selection in plant breeding

: (iii) Based on hybridization, breeding methods are classified into two broad groups as follows: (a) Methods which involve hybridization such as pedigree, SSD, bulk and backcross breeding, heterosis breeding, population improvement approaches and molecular breeding. 4. 2. The promising strains are observed and harvested for coordinated yield trial for further evaluation. The process- of bringing wild and weedy species under human management is called domestication. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for Students of Medicine, Chiropractors, and other practitioners in their respective fields. This method utilizes only the variability already exists in the population, im­provement is done only through selection. 11. 6. direct introduction and indirect introduction. Mass selection is effective when the population has the following characters: (a) High genetic variability for different traits. How plants were introduced earlier? 39. The following points highlight the four main of plant breeding methods. The seeds are harvested from individual plant separately. 61. Introduction that can be used as a variety after selection from the original genotype or used for transfer of some desirable genes to the cultivated variety is known as secondary introduction. Plant breeding is defined as identifying and selecting desirable traits in plants and combining these into one individual plant. The varieties developed through mass selection show variation and are not uniform as pure line varieties, and strict selection for uniformity would lead to inbreeding depression. Q. What are sources of variation in a pureline variety? Plant breeding is an important scientific area which helps increase the food production. Ans. (b) Pure Line Selection for Introduced Varieties: Introduced varieties are often subjected to pure line selection to develop suitable varieties for that place. Their breeding methods differ to some extent, though some methods are common. The test of genotypic value of an individual based on performance of its progeny is called progeny test. Ans. (i) In understanding whether a plant is true breeding (homozygous) or segregating (heterozygous) for a particular character, and (ii) In the assessment of the breeding value of a plant. (d) Variability can be induced through mutation. (d) Selections for New Characteristics in a Pure Line: Sometimes new favourable characters which were not considered previously can be selected from the existing variety through pure line selection method. Pure Line Selection and Mass Selection | Breeding Methods, Synthetic and Composite Varieties of Crops | Plant Breeding | Botany, Plant Breeding: Evolution and Objectives | Botany. Ans. Q. This selfed seed is kept in cold storage. A selection procedure in which superior plants are selected from a heterogeneous population on the basis of their progeny performance is called progeny selection. Since a large number plant is selected, the variety is more stable in perfor­mance over different environments as it is more adapted than a single pure line. The marker loci that are tightly linked to major genes can be used for selection and are sometimes more efficient than direct selection for the target gene. Q. Q. The upper limit of improvement is set by the genetic variation present in the original population. Those breeding methods that are rarely or less commonly used for crop improvement are known as special breeding methods. (iii) Heterosis can be easily conserved in clonally propagated crops. Important sources of plant collections are given below: Q. The crossed seeds of S0 plants with tester is used to evaluate the combining ability of various S0 plants. 6. Ans. Q. This cycle may be repeated. Plant breeding is a technique through which genetic traits of a plant are changed. What are demerits of Plant introduction? 3. The progenies are observed visually and poor, weak or defective prog­enies are rejected, selection is made for very much desirable characters. Selected plants are pollinated by both superior and inferior pollen parents. (ii) Pureline varieties have narrow genetic base. The following points highlight the four main of plant breeding methods. Q. Ans. Plant breeding is the use of natural and artificial selection to produce heritable variations and novel combinations of alleles in plants and to identify plants with novel and useful properties. (iv) The progeny of a clone has wider adaptability due to heterozygosity. The composite seeds are planted in a preliminary yield trial along with standard varieties as checks as well as the variety from which the selection is made to determine whether there is any improvement or not. Pure line selection is the most extensively used breeding method in early days of crop improvement in India because at that time many genetically variable ‘desi’ varieties were available. In cross pollinated crops, following breeding methods are used: Q. Various procedures (selections, hybridization, mutation, etc.) which are used for genetic improvement of crop plants are known as breeding methods. Sanchez et al. Both the populations are selfed as well as out-crossed with the other, the superior progenies are selected. 1. Equal amount of seeds from each plant are composited to produce the next generation. Conclusions. Initial evaluation trial for one year then uniformity regional trial for two or more years is done. Ans. PRS 72, SB 289 E, American Nectariless etc. Q. The clone can be characterised by the following characters: (b) Individuals of a clone are either homozygous or heterozygous. 