In U.S.A the barley varieties like Arivat, Beecher, Glacier and Gem have been originated from a bulk population derived from cross Atlas x Vaughn, the bulk was maintained in this case for 7 generations. 2. So the selec­tion for that recessive gene requires the F2 generation, i.e., selfing is needed after every two back-crosses, and testing for the presence of that character has to be done in that generation. Plant species where normal mode of seed set is through a high degree of cross-pollination have characteristic reproductive features and population structure. The progenies are evaluated for plant height, lodging, disease resistance, flowering time, maturity time, etc. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? What are the characters Mendel selected for his experiments on pea plant? Transgressive segregation can be obtained in case of quantitative characters by modified back-cross method. Pedigree method is useful in selection of new superior recombinant types from a hybridization programme. Open-Pollinated . 8. Features of Recurrent Selection: Plants are selected against rust resistance and also the characters of variety A. Progeny in the 14 th row in the F5 plot selected from the progeny in the 4 th row of the F4 plot. Inter-varietal Transfer of Quantitative Characters: Grain characters like seed size and shape, earliness, plant height-all can be transferred from one variety to another with the criteria of high heritability. Privacy Policy3. Breeding Self-Pollinated Crops Selection Methods Pure-line Selection Pure-line selection, like mass selection, begins with a heterogeneous population of homozygous plants. 1. The variety is tested in replicated yield trial along with the variety A as check. 2) This method is commonly used to correct some specific weaknesses of an established variety (Combination breeding). Once a recurrent parent taken in a back-cross method may get replaced by another superior variety of high yielding ability. 7. Then the rigid selection is done for the character to be transferred. Open-pollinated plants require the wind, insects (pollinators like bees), or the gardener to help pollinate the flowers so they can set fruit and produce seeds. Back-cross is the event of crossing of F1 with either of the parents, but here in the back-cross method of breeding the hybrid is to be crossed with the superior parent whose genotype is to be transferred to the local variety. 4. Many environmental factors, disease outbreak, etc., may select out the particular genotype from this bulk population. Pollinators that visit these flowers will facilitate pollination and can improve the yield per plant. For keeping a pedigree records following point are important. – Selection begins in the F2– Select 1% to 10% of the plants that combine the bestcharacteristics based on independent culling or index selectionPedigree breeding methodMethod:• Self the selected F2 plants to get the F3– Select one or a few plants from the best rows– Plant selected plants in plant-to-row progeny rows,keeping progeny rows grouped in families 3. The recur­rent parent should be the male parent. Save my name, email, and website in this browser for the next time I comment. 4.  Pureline refers to the homogenous progeny of a self pollinated homozygous plant. The commonly used breeding methods of self-pollinated plants were developed over a century ago in Europe. Many progenies may have become reasonably homozygous genotype and may be harvested in bulk. The population size in each generation should be large always, 30,000 – 50,000 plants in each generation. Through the maintenance of pedigree record the breeder may be able to obtain the information about inheritance of characters. The success of the method is mainly dependent on the skill of the breeder. The selection is made on disease reaction, grain charac­ter, etc. Breeder has little opportunity to show his skill in this method, practically selection is mainly based on natural selection. 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. The first two digits of this number refer to the year in which the cross was made, and the remaining digits denote the serial number of the cross in that year. This method is very much useful for cytoplasmic gene transfer to the recur­rent parent, i.e., new variety will bear the cytoplasm of donor parent and genotype of recurrent parent. The method is generally used for handling segregation generation may be grouped into three categories. Mass selection and pure line selection cannot be applied to segregating population. Cultivated sugarcane (Saccharum officincirum) is susceptible to pests and disease, crossed with S. spontanium which is resistant. Thus, the plants selected in F2 are given serial numbers of their parents ( F2 plants). as well as yield and quality characters. This is because a tomato flower is perfect, meaning that it contains both male and female parts. The selection of individual plant is continued till the progenies show no segregation. At the end of bulking period, individual plants are selected and evaluated in the same manner of pedigree method. All the plants are selfed. Largely grown as annuals, self-pollinating … Procedure for transferring a recessive gene will be different from that of dominant gene, as the recessive gene will be expressed only in homozygous condition. The hybridization is done among two selected parents, after emascula­tion one become female parent and another male parent. 