses, or bacteria. The process of clonal selection involves selecting superior individuals from a population, evaluating their performance over multiple years and locations, and releasing the best clone as a new variety.
This document outlines the principles and methods of plant breeding. It discusses the impact of parents, quality of parents, objectives of breeding, breeding methods, and pedigree. The main methods covered are for cross-pollinated crops, including mass selection, progeny selection, and recurrent selection, and for self-pollinated crops, like mass selection, pure line selection, bulk method, and back-cross method. It also defines a pure line as the progeny of a single homozygous plant of a self-pollinated species.
This document provides information on genetic incongruity and techniques for overcoming barriers in distant plant hybridization. It defines genetic incongruity as evolutionary divergence between two taxa that results in gene incompatibility. Techniques discussed include embryo rescue, somatic hybridization, alien addition/substitution lines, and transferring small chromosome segments. Applications in crop improvement involve transferring traits like disease resistance, yield, and hybrid seed production from wild species. Challenges include sterility, incompatible crosses, and linkage of undesirable genes.
This document provides information about breeding methods for self-pollinated crops. It discusses pureline selection, mass selection, and multiline breeding. Pureline selection involves selecting homogeneous progeny from a self-pollinated homozygous plant. Mass selection is when plants are selected based on phenotype from a mixed population and their seeds are bulked. Multiline breeding involves developing a variety from a mixture of isolines or related lines to provide genetic diversity and disease resistance.
Heterosis, or hybrid vigor, results in offspring exhibiting greater traits than both parents. This can be due to interactions between parental alleles. Several biochemical mechanisms have been proposed to explain heterosis, including complementary parental alleles ("bottlenecks") allowing optimal production; hybrids producing an optimal amount of gene products; and hybrids producing novel hybrid gene products. Evidence also suggests roles for balanced metabolism, increased DNA and RNA synthesis, and more efficient mitochondrial function in hybrids compared to parents.
This document discusses the diallel selective mating approach (DSM) for genetic improvement of autogamous crops. DSM involves three steps: 1) a parental diallel series of crosses between multiple parents, 2) F1 diallel series of crosses between F1 plants, and 3) selective mating series where selected F2 plants are intercrossed and selfed in successive generations. The goal is to accumulate desirable genes and increase recombination through restoring heterozygosity via intermating selected plants over multiple cycles. While it broadens the genetic base, DSM is more complex than pedigree methods and success depends on identifying desirable plants in segregating generations.
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 document discusses a doctoral seminar presentation on doubled haploid (DH) technology. It begins with introducing the speaker and others involved. It then provides background on DH technology, describing it as a method to produce completely homozygous plants from haploid cells whose chromosome number has been doubled. The document discusses various chromosome doubling methods, approaches for DH production, applications in plant breeding and genomics, advantages and disadvantages. It provides timelines of haploid development and DH production in some crops. In conclusion, the document discusses DH technology as a valuable tool for plant improvement and addresses future strategies.
This document summarizes methods for producing haploid and doubled haploid plants for plant breeding programs. It discusses dihaploid production through halving tetraploid chromosome numbers. It also describes protocols for in vitro haploid production through unfertilized ovule/ovary culture and isolated microspore culture, including donor plant growth, explant collection and sterilization, culture medium, induction methods, and embryo regeneration. The goal is to accelerate the production of homozygous lines for more efficient plant breeding.
Breeding methods in cross pollinated crops with major emphasis on population ...Vinod Pawar
ย
This document summarizes a doctoral seminar presentation on breeding methods in cross-pollinated crops with an emphasis on population improvement. The presentation covered topics like introduction, breeding methods, population improvement, and a case study. Some key breeding methods discussed include mass selection, progeny testing, recurrent selection, hybrids, and synthetics/composites. The document provides details on backcross breeding methods for both transferring dominant and recessive genes, including the steps involved in multiple generations of backcrossing and selection.
Hybridization between individuals from different species belonging to the same genus or two different genera, is termed as distant hybridization or wide hybridization, and such crosses are known as distant crosses or wide crosses.
