The base line of plant breeding

1. The base line of plant breeding Zoltán Bedő EUROPEAN ASSOCIATION FOR RESEARCH ON PLANT BREEDINGEUROPÄISCHE GESELLSCHAFT FÜR ZÜCHTUNGSFORSCHUNG ASSOCIATION EUROPÉENNE POUR L'AMÉLIORATION DES PLANTES

2. Main trends of plant breeding in the 20th centuryR. W. Allard (1996) Level of Cultivated crops population heterogeneity Landraces high Old variety populations high Selected old varieties medium Modern varieties homogen • As a result of the selection by breeders a genetic erosion occured by the disappearance of old landraces and varieties having high level of heterogeneity in their populations • Continuous efforts during several breeding cycles have led to the accumulation and preservation of favourable alleles for a better adaptation and agronomic performance in modern varieties • Breeding progress • Discovery and generation of genetic variation • Accurate selection genotypes with new traits • Transgressive segregation is the source for continued progress

3. Vegetatively propagated crops • (bulbs, tubers or cuttings, etc. • Self fertilzers crops like wheat, • soybean, leading to variety • selection • Heterosis breeding to develop • hybrids by crossing inbred lines Principles of classical breeding Biology of sexual reproduction Knowledge of trait heritability Mode of inheritance Number of genes controlling inheritance Classical variety breeding Determination of the ideotype, breeding objective Assesment of genetic variation, genetic resources Crossing + Evaluation + Selection Screening, data management Release of new variety Maintenance breeding – stability of traits (UPOV regulations)

4. Modern crop varieties selected by classical breeding • wide adaptability across different environments instead of locally adapted crop populations • high level of yield potential and high interplant competition ability Changing plant architecture Harvest index – ratio of vegetative/generative parts Genetic improvement in yield-related traits in cereals (Evans et al. 1981) Van Dobben (1962) 34% old 40% new varieties Vogel et al. (1963)32% old 38% new varieties Leaf size Szunics et al. (1985) 22.9% old 47% new varieties Flag leaf area Litvinenko (2001) 21.2% old 43.5% new varieties Flag leaf senescence Lukjanenko (1966) optimal ratio 50% Rate and duration of grain filling period Assimilate translocation to the grain, etc.

5. Genetic resources to increase genetic variation Genetic resources elite varieties exotic germplasm old landraces and variety populations wild and cultivated relatives mutant genotypes Genetic variation X XX XXX XXXX XXXX Elite x elite crosses - differences between alleles in new commercial varieties are diminishing potential increase of genetic vulnerability Wild and cultivated relatives - sources of new disease resistance genes drought tolerance, nutritional quality traits, etc. best sources to widen genetic variation Disadvantages of the classical use of wild and cultivated crop relatives • crossability • genetic linkage to unfavorable traits • low yield potential • low efficiency of breeding

6. Most successful introduction of a foreign chromosome segmentfrom a cultivated relative into wheat with classical breeding methodThe wheat × rye translocation story • The first wheat × rye crosses were made by Riebesel with Petkus rye in 1924 • The Criewener 104/Petkus rye hybrid combination resulted in the line Riebesel 47-51 • The first commercial cultivars were released in Germany in 1957 (Halle 14-44, ST 14-44 and Neuzucht 14-44) : Pm 8, Lr 26, Sr 31, Yr 9, etc. • Broad dissemination in 1980-90: many tens of millions of hectares/year worldwide • Regardless the introduction of foreign genes there were no food safety problems reported until now Disadavantages of the introduction with classical breeding methods very long breeding period (33 years) close linkage with unfavorable traits – poor breadmaking quality sticky dough Looking for new methods to improve efficiency Development of tissue culturing Doubled haploid breeding Induction of somaclonal variation

7. Origin of the gene in traditional plant breeding with history of safe use(Jacobsen, 2009) • Domestication of crops with selected alleles • Genetic variation in natural populations within crop species or in crossable species; • Natural and induced mutations of existing alleles • Synthesis of new crops like Triticale, Hordecale and resynthesis of existing allopolyploid crops • Domestication of individual traits by introgression and translocation with linkage drag Breeders gene pool is within species or crossable wild species (including bridge crosses; embryo rescue, etc.) leading to varieties as sources of safe food production

8. Results achieved by classical breeding Cereal example: production and area saved by improved yield (Borlaugh and Dowswell 2005) World cereal production 1949-51 620 million tons 1999 1,874 million tons Genetic gain of yield due to the breeding efforts England 1908-1985 38 kg/ha/year (Austin 1989) France 1950-1999 50 kg/ha/year (Bonjean 2001) Hungary 1960-198559 kg/ha/year (Balla et al. 1986) Mexico 1950-1982 60 kg/ha/year (Hernandez Sierra 1988) Kansas USA 1919-1987 16 kg/ha/year (Cox et al. 1988)

9. Plant breeding faces new challengesAnnual average increase in world wheat production in the 2nd half of the 20th century (L. R. Brown 1998) • The yield increase slowed down – main constraints of the yield improvement: • yield stability • higher quality requirements • chemical input limits • climate change effects • food safety concerns Risk of safe food production - will the pathogens always win? • Wind and modern transport systems disperse new, aggressive pathogens world-wide • Recombination generates new genotypes • New pathogen effector genes evolve to overcome new host resistance genes • Pathogens adapt faster to a changing climate than crops can Barriers of classical breeding It is impossible to combine all the best alleles at all loci that are segregating for a quantitative trait into a single genotype and to identify that genotype (Sorrels et al. 1997)

10. Classical plant breeding and biotechnology in Europe (Forecast by: Arundel et al. Nature Biotechnology 2000) • Genetic engineering and classical breeding 49% (???) • Assisted classical breeding involving marker technologies and sequencing 31% • Only classical breeding 20% Improvement of conscious selection - marker technologies • Genome projects in plant breeding - availability of sequence data (public databases) • Transfer of data from fundamental research to plant breeding • Development of user- friendly markers for molecular marker assisted selection (MAS) • Implementation of molecular markers in classical breeding Introduction of new technologies in agriculture? • Tremendous development in life sciences like health care, food industry, environmental sector • Focused narrowly on gmo crop breeding can cause delay in the application of other new rapidly emerging technologies in agriculture

11. Baseline of plant breeding and its future perspectives • Continuous efforts have led to the accumulation and preservation of favourable alleles for a better adaptation and agronomic performance of cultivated crops • The results achieved in classical breeding during the period from the discovery of Mendel’s Laws to the present form one of mankind’s success stories • Further improvement will be necessary taking into consideration new challenges in food security and safety for the well being of the society • Integration of novel technologies into classical breeding is necessary to identify and use of new genetic variation for the future progress • Maybe cisgenesis is one of the new technologies to help classical plant breeding?

12. Thank you for your attention