Influence of Degradation of Chitosan by Gamma Radiation on Growth Enhancement of Corn

The present study reports the effect of different molecular weight and concentration of irradiated chitosan on preliminary plant growth promoter test of corn in potting experiment. The average molecular weights of degraded chitosan were determined by intrinsic viscometric and GPC analysis. Four kinds of ultrafiltration membrane were used to separate the 100 kGy irradiated chitosan into five fractions (<10, 10-30, 30-50, 100-300, and >300 kDa). All five separated fractions, the irradiated and unirradiated chitosan were used for plant growth test of corn. The effects of different molecular weight fractions and concentrations of chitosan on average plant height, leaf greenness, average ear number and average ear weight of corn were studied. The results show that irradiated and unirradiated chitosan at concentrations ranging from 20, 50 and 100 ppm are effective for the growth promotion of corn plant, such as plant height, number of ear and ear size, in comparison with the control (untreated chitosan).