This document discusses the production of inbred lines and hybrid varieties. It describes various methods for producing inbred lines, including inbreeding through self-pollination over multiple generations, and producing haploid plants through anther culture or colchicine treatment. Inbred lines are evaluated through phenotypic and topcross testing before being improved through various breeding methods. Hybrid varieties are produced by crossing two inbred lines and exhibit heterosis. Advantages of hybrids include increased uniformity and yield, while disadvantages include the need to purchase new seed annually. The document outlines achievements and future prospects of hybrid crop development.
Double haploids are produced by doubling the chromosomes of haploid cells. Haploid cells have half the number of chromosomes as the original organism due to meiosis. A doubled haploid would have the full chromosome number and be homozygous. There are two main methods to produce haploids - anther/pollen culture (androgenesis) and ovary/ovule culture (gynogenesis). The haploids can then be doubled using chemicals like colchicine to produce doubled haploids. Doubled haploids have benefits for plant breeding as they are fully homozygous in the first generation, allowing for faster breeding cycles.
Breeding techniques in self pollinated crops presentationDev Hingra
ย
1. Plant breeding techniques for self-pollinated crops include plant introduction, pure line selection, mass selection, pedigree method, bulk method, backcross method, and mutation breeding.
2. Pure line selection involves selecting individual plants, evaluating their progeny, and conducting yield trials to develop uniform varieties. Mass selection composites seed from selected plants for future planting.
3. Plant introduction is an oldest method that can introduce entirely new crop species or superior varieties from other regions. It provides germplasm for breeding programs.
BREEDING METHODS FOR ASEXUALLY PROPAGATED SPECIES Naveen Kumar
ย
This document discusses breeding methods for asexually propagated plant species. It describes two main modes of reproduction - asexual and sexual reproduction. Asexual reproduction, which includes vegetative propagation methods like rhizomes, tubers, bulbs and modified stems/roots, is common in species that cannot or do not flower and sexually reproduce. Methods to develop new varieties in asexually propagated crops include clonal selection, clonal hybridization, and inducing mutations. Clonal selection involves selecting superior clones from a mixed population, while clonal hybridization crosses two desirable clones and selects progeny with superior traits. These methods have been used successfully to develop new varieties of crops like potato, sugarcane, banana and citrus.
1. Inbred lines are developed through repeated self-pollination or inbreeding of plants over multiple generations to produce genotypes that are homozygous and genetically uniform.
2. The pedigree method is most commonly used to develop maize inbred lines, involving self-pollination over 6-7 generations with selection of desirable plants each generation.
3. Doubled haploid lines can also be used, in which haploid cells are induced and then chromosome doubled to instantly produce completely homozygous lines.
This document discusses speed breeding, a technique to accelerate crop breeding cycles. Traditional breeding can take many years to develop new varieties while meeting future food demands poses challenges. Speed breeding uses controlled environmental conditions like extended photoperiod and supplemental lighting to complete multiple generations in a year. Case studies show this approach led wheat and barley to flower in half the time and generated 5 soybean generations per year. Speed breeding holds potential to rapidly develop climate-resilient varieties on a smaller scale while combining with genomics and other innovations.
Heterosis breeding-Classical and molecular concepts Rahul Chourasia
ย
This document discusses heterosis (hybrid vigor) in plants. It begins by defining heterosis as superior performance of F1 hybrid plants compared to their parental inbred lines. It then discusses several historical concepts and models that have been proposed to explain the genetic basis of heterosis, including dominance, overdominance, epistasis, and molecular mechanisms involving gene expression, small RNAs, and epigenetics. It also discusses using QTL mapping to identify genomic regions contributing to heterosis. The document concludes with several case studies, including one on delayed flowering times in tomato plants that are heterozygous for the sft mutant gene.
Clone is a group of genetically identical plants derived from a single individual through vegetative propagation. Clones are true to type of the mother plant and are immortal, identical in genotype, and homogeneous. However, clones can experience decreased vigor and loss of productivity over time due to mutations, viruses, or bacteria. The process of clonal selection involves selecting superior individuals from a population, evaluating their performance over multiple years and locations, and releasing the best clone as a new variety.
This document outlines the principles and methods of plant breeding. It discusses the impact of parents, quality of parents, objectives of breeding, breeding methods, and pedigree. The main methods covered are for cross-pollinated crops, including mass selection, progeny selection, and recurrent selection, and for self-pollinated crops, like mass selection, pure line selection, bulk method, and back-cross method. It also defines a pure line as the progeny of a single homozygous plant of a self-pollinated species.