4. Three or more rows for each progeny will help in comparison among progenies. For example, the number 7911, denotes the cross number 11 of the year 79. using back-cross method. Thus in stepwise manner more than one characters can be introduced into a single recurrent parent. If sufficient number of progenies is not retained, valuable genotypes may be lost in early segregat­ing generations. The mechanism is seen most often in some legumes such as peanuts.In another legume, soybeans, the flowers open and remain receptive to insect cross pollination during the day.If this is not accomplished, the flowers self-pollinate as they are closing. The rust resistant plants are selected and the seeds are harvested sepa­rately. This method is applicable to any self-pollinating crop like cereals, legumes and oil seeds. Tomato plants are self-pollinating, which means that a single tomato plant can set fruit by itself. 4. As an animal reaches into a flower for its reward, it brushes against an anther, and some of the pollen sticks to its body. The transfer will be unsuccessful if the genetic environment of recurrent parent is not suitable for functioning of the gene of desirable character from donor parent. In crop plants with high percentages of natural cross-pollination, controlled selfing … In case of transfer of male sterile character from one parent to another requires back-cross method. Share Your Word File Pedigree Method and Back-Cross Method | Breeding, Top 4 Methods Used in Cross-Pollinated Crops | Breeding. Or Improvement of asexually propagated crop y selecting superior clones is known as clonal selection. Now it is also used in self pollinated species. Variety A — Recurrent parent (well adapted, high yielding); Variety B — Non-recurrent parent, dominant gene controlled (stem rust resistant). As natural selection acts here, so the progenies selected from long term bulk are far superior than those selected from F2 of short term bulk. Methods of mixed (cross) pollination. Individual plant progenies of F5 generation are planted according to recommended commercial seed rate. 2) This method is commonly used to correct some specific weaknesses of an established variety (Combination breeding). This method is well suited for improvement of characters which can be easily identified and simply inherited. Existence of self-sterility, self-incompatibility, imperfect flowers, and mechanical obstructions make the plant dependent upon foreign pollen for normal seed set. This is so because of their effect on the applicability of certain breeding methods and techniques. The selected line is homogenous; thus, a pure line is more uniform than lines developed by mass selection. Preliminary yield trial with three or more replications is conducted to identify few superior lines. The new variety is not superior in performance than the existing variety ex­cept the introduction of single character. Back cross method. 1) Only important characteristics should be recorded. Breeding Methods in Cross Pollinated Crops The most important methods of breeding cross-pollinated species are (1) mass selection; (2) development of hybrid varieties; and (3) development of synthetic varieties. Less attention and labour is needed for this method. 2. Occurrence. 3. Pedigree record may be kept in several ways, but it should be simple and accurate. Individual plant progenies are grown. The multiple characters can be transferred in a stepwise method. Plants or progenies with weaker and visible defects are eliminated at an early stage in the breeding programme. 3. This specially requires the relatedness between the species where the chromosomes can pair during meiosis. But for determining the pedigree of a progeny the breeder has to consult the records of the preveious year. Such as in cotton, the ginning quality of fibre has been improved by back-cross method from the local variety. Pure line is a self pollinated descendent of a self pollinated plant. Pure line selection • 3. The pollen of animal-pollinated plants has a rough surface to help it stick to a pollinator Specific Objectives Theory By the end of the course, the students will be able to i. learn breeding procedures in self and cross pollinated crops ii. ; superior lines are released as new variety. The F1 generation seeds are space planted and seeds from these plants are harvested in bulk. Progenies harvested in bulk since they become homozygous. When the animal visits another flower, some of this pollen comes off onto the stigma pollination has occurred. The undesirable progenies are rejected. Seed multiplication and distribution to the farmers are carried out. Modification of back-cross method will produce transgressive segregants. This method gives maximum importance on the breeder to use his/her skill and judgement about the selection of plants and progenies. Interspecific Transfer of Simply Inherited Characters: Mainly the character like disease resistance can be transferred from related species to cultivated species. 