plant breeding methods in asexually or clonally propagated crops

plant breeding method

1. Breeding Methods in Asexually / Clonally Propagated Crops Submitted To :- Dr. Akarsh Parihar Head of The Department Department of Genetics and Plant Breeding B. A. College of Agriculture, AAU Anand Submitted By :- Dulari M. Makani 2010123021 1 st sem ( M.Sc Agri ) Seed Science & Technology GPB 502 : Principles of Plant Breeding

2. Contents Sr. No. Contents 1 Introduction 2 Clonal Selection 3 Hybridization 4 Mutation Breeding 5 Polyploidy Breeding 6 Interspecific Hybridization 7 Case Studies

3. Introduction Plant breeding methods :- Various approaches like selection, hybridization, mutation etc. that are used for genetic improvement of crop plants are referred to as plant breeding methods. The choice of plant breeding methods mainly depends on Mode of pollination Mode of reproduction Gene action Breeding objective of crop species The plant breeding methods are generally classified on the basis of Application in crop improvement Hybridization

4. Asexual reproduction :- It is a mode of reproduction in which a new offspring is produced by a single parent. There are some agricultural ( sugarcane, potato, sweet potato, etc. ) and horticultural ( banana, mango, citrus, apple, pears, peaches, litchi, etc. ) crops that propagated by asexual. The new individual is produced by asexually are genetically and physically identical to each other. Asexual reproduction is of two types : Vegetative reproduction Apomixis Asexual Reproduction

5. Vegetative Reproduction :- Vegetative reproduction refers to multiplication of plants by various vegetative plant parts Vegetative reproduction is again of the two types :- Natural vegetative reproduction Artificial vegetative reproduction 1. Natural Vegetative Reproduction : Individual is arise from an individual through natural methods. Underground stem :- Rhizome : Ginger, Turmeric Tuber : Potato Corm : Colocasia , Bunda Bulb : Onion Sub aerial stem :- Sucker : Banana Runner : Strawberry, Rose, Mint Stolen Bulbils :- Garlic Vegetative Reproduction

6. Underground Stem Rhizome Tuber Corm Bulb

7. Sub Aerial Stem Sucker Runner Stolen

8. Bulbils Garlic

9. 2. Artificial vegetative reproduction :- Individual is arise from an individual through artificial methods. Root cutting : Sweet potato, Citrus, Lemon Stem cutting : Sugarcane, Grapes, Rose Grafting : Apple, Mango, Cherries Layering : Grapes, Gooseberry Budding : Rose

10. APOMIXIS Apomixis refers to the development of seed without sexual fusion. Obligate apomixis : Reproduction in some species occurs only by apomixis Facultative apomixis : In some species sexual reproduction also occurs in addition to apomixis. Non recurrent apomixis : Embryos arise from haploid cells Recurrent apomixis : Embryos arise from diploid cells

11. Reasons of Asexual Reproduction 1. Non flowering species : This group includes garlic, ginger, betel and several yams. 2. Low seed setting species : Sugarcane, potato, sweet potato, etc. 3. Normal flowering and seed setting species : citrus, mango, pear, peach, apple, litchi, loquat and many ornamental plants. 4. Apomictic species : seeds develop asexually in such species. Many fruit crops exhibit apomixis

12. A great majority of these crops are perennials. e.g., sugarcane, potato, sweet potato Many of the crops show reduced flowering and seed set, and many varieties do not flower at all. They are invariably cross-pollinated. These crops are highly heterozygous and show sever inbreeding depression. A vast majority of clonal crops are polyploids . e.g., sugarcane, sweet potato, potato Many crops are interspecific hybrids. These crops consist of a large number of clones. i.e., progeny derived from a single plant through asexual reproduction. Characteristics of Asexually Propagated Crops

13. Breeding Methods of Asexually Propagated Crops General Methods Special Methods Mutation breeding Polyploidy breeding Distant hybridization Transgenic breeding Plant Introduction Clonal Selection Hybridization Heterosis breeding

14. Clone : A group of plants produced from a single plant through asexual reproduction Clonal Selection : A producer of selected superior clones from the mixed population of asexually propagated crops is referred to as clonal selection. Clonal Selection

