Method of Plant Breeding in Self Pollinated Plants – Hybridization
- 1) Combination Breeding: The main aim of combination breeding is the transfer of one or more characters into a single variety, from other varieties. These characteristics may be governed by oligogenes or Polygenes.
- 2) Transgressive Breeding:
How do you breed a self pollinated species?
The breeding methods that have proved successful with self-pollinated species are: (1) mass selection; (2) pure-line selection; (3) hybridization, with the segregating generations handled by the pedigree method, the bulk method, or by the backcross method; and (4) development of hybrid varieties.
What are the methods of further breeding in hybrids?
Further breeding in these hybrids is carried out according to either pedigree or bulk method. 1. In self-pollinated crops this method is used when three or four monogenic characters scattered in three or four different varieties are to be combined into one.
What is hybridization in cross-pollinated crops?
Like self-pollinated crops, hybridization in cross-pollinated crops involves crossing of two or more inbreeds. The inbreeds are combined in any one of the following types of crosses and released as improved strains. Crossing of two inbreeds or varieties are called single cross such as A x B or C x D. This cross was proposed by Shull (1909).
What are the different methods of genetic testing of plants?
Pedigree method, 2. Bulk method, 3. Back cross method. Method # 1. Pedigree Method: Individual plant progeny is selected from F 2 and subsequent generations, and their progenies are tested. During this process the record of parents as well as off-springs is kept, for which it is known as pedigree method.
Which method is only used in self-pollinated crop?
The breeding methods that have proved successful with self-pollinated species are: (1) mass selection; (2) pure-line selection; (3) hybridization, with the segregating generations handled by the pedigree method, the bulk method, or by the backcross method; and (4) development of hybrid varieties.
Is hybridization possible in self-pollinated crops?
Reliable and effective hybridization methods are required in self-pollinating crops for genetic analysis, recurrent selection and large-scale production of hybrid seed. The objective of this review was to document the different methodologies available for hybrid seed production in predominantly self-pollinating crops.
What are the methods of hybridisation?
Hybridization methods represent standard techniques in molecular biology. In general, they are used to detect particular sequences (target) within a complex mixture of DNA or RNA molecules. DNA or RNA are usually transferred and immobilized to nitrocellulose or, more commonly, to nylon membranes.
What is hybridization in pollination?
“Artificial hybridization is the process in which only desired pollen grains are used for pollination and fertilization.” Pollination is the process of reproduction in plants in which plants transfer pollen grains from anther to stigma.
Which method is not applicable for self-pollinated crops?
Answer: pure line is not applicable for self pollinated crops.
Which type of hybridization is commonly used in plant breeding?
The most common type of hybridization in plant breeding is intraspecific hybridization. In this process individuals from the same species are crossed.
What are the two types of hybridization?
Nature of the Types of HybridizationType Of HybridizationShapeNumber Of Orbitals Participating In Hybridizationsp³Tetrahedral4 (1s + 3p)sp²Planar trigonal3(1s + 2p)spLinear2(1s + 1p)
Which of the following method does not include hybridization?
2. Which of the following is not termed as hybridization? Explanation: The process of base – pairing between complementary DNA strands from different sources of species is termed as hybridization. Thus DNA from male and female of same species is not known as hybridization.
What is hybridization in crop production?
Crossing two genetically dissimilar plants is referred to as Hybridization. It may be inter-varietal, interspecific, or intergeneric. Two plants with the desired characteristics are chosen and crossed to produce a new plant with the parental plants' desired characteristics.
What is the pedigree method?
The pedigree method describes a selection protocol utilized during the inbreeding of populations of self- and cross-pollinated species in the development of homozygous lines.
What are the steps for hybridization for plant breeding?
Table of ContentsHybridization Technique # Step 1. Selection and Preparation of Parents:Hybridization Technique # Step 2. Emasculation:Hybridization Technique # Step 3. Bagging:Hybridization Technique # Step 4. Pollination:Hybridization Technique # Step 5. Selection:
How is hybridization used in agriculture?
Hybridization is growing two plants together in a special way to help the plants develop the natural traits we like. Hybridization differs from Genetically Modified Organisms (GMOs) because hybridization takes advantage of traits natural to the plant, where GMOs insert traits that are not natural to the plant.
What is hybridization and its types in chemistry?
The concept of hybridization is defined as the process of combining two atomic orbitals to create a new type of hybridized orbitals. This intermixing typically results in the formation of hybrid orbitals with completely different energies, shapes, and so on.
What are the plant breeding methods?
Such varieties of plants are called resistant plants. The basic method is the same as normal hybridization....Plant Breeding for Developing a Resistance to Insect Pest.CropVarietyInsect pestOkraPusa SawniShoot and fruit bores2 more rows
What is the formula of hybridisation?