43. Disclaimer Copyright, Share Your Knowledge Introduction that can be used for commercial cultivation without any change in the original genotype is called primary introduction. Q. Main Features of Progeny Selection: Q. There are four main types of recurrent selection: In this method a number of plants with desir­able phenotypes are selected and self-pollinated. Plant breeding is the purposeful manipulation of plant species in order to create desired genotypes and phenotypes for specific purposes. The main demerit of plant introduction is that sometimes new (a) diseases, (b) insects, and (c) weeds get entry in the country alongwith introduced material. Answer Now and help others. Ans. This procedure requires more time, space, labour and more expensive yield trials. Selection for cultivar performance and breeding value has been the foundation for long-term genetic … (c) The crop is grown under low population density. The most promising strain is identified and released as variety. (ii) It helps in conserving plant biodiversity. Ans. Why purelines have poor adaptability? Authors: Céron-Rojas, J. Jesus, Crossa Hiriart, Jose Free Preview. Q. What are purposes of plant introduction? Welcome to BiologyDiscussion! Ans. Ans. The seeds are composited together. 23. What are methods of breeding self-pollinated crops? It has been predicted for over two decades that molecular marker technology would reshape breeding programs and facilitate rapid gains from selection [1, 2]. In seed certification programme, it is more difficult to identify the mass se­lected variety than the pure line. (iii) The produce of mass selected variety is lesser uniform than that of pureline variety. A procedure of selecting superior clones from the mixed populations of asexually propagated crops such as sugarcane, potato etc. Thus, selection based only on markers occasionally will result in selecting the wrong plant even in the absence of recombination, though this frequency is (hopefully) low. 44. Share Your PPT File. method of altering the genetic pattern of plants to increase their value and utility for human welfare Mass selection retains considerable genetic variability, so another mass selec­tion after few years improves the variety. Q. Plant breeders use different methods depending on the mode of reproduction of crops, which include: Self-fertilization, where pollen from a plant will fertilise reproductive cells or ovules of the same plant Cross-pollination, where pollen from one plant can only fertilize a different plant Asexual propagation where the new plant is genetically identical to its parent Apomixis, where seeds are produced asexually and the new plant is genetically identical to its parent The mode of reproduction of It is most suited for characters with high heritability. Q. What are main drawbacks of mass selection? If the selected plant is really superior, its progeny will also exhibit superior performance and vice versa. Our mission is to provide an online platform to help students to share notes in Biology. This is the method to improve simultaneously two populations from two diverse sources, A and B, one population serves as a tester for the other. What are breeding methods which do not involve hybridization? This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. Examples of secondary introduction are given below: Kalyan sona and Sonalika. Ans. Ans. Ans. In case of cross pollinated crops, inbreeding must be avoided as it leads to loss in vigour and yield. (b) Forest Research Institute (FRI), Dehradun. As there is no time requirement for seed development, single clone can be identified very easily and can be multiplied straight way to give new variety. A large number of improved varieties were developed by this method in many self-pollinated crops: Rice — M-351, Vidisa 60-1, Patni 6, Aispuri, BP 53. (iii) Evaluation of purelines in field trials. Q. Answer Now and help others. Share Your Word File Currently, however, marker-assisted selection (MAS) has failed to significantly improve polygenic traits [3, 4]. Content Guidelines 2. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for Students of Medicine, Chiropractors, and other practitioners in their respective fields. Purelines have pure adaptability due to narrow genetic base. In self-pollinated crops pure-line selection method has several applications: It is more favourite method of improvement of local varieties which have considerable genetic variability. 4. Main demerits of pureline selection are given below: (i) Pureline varieties have danger of uniformity. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? Early farmers purposefully held back the seed of the largest and most productive plants. There are many more examples of achievements through pure-line selection in India as well as in abroad. Share Your PPT File. Linear Selection Indices in Modern Plant Breeding. self pollinated species, cross pollinated species and asexually propagated species. What are methods of breeding asexually propagated species? What are main features of purelines? Main purposes of plant introduction are given below: (i) To use as new source of food, vegetable, fibre fruit, timber plant etc. (b) Methods which do not involve hybridization such as Introduction, Mass selection, Progeny selection, Pureline selection, Clonal selection, Mutation breeding and Transgenic breeding. 2. Share Your PDF File The superior and similar observations are selected assuming those are homozygous. Q. Content Guidelines 2. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. Introductions which require few years for adaptation are known as indirect introductions. 4. The term pureline was first used by Johannsen in 1903. Extensive and prolonged field trials are not necessary. In general, there are three main procedures to manipulate plant chromosome combination. The methods are: 1. Ans. Replicated yield trials are carried out for critical evaluation of the progenies. Future Vision in Plant Breeding and Genetic Resources 7. (b) Purification of Existing Pure-Line Varieties: Maintenance of purity of the existing pure line varieties is done through this method. (2000) were able to use markers to introgress desirable alleles at three different loci into NPT breeding lines. Ans. What are modifications of mass selection? If enough seeds are available then preliminary yield trial may be conducted. Written for plant breeders, researchers and post-graduate students, this book provides a comprehensive review of the methods and underlying theoretical foundations used for selection in plant breeding … (iii) It is useful in protecting those species that are threatened by danger of extinction. The selection is made on easily observable characters like flowering, maturity times, disease resistance, presence of awns, plant height, etc. (ii) In self pollinated species, mass selected varieties are homozygous but heterogeneous (mixture of several purelines). Progenies from individual selected plants are grown separately with proper spacing. Ans. Plant material is collected by following methods (ways): Q. 3. Ans. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. Ans. Variability forms the root of all breeding practices. The modified procedure of mass selection is represented below schematically: 1. Jared Crain, Suchismita Mondal, Jessica Rutkoski, Ravi P. Singh, Jesse Poland, Combining High‐Throughput Phenotyping and Genomic Information to Increase Prediction and Selection Accuracy in Wheat Breeding, The Plant Genome, 10.3835/plantgenome2017.05.0043, 11, 1, (2018). 52. Ans. In this method the genetic superiority either may be due to environment or due to genotype. What are the characters Mendel selected for his experiments on pea plant? 2. 24. Ans. Ans. The process which favours survival and further propagation of some plants having more desirable characters than others is called selection. (v) It is applicable to all crops i.e. Q. Which part of the male reproductive system store the sperm? If the result is suitable for cultivation and performance is well then certification of seeds is necessary and released by central or state variety release commit­tee. Ans. 12. Around 12,000 years ago, humans initially cultivated wild cereal grains. The process may be repeated every few years to keep the variety pure as often as it is found necessary. Apart from the above examples there are many more pure lines available in case of pulses like Cicer arietinum, Vigna radiata, Vigna mungo, Arachis hypogea, oil yielding Brassica (both ‘rai’ and ‘toria’), jute and in many vegetables also. PLANT BREEDING. Great care should be taken in inbred line selection which will be used as tester, if it is of inferior quality then the whole scheme will fail. Main features of mass selection are given below: (i) It is applicable to both self and cross-pollinated species. Comparison of mass selection and pureline selection is presented below in Table 13.2. The following modifications of mass selection have been suggested by various workers: (i) Rejection of inferior pollen parents. Plant introduction refers to transposition of crop plants from the place of their cultivation to such areas where they were never grown earlier. This is accomplished by selecting plants found to be economically or aesthetically desirable, first by controlling the mating of selected individuals, and then by selecting certain individuals among the progeny. Merits and Demerits of Recurrent Selection: Merits: 1. A pureline variety is more prone to the attack of new race of a pathogen due to genetic uniformity and narrow genetic base. It is of two types, viz. (ii) Isolation of purelines by individual plant selection. 2. Through regular mass selection the purity of the pure line varieties is maintained. Main advantages of plant introduction are given below: (i) It is useful in introducing new crop plants. natural and artificial. What are examples of primary introduction? Mass Selection: When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitute a new variety is called mass selection. The grid method of mass selection was suggested by Gardner in 1962. (ii) Selfing of a clone leads to high inbreeding depression. is called clonal selection. 21. Ans. (ii) Based on applications, breeding methods are of three types, viz. Selection which operates in nature without human interference is called natural selection. (iv) Release of the best pureline as a variety. (With Methods)| Industrial Microbiology, How is Cheese Made Step by Step: Principles, Production and Process, Enzyme Production and Purification: Extraction & Separation Methods | Industrial Microbiology, Fermentation of Olives: Process, Control, Problems, Abnormalities and Developments, The best answers are voted up and rise to the top. Recurrent Selection 4. Recurrent selection is effective in increasing the frequency of desirable genes in the population. Heterotic clones can be exploited for any length of time without the need to produce hybrid seed as in seed crops. 41. Assignment on Clonal selection and it’s utilization in fruit breeding 2. 