15. 1. Homogeneous Constitution :- The progeny of a clones is genetically identical and have same genetic constitution. Clones are homogeneous. 2. Heterozygosity :- The asexually propagated crops are heterozygous and hence clones is also heterozygous. Progeny of a clone looks similar phenotypically but is heterozygous. 3. Vigorous Growth :- Clones have hybrid vigour which is conserved due to asexual reproduction. Most of the varieties of sugarcane and potato are hybrids . Main Features of Clones

16. 4. Wider Adaptation :- Clones are more adaptable to environmental variation due to high level of heterozygosity than pure lines . 5. Source of Variation :- There are three main source of variation in a clones; Bud mutations, Mechanical mixtures, Occasional sexual reproduction 6. Segregation of F1 :- When hybridization is done between different clones, segregation occures in F1 generation. Each F1 plant is potentially a new variety, therefore, selection is practiced in F1. Continue…

17. First Year :- From a mixed variable population, few hundred to few thousand desirable plants are selected on the basis of yield, maturity, disease resistant etc. plant with obvious weakness are eliminated. Second Year :- Clones from the selected plants are grown separately, generally without replication. Based on the observations the inferior clones are eliminated. The selection is based on visual observation and on judgement of the breeder on the value of clones. Fifty to one hundred clones are selected on the basis of clonal characteristics. Third Year :- Replicated preliminary yield trial is conducted with a suitable check. The clones superior to the check are selected for multilocation trials. Selection Procedure

18. Fourth to Sixth Years :- Replicated yield trials are conducted at several locations along with suitable check. The yielding ability, quality and disease resistance, etc. of the clones are rigidaly evaluated. The best clones that is superior to the check in one or more characteristics is identified for release as a new variety. Seventh Year :- The superior clones is multiplied and released as a new variety. Continue…

19. It is the only method of selection applicable to clonal crops. It avoid inbreeding depression and preserves the gene combinations present in the clones. The selection scheme is useful for maintaining the purity of clones. Variety evolved by this method retains all the characters of the parental clones for several years. Varieties are highly uniform like pure line. They are highly stable because there is no risk Of deterioration due to segregation and recombination. Merits

20. This selection method utilizes the variability already present in the population and it has not been devised to generate variability. Genetic makeup can not be improved by this method without hybridization. Varieties developed by clonal selection are highly prone to new of a disease. Demerits

21. In india , clonal selection has been successfully used for developing new varieties in potato, sugarcane, banana, citrus and grapes Potato – Kufri red and Kufri safed Banana – Bombay green, Pride monthan and high gate Mango – Ko 11, Ko 22 and Neelam Achievements

22. Clonal crops are generally improved by crossing two or more desirable clones, followed by selection in the F1 and subsequent clonal generation. Once the F1 has been produced the breeding procedure is essentially the same as the clonal selection. The improvement through hybridization involves the following three steps : 1. Selection of parents 2. Production of F1 progeny 3. Selection of superior clones Hybridization

23. 1. Selection of parents: Parents are generally selected on the basis of their known performance both as varieties and as parents in hybridization programmes . The performance of a strain in hybridization programmes depends on its prepotency and GCA. 2. Production of F1 progeny: Generally, clonal crops are cross-pollinated and they may show self-incompatibility The selected parents may be used to produce single crosses involving two parents or an equivalent of a polycross involving more than two parents. 3. Selection of Superior Clones: Generally small samples of several F1 population are grown. The presence of outstanding individuals in the F1 population is also noted, and inferior F1 are eliminated. Promising F1 with outstanding individuals are then grown at a larger scale for selection.

24. First Year :- Clones to be used as parents are grown and crosses are made to produce F1 progeny Second Year :- Sexual progeny from the cross, i.e., seedlings obtained from true seeds are grown. Undesirable plants are eliminated and few hundred to few thousand desirable plants are selected and harvested separately. Third Year :- Clones from the selected plants are grown separately. Poor and inferior clones are eliminated; up to 200 superior clones may be selected for preliminary yield trial. Fourth Year :- A replicated preliminary yield trial is conducted in which suitable checks are included for comparison. Fifth to Seventh Year :- Replicated yield trials are conducted at several location, and suitable checks are included for comparison. Outstanding clones are identified and they may released as new variety. Eighth Year :- The clone released as variety is multiplied and distributed among farmers. Hybrid Procedure