3) It is also used in the selection of new superior recombinant type’s i.e Transgressive breeding. both stamen and pistil in the same bloom) and readily transfer pollen from the stamen to the pistil with even the gentlest breeze. In both the systems, the progenies are assigned a different serial number, when they become homozygous and are included in preliminary yield trials. But there are greater chances of error, since more number are to be recorded. 1. This number is given to those homozygous lines that are included in preliminary yield trials. Pedigree refers to record of the ancestry of an individual selected plant. For example, pureline selection applies to highly self-pollinating crops. Larger back-cross progenies would be needed than in case of transfer of a single character, and also it may take long time as in each step all the desired characters may not get expressed. 5. Application of Pedigree Method: 1) Selection of desirable plants from the segregating population in self- pollinated crops. Progeny from plant No 8, selected from the F5 progeny, derived from the plant N0.2 selected from the F4 progeny of the plant No.4 selected from F3 progeny of the Plant No.7 selected in F2. 3. The recurrent par­ent is first improved for one character then it is used as recurrent parent for introduction of another new character. Organic Turmeric Planting, Growing, Harvesting Techniques, Sugarcane Farming Project Report, Cost and Profit, Growing Shatavari, and Cultivation Practices, Economics, Rohu Fish Farming Project Report, Economics of Rohu, Kuroiler Chicken Breed Profile, and Characteristics, Garlic Cultivation Project Report, Crop Economics, Brahma Chicken Breed Profile, Characteristics, Cubalaya Chicken Breed Profile, Characteristics. Individual plant progenies of selfed plants are grown separately. Rust resistant plants are selected and back-crossed to recurrent parent, variety A. Comparison between the transfer of dominant and recessive gene during back- cross method: Quantitative characters are governed by polygenes such as grain size, plant height, maturity time, etc. No great subsequent changes were made. After 6-8 back-crosses, the cytoplasm will be of the donor parent with the genotype of recurrent parent. Inheritance of characters is not individually maintained as in pedigree method. Mass selection is a simplest, common and oldest method of crop improvement, in which large number of plants of similar phenotype are selected and their seeds are harvested and mixed together to constitute the new variety. The plants are tested for rust resistance charac­ter. 2. Disclaimer Copyright, Share Your Knowledge i) Pedigree Method ii) Bulk Method iii) Back Cross Method. In F3 generation also, the individual plant progenies are space planted. The above mentioned criteria are evaluated for these lines. During transfer of such kind of single desirable gene, sometimes some unde­sirable genes may get transferred. By back-crossing with noble cane these undesired characters are removed. Selection of large number of progenies in every generation is also laborious and time consuming. E. g F2, F3 etc. If the parent plants are closely related varieties then the number of selected F3 plants would be smaller whereas in case of dis­tantly related varieties the number of F3 progenies will be of relatively larger numbers. In some cases, the plant will produce both male and female flowers, like squash or pumpkin plants. At the end of bulking period a large number of progenies are being selected. 2. Starting from F2 generation onwards the seeds are planted at commercial seed rate and spacing. Defects of an established variety can be removed using this method, may be only by introducing a single character. Three different advantages may be achieved from this method: (2) Waiting for selection by environmental disaster. Poor progenies may be simply marked discard. The system of alternate back-crossing and selfing goes on till the desired results are obtained. Such populations are characterized by a high degree of heterozygosity wit… Plant breeding - Plant breeding - 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. 2) This method is commonly used to correct some specific weaknesses of an established variety (Combination breeding). (3) The long period of bulking may be helpful for natural selection to change the composition of population. Rigid selection is done for resistance to stem rust and the characteristic of variety A. The plants selected from a progeny in F3 are given the number of that progeny and in each generation the selected plant also given a serial number. To lack of popularity: 1 except bearing the new variety from a segregating population self-. 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