This document provides information on genetic incongruity and techniques for overcoming barriers in distant plant hybridization. It defines genetic incongruity as evolutionary divergence between two taxa that results in gene incompatibility. Techniques discussed include embryo rescue, somatic hybridization, alien addition/substitution lines, and transferring small chromosome segments. Applications in crop improvement involve transferring traits like disease resistance, yield, and hybrid seed production from wild species. Challenges include sterility, incompatible crosses, and linkage of undesirable genes.
This document provides information about breeding methods for self-pollinated crops. It discusses pureline selection, mass selection, and multiline breeding. Pureline selection involves selecting homogeneous progeny from a self-pollinated homozygous plant. Mass selection is when plants are selected based on phenotype from a mixed population and their seeds are bulked. Multiline breeding involves developing a variety from a mixture of isolines or related lines to provide genetic diversity and disease resistance.
Heterosis, or hybrid vigor, results in offspring exhibiting greater traits than both parents. This can be due to interactions between parental alleles. Several biochemical mechanisms have been proposed to explain heterosis, including complementary parental alleles ("bottlenecks") allowing optimal production; hybrids producing an optimal amount of gene products; and hybrids producing novel hybrid gene products. Evidence also suggests roles for balanced metabolism, increased DNA and RNA synthesis, and more efficient mitochondrial function in hybrids compared to parents.
This document discusses the diallel selective mating approach (DSM) for genetic improvement of autogamous crops. DSM involves three steps: 1) a parental diallel series of crosses between multiple parents, 2) F1 diallel series of crosses between F1 plants, and 3) selective mating series where selected F2 plants are intercrossed and selfed in successive generations. The goal is to accumulate desirable genes and increase recombination through restoring heterozygosity via intermating selected plants over multiple cycles. While it broadens the genetic base, DSM is more complex than pedigree methods and success depends on identifying desirable plants in segregating generations.
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 document discusses a doctoral seminar presentation on doubled haploid (DH) technology. It begins with introducing the speaker and others involved. It then provides background on DH technology, describing it as a method to produce completely homozygous plants from haploid cells whose chromosome number has been doubled. The document discusses various chromosome doubling methods, approaches for DH production, applications in plant breeding and genomics, advantages and disadvantages. It provides timelines of haploid development and DH production in some crops. In conclusion, the document discusses DH technology as a valuable tool for plant improvement and addresses future strategies.
This document provides an introduction to hybrid seed production technology for solanaceous vegetable crops such as tomato, brinjal, chilli, and capsicum. It discusses the history and importance of hybrids, describing their benefits over open-pollinated varieties. The key hybrid seed production techniques used for each crop are manual emasculation and pollination or use of genetic male sterility systems. The document also outlines challenges in hybrid seed production and provides practical tips.
The document discusses haploidy and doubled haploid technology. It describes three main methods for producing haploids: parthenogenesis and apogamy, chromosome elimination, and culture methods. Haploids are useful in plant breeding as they allow for the rapid creation of fully homozygous lines, shortening breeding cycles. Doubled haploids can be used to generate mapping populations for QTL analysis and marker-assisted selection can then be used to introgress traits of interest.
12 Production of Haploid Plants through androgenesis and gynogensisYoGeshSharma834784
ย
There are two main approaches for producing haploid plants - in vivo and in vitro. In vivo methods include androgenesis, gynogenesis, distant hybridization, and chemical/radiation treatments. In vitro techniques involve anther or pollen culture (androgenesis) or ovary/ovule culture (gynogenesis) to induce haploid development. Successful haploid production depends on factors like the donor plant genotype, microspore developmental stage, environmental conditions, and composition of the culture medium when using in vitro methods.
Maize breeding in east africa region presentationBaraka Mdenye
ย
This document discusses maize breeding in East Africa. It aims to overcome challenges like low yield, diseases, pests, and drought. Breeding programs in the region work to develop hybrid and open-pollinated varieties using conventional methods like selection, hybridization, and germplasm collection as well as modern techniques such as doubled haploid breeding which can produce homozygous lines faster. The document provides information on various maize breeding methods and programs in countries in East Africa.
