Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

Breeding methods in cross pollinated crops

  • Inicia sesión para ver los comentarios

Breeding methods in cross pollinated crops

  1. 1. BREEDING METHODS IN CROSS POLLINATED CROPS Deva Ram E-mail-mail2devhingra@gmail.com DEPARTMENT OF GENETICS AND PLANT BREEDING ALLAHABAD SCHOOL OF AGRICULTURE SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE, TECHNOLOGY AND SCIENCES
  2. 2. Selection method in cross pollinated crops
  3. 3. Breeding methods in cross pollinated crops Breeding methods | Population improvement Hybrid and Synthetic varieties (Used to increase the (A variable no. of frequency of desirable strains are crossed alleles) to produced a hybrid population)
  4. 4. Breeding methods in cross pollinated crops Methods of population improvement Breeding methods Breeding methods with without progeny progeny test Test Eg:-(Mass selection) (Progeny test, Ear to row method and Recurrent selection)
  5. 5. Methods with cross-pollinating crops  Intrapopulation improvement 1. Mass selection 2. Modified mass selection 3. Ear to row method 4. Modified ear to row method 5. Half sib selection 6. Modified half sib selection 7. Full sib selection 8. Recurrent selection recurrent selection for sca recurrent selection for gca
  6. 6. Methods with cross-pollinating crops  Inter population improvement 1. Reciprocal recurrent selection
  7. 7. Breeding methods in cross pollinated crops MASS SELECTION
  8. 8. Mass Selection  Selection of individuals  Sampling seed of selected individuals to plant next generation  Oldest method of crop improvement  Improvement of heterogeneous native populations or landraces
  9. 9. Mass selection  Mass Selection  same form as with self-pollinated crops  essentially a form of maternal selection since no pollination control  select desirable plants  bulk seed  repeat cycle  with strict selection breeder will reduce population size  slow genetic gain since lack pollination control  must be able to ID superior phenotypes  Not suitable for quantitative traits
  10. 10. MASS SELECTION X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Grow population Allow random mating Harvest and bulk seed from desirable plants Plant new generation Repeat (Source: Tinker, 2008)
  11. 11. Mass Selection  Higher percentage of desirable genotypes  Method can only be used in environments where trait is expressed - may not be suitable for off- season winter nurseries  Effectiveness is function of heritability  Manage field to enhance differences: eg. irrigate excessively to increase disease pressure
  12. 12. Mass Selection Achievements :-  Early varieties of bajra - Babapuri, Jamnagar giant, Pusa moti.  Toria – increase the yielding ability by 30% and oil 56%, in Abohar.  Rai – many early, erect to semierect types developed, Type- 11.  Yellow sarson – T-42, T-16.  Brown sarson – 17 dwarf, 17 medium, DS-1, DS-2.  Maize – T-41, 19, Jaunpuri.  Desi cotton – C-402, C-520.  American cotton – 100F, 216F  castor – B-1, B-4.
  13. 13. Breeding methods in cross pollinated crops MODIFIED MASS SELECTION
  14. 14. Modified mass selection  Also known as stratified mass selection or grid method of mass selection.  This modification is suggested by Gardner in 1961.  Field is divided into several small plots, eg., having 40-50 plants each.  Selection is done within the plots and not among the plots.  Seeds are selected and composite to raise the next generation.
  15. 15. Breeding methods in cross pollinated crops EAR-TO-ROW METHOD
  16. 16. Ear-to-row method Ear-to-row selection, generalized scheme (Source: Acquaah, 2006)
  17. 17. Breeding methods in cross pollinated crops MODIFIED EAR-TO-ROW METHOD
  18. 18. Modified ear-to-row method 1. First year. Plants selected on the basis of phenotype. open pollinated seed from each plant harvested separately. 2. Second year. Small progeny rows are grown and evaluated. The remaining seed from the plants producing superior progenies bulked to raise the next generation. 3. Third year. The bulked seed of 2 year planted and allowed to open pollinate. Plants with superior phenotype selected and seed harvested separately. The selection cycle may be repeated one or more times.
  19. 19. Modified ear-to-row method This modification of ear to row method was widely used in breeding of maize in U.S.A. and was responsible for the development of several varieties.
  20. 20. Breeding methods in cross pollinated crops RECURRENT SELECTION
