Keanne Paula H. Amamanglon (March 2007)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Ultraviolet radiation from the sun plays a major role in the environment. UVB, one of its three bands cause changes in the molecular structure of plants. Recent studies show UVB alters cell wall of plants.
This study determined and compared the amount of cell wall components (lignin, cellulose, hemicellulose) in the leaf, stem and roots of pechay exposed to Ultraviolet-B (40 W, 260 nm) for 0, 4, 6, 8, and 10 hours per day for three weeks. The amount cell wall components (% by weight) in the different plant parts were determined using Neutral Detergent Fiber, Acid Detergent Fiber, and Acid Detergent Lignin Analysis.
One-way Analysis of Variance (a=0.05) showed a significant difference in the hemicellulose content in the leaf (p=0.048), stem (p=0.001) and roots (p=0.003), cellulose content in the stem (p=0.007) and roots (p=0.000) and lignin content in the stem (p=0.000). Fisher’s LSD showed pechay plants which were exposed to UVB have less amount of hemicellulose in the leaves, hemicelulose, cellulose and lignin in the stem and hemicellulose and cellulose in the roots when compared to plants exposed to sunlight. There is no difference in the amount of hemicellulose in the leaves, hemicelulose, cellulose and lignin in the stem and hemicellulose and cellulose in the roots that were exposed to UVB from two to 10 hours.
It is concluded that pechay plants exposed to UVB have less hemicellulose content in the leaf, stem and roots, cellulose content in the stem and roots and lignin content in the roots.