Synthetic hexaploid wheat is an artificial hybrid of tetraploid wheat and Aegilops tauschii that contains 42 chromosomes. It was first created in 1946 and numerous synthetic hexaploid wheats have since been produced globally. Compared to natural hexaploid wheat, synthetic hexaploid wheat is estimated to have lost fewer genes following polyploidization and shows subgenome dominance of the D genome over the A and B genomes. Allopolyploidization leads to genomic changes in synthetic hexaploid wheat including DNA elimination, gene silencing, and duplication. Molecular characterization shows that synthetic hexaploid wheat retains parental expression level dominance and has nonadditively activated gene expression contributing to its hybrid vigor.
This document discusses haploid plant production. Haploid plants have half the normal number of chromosomes. They are important for breeding programs. Methods to produce haploids include anther or pollen culture (androgenic haploids) and ovary or ovule culture (gynogenic haploids). Both in vivo and in vitro techniques have been used, with higher success rates for in vitro methods like anther culture. Gynogenesis involves culturing unpollinated ovaries to trigger female gametophytes to develop into plants. While useful, ovary culture is less common than anther culture due to difficulties in dissecting ovaries.
Haploid and double haploid Production and their roles in crop improvement by ...Shahnul Pathan
ย
This document discusses haploid and double haploid production and their roles in crop improvement. It begins by defining haploids as plants containing a single set of chromosomes, and double haploids as genotypes formed when haploid cells undergo chromosome doubling. It then describes various methods for producing haploids and double haploids, including anther, pollen, and ovule culture, temperature treatments, chemical treatments, alien cytoplasm, and haploid initiator genes. The advantages of double haploids in plant breeding are also summarized, such as achieving homozygosity in one generation.
The document discusses the production of double haploid (DH) plant lines in cucumber. It describes screening cucumber accessions for resistance to Cucumber mosaic virus (CMV) using DAS-ELISA. Ovule culture techniques were used to establish DH plant lines from selected CMV-resistant accessions. The DH lines were then screened for CMV resistance to develop homozygous cucumber lines with improved virus resistance.
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.
Haploid plant production and germplasm conservation of plantsRuchiMishra80
ย
This document describes a student's class project on the topics of haploid plant production and germplasm conservation. It discusses in vivo and in vitro techniques for producing haploid plants through anther/pollen culture (androgenesis) and ovary/ovule culture (gynogenesis). It also addresses methods for generating homozygous lines from haploids, as well as applications and limitations. For germplasm conservation, it outlines ex situ techniques including cryopreservation, slow growth culture, and DNA banking.
SIGNIFICANCE OF HAPLOIDS,DIPLOIDIZATION AND BULBOSUM TECHNIQUE.pptxVandana Yadav03
ย
This document discusses haploid plants, diploidization, and the bulbosum technique. It begins by defining haploid and diploid plants and describing methods of haploid production, including anther culture. It then covers diploidization methods like colchicine treatment and endomitosis. The bulbosum technique is described as using interspecific crosses between Hordeum vulgare and H. bulbosum to produce haploid H. vulgare plants through chromosome elimination. Haploids have various applications including early variety release, hybrid sorting, and developing disease resistant varieties. However, limitations include low yields and albinism in cereals.
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.
This document describes research on producing double haploids in the ornamental plant Primula via anther culture. The researchers determined the optimal microspore developmental stage for culture by examining bud size and morphology. Anthers at specific stages were cultured on media with different plant growth regulator combinations. Callus formed from some anthers, and some calli regenerated shoots. The ploidy levels of regenerated plants were determined using flow cytometry and cytology. Plants with haploid, diploid and mixoploid levels were identified. The study developed a protocol for generating double haploids in Primula through microspore culture, aiming to provide a more efficient breeding method for this ornamental crop.
this slide is all about the different cultures in plant tissue cultures such as seed culture, root culture, cell suspension culture, anther culture etc
Ovule and seed culture techniques and their applications are summarized. Ovules and seeds can be isolated and cultured aseptically on nutrient media. This allows for applications like in vitro pollination and fertilization, hybridization of incompatible species, production of haploid callus, circumventing the need for host stimuli in parasitic plants, and inducing polyembryony. Seed culture is useful for propagating plants with reduced embryos, parasitic plants, orchids, and producing large numbers of uniform seedlings. However, in vitro culture still poses challenges like slow growth, low multiplication, poor rooting, and somaclonal variation.
