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Katsumi Ohta, Mika Suzuki, Shingo Matsumoto, Takashi Hosoki and Nobuo Kobayashi

We previously reported that growth of lisianthus [Eustoma grandiflorum (Raf.) Shinn.] seedlings is accelerated by amending the growing medium with 1% (w/w) chitosan. This finding prompted us to search for organic nitrogenous other substances like chitosan which could accelerate seedling growth. Seeds of E. grandiflorum `Peter blue line 2'were sown in a sandy loam growing medium containing 1% (w/w) chitosan, tryptone, casein, collagen or gelatin. At eleven weeks after sowing, leaf length and width, fresh and dry weights of the shoots and roots of twelve plants were determined for each treatment. Eleven weeks after sowing, the leaves at the fifth node had expanded in the chitosan, tryptone and collagen treatments while the leaves of the third node had not yet expanded in control plants. Fresh and dry weights of shoots and roots were significantly greater for plants grown in media amended with chitosan or tryptone. Percent nitrogen (N) and potassium (K) in the shoots and roots and percent phosphorus (P) in the shoots was greater only in the N side dressing treatment. The nitrate nitrogen (NO3-N) concentration was significantly greater in media amended with tryptone or collagen compared to the other treatments.

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Tomoo Maeda, Hideo Kakuta, Takahiro Sonoda, Satoru Motoki, Reiichiro Ueno, Takashi Suzuki and Katsuji Oosawa

The antioxidation capacities of green `Welcome', green and white `Gijnlim', and purple `Purple passion' asparagus spears were evaluated. Analyses of rutin and total polyphenols, and assays of DPPH radical absorbing and low-density lipoprotein (LDL) antioxidation were conducted. Varietal differences associated with the colors of spears were observed both in the amounts of rutin, total polyphenols and in DPPH radical absorbing activities, although not in LDL antioxidation activities. DPPH radical absorbing activities seemed to be affected by both rutin and other polyphenolic compounds. However, LDL antioxidation activities were likely to be influenced more by other polyphenolic compounds than by rutin. Total polyphenol content showed a fairly close relationship with rutin content, DPPH radical absorbing activity and LDL antioxidation activity. To determinate total polyphenol content using the Folin–Denis' method seemed to be useful for selecting the breeding lines that show high antioxidative capacities.