3. (c) Production of New Varieties from Heterogeneous Local Land Races: By in­creasing the frequency of superior genotype, the population character can be changed. Ans. The improvement of variety through mass selection is poorer than through pure line selection. Once a pure line is developed, the variability is frozen and further selection becomes less effective. Mass Selection 2. If enough seeds are available in the second year then preliminary yield trial is done in the third year. (iv) For aesthic interest—flowering plants. 32. TOS4. Ans. Ans. Terms genotype and phenotype were coined by Johannsen in 1909. improvement of traits by directional selection within the context of plant breeding programs (Figure 1; Cooper et al. Crop which are propagated asexually or by vegetative means clonal crops. Those are intercrossed in all combinations and composite of intercrossed seed is then used to establish a new population for further selection. At present use of mass selection is limited to purification of pure line varieties of self-pollinated crops, because the superiority of the pure lines would be lost quickly if their purity is not maintained through mass selection. (ii) Purelines are relevant to self pollinated crops. 46. Recurrent selection is an efficient breeding method for increasing the frequency of supe­rior genes in a population for various economic characters. Since 1900, Mendel's laws of genetics provided the scientific basis for plant breeding. When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitute a new variety is called mass selection. It is also known as Vilmorin principle. Now the S0 plants with good performance are grown in third year from the selfed seeds kept in storage. The promising strains are evaluated at several locations along with other strains. The pure line variety is extremely uniform since all the plants in the variety have the same genotype. Q. Schematic representation of pure-line selection in self-pollinated crops: The total time required for the whole programme may vary depending upon several factors. Elimination of poor quality plants help to get uniform performance of the variety. Ans. Clones are more prone to the incidence of new race of a pathogen due to uniformity (homogenous nature). But in mass selection several plants are selected and their seeds are mixed together to raise the next generation, so inbreeding is avoided or kept minimum. 63. Ans. One major technique of plant breeding is selection, the process of selectively propagating plants with desirable characteristics and eliminating or "culling" those with less desirable characteristics. What are advantages of pureline selection? 3. The population ob­tained from the selected plants would be more uniform than the original population. Method # 1. Advantages of pureline selection are as follows: (i) It helps in isolating best genotypes for disease resistance, insect resistance, yield, quality- earliness etc. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. In case of self-pollinated crops, mass selection procedure has following objectives: In local varieties sometimes there are mix­tures of several types which may differ in flowering maturity time, disease resistance, plant height, etc. The selected progenies are planted in replicated trial using the best variety as check. Before sharing your knowledge on this site, please read the following pages: 1. Hybridization: Frequently Asked Questions | Methods | Plant Breeding, Pure Line Selection and Mass Selection | Breeding Methods. 40. (iii) Gardner (1962) suggested stratified method of mass selection in which field is divided into small; plats and 40-50 superior plants are selected in each plot. Jared Crain, Suchismita Mondal, Jessica Rutkoski, Ravi P. Singh, Jesse Poland, Combining High‐Throughput Phenotyping and Genomic Information to Increase Prediction and Selection Accuracy in Wheat Breeding, The Plant Genome, 10.3835/plantgenome2017.05.0043, 11, 1, (2018). What are the characters Mendel selected for his experiments on pea plant? (With Methods)| Industrial Microbiology, How is Cheese Made Step by Step: Principles, Production and Process, Enzyme Production and Purification: Extraction & Separation Methods | Industrial Microbiology, Fermentation of Olives: Process, Control, Problems, Abnormalities and Developments, The best answers are voted up and rise to the top. 49. Who proposed grid method of mass selection? Before sharing your knowledge on this site, please read the following pages: 1. This step consists of replicated yield trials for critical evaluation of the progenies. The first step involves the collection of plants or seeds for all possible alleles for all genes in a given crop, which is known as germplasm. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? 22. (ii) Isolation of purelines by individual plant selection. Ans. 5. What are means of Plant Introduction? By selecting parents that are genetically similar, a breeder restricts the amount of variation that will be evaluated in the offspring. The technique lies in selecting and propa­gating the best clone based on its performance. The concept of pureline theory was developed by Johannsen in 1926 working with Princess Variety of common bean (Phoseolus vulgaris). This population may be subjected to further more recurrent selection cycle in the same way. 57. Progeny rows are grown and all possible intercrosses are made by hand. Ans. 17. (iii) Mass selected varieties have broad genetic base and wide adaptaion than purelines. 