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.
Grain Quality of Doubled Haploid Lines in Rice (Oryza sativa L.) Produced by ...Galal Anis, PhD
ย
Genetic devlopment to imrove genotypes with high quality is the most important approach of rice. Thus, anther culture technique is one of straight forward approaches for improvement of rice cultivars with good grain quality. Therefore, this investigation aimed to develop some doubled haploid lines (DH) through anther culture technique and evaluate them along with their five parents including two check varieties for some nutritional characteristics. The results indicated that the three mineral element contents (Zn, Mn and Fe) of rice grain were clearly different among genotypes (DH), which implied that genotypic variations might provide opportunities to select for higher mineral element content. Analysis of variance revealed that the differences among genotypes were significant for all studied traits. Highly significant positive correlations were recognized among the studied characteristics. Accordingly, Rice lines with the high nutritional values will use as donors for this trait in rice breeding programs for exploitation and in hybridization.
Biotechnological strategies for development of line B S MEENA
ย
1) Haploid plants can be produced through anther, ovule, or flower bud culture to speed up the production of homozygous parental lines needed for hybrid breeding. This is an alternative to the slower traditional inbreeding process.
2) Doubled haploid plants are produced when haploids undergo spontaneous or induced chromosome doubling, restoring fertility. Doubled haploids are homozygous and can be used directly in breeding programs or as parental lines for hybrid varieties.
3) There are two main techniques for producing haploids - androgenesis using anther culture, and gynogenesis using culture of unpollinated flower parts like ovules. Androgenesis is more widely used due
Similar to Doubled Haploid Technology for Line Development in Maize (20)
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
ย
(๐๐๐ ๐๐๐) (๐๐๐ฌ๐ฌ๐จ๐ง ๐)-๐๐ซ๐๐ฅ๐ข๐ฆ๐ฌ
๐๐ข๐ฌ๐๐ฎ๐ฌ๐ฌ ๐ญ๐ก๐ ๐๐๐ ๐๐ฎ๐ซ๐ซ๐ข๐๐ฎ๐ฅ๐ฎ๐ฆ ๐ข๐ง ๐ญ๐ก๐ ๐๐ก๐ข๐ฅ๐ข๐ฉ๐ฉ๐ข๐ง๐๐ฌ:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
๐๐ฑ๐ฉ๐ฅ๐๐ข๐ง ๐ญ๐ก๐ ๐๐๐ญ๐ฎ๐ซ๐ ๐๐ง๐ ๐๐๐จ๐ฉ๐ ๐จ๐ ๐๐ง ๐๐ง๐ญ๐ซ๐๐ฉ๐ซ๐๐ง๐๐ฎ๐ซ:
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With Metta,
Bro. Oh Teik Bin ๐๐ค๐ค๐ฅฐ
Doubled Haploid Technology for Line Development in Maize
1.
2. Indian
Agricultural
Research
Institute
New
Delhi,
India
Department of Plant Breeding and Genetics
S.K.N. College of Agriculture, Jobner
Sri Karan Narendra Agriculture University, Jobner
Credit Seminar on
Doubled Haploid Technology for Line
Development in Maize
Major Advisor
Dr. D.K. Gothwal
Professor
Seminar Incharge
Dr. S.S. Rajput
Assistant Professor
Presented by
Giradhari Lal Yadav
Ph.D. Scholar (PBG)
3. Indian
Agricultural
Research
Institute
New
Delhi,
India
Contents
๏ Introduction
๏ History of maize doubled haploids
๏ Types and techniques of doubled haploids
๏ Selection of individual for haploid induction
๏ Induction of haploids
๏ Identification of haploids
๏ Chromosome doubling in the haploids
๏ Seed production from D0 nursery
๏ Case study
๏ Advantages of doubled haploids
๏ Disadvantages of doubled haploids
๏ Applications of DHs in plant breeding
๏ Conclusions
5. Indian
Agricultural
Research
Institute
New
Delhi,
India
History of maize doubled haploids
๏ผ Chase(1949): spontaneous haploid production 0.1% HIR
and chromosome doubling
๏ผ Coe(1959): Identified a line having higher haploid
production and designated as โSTOCK 6โ with 2-3% HIR
๏ผ Rober et al., (2005): RWS line with 8.1% HIR frequency
based on R-nj marker
๏ผ Li et al., (2009): CAUHOI line with 2% HIR frequency,
based on kernel oil content
6. Indian
Agricultural
Research
Institute
New
Delhi,
India
In vitro In vivo/ in situ
Paternal
Anther Culture and
Pollen Culture
Inducer line used as female
and Donor parent used as
male
Maternal Ovule culture
Inducer line used as male
and Donor parent used as
female
Techniques
Different techniques of Doubled Haploids
production in maize
Types
7. Indian
Agricultural
Research
Institute
New
Delhi,
India
(A) In vitro methods of doubled
haploid production
๏ถ These methods use tissue culture techniques for the production
of haploids.