  21. 21. Recurrent Selection designed to increase the freq. of desirable genes within a population  developed in the 1940s for developing inbred lines  first suggested by Hayes and Garber in 1919 and independently by East and Jones in 1920.
  22. 22. Recurrent Selection The schemes are divided into following four types:- 1. Simple recurrent selection 2. Recurrent selection for gca 3. Recurrent selection for sca 4. Reciprocal recurrent selection
  23. 23. Simple recurrent selection (Source: Acquaah, 2006)
  24. 24. Recurrent selection for sca & gca (Source: Acquaah, 2006)
  25. 25. Reciprocal Recurrent Selection  Proposed by Comstock, Robinson, and Harvey (1949) to select for both general and specific combining ability  General combining ability (GCA) is the ability of a breeding strain to combine favorably with many other strains or inbred lines. Analogous to ADDITIVE gene action  Specific combining ability (SCA) is the ability of a genotype to combine favorably with one or a few other genotypes. Analogous to DOMINANT gene action
  26. 26. Reciprocal recurrent selection (Source: Acquaah, 2006)
  27. 27. Reciprocal Recurrent Selection  Proposed by Comstock, Robinson, and Harvey (1949) to select for both general and specific combining ability  General combining ability (GCA) is the ability of a breeding strain to combine favorably with many other strains or inbred lines. Analogous to ADDITIVE gene action  Specific combining ability (SCA) is the ability of a genotype to combine favorably with one or a few other genotypes. Analogous to DOMINANT gene action
  28. 28. Reciprocal Recurrent Selection  Although Recurrent and Reciprocal Recurrent Selection methods were originally designed and used to improve the chances of developing superior inbreds of corn, these procedures are not used explicitly in private industry for that purpose today.  Most new inbreds in sorghum are developed through pedigree or pedigree type procedures and in corn doubled haploids procedure have become popular since about 2000.
  29. 29. Breeding methods in cross pollinated crops HYBRID VARIETY
  30. 30. Hybrid Production Production of heterozygous populations from the crossing of homozygous lines Mostly used for cross-pollinated crops The hybrid seed must be reproduced each year The word HYBRID denotes a population of F1 plants derived by crossing inbred lines, clones, open-pollinated varieties or any population that are genetically dissimilar.
  31. 31. Hybrid Production Steps involved  Produce inbred lines  Cross the inbred lines  Single cross hybrid  Harvest the female rows because they have the hybrid seed  Double cross hybrid  Three way cross hybrid
  32. 32. Hybrid Production Achievements:-  First hybrid varieties in maize were released in 1961, viz., Ganga-1, Ganga-101, Ranjit & Deccan  First hybrid bajra was developed by PAU. Ludhiana in 1965 as HB-1. Subsequently, HB-3 & HB-5 were released.  Bajra – PHB-10, PHB-11, BJ-104 & BK-560.
  33. 33. Weaknesses  Many years to provide a commercially marketable seed.  Crossing can only occur within the same species, and often selection is inefficient because it depends primarily on phenotypes.  Finding the desirable trait takes large numbers of crosses so space can be a premium.
  34. 34. Breeding methods in cross pollinated crops SYNTHETIC VARIETY
  35. 35. Synthetic varieties Steps involved in the production of synthetic varieties:- Step-1 Evalulation of lines for gca  Topcross or polycross test for gca; outstanding lines selected as parents. Step-2 Production of the synthetic Method 1. Equal seed from all the lines mixed and planted in isolation. Open-pollinated seed harvested as the synthetic variety(syn1)
  36. 36. Synthetic varieties Method 2. The parental lines are planted in a crossing block. All possible intercrosses are made. Equal seed from all the crosses mixed to produced the synthetic variety (syn1). Step-3 Seed multiplication  Seed of the synthetic variety may be multiplied for one or two generations before distribution.  Open pollination in isolation (syn2 or syn3).
  37. 37. Synthetic varieties Achievements:-  Widely used in forage crops.  Synthetic varieties have been developed in maize, pearlmillet, sunflower, sugarbeet, alfalfa, lucerne and several other crops in USA.  In India, synthetic varieties have been developed in pearlmillet at ICRISAT and in sugarbeet at Pantnagar university.  Sugarbeet – Pant synthetic-3  Cauliflower – synthetic-3
  38. 38. THANK YOU

×