International Student Symposium "Hortus Academicus “ March 31, 2017 - Bucharest, Romania

1. Antifungal potential of colloidal silver – alternative method in seeds pathogens control Coordinator Professor: Assoc. Prof. Adrian Peticila Assoc. Prof. Beatrice Iacomi Authors names: Oana Venat International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

2. We are not alone… Pathogens on humans Variola viruses – The new worl was infected by europeans over the ocean; in 1967 over 2 mil people died from variola, even the cure is available. Spanish influenza – 1918 - between 50-100 mil people died over the world; consider the most lethal pandemic disease from the beginning of human kind. Black death - bubonic fever?/plague? – consider by scientists the first form of Ebola; 1348 - killed over half on European population; spread by a bacteria call Yersinia pestis; if is a plague, is still here. Malaria - cause by for Plasmodium microbes species and hosted by mosquitoes and humans as well; still here. Tuberculosis - The great white plague - discover in Egyptian mummies caused by a air speeded bacteria called Mycobacterium tuberculosis; 8 mil people are infected yearly and over 2 mil are dying. And so on......Yellow fever, AIDS (spread by virus), cholera (spread by bacteria Vibrio cholerae) International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

3. Pathogens on plants/ Fungi Source: Journal Molecular Plant Pathology nominate which fungal pathogens could take a place in a “Top 10” based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. (2012) International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

4. Pathogens on plants/Bacteria Source: Journal Molecular Plant Pathology nominate which bacteria could take a place in a “Top 10 of plant viruses based on their perceived importance, scientifically or economically”. The survey generated 458 votes from the international community, and resulted in the generation of a Top 10 bacteria plant pathogen list for Molecular Plant Pathology. (2012) International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

5. Pathogens on plants/Viruses Source: Journal Molecular Plant Pathology nominate which viruses could take a place in a “Top 10 of plant viruses based on their perceived importance, scientifically or economically”. The survey generated 250 votes from the international community, and resulted in the generation of a Top 10 viruses plant pathogen list for Molecular Plant Pathology. (2012) International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

6. About 80% of plant diseases can be traced to fungi, which have a great capacity to reproduce themselves both sexually and asexually.  • More than 300 plant viruses have been identified, new strains continually appear because these organisms are capable of mutating.Bacteria can be spread by water, insects, infected soil, or contaminated tools.Pesticide resistance is a natural ability of a biotype of an organism to survive exposure to a pesticide that would normaly kill an individual of that species. • Development of Resistance: Organisms can develop resistance by: • developing a means of detoxifying the pesticide; • altering the target site (part of the body’s metabolism affected by the pesticide) to reduce its sensitivity or the pesticide’s ability to bind; • decreasing pesticide penetration. Alternaria alternata Fusarium oxysporum International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

7. Objectives Integrated pest and disease control intend to limit the effects on plants that chemicals can have, the impact on the environment and on the humans health. The main objective of the research willing to finding solutions refers to non-chemical, non-toxic and non-residual pesticides for the replacement even partial of conventional chemicals that already producing drug resistant on diseases and pests. Colloidal silver and SNP are a new direction in this area

8. Materials and Methods I. In vitro tests on mycelial growth *fungal collection II. In vitro tests on seeds International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

9. Materials and Methods I. In vitro test on mycelial growth Methods: poisoned food technique Tested compounds V15 ppm M15 ppm Results are expressed as Inhibitory concentration IC50 and IC 90, based on inhibition of mycelial growth. International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

10. Materials and Methods II. In vitro tests on seeds Methods II A: Colloidal Silver Seed Treatment (artificially contaminated seeds) Tested variants International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

11. Materials and Methods II. In vitro tests/seeds Methods II B: Colloidal Silver Seed Treatment (onseeds harvested from inoculated plants) Tested variants International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

12. 0 1 0 1 3 5 7 9 2 3 Materials and Methods II. In vitro tests on seeds Results expressed as: 1) Developmental stages (0-3 grade scale) 2) Disease severity (0-9 grade scale) 3) Attack incidence on seedlings (%) = n/N x 100 ( n = number of attack seedlings, N = total number of seedlings) International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

13. Results and discussions • In vitro test: Sensitivity of Fusariumnivale to colloidal silver Medicer CS Crafts CS International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

14. Results and discussions • In vitro test: Sensitivity of Aspergillusniger to colloidal silver Medicer CS Crafts CS International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

15. Results and discussions • In vitro test: Sensitivity of Aspergillusflavus to colloidal silver Medicer CS Crafts CS International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

16. Results and discussions • In vitro test: Sensitivity of Alternariabrassicicola to colloidal silver Medicer CS Crafts CS International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

17. Results and discussions II. A In vitro tests/artificially contaminated seeds Effect of craft colloidal silver on seed development, necrosis index and incidence of attacked seedlings Disinfected seeds International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

18. Results and discussions II. A In vitro tests/artificially contaminated seeds Effect of craft colloidal silver on seed development, necrosis index and incidence of attacked seedlings Necrosis index - Ab43 attack on seed Mycelial growth of Ab43 International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

19. Results and discussions II. B In vitro tests on seeds harvested from contaminated plants Effect of craft colloidal silver on seed development, necrosis index and incidence of attacked seedlings SND SNDT International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

20. Results and discussions II. B In vitro tests/seeds harvested from contaminated plants Effect of craft colloidal silver on seed development, necrosis index and incidence of attacked seedlings International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania

21. Conclusions and perspectives Efficiency of colloidal silver on mycelial growth inhibition of different fungi isolated from radish seeds (starting at 15 ppm). Seed treatment with colloidal silver at 19 ppm reduces Alternaria brassicicola incidence on seedlings (about 80%) compared to control. Ongoing research on foliar treatment on plants with colloidal silver, pathosystem A. brassicicola - cruciferous plants. • Preliminary results on: • Colloidal silver as preservative solution to improve cut flowers self life; • Potential disinfected agent on fungal meristems culture contamination International Student Symposium "Hortus Academicus“March 31, 2017 - Bucharest, Romania