Hybridization=1/2[V+M-C+A] Alternatively, we can also determine the hybridization of I3- by knowing the number of bond pairs and lone pairs.
What is hybridization explain with example?
Hybrid orbitals are mixtures of atomic orbitals in various proportions. For example, the hybrid orbitals on the C atom of methane consist of one-fourths character and three-fourths p character. We say they are sp3 ("s-p-three") hybridized. The four new hybridized orbitals have both s and p character.
What is the purpose of combination breeding?
The main aim of combination breeding is the transfer of one or more characters into a single variety, from other varieties. These characteristics may be governed by oligogenes or Polygenes.
What is transgressive breeding?
Transgressive breeding aims at improving yield or its contributing character through Transgressive segregation. Transgressive segregation is the production of plants in F2 generation that are superior to both the parents for one or more characters.
What is the object of hybridization?
The object of hybridization is to combine desirable genes found in two or more different varieties and to produce pure-breeding progeny superior in many respects to the parental types . Genes, however, are always in the company of other genes in a collection called a genotype.
How is mass selection used in biology?
A modern refinement of mass selection is to harvest the best plants separately and to grow and compare their progenies. The poorer progenies are destroyed and the seeds of the remainder are harvested. It should be noted that selection is now based not solely on the appearance of the parent plants but also on the appearance and performance of their progeny. Progeny selection is usually more effective than phenotypic selection when dealing with quantitative characters of low heritability. It should be noted, however, that progeny testing requires an extra generation; hence gain per cycle of selection must be double that of simple phenotypic selection to achieve the same rate of gain per unit time.
What is pure line breeding?
Any progeny superior to an existing variety is then released as a new “pure-line” variety. Much of the success of this method during the early 1900s depended on the existence of genetically variable land varieties that were waiting to be exploited. They provided a rich source of superior pure-line varieties, some of which are still represented among commercial varieties. In recent years the pure-line method as outlined above has decreased in importance in the breeding of major cultivated species; however, the method is still widely used with the less important species that have not yet been heavily selected.
How is pure line selection done?
Pure-line selection generally involves three more or less distinct steps: (1) numerous superior appearing plants are selected from a genetically variable population; (2) progenies of the individual plant selections are grown and evaluated by simple observation, frequently over a period of several years ; and (3) when selection can no longer be made on the basis of observation alone, extensive trials are undertaken, involving careful measurements to determine whether the remaining selections are superior in yielding ability and other aspects of performance.
How does pedigree breeding work?
Pedigree breeding starts with the crossing of two genotypes, each of which have one or more desirable characters lacked by the other. If the two original parents do not provide all of the desired characters, a third parent can be included by crossing it to one of the hybrid progeny of the first generation (F1).
What is mass selection?
Mass selection, with or without progeny test, is perhaps the simplest and least expensive of plant-breeding procedures. It finds wide use in the breeding of certain forage species, which are not important enough economically to justify more detailed attention.
What is the F2 generation?
The F2 generation is sown at normal commercial planting rates in a large plot. At maturity the crop is harvested in mass, and the seeds are used to establish the next generation in a similar plot. No record of ancestry is kept.
How is hybridization done?
The hybridization is done among two selected parents, after emasculation one become female parent and another male parent. After seed set and maturation, the F 1 seeds are harvested separately from each plant individually. On the basis of choice of parents, the type of cross will be of two types — it will be simple cross or complex cross.
What are the three methods of selection for a new variety from a segregating population?
For selection of a new variety from a segregating population after hybridization the methods followed in self-pollinated crop are of three types: 1. Pedigree method, 2. Bulk method, 3. Back cross method. Method # 1.
What is the selection procedure for the fifth year?
Fifth Year: The selection procedure is same as previous year, only if two or more progenies coming from the same F 3 progeny are similar and comparable, then only one may be saved and others may be rejected. The emphasis is given on the selection of desirable plants from superior progenies.
What is the bulk method?
After hybridization programme when the F 2 and subsequent generations are harvested in mass or as bulk to raise the next generation, it is called bulk method. At the end of bulking period, individual plants are selected and evaluated in the same manner of pedigree method. This method is applicable to any self-pollinating crop like cereals, legumes and oil seeds.
Why is the pedigree method useful?
Pedigree method is useful in selection of new superior recombinant types from a hybridization programme. This method is suitable for improving specific characteristics, such as disease resistance, plant height, maturity time, etc. as well as yield and quality characters.
When does natural selection become operative?
1. This method takes a long time to release a new variety, as the method of natural selection becomes operative only after F 8 or F 10.
Which character is most suited for transfer through back-cross method from one variety to another?