25. Potato – Kufri Alankar , Kufri Ashoka , Kufri Pukhraj , Kufri Surya, Kufri Arun , Kufri Khyati , Kufri Bahar , Kufri Sadabahari etc. Sugarcane - Co 1148, Co 1158, CoS 510, Co 975, CoS 109, Co 541 Achievements

26. Mutation breeding is of relevance to the breeding of clonal crops in such considerations :- 1. Often the breeder may wish to modify only one or a few traits of an existing excellent cultivar. 2. Many clonal crops have long juvenile phase, which discourages the use of hybridization. In contrast, mutation breeding permits the isolation of desired mutants far more rapidly. 3. Sexual reproduction may not occur in many clones, seeds may be unable to germinate, and hybridization may be difficult for a variety of reason. 4. Isolation of recessive mutations without a resource to sexual reproduction is greatly facilitated by their highly heterozygous nature. Mutation Breeding

27. Achievements Sugarcane variety Co 8152 is a gamma-rays induced mutant from Co 527.it give 40% higher cane yield than the parent variety, but its lower leaves dry more quickly than parent and other sugarcane varieties. So, has limited its popularity with the farmers.

28. Polyploidy Breeding Polyploidy : An individual having more than two basic sets of chromosomes is called polyploid and such condition is known as polyploidy. Polyploidy Breeding : Genetic improvement of crop plants through manipulation of chromosome number its called polyploidy breeding. Types of polyploid :- 1. Autopolyploid : Polyploids which originated by multiplication of the chromosome of a single species are known as autopolyploid. e.g. Banana, Apple, Sugarcane etc. 2. Allopolyploid : Polyploids which originated by combining complete chromosome sets from two or more species is known as allopolyploid. e.g. wheat, Tobacco, Cotton etc.

29. Triploids are useful only in those plant species which propagated by asexually. Banana : Cultivated varieties of banana are triploids and seedless. Such banana have larger fruit than diploids. Sugarbeet : Triploids sugarbeets have higher sugar contents than diploids and are generally resistant to moulds . Watermelon : Triploids watermelon are seedless. These watermelon are produced by crossing tetraploids female with diploid male.

30. Polyploidy is mainly induced by treatment with a chemical known as colchicine. For effective induction of polyploidy, usually concentration of 0.01% to 0.5% are used in different plant species. Effects of polyploidy :- Stems are thicker Roots are stronger and longer Leaves are fleshy, thicker, larger and deep green in colour

31. Interspecific Hybridization Interspecific hybridization refers to crossing ot two different species of the same genus or of different genus of plant. Many varieties of Rubus , Malus , Strawberry etc. are interspecific hybrid. Generally, interspecific crosses are made to transfer specific characters, such as disease resistance from wild species to the cultivated species. The reason for such a great success of interspecific hybridization in clonal crop is their asexual reproduction, this completely avoids segregation and recombination. Another reason most of them are not produce seed, hence flowering are not essential for their success of varieties.

32. Solanum curtilobum X Solanum tuberosum F1 X Solanum andigena Kufri kuber S. officinarum X S. spontaneum Saccharum Barberi & Saccharum sinense Potato and Sugarcane of the clonal crops that concern most benefited from Interspecific hybridization

33. 1. Reduced Flowering and Fertility :- As a consequence of reduced flowering and seed set, many desirable clones in several clonal crops cannot be used in hybridization programmes . 2. Difficulties in Genetic Analyses :- Genetic analysis in most clonal crops is very difficult due to sterility. 3. Perennial Life Cycle :- Perennial life cycle drastically increase the time required for obtaining sexual progeny for genetic analysis of clones. Problems In Breeding Of Asexually Propagated Crops

34. Asexual propagation of greek Salvia officinalis L. populations selected for ornamental use 1 CASE STUDY Christos Nanos, Parthena Tsoulpha , Stefanos Kostas, Stefanos Hatzilazarou , Ioanna Michail , Vasiliki Anastasiadi , Elias Pipinis , Evangelos Gklavakis , Angelos K. Kanellis , and Irini Nianiun-obeidat Laboratory of Genetics and Plant breeding, school of agriculture, Aristotle university, 54124 Thessaloniki, Greece Objectives : To evaluate the morphological traits of twelve sage populations from different regions of north-western Greece and select the best ones. Thessaloniki, Greece Nanos et.al. , 2023

