关键词: 秸秆, 生物有机肥, 土壤生物量氮, 肥料氮利用率

Abstract: The study on the relationships between antioxidant activities and heat-resistant features of two Laminaria japonica gametophyte mutants Kelp 901(abbreviated as 901)and Rongcheng No.1(abbreviated as RC)under different temperature conditions showed that under normal temperature condition(10 ℃),there were no positive relationships between the basal antioxidant activities and heat-resistant features of 901 and RC,while under heat stress(18 ℃),the reactive oxygen species(ROS)contents kept constant in 901,but accumulated rapidly in RC,suggesting that ROS played an essential role in oxidative stress.The enzyme activities in RC were more vulnerable to high temperature,and its antioxidant enzyme activities decreased more sharply under heat stress.Ascorbic acid(ASA),vitamin E,superoxide dismutase(SOD)and glutathione peroxidase(Gpx)might play important roles in kelp's heat-resistance.Chlorophyll a was sensitive to heat stress,and its 50% nocuity time could be used as an indicator to distinguish kelp strains with different heat-resistance.It was suggested that the antioxidant system's responses to heat stress instead of its basic activities accounted for the kelp's heat-resistance.

Key words: Rice straw, Bioorganic manure, Soil biomass N, Use efficiency of fertilizer nitrogen