200 likes | 598 Views
Light. The Source of all Biological Energy Trapped in Photosynthesis Used to determine Seasons. Light: An Energy Waveform With Particle Properties Too. wavelength. violet. blue. green. yellow. orange. red. 400 500 600 700 nm.
E N D
Light The Source of all Biological Energy Trapped in Photosynthesis Used to determine Seasons
Light: An Energy Waveform With Particle Properties Too wavelength violet blue green yellow orange red 400 500 600 700 nm wavelength (nm) 10-9 meter 0.000000001 meter!
Light: An Energy Waveform With Particle Properties Too wavelength visible spectrum 400 500 600 700 nm wavelength (nm) 10-9 meter 0.000000001 meter!
White light: all the colors humans can see at once http://www.alanbauer.com/photogallery/Water/Rainbow%20over%20Case%20Inlet-Horz.jpg
http://www.chez.com/uvinnovation/site/images/introduction/apple_logo.gifhttp://www.chez.com/uvinnovation/site/images/introduction/apple_logo.gif Which side of our brains are we using? http://jojoretrotoybox.homestead.com/files/Rainbow_Brite_Logo_2.jpg http://www.astrostreasurechest.net/websmurfclub/images/pinsmurfoncloudrainbow.jpg http://www.tvtome.com/images/shows/4/8/40-11946.jpg http://www.coreywolfe.com/NOV%202004/mlp.jpg
White Light Green is reflected! Leaf Pigments Absorb Most Colors
Light: An Energy Waveform With Particle Properties Too amplitude brightness intensity Many metric units for different purposes We will use an easy-to-remember English unit: foot-candle 0 fc = darkness 100 fc = living room 1,000 fc = CT winter day 10,000 fc = June 21, noon, equator, 0 humidity
Photomorphogenesis light form origin process Growth in Dark Etiolated Growth in Light Normal Short Stocky Green Expanded leaves Usereserves Tall Thin White/Yellow Unexpanded leaves Preserve reserves How deeply buried am I? Make Hay!Gravity! http://botit.botany.wisc.edu:16080/images/130/Tropisms/Etiolation/Etiolated_-_light_beans_MC_.jpg
Phototropism IAA IAA Darwin 1860s light growth toward act Went: IAA transduction by IAA differential transport perception by zeaxanthin growth response + http://www.ppdl.purdue.edu/ppdl/images/coleoptile3.jpg
Photosynthesis: Review and Expansion We have been hiding considerable truth from you! Not 1 step…more like 50! light CO2 + H2O O2 + CH2O chlorophyll Light Reactions: perhaps 25 steps light ADP + P + NADP + H2O O2 + NADPH2 + ATP chlorophyll Interdependent! Calvin Cycle Reactions: perhaps 25 steps AKA: Dark Reactions ATP + NADPH2 + CO2 CH2O + NADP + ADP + P light In sum: CO2 + H2O O2 + CH2O chlorophyll The light and Calvin cycle reactions are interdependent…no dark reactions!
100% Photosynthetic Rate 0 What wavelengths of light drive photosynthesis? Action Spectrum green light reflected some still drives photosynthesis visible spectrum 400 500 600 700 nm wavelength (nm) Light beyond 700 nm has insufficient energy to drive photosynthesis
100% Reaction Rate 0 0 10 100 1,000 10,000 fc Light Intensity (fc) What intensities of light drive photosynthesis? Photosynthesis add to reserve grow reproduce Respiration Using reserves and may die compensation point The example plant shown here “breaks even” at an intensity we have in our homes…a house plant!
100% Reaction Rate 0 0 10 100 1,000 10,000 fc Light Intensity (fc) What intensities of light drive photosynthesis? Photosynthesis A Photosynthesis B Respiration Shade tolerant plant dies in intense light! compensation points The second example plant shown here cannot survive in our homes…it is a sun-loving crop plant!
N W E House downspout downspout PM AM S Where in a CT landscape is the light intensity the brightest…the longest? Ferns Hosta Impatiens MOD. MOIST COOL MOIST Shade all Day! AM Cool Shade PM Hot Sun AM Cool Sun PM Warm Shade Sun all Day! HOT DRY! MOD. DRY! Daisies Roses Petunias
N W E House PM AM S Where in the house is the light intensity the brightest…the longest? Too Dark! Sun Lovers Shade Lovers African Violets Ferns Philodendrons General Houseplants Greenhouse Effect! General Houseplants if Sheer Drapes
USDA Hardiness Zones of “Lower 48” States Note: Willimantic is Zone 6
Winter Wind N W E House snow profile PM AM S Where should plants be placed in a CT landscape for winter hardiness? Exposed MORE UNIFORM COLD ZONE 4-5 WINDWARD INSULATED Shade all Day! ZONE 5-6 AM Cool Shade PM Hot Sun AM Cool Sun PM Warm Shade ZONE 6-7 ZONE 2-3 Sun all Day! ExposedFREEZE DRY LEEWARD INSULATED
Short Day Plant Long Day Plant Chrysanthemum Poinsettia Lettuce Spinach Summer (June 21) vegetative flowering 16 hr 8 hr no change Winter (December 21) flowering vegetative 8 hr 16 hr reversed Night Interruption 10 sec vegetative flowering 8 hr 8 hr W 8 hr Day Interruption 10 sec vegetative flowering 8 hr W 8 hr 8 hr Photoperiodism-Sensing Seasons by Daylength Noctoperiodism? Long Night Plant? Short Night Plant? Plants measure the length of the night…not the length of the day.
Red 660nm Interruption 10 sec 8 hr 8 hr R 8 hr Control Far-Red 730nm Interruption 10 sec flowering flowering flowering vegetative vegetative vegetative 8 hr 16 hr 8 hr 8 hr FR 8 hr Sequences Ending in Red 10 sec each vegetative vegetative flowering flowering 8 hr 8 hr R FR 8 hr R Sequences Ending in Far-Red 10 sec each 8 hr 8 hr FR R 8 hr FR Photoperiodism-Does Light Wavelength Matter? Short Day Plant Long Day Plant 660 nm Plants use Phytochrome to sense Night Light Status. * Pr Pfr Pfr present for significant time in night blocks flowers. 730 nm
Photoperiod Applications: Chrysanthemum Story Poinsettia Story LDP Lettuce Problem: Equinoxes LDP Onions: Bermuda=11+ Sweet Spanish=15+ How long does light need to be on inside house?: Comp Point