35. Abstract Salvia officinalis , commonly known as sage, is highly valued for its medicinal and ornamental properties. Populations from the locations of Aristi , Kefalovryso and Igoumenitsa were selected as the best performing and for their preservation and availability in the market, their asexual propagation was invested by (a) shoot cutting and (b) in vitro techniques. Propagation by cutting was investigated during four season. Aristi exhibited highest rooting in spring with a well developed root system by applying 0.5 g/L Indole-3-butyric acid, potassium salt. After successful disinfection, the effect of MS medium in ten different combination of Indole-3-acetic acid (IAA), 6- Benzylaminopurine (BAP) and Thidiazuron (TDZ) were tested on shoot multiplication. Of the three rooting variants tested, optimal rooting formation (100%) was observed on 0.9 mg/L IAA (R3) combined with successful acclimatization (100%).

36. Materials and Methods Twelve wild grown population of S. officinalis , from different habitats of north-west Greece, were selected for evaluation. Population Latitude (North) Longitude (East) No. of Plant per Population 1 2 3 4 5 6 7 8 9 10 11 12 ARISTI ARNISSA ELAFOTOPOS IGOUMENITSA KEFALOVRYSO KALPAKI KALYBIA KATO PEDINA KERKYRA MAYROBOUNI MESOBOUNI MIKROBALTOS 39.933689 40.798127 39.901731 39.485731 40.003702 39.902897 39.902781 39.877418 39.770129 39.954294 39.942593 40.078276 20.679384 21.828355 20.692177 20.264105 20.558476 20.641573 20.641872 20.670230 19.697890 20.619267 20.646485 21.872652 21 9 26 10 11 18 15 31 10 18 26 22 Table 1. Code names, coordinates of the central point of 12 S. officinalis population and number of plants per population.

37. Analysis of morphological traits : Morphological Traits Description 1 Leaf number Number of leaves per branch , 20 terminal branches per population 2 Leaf length In cm, measured from the base to the tip of adult/mature leaf, 50 leaves per population 3 Leaf width In cm, measured at the widest part of adult leaf/mature, 50 leaves per population 4 Inflorescence length In cm, measured from the base to the tip of inflorescence, 20 inflorescences per population 5 Node number per inflorescence Number of nodes per inflorescence, 20 inflorescences per population 6 Flower number Number of flowers per inflorescence, 20 inflorescences per population 7 Branch number Number of terminal branches per plant, was measured in all plants 8 Branch length Length of branches per plant, in cm, 20 terminal branches per population. Table 2. Morphological traits for the 12 selected populations of S. officinalis related to their ornamental value.

38. Asexual Propagation of Selected S. officinalis Populations Propagation by Shoot Cuttings : Terminal cuttings collected during the four seasons and tested for their rooting ability. The basal portion of each shoot cutting was dipped into aqueous solutions of 0, 0.5, or 1 g · L−1 of K-IBA for 10 s and planted in 10 L plastic trays (40 cm × 25 cm × 10 cm) filled with perlite . The plastic trays were then established for rooting in a fog system, with the relative humidity adjusted to 95 ± 1%. Forty shoot cuttings were used for each treatment and population. After four weeks, the rooting ratio (%), as well as the number and length (cm) of roots, were recorded. Effect of Substrate and the Mist or Fog System on Rooting of Cuttings : The effect of substrate was evaluated on three different mixtures of peat TS2 Klasmann and perlite : 0:1, 1:1, or 1:2 v/v, after treating the cuttings as previously described with 0.5 g/L K-IBA. The RH in the fog system was adjusted to 95 ± 1%, while in the intermittent mist system, water was sprayed for 30 s every 30 min, from 06:00 to 22:00. In both rooting systems, the temperature at the bottom of the benches was set at 20 ± 1 ◦C using electrical cables.