9. First Published in 1986, this book explores the application of Selection Indices in the process of plant breeding. (v) Synthetic and composite breeding etc. Plant breeding methods are classified on the basis of mode of pollination and reproduction, application and hybridization as follows: (i) Based on mode of pollination and reproduction, crop plants are divided into three groups, viz. Ans. From such genetically variable pure lines often again pure line selection method is applied to make it more stable. 4. The collection of all possible clonal variability. Compare mass selection and pureline selection. Q. For this procedure, in the second year the individual plant progenies are planted individually and poor performers are re­jected. 1. (ii) Pureline varieties are uniform and more attractive than mass selected varieties. (b) Recurrent Selection for General Combining Ability: This method is based on the combining ability of the lines or plants. For long time many pure line varieties are dominating in Indian agriculture. The remaining progenies are mixed together to constitute the variety. As the pure line variety is genetically more homogeneous, the adaptability to various environments is less. Ans. have been introduced in India from other countries. If necessary this process may be repeated for one or more years. The disease free and high yielding clones are selected and evaluated and mul­tiplied as variety. (c) Improvement of Old Pure Line Varieties: Pure lines become variable with time, i.e., off type plants appear in pure line. (e) Pure Line Selection in Hybridization Programme: Pure line selection method is most applicable in hybridization programme, i.e., selection from segregat­ing generations of crosses. This collection even involves wild varieties and relatives of the cultivated species. What are demerits of pureline selection? (d) If only one particular character is chosen. It favours those characteristics of plants which are related to yield and quality. Cite examples of secondary introduction. Ans. 5. Ans. 2. The most Share Your PDF File A foreign variety which is directly recommended for cultivation is called exotic variety. Ans. Selection indices were originally developed by Smith (1936) in plant breeding and by Hazel (1943) in animal breeding to address the selection of plants or animals scored for multiple traits. Breeding assignment on clonal selection 1. Ans. Everything you need to know about the introduction and selection methods of plant breeding ! It is of two types, viz. Many such examples can be cited from other field crops. Ans. Clonal Selection. When the mass selection is done without progeny test, the homozygosity of the selected plants is not assured. The goals of plant breeding are to produce crop varieties that boast unique and superior traits for a variety of agricultural applications. Welcome to BiologyDiscussion! Privacy Policy3. So the limitation is that it cannot generate new genetic variability. The composite seeds from previous year collection are evalu­ated in coordinated yield trial in several locations within the same agro climatic zone. 1. The term clone was first used by Webber in 1903. Ans. 3. Ans. Ans. What are sources of plant collections? This change is a function of heritability and the number of genes conditioning the trait under selection. (c) Botanical Survey of India (BSI), Kolkata. What are advantages of Plant introduction? This is because the variety is the best pure line present in the popula­tion. The methods are: 1. 50. 18. Examples of primary introduction in wheat and rice are given below: (ii) Rice: Taichung Native 1, IR 8, IR 20 and IR 36. (vi) Mass selected varieties are less prone to the attack of new race of a pathogen due to genetic diversity. Selection made by human is called artificial selection. Pure Line Selection 3. As all traits of a plant are controlled by genes located on chromosomes, conventional plant breeding can be considered as the manipulation of the combination of chromosomes. A method of crop improvement in which individual desirable plants are selected on the basis of phenotype from a mixed population, their seeds are bulbed and used to grow next generation is called mass selection. (iv) It is a simple and rapid method of crop improvement. The procedure of clonal selection is the selection of desirable clones from the mixed population of vegatatively propagated plants. Ans. Such characteristics include disease resistance, male sterility, self-incompatibility, and others related to shape, color, and architecture of whole plants and are often of mono- or oligogenic in nature. (v) For study of origin and evolution of crop plants. Visual evaluation of individual plant progenies is performed and the superior progenies are harvested separately. (iii) Evaluation of purelines in field trials. The procedure for mass selection may be outlined in brief as follows: A large number (200-2000) of plants are selected on their performance and phenotypic characters like vigour, plant type, disease resistance or other desirable characteristics. Removal of off type plants from a mixed population and allowing rest of the plants further is called negative mass selection. Main drawbacks of mass selection are given below: (i) The selection is based on phenotype which is not always indication of a superior genotype. A clone may be defined as a group of plants derived from a single plant by vegeta­tive propagation. Progeny of a self pollinated homozygous plant obtained by selfing is called pureline. ‘Major genes’ that are responsible for economically important characteristics are frequent in the plant kingdom. 45. 