๏ถ In vitro methods have shown little promise to reliably produce
the large numbers of DH lines required by maize breeding
programs.
๏ถ In vitro methods had very limited success due to non
responsiveness of many maize genotypes.
๏ถ These methods require a good laboratory and skilled staff.
๏ถ In vitro methods are of two types:
1. Androgenesis: includes pollen culture and anther culture
2. Gynogenesis: includes ovule culture and ovary culture
8. Indian
Agricultural
Research
Institute
New
Delhi,
India (1) Anther Culture/ Pollen Culture
(In Vitro Androgenesis)
๏ถ Anon (1975) first reported the successful anther culture of
maize.
๏ถ The successful application of anther culture techniques in
maize breeding is largely dependent on the androgenic
responses of the genotypes and on the frequency of induced or
spontaneous genome doubling in plants of microspore origin.
๏ถ Intensive studies have been carried out to improve the culture
conditions, leading to greater androgenic response, but most of
the genotypes responsive to anther culture have been found in
non-commercial maize germplasm.
10. Indian
Agricultural
Research
Institute
New
Delhi,
India (2) Ovary/Ovule Culture
(In Vitro Gynogenesis)
๏ถ In vitro gynogenesis so far has been reported only by
two groups i.e. Ao et al. (1982); Truong-Andre &
Demarly (1984). So more research will be required to
evaluate the potential of this method for maize
๏ถ The induction of ovule responses is strongly genotype-
dependent.
๏ถ The frequency of response with permissive genotypes
ranged from 3.4 to 12%. Only 6 responses were found
from 175 cultured ovules (Ao et al. 1982)
๏ถ Truong-Andre and Demarly (1984) obtained 6 plants
from 317 cultured ovules.
11. Indian
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Delhi,
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Merits & Demerits
Merits:
๏ถIt is useful in production of doubled haploids where
plant is male sterile.
๏ถThis method is useful in embryo rescue technique.
Demerits:
๏ถIt is highly genotype dependent.
๏ถThis method gives less number of haploid plants as
compared to anther / pollen culture.
12. Indian
Agricultural
Research
Institute
New
Delhi,
India
(B) In vivo methods of doubled
haploid production
๏ถIn vivo methods of DH production in maize is
relatively easier and widely used.
๏ถIn this method special genetic stocks are used for
haploid production which are known as Haploid
Induction Lines (HILs)
๏ถ These methods do not require any sophisticated
laboratory.
๏ถThere are two types of doubled haploids-
(1) Paternal doubled haploids
(2) Maternal doubled haploids
13. Indian
Agricultural
Research
Institute
New
Delhi,
India (1) Paternal Doubled Haploids
(In Situ Androgenesis)
๏ถ Reported by Kermicle in 1969.
๏ถ It is due to mutant gene โig1โ (indeterminate gametophyte).
๏ถ Homozygous ig1 mutants show several embryological
abnormalities such as development of egg cell without nuclei.
cc
(HIL)
Note: line W 23 (which carries the ig = indeterminate gametophyte
mutation; Kermicle, 1969) is used as the female parent.
