1. The Effects of Blue Light at 440 nm on Potato Tuberization for Solanum tuberosum L. cv. Desiree and L. cv. Norland Erin Austad 2003-04

2. Background Effect of blue light on: –Callus –Tubers –Entire Plant

3. Light has one of the greatest effects Plants absorb mostly blue and red light Wavelength determines color of tubers A previous experiment by Tong et al. found that Desiree formed pink tubers under blue light and white tubers in darkness Tong et al. also found that Norlands formed no tubers under blue light and red tubers in darkness Somatic mutations react differently and are rare

4. Goals Grow a somatic mutation Find differential responses

5. Methods: Somatic Mutations Started with 1 Norland, 1 Red Norland and 1 Dark Red Norland Performed subcultures Grew plants in solid media for 2 weeks Took 25 2-week old plants from each variety Transferred to liquid media Grew plants under blue light at 440 nm for 8 weeks

6. Methods: Somatic Mutations (cont.) Looked for: –Callus –Callus color –Tubers –Tuber color

7. Results: Cloned Norland Plants Weeks Under Blue Light % With Callus Callus Color # of Plants With Tubers Tuber Color 112White0- 212White0- 324White0- 429White/Pink0- 535White/Pink0- 641White/Pink1White 741White/Pink1White/Green 865White/Pink1White/Green

8. Results: Cloned Red Norland Plants Weeks Under Blue Light % With Callus Callus Color # of Plants With Tubers Tuber Color 110White0- 210White0- 350White0- 465White/Pink0- 575White/Pink0- 675White/Pink0- 775White/Pink/Red1Pink 890White/Pink/Red1Pink/Purple

9. Results: Cloned Dark Red Norland Plants Weeks Under Blue Light % With Callus Callus Color # of Plants With Tubers Tuber Color 10-0- 20-0- 315White0- 425White0- 535White0- 640White/Pink0- 740White/Pink0- 850White/Pink0-

10. Conclusion: Norland, Red Norland, and Dark Red Norland Clones Many plants produced callus as they spent more time growing Norland and Dark Red Norland clones grew white and pink callus under blue light Red Norland clones grew white, pink, and red callus under blue light Cloned plants seemed to produce the same color callus as plants that were not cloned

11. Methods: Blue Light vs. Darkness for Norland Plants Potato Plant Set Number of Norland Plants Weeks Under Blue Light Weeks in Darkness Set A5010 Set B528 Set C546 Set D564 Set E582 Set F5100

12. Results: Blue Light vs. Darkness for Norland plants Potato Plant Set Weeks Under Blue Light Weeks in Darkness % With Callus Callus Color % With Tubers Tuber Color Set A01075White/Pink0- Set B28100 White - on top Red - base 0- Set C4675 White - on top Red - base 0- Set D6475 White - on top Red - base 0- Set E8240 White - on top Red - base 0- Set F10075 White - top Red - base 0-

13. Conclusion: Blue Light vs. Darkness for Norland Plants There was no tuberization, only callus Callus was white on top and red near base Tuberization will not occur under blue light for Norland potatoes Tubers will not grow after 8-10 weeks

14. Methods: Blue Light vs. Darkness for Desiree Plants Potato Plant Set Number of Desiree Plants Weeks Under Blue Light Weeks in Darkness Set A5010 Set B528 Set C546 Set D564 Set E582 Set F5100

15. Results: Blue Light vs. Darkness for Desiree Plants Potato Plant Set Weeks Under Blue Light Weeks in Darkness % With Callus Callus Color % With Tubers Tuber Color Set G01075White25White Set H28100White50White/Green Set I4650White75White/Green Set J6475White75White/Green/ Pink Set K8280White/ Pink 40White/Green/ Pink Set L10020White20White/Green

16. Conclusion: Blue Light vs. Darkness for Desiree Plants All sets of plants produced tubers Desiree plants exposed to blue light from 4-6 weeks and darkness for 4-6 weeks produced the most tubers Tubers were white, green, and pink Callus was mostly white and pink Tubers grown under blue light were not ideal

17. Further Study Study whether or not plants are true somatic mutations See if plants grow differently in larger test tubes or in magenta boxes Try grafting experiment

18. Acknowledgements I would like to thank Dr. Cindy Tong and Katie Goeden for their wonderful support and for sharing their knowledge in the lab I would also like to thank Ms. Fruen and Team Research for their help with my paper and project

19. The Effects of Blue Light at 440 nm on Potato Tuberization for Solanum tuberosum L. cv. Desiree and L. cv. Norland Erin Austad 2003-04