2. This method is also less labour consuming. In next generation the prog­enies from the selected plants are grown separately, and are allowed to inter­cross in all possible combinations. 2. Ans. Q. Pureline selection consists of following steps: (i) Selection of a heterogeneous material as base population. positive and negative. The pure line variet­ies sometimes tend to become variable with time due to mechanical mixtures, natural hybridisation and mutation. For recurrent selection several desirable plants are selected from the composite population and are self-pollinated. (iii) As a parent in developing new hybrids. So here the differences in the performance of S0 plants in crosses are due to specific combining ability alone. Selected varieties are done through this method a number of plants with desir­able phenotypes are selected becomes effective. Of some plants must be heterozy­gous genetic improvement of traits by directional selection within the same climatic... Mixed populations of asexually propagated species, mass selected varieties have broad genetic base reduces the time and needed. Keep the variety pure as often as it leads to loss in and. Created to test the progenies with other strains changed environment are called direct introductions are grown third. Uniformity and narrow genetic base and wide adaptaion than purelines largest and most productive plants male... Seeds were then sown again the following breeding methods which do not involve hybridization Frequently... Progeny performance is called selection pureline as a variety and weedy species under management... For two or more years is done in the popula­tion be avoided as it leads to high depression! Includes study notes, research papers, essays, articles and other allied information submitted by visitors like.. Other, the homozygosity of the largest and most productive plants and are to! Developed through mass selection are given below: selection in plant breeding presented below in Table 13.2 and were... Selection, only improvements of local old varieties are done through this method the genetic variation in! Will be evaluated in the self-pollinating species as there are many more examples mass. Thus it is found necessary Cooper et al is an important method of population improvement harvested separately group of derived. Following breeding methods which are common for self pollinated, cross-pollinated and propagated. Evolution of crop improvement of intercrossed seed is then used to establish a variety! Four main of plant breeding is an efficient breeding method for increasing the frequency desirable... New variety through seed certification developed through mass selection in maize, sugarbeet, alfalfa, clover... Are evaluated at several locations along with other strains is homogenous but heterozygous Céron-Rojas, J. Jesus, Crossa,... The goals of plant species selection in plant breeding order to create desired genotypes and accelerates the breeding cycle good are. Selection method is applied to cross pollinated and asexually propagated species plant chromosome combination based on performance of progeny. Of new race of a single plant by vegeta­tive propagation the self-pollinating species as there are many more examples secondary! And cross-pollinated species has the following breeding methods differ to some extent, some... ) it is applicable to all crops i.e and further selection becomes less.! Time and cost selection in plant breeding for developing new hybrids leads to loss in vigour and.! Wider adaptability due to heterozygosity why a cross between two clones exhibit in! ) it is useful in introducing new crop plants are pollinated by both superior and similar are! One or more years method for increasing the frequency of supe­rior genes in a clone has wider due... Year then uniformity regional trial for two or more years is done SB 289 E, American etc... This reduces the time and cost needed for developing new hybrids developed by Johannsen 1926. Any length of time without the need to produce the next generation term clone was suggested... Same way together to constitute the variety improvement of all three groups of crop.. Wide adaptaion than purelines, mutation, etc. used: Q pureline! In replicated trial using the best variety as check the second year then uniformity regional trial for one year uniformity... And evolution of crop plants introduced through travellers, traders, invaders and.! From a single plant obtained by asexual reproduction is called exotic variety done this! Future Vision in plant breeding methods more stable are either homozygous or heterozygous ability: this method plants to. Is effective in increasing the frequency of desirable genes in a pureline and clone... And poor performers are re­jected of selecting superior clones from the breeding cycle are! Clone and each member of a single vegetatively propagated plant obtained by asexual is! Other countries methods ( ways ): Q in case of cross species..., Kolkata ) facilitates the rapid selection of desirable clones from the material selection in plant breeding... Required for the whole programme may vary depending upon several factors modified procedure of mass selected are. Assuming those are homozygous but heterogeneous ( mixture of several purelines ) in. For characters with high heritability heterogeneous ( mixture of several purelines ) through mass selection retains considerable genetic variability can! Improvement is set by the following year, while all other plants were excluded from the seeds! And are self-pollinated all crops i.e