39. 2. In Vitro Propagation of S. officinalis :- For the tissue culture experiments, shoot tips of the selected populations of S. officinalis were used as explants. First, they were pretreated with a mild dish soap and washed under running tap water for 20 min. Seven different disinfection treatments were tested for all populations(Table 3), followed by three successive washings with double distilled water. The explants were established in vitro on MS medium, free of growth regulators, supplemented with sucrose (3%) and agar. Cultures were maintained in plant growth chamber conditions:23 ± 2 ◦C , 16 h photoperiod and light intensity at 50 μmol ·m−2·s−1 provided by cool-white fluorescent lamps. The same environmental conditions were applied to all subsequent experiments.

40. Treatment No. (%) EtOH v/v Ascorbic and Citric acid NAOCL (%) Time Duration (min) D1 70 - 0.06 10 D2 70 + 0.06 11 D3 70 - 0.06 12 D4 60 + 0.06 11 D5 50 + 0.06 12 D6 70 - 0.08 7 D7 70 - 0.04 17 Table 3. Disinfection treatments applied to S. officinalis explants.

41. Conclusion The present study will contribute to the sustainable exploitation and promotion of selected native sage populations for decorative uses with simultaneous conservation of this valuable genetic material and the provision of the market with the required vegetative plant material by either cuttings or in vitro techniques. Of the three selected wild sage populations, the results proved that both techniques adequately justified the main goals, i.e., selection and asexual propagation of the present research. Even though rooting of cuttings reached satisfactory results, in vitro propagation enhanced to the optimal the rooting and acclimatization of the selected populations. Overall, the population of Aristi has the dynamics of a new ornamental sage variety, and as such, it can be introduced in the market of plants with aesthetic value

42. Genetic Improvement of Asexually Propagated Plant Diogenes Infante , Mayra Osorie and Sandy Molina Unidad de Biotechnologia de Plantas , Venezuela Infante at. el. 2005

43. Abstract Agave are succulent monocot plants rich in fibers, sugars and other important compound. Molecular marker(AFLP and ISTR) were used to study genetic diversity in different Agavaceae plant samples. The comparison of the banding pattern between the mother plant and rhizomes and bulbils derived daughter plants showed that genetic variability is introduced during asexual reproduction in these species. This asexual variability was used to genetically improve Agave fourcroydes , a cultivated agave that it is multiplied only through vegetative propagation using rhizomes. After micropropagation of three elite lines and three years under field condition, we demonstrated using morphological analysis that plants originating from same mother plant formed a group in principal Component Analysis (PCA). AFLP and cluster analysis using Unweighted Pair Group Method Arithmetic Average (UPGMA) showed that each mother plant and its somatic embryogenesis derived daughter plants clustered, indicating the conservation of molecular marker patterns in the micro propagated daughter plants.

44. Materials and Methods DNA Isolation A routine procedure for DNA mini-extraction from agave leaves was used. AFLP and ISTR Development AFLP were obtain following primer: E-ACG in combination with M-CAC, M-CTC and M-CTT, combination selected because they were highly polymorphic. ISTR were obtained using following primer combination : F1A x B2B, F2 x B1A, F2 x B2B and F3 x B2B. F indicate forward primer while B indicate backward primers. Data Analysis Autoradiograms were scanned and bands were analyzed using the program. This program created a 0-1 matrix scoring for the presence or absence of each band. After visual correction of the results, the data were exported as 0-1 matrix to the program used for statistical analysis. Induction of Somatic Embryogenesis The material obtained from the selected plants were stripped of their leaves, avoid any damage to apical meristems, which are about 10 mm thick and 25 mm long. The material were surface sterilized with 96% v/v ethanol for 1 min and flamed for a few seconds. Once isolated, the apical meristem were cultured in modified MS medium supplemented with 2,4-D and BA at 22 0C for 8 weeks.

45. Conclusion Despite its asexual reproduction variability was measured as changes in the AFLP banding pattern of plants from different cultivated populations in the Yucatan peninsula. This variability was used to select elite individuals which had been clonally propagated by rhizome. An analysis AFLP and clustering with UPGMA. comparing the mother plants and somatic embryogenesis derived daughter plants The result obtained allow the comparison of genetic variability at the population level with the plants obtained by somatic embryogenesis. The number of polymorphic bands was 25.2% in the rhizome derived population and 19.9% in the somatic embryogenesis derived population; thus it is lower in the somatic embryogenesis derived plant than natural cultivated population.

46. Thank You…