低温秸秆降解真菌的筛选及在秸秆还田中的应用

旨在针对黄淮海北部小麦-玉米一年两熟区的气候特点,进行低温秸秆降解真菌的筛选及其应用效果研究。以纤维素钠-刚果红培养基、秸秆液体培养基为筛选培养基,在16℃培养温度下进行秸秆降解真菌的筛选;采用形态学和分子生物学相结合的方法进行菌株鉴定;用沙袋法和田间小区试验法测定菌株的秸秆降解能力。筛选获得一株低温秸秆降解真菌SDF-31,该菌株为长枝木霉(Trichoderma longibrachiatum)。该菌株接种15天时和45天时的秸秆降解率分别为43.89%和56.73%,显著高于常温秸秆降解菌剂和空白对照。SDF-31处理的秸秆原有纤维结构高度破环、产生大量纤维碎片,且土壤全氮、碱解氮、有效磷、速效钾等指标都显著高于常温降解菌剂和空白对照,其中速效钾和碱解氮的含量分别比常温秸秆降解菌剂提高17.00%和5.12%,比空白对照分别提高25.53%和15.09%。筛选获得一株具有低温秸秆降解作用的长枝木霉(T. longibrachiatum) SDF-31,为黄淮海北部秋冬季节玉米秸秆还田提供菌株资源。

Fungi with Corn Straw Decomposing Characterization at Low-temperature: Screening and Application in Straw Returning Field

The aim of this study is to screen the fungi with straw degradation characterization at low temperature and to determine the application effect of these strains in the wheat-maize double cropping areas of northern Huanghuaihai. Straw degradation fungi were screened by Cellulose sodium-Congo red medium and liquid straw medium at 16℃. Morphological and molecular biological methods were used to identify the strains. Sandbag method and field plot test were used to determine the straw degradation ability of the strains. A low temperature straw degradation fungus named as SDF-31 was screened and identified as Trichoderma longibrachiatum. The degradation rate of this strain was 43.89% and 56.73% respectively at 15 and 45 days after inoculation, significantly higher than that of the normal temperature inoculants and control. The original fiber structure of straw treated by SDF-31 was highly broken and a large number of fiber fragments were produced. Total nitrogen, available phosphorus and available potassium of treatment SDF-31 were significantly higher than those of normal temperature inoculants and control. The content of available potassium and alkali hydrolyzed nitrogen of treatment SDF-31 were 17.00% and 5.12% higher than that of normal temperature inoculants, 25.53% and 15.09% higher than that of control respectively. A strain of T. longibrachiatum SDF-31 with low temperature straw degradation is screened, and the research provides strain resources for straw returning at autumn and winter in northern Huanghuaihai.