The characters like disease resistance, seed colour, plant height, etc. , which are controlled by one or two major genes are most suited for transfer through back-cross method from one variety to another of the same species. The successful transfer depends on the minimum linkage between desirable and undesirable trait.
What are the methods of breeding self-pollinated species?
Breeding self-pollinated species. The breeding methods that have proved successful with self-pollinated species are: (1) mass selection; (2) pure-line selection; (3) hybridization, with the segregating generations handled by the pedigree method, the bulk method, or by the backcross method; and (4) development of hybrid varieties.
How are plants selected from a genetically variable population?
Pure-line selection generally involves three more or less distinct steps: (1) numerous superior appearing plants are selected from a genetically variable population; (2) progenies of the individual plant selections are grown and evaluated by simple observation, frequently over a period of several years; and (3) when selection can no longer be made on the basis of observation alone, extensive trials are undertaken, involving careful measurements to determine whether the remaining selections are superior in yielding ability and other aspects of performance. Any progeny superior to an existing variety is then released as a new “pure-line” variety. Much of the success of this method during the early 1900s depended on the existence of genetically variable land varieties that were waiting to be exploited. They provided a rich source of superior pure-line varieties, some of which are still represented among commercial varieties. In recent years the pure-line method as outlined above has decreased in importance in the breeding of major cultivated species; however, the method is still widely used with the less important species that have not yet been heavily selected.
How is mass selection used in biology?
A modern refinement of mass selection is to harvest the best plants separately and to grow and compare their progenies. The poorer progenies are destroyed and the seeds of the remainder are harvested. It should be noted that selection is now based not solely on the appearance of the parent plants but also on the appearance and performance of their progeny. Progeny selection is usually more effective than phenotypic selection when dealing with quantitative characters of low heritability. It should be noted, however, that progeny testing requires an extra generation; hence gain per cycle of selection must be double that of simple phenotypic selection to achieve the same rate of gain per unit time.
What is pure line variety?
Any progeny superior to an existing variety is then released as a new “pure-line” variety. Much of the success of this method during the early 1900s depended on the existence of genetically variable land varieties that were waiting to be exploited.
What is mass selection?
Mass selection, with or without progeny test, is perhaps the simplest and least expensive of plant-breeding procedures. It finds wide use in the breeding of certain forage species, which are not important enough economically to justify more detailed attention.
Is pure line breeding still used?
In recent years the pure-line method as outlined above has decreased in importance in the breeding of major cultivated species; however, the method is still widely used with the less important species that have not yet been heavily selected.
What is self pollination?
Self-pollination is the process of transfer of pollen grains from the anther of a flower to the stigma of the same flower. Self-pollinated crops have a genetic structure that has implications in the choice of methods for their improvement. Naturally self-pollinated and hence inbreeding to fix genes is one of the goals for a breeding program for se lf-pollinated species in which variability is generated by crossing. Crossing does not precede some breeding methods for self-pollinated species. Self-pollinated crops differ from cross-pollinated crops in genetic make-up. Breeding method is designed to enhance genetic yield potential based on modifying individual traits where the breeding goal for each trait is specified. When adopting any breeding method for any crops, the type of reproduction of the species should be considered, whether it is self-pollinating, cross-pollinating or asexual. Since the individual crop plants react differently to similar abiotic stress factors, therefore it can be difficult to breed a crop species for more than one resilient trait at a time; due to this reason plant breeders should focus on the breeding methods that use to improve different crop species for different purposes.
What is the process of hybridization?
The natural or artificial process that results in the formation of hybrid is known as hybridization. Individual produced as a result of cross between two genetically different parents is known as hybrid. Hybridization is an important method of combining characters of different plants. The first natural hybridization was recorded by Cotton Mather (1716) in corn. The first artificial interspecific plant hybrid was produced by Thomas Fairchild in 1717. Hybridization was first of all practically utilized in crop improvement by German botanist Joseph Koerauter in 1760. Today, it is the most common method of crop improvement through crossing or mating of two plants of dissimilar genotype, and the vast majority of crop varieties have resulted from hybridization (Jensen, N.F, 1970). Hybridization is the natural or artificial process of producing hybrids through crossing two individuals from different populations that are genetically different (Goulet BE et al., 2017). This process does not change the genetic contents of organisms but rather produces new combinations of genes which could have certain desirable characteristics. This technique also circumvents problems such as sexual incompatibility, polyembryony, and male sterility encountered in conventional sexual crossing (Liu J et al., 2011). Sexual hybridization is an important tool to plant breeders which enables the transfer of desirable traits from one species to another (Zeliang PK et al., 2013). The steps of sexual hybridization involve a series of events which include germination of the pollen, pollinating the maternal taxa with pollen from the paternal taxa, growth of the pollen tube, fertilization, embryo and endosperm development and seed maturation (Debbarama C et al ., 2013). When two genotypically different plants are crossed, the genes from both the parents are brought together in Fl. Heterosis is a hybrid phenomenon which involves phenotypic superiority than their parents in terms of biotic and abiotic resistance, increased yield and growth rate (Yang L et al., 2015).
