Title of article :
Pre-visual detection of iron and phosphorus deficiency by transformed reflectance spectra
Author/Authors :
Li، نويسنده , , Bingqing and Liew، نويسنده , , Oi Wah and Asundi، نويسنده , , Anand Krishna، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
9
From page :
131
To page :
139
Abstract :
Reflectance spectroscopy and strategies for spectral analysis over the visible range from 380 to 780 nm were used to provide diagnostic information on iron (Fe) and phosphorus (P) status of Brassica chinensis L. var parachinensis (Bailey) grown under hydroponics conditions. Leaf reflectance (R) spectra were collected and normalized inner reflectance (NRI) spectra were calculated. The regression coefficients (B-matrix) and variable importance for projection (VIP) in partial least squares regression were used to determine important wavelengths that correlate with total chlorophyll (Chl) content. No single wavelength that showed good correlation with Chl content was found. Therefore, NRI was transformed into CIELAB color values, which simplified the whole visible spectrum into three values. Our results showed that upon Fe deprivation, plants entered into a deficiency state very rapidly, highlighting the importance of early diagnosis. The direct effect of Fe on leaf Chl content allowed CIELAB color values to be used for pre-visual detection of Fe deficiency 2 days before the appearance of visually distinguishable morphological changes. On the other hand, P-deprived plants showed a marked decline in cellular P levels but remained above critical threshold concentrations after 7 days. The Chl content was not affected by the leaf P content and CIELAB color values showed no difference with control plants.
Keywords :
Chlorophyll , CIELAB color space , Iron deficiency , Partial least squares regression , Phosphorus deficiency , Reflectance spectroscopy
Journal title :
Journal of Photochemistry and Photobiology B:Biology
Serial Year :
2006
Journal title :
Journal of Photochemistry and Photobiology B:Biology
Record number :
1875632
Link To Document :
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