CC
(Donor Source)
x
Haploid
(C)
Chromosome Doubling
DH Plant
(CC)
15. Indian
Agricultural
Research
Institute
New
Delhi,
India Merits and Demerits of Paternal Doubled
Haploids
Merits:
๏ These are helpful in transferring cytoplasmic male
sterility (CMS) to a different genetic background
within a short period of time (within 2-3 generations)
๏ Demerits:
โข Low frequency of haploid induction i.e. 1-2%.
โข Such DHs contain cytoplasm of the inducer and
chromosomes from the donor parent, so this system is
not very attractive to derive inbred lines for breeding.
16. Indian
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Delhi,
India
(2) Maternal Doubled Haploids
(In Situ Gynogenesis)
๏ It is very common in maize breeding.
๏ In this method HIL is used as male parent.
๏ The first inducer recorded by Coe (1959) called
โStock 6,โ produced maternal haploids at a frequency
of 2โ3%.
CC
(Donor Source)
cc
(HIL)
x
Haploid
(C)
Chromosome Doubling
DH Plant
(CC)
17. Indian
Agricultural
Research
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India
Mechanism of maternal haploid induction
๏ถThe exact mechanism of maternal haploid induction
have not yet been clearly understood.
๏ถThe regular double fertilization is distorted after
pollination with the pollen of a haploid inducer line
๏ถOne sperm cell fuses with the central cell but the
other sperm cell does not fuse with the egg cell. But a
fertilized and dividing central cell stimulates the
unfertilized haploid egg cell to develop into a haploid
embryo (Chase, 1969).
19. Indian
Agricultural
Research
Institute
New
Delhi,
India (1) Selection of individual for haploid
induction
๏ Individual plant can be selected by two ways-
a) From a cross between two parents
b) From heterozygous population.
Selection of individual also depends on the breeding objective:
๏ For inbred development best plant is selected from a
population or from a cross, as a donor and only superior
haploid is developed as inbred after chromosome doubling.
๏ For development of mapping population F1 from contrast
parents is used as a donor and all haploids are used to make
DH population.
22. Indian
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India
a) R1-nj (Navajo) marker
๏ Inducer lines carry dominant โR1-nj alleleโ which codes for
anthocyanin pigment which give purple coloration in seed.
r1r1r1
X
R1 - -
r1r1
R1R1
R1r1r1
r1r1r1
r1r1 r1
Haploids
Out crossed or
Selfed seed
Donor
Source
HIL
23. Indian
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India
R1-njโฆ.Contโฆ.
Merits:
๏ It identifies haploids at seed level, hence no need to grow
diploid seed.
Demerits:
๏ Marker expression can be inhibited by anthocyanin inhibitor
genes like C1-I
๏ It is a manual method of haploid identification.
๏ If source germplasm has โR1-njโ allele, then this method canโt
be used.
๏ Intensity of color expression depends on moisture content of
seed.
24. Indian
Agricultural
Research
Institute
New
Delhi,
India b) Purple root and purple stem marker
system
๏ Two genes Pl1 (Purple1) & B1 (Booster1) involved in this
system, which can impart purple or red color to the plant tissues.
๏ Pl1 (Purple1) conditions sunlight independent purple
pigmentation in plant tissues, and B1 (Booster1) conditions
sunlight dependent purple pigmentation in most of the above
ground plant tissues (Coe, 1994).
๏ HILs like MHI and Procera have this system along with R1-nj.
Diploid seedlings: Purple roots and stems
Haploid seedlings: No coloration
25. Indian
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Delhi,
India
Purple rootโฆContโฆ.
Merits:
๏ It can be used in a wide array of maize germplasm as root
color phenotype is very rare in maize germplasm.
๏ It is recommended when the R1-nj marker is not effective.
Demerits:
๏ It demands germination of large numbers of induced seeds,
which is labor intensive.
๏ Expression of the B1 and Pl1 genes are affected by plant
growth conditions, especially sunlight and temperature.
26. Indian
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Institute
New
Delhi,
India c) Transgenic method
๏ In this method, Transgenic HILs are used which carry
herbicide tolerance gene.
๏ At seedling stage screening is done by herbicide
application.
๏ Haploids are herbicide susceptible and diploids are
herbicide tolerant.
๏ In order to identify haploids herbicide is applied on
small portion of seedling.
๏ The application of transgenic haploid inducers may
not be possible in many countries due to restrictions
on the use of transgenics.