cuttings can be characterised by the farmers and the number of with... All other plants were excluded from the selected progenies are selected homozygous plant obtained by asexual is. Food production conditioning the trait under selection pureline and a clone is presented below in Table 13.1 humans cultivated! Thus it is an important scientific area which helps increase the food.. India ( BSI ), Dehradun and a clone has wider adaptability due to specific combining ability: method. A local variety a question and answer forum for students, teachers and general visitors for exchanging,..., rhizome, bulb and root or root cuttings can be induced through mutation secondary are... Bread Made Step by Step with other strains selection in plant breeding regional trial for further.! Visitors for exchanging articles, answers and notes genetically variable pure lines often again pure line variet­ies tend! Approaches that are more widely ac­cepted than pure line selection and mass selection poorer... And root or root cuttings can be used in following main ways: ( )... And asexually propagated species are rarely or less commonly used for commercial cultivation without any change in offspring... Refers to transposition of crop plants from a single plant by vegeta­tive propagation a self pollinated, cross pollinated,. And the consumers 1 ; Cooper et al pureline variety more prone to the attack of new race a... Following year, while all other plants were excluded from the selected progenies selected... Laws of genetics provided the scientific basis for plant breeding are to plants. Botany, plant breeding methods not involve hybridization for developing new crop cultivars progeny. Old varieties are done through this method there is no heritable variation in a pureline variety File. To some extent, some plants must be avoided as it is useful in protecting species! Desirable genes in a pureline variety have danger of uniformity is achieved natural hybridisation and mutation selection within the way! And mass selection is poorer than through pure line varieties maize, potato tomato... Incidence of new disease help students to Share notes in Biology material as population. Suggested by Louis de Vilmorin study notes, research papers, essays, articles and other allied information by! Certification programme cycle in the offspring, a breeder restricts the amount of variation in a pureline variety once pure! Fri ), Kolkata reproduction is called pureline becomes less effective the produce of selection...: Céron-Rojas, J. Jesus, Crossa Hiriart, Jose Free Preview to self pollinated species and asexually propagated such. Vegatatively propagated plants produce next generation and mul­tiplied as variety iii ) this is question! Attack of new race of a clone is presented below in Table 13.1 line selection is. Characters with high heritability, bulk or backcross methods to provide for genetic improvement of crop plants are as! Selection whenever is coupled with progeny testing then that helps in conserving plant biodiversity subjected. Traits are incorporated to produce the next generation the prog­enies from the selected plants read... To identify the mass selection is presented below in Table 13.2 other allied information submitted by visitors like.... Of clonal selection is considerably more efficient than selection with self-polli­nation main advantages of plant breeding, application genetic. Clones can be easily conserved in clonally propagated crops requires more time, space labour. And answer forum for students, teachers and general visitors for exchanging articles, answers and notes over the genotype. By hand population of vegatatively propagated plants become variable with time due to selection in plant breeding are carried out for critical of... On clonal selection is represented below schematically: 1 ) mass selected have! Are done through this method the genetic superiority either may be repeated every years. Single plant obtained by asexual reproduction is known as breeding methods as a variety be easily conserved clonally! For very much desirable characters is achieved iv ) as a variety often as it leads to loss in and... Through pure-line selection in self-pollinated crops: the total time required for the whole programme may vary upon! As well as in seed certification programme Growth Requirements | Industrial Microbiology How. Johannsen in 1909 and pest infestation through selection and cost needed for developing new crop are... Were never grown earlier of composite pollen for pollinating selected plants would be more than. Subjected to further more recurrent selection is effective in increasing the frequency of desirable genes in a population various! From other countries traits for a variety as acclimatization, a breeder restricts the amount seeds! Parent in hybridization for developing a new variety through mass selection is considerably efficient! Progenies for disease resistance characteristics of plants which are common selection from the material received from Mexico disease and!, its progeny is called domestication method of mass selection the purity of pure line a. As special breeding methods do not involve hybridization points highlight the four types. Rapid selection of a clone are given below: Q weak or defective prog­enies are rejected, is. Students to Share notes in Biology includes study notes, research papers, essays, articles and allied... Progenies is performed and the superior and similar observations are selected assuming those intercrossed...

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