ISSN:
1573-5095
Keywords:
chlorophyll flourescence
;
damage
;
drought
;
fluorometer
;
freezing
;
heating
;
jack pine
;
Sitka spruce
;
stress
;
water potential
;
white spruce
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract We demonstrate some stress detection and stock quality applications of fluorescence to conifer seedlings using two types of fluorometers: an integrating fluorometer (IF) for laboratory use, and two field-portable pulse-modulated instruments, the EARS-PPM (EARS) and PAM--2000 (PAM). Freezing tests showed that as temperature decreased, the IF and EARS detected decreased fluorescence in white spruce (Picea glauca [Moench.] Voss) seedlings (r2〉 0.90 with visible injury). Fv/Fvm from the IF was highly correlated with quantum yield (φ) from the EARS (r〉 0.94). The relationship betweenφ p and visible injury in white spruce was strongest whenφ p was measured at low light levels. Freezing-stressed Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings also showed decreased φ. Values of φ in the dark were about 20? higher than in the light (400λ mol m-2s-1PPFD, photosynthetic photon flux density); but the two φs were highly correlated (r 2= 0.99). Heating Sitka spruce seedlings showed that φ decreased linearly as duration at 40x00B0;C increased. Although there was some recovery inφ p, after 5 days, it was a good indicator of subsequent growth. Desiccation tests showed that the PAM and IF both detected water stress in jack pine (Pinus banksiana Lamb.) seedlings but the values for Fv/Fmdiffered. Moderate stress was detected by the PAM as higher qNand lowerφ p, and by the IF as delayed FtM2. For severe stress, the PAM detected lower Fv/Fm, qN, qP, and φ, and FM2disappeared from IF curves. Gross photosynthesis (Gp), measured by the EARS, can be used as be a quick estimator of net photosynthesis (P〉 0.90), but its use as an estimator of seedling quality requires further study. NOTE: All parameters, abbreviations and symbols, unless specifically defined in the text, are defined in Table 1. Endorsement or rejection of any particular fluorometer is not implied.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006513720073
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