27. Indian
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New
Delhi,
India
d) High oil marker method
๏ This method can facilitate mechanical screening by using NMR
(Nuclear Magnetic Resonance) technique.
๏ Haploids seeds and diploid seeds naturally show differences in
their average kernel oil content with haploids showing 0.6โ
0.8% less oil than the diploids, as >85% oil accumulates in the
seed embryo (Rotarenco et al. 2007; Melchinger et al. 2014).
๏ Several high oil inducers such as CAUHOI (7.8% Oil content),
UH600 (10.8% OC) and UH601 (11.7% OC) has been
developed.
2n n
3n 3n
Diploid
(High oil content)
Haploid
(low oil content)
28. Indian
Agricultural
Research
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Delhi,
India
High oilโฆ.Contโฆโฆ
Merits:
๏ It identifies haploids at seed level.
๏ This method can be automated.
๏ It can be applicable in all germplasm including land races and
wild relatives of maize.
Demerits:
๏ Requires inducer with high oil content for clear difference
between haploids and diploids.
๏ Requires high cost for establishment of NMR-based
automation platform.
29. Indian
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Research
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New
Delhi,
India
(4) Chromosome doubling in the haploids
๏ A commonly used chromosome doubling agent is colchicine,
which is a water-soluble alkaloid produced from the bulbs of
Colchicum autumnale.
๏ Colchicine binds to tubulins and prevents the formation of
spindle microtubules during the metaphase stage of mitosis.
๏ 4-5 days old seedlings are used for colchicine treatment.
๏ A solution with 0.04% colchicine and 0.5% DMSO is used for
chromosomal doubling.
๏ Seedlings are kept in the colchicine tank for 12 hours.
๏ Seedlings are washed at least three times by distilled water.
30. Indian
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New
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Steps involved in chromosome doubling
(E)
Recovery of
treated D0
seedlings in a
greenhouse
(A)
Germination
of putative
haploid seed
(D0 seed) on
paper towels.
(B)
Cutting of the
coleoptile tip of
D0 seedlings to
facilitate better
penetration of
colchicine.
(C)
Placement of
coleoptile cut
D0 seedling into
mesh bags.
(D)
Treatment of
D0 seedlings
with colchicine
in an iron tank.
31. Indian
Agricultural
Research
Institute
New
Delhi,
India (5) Seed production from D0 nursery
๏ Colchicine treated seedlings are very weak, hence need to be
handled with care under controlled condition.
๏ In D0 nursery there is limited number of pollen production.
๏ There will be fertile and sterile pollens, so fertile pollens are
used for selfing
๏ During selfing โfalseโ diploid should be discarded to avoid
contamination.
๏ Self pollinated ear should be harvested after physiological
maturity.
๏ Each D0 derived seed will represent distinct DH line.
๏ In D1 nursery seed is multiplied by selfing and DH lines are
developed.
32. Indian
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Delhi,
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Case study
Objectives :
(1) To study the differences between haploids and diploid seedlings
in terms of radicle length (RL), coleoptile length (CL), and
number of lateral seminal roots (NLSR) during early growth
stages
(2) To validate the use of such traits for haploid identification in
populations with complete inhibition of Navajo marker
(3) To determine if seedling traits can be effectively used for early
identification of false positives.
35. Indian
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Advantages of doubled haploids
๏ Development of complete homozygous line in 2-3
generations
๏ Perfect fulfillment with DUS criteria for variety
protection
๏ Require less time and labor for development of new
breeding lines
๏ Higher frequency of desirable homozygous plant
๏ DH can be developed from any material like F1, F2
and Landraces
36. Indian
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Disadvantages of doubled haploids
๏ The main disadvantage with the DH population is that
selection cannot be imposed on the population.
๏ Another disadvantage associated with the double
haploidy is the cost involved in establishing tissue
culture and growth facilities.
๏ The over-usage of doubled haploidy may reduce
genetic variation in breeding germplasm.
38. Indian
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Conclusions
๏ Technological advances have now provided DH
protocols for most plant genera.
๏ The number of species amenable to doubled haploidy
has reached a staggering 250 in just a few decades.
๏ Response efficiency has also improved with gradual
removal of species from recalcitrant category. Hence
it will provide greater efficiency of plant breeding