Enhancement of plant growth activity of irradiated alginate

Nagasawa, Naotsugu; Luan, L. Q.*; Yagi, Toshiaki; Yoshii, Fumio; Kume, Tamikazu; Nakanishi, Tomoko*; Tamada, Masao

The sodium alginate was irradiated by -ray, and plant growth activity test and structural change of the product were studied. It was found that the concentration of 100 mg/L of alginate irradiated at 75 kGy in 4 % aqueous solution was the highest for plant growth. Separation of the degraded product was performed using ultrafiltration membranes and found that fraction with molecular weight in the range of 1-3 kDa (6-15 units) not only showed a remarkable effect on the plant growth, but also increased the activity of plant enzymes; . This fraction was stronger than one of the enzymatic degradation product. This differences proposed formation of carbonyl and carboxyl groups along with the main-chain scission.