What is single seed descent?
breeding procedure used with segregating populations of self-pollinated species in which plants are advanced by single seeds from one generation to the next is referred to as single seed descent method. This method was suggested by Gulden (1939) for advancing segregating generation of self-pollinated crops. Later on this method was applied by Grafius (1965) in oats, Brim (1966) in soybean, and several other workers in soybean, wheat, barley oats, rice, chickpea, green-gram and some other crops. Single seed descent method is a selection method carried out by selecting only one seed from each plant. Single seed descent method is another modification of bulk method and involves harvesting one seed from each plant from the F2 to the F6 and sowing them in the next generation. The concept of single seed descent method was first proposed by C. H. Goulden in 1941. The objective of the single-seed descent method is to advance rapidly the generations of crosses and reduce a loss of genotypes during the segregating generations (Jinks J.L and Pooni H.S, 1984).
What is pedigree breeding?
Pedigree refers to record of the ancestry of an individual selected plant. Pedigree breeding is a method of genetic improvement of self-pollinated species in which superior genotypes are selected from segregating generations and proper records of the ancestry of selected plants are maintained in each generation (H.H Lowe, 1927). In other words, it is a selection procedure in segregating population of self- pollinated species that keeps proper record of plants and or progeny selected in each generation. This method is widely used for the improvement of self-pollinated species. It is generally used when both the parents that are used in the hybridization have good agronomic characters or are well adapted. Moreover, it is more commonly used for the improvement of polygenic traits than oligogenic characters. In self-pollinated species, it is used for development of new varieties while in cross pollinated species it is used for development of inbred lines. The main difference is that in the self-pollinated species inbreeding occurs naturally while in cross pollinated species inbreeding is done manually. Individual plants progeny is selected from F2 and subsequent generations and their progenies are tested.
What is the basic process of selection?
Selection is basic to any crop improvement. Isolation of desirable plant types from the population is known as selection. It is one of the two fundamental steps of any breeding programme viz. creation of variation and selection. Before domestication, crop species were subjected to natural selection. The basic for natural selection was adaptation to the prevailing environment. Selection involves identification of individual genotypes or groups of genotypes from mixed populations or from segregating population following hybridization. Selection is the ability to pick superior plants in a limited or vast array of variability. Selection is the oldest method of breeding and the basis for all crop improvement which practiced by farmer in ancient times. The key prerequisite to successful plant breeding is the availability of genetic diversity. The most important issue in plant breeding is creating genetic diversity and manipulating genetic variability.
What is the introduction of plants?
Introduction of plants is the earliest of the methods followed in plant breeding. Established plants of one area are taken to the newer area for the use of mankind. Plant introduction is the most known conventional breeding method which uses for obtaining new parental material for development of cultivars of existing crops. Breeding for any trait start with the assembly of genetic variation through the collection and evaluation of the available germplasm. If the desirable variability is not available within a locality or species, introduction of the exotic germplasm can be resorted. This classical approach is still very relevant in all breeding strategies. Plant introduction is the oldest and rapid method of crop improvement (Allard, 1964). This is mainly contributes amble genetic diversity through the movement of germplasm from the center of origin to other new environments where the genetic vulnerability is becoming problems for improvement for crop yield, resistant to biotic and abiotic stresses. It also plays significant role in the prevention of genetic uniformity, dramatic yield increases through introgression of desired gene, introduction of new quality traits, introduction of disease and insect-resistance genes, introduction of environment-resistance genes (example, drought resistance).
What is bulk breeding?
The bulk method of plant breeding is the method in which selection is delayed until a later generation usually up to F5 or F6 after hybridization (Poehlman, 1987). Delay artificial selection to allow natural selection pressure to act. It is a method which can handle segregating generations in which F2 and subsequent generations are harvested in bulk to grow the next generation (Singh, 1983). At the end of bulking period, individual plant selection and evaluation is carried out in the similar fashion as in the pedigree method. Bulk or population breeding is ideal for crops that are planted at higher density (Mak C. and Harvey BL, 1982). Bulk method is ideal for crops that are planted at higher density and in which no records are maintained, thus require less labour and time. It is also preferable for crosses where no high heritability trait is desired. Plants are grown at commercial spacing in all generation F2 to F5 plants grown in bulk survival of the fittest, best plant selection in F5 based on phenotypes and harvested individually. Bulk method is a strategy of crop improvement in which the natural selection effect is more directly in the early generations of the procedure by delaying stringent artificial selection until later generations.