|Richard Jr, Edward|
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: May 16, 2005
Publication Date: July 20, 2005
Citation: Johnson, R.M., Viator, R.P., Veremis, J.C., Richard Jr, E.P., Zimba, P.V. 2005. Discrimination of Sugarcane Varieties with Hyperspectral Reflectance Measurements and Plant Pigment Analysis [abstract]. Journal of the American Society of Sugar Cane Technologists. 25:111. Available: http://www.assct.org/journal/journal.htm Technical Abstract: High resolution, hyperspectral leaf reflectance and pigment measurements was evaluated as a potential tool to aid in the identification and delineation of commercial sugarcane varieties (interspecific hybrids of Saccharum spp.), noble canes (Saccharum officinarum L.) and wild canes (Saccharum spontaneum L.). Seven varieties of sugarcane were selected from the USDA-ARS-SRRC, Sugarcane Research Unit (SRU) breeding program for reflectance analysis, including: five commercial cultivars, one noble cane, and one wild cane. Hyperspectral reflectance data at 0.4-nm intervals were collected from the third youngest fully open leaf from nine replicates using a dual input fiber optic spectrometer under natural light conditions from ~ 1200 to 1600-h. After reflectance measurements were completed the same leaf was sampled for plant pigment analysis by boring a 0.5 cm disc from ca. 10 cm from the leaf tip. The discs were extracted with 100% acetone and analyzed by HPLC. Reflectance data were condensed into 5, 10 or 20-nm intervals and then with plant pigment data were subjected to analysis of variance and multivariate mean separation techniques. Differences in reflectance were observed for each variety, with the seven cultivars having ~3-fold difference in reflectance values. Reflectance measurements at 560 and 700 nm and reciprocal reflectance at 700 and 710 nm provided the best discrimination (76%) with single wavelengths, while vegetation indices based on multiple wavelengths improved the varietal discrimination to 81%. Multivariate analysis of leaf reflectance and plant pigment data using canonical discrimination and discriminant analysis resulted in a 100% correct classification for plant pigment data and an 89% correct classification for reflectance data. Finally, there were no false negative S. spontaneum species classifications and only one false positive classification when variety Ho 95-988 was classified as the S. spontaneum MPTH 97-216.