真菌及昆虫在储藏小麦中生长产生CO2气体的特点

Characteristics of Carbon Dioxide Production by Insect and Fungus Growth in Stored Wheat

摘要:

在各种温、湿度条件下对小麦储藏期间真菌和昆虫活动产生二氧化碳气体（CO2）进行监测，研究可用于判断小麦储藏安全性的方法。试验结果表明，储粮温度对处于生长状态的真菌产CO2速率影响最大，从20 ℃升高到25 ℃，产CO2速率可提高10倍。在安全水分小麦中，昆虫是产CO2的主要类群，对高水分小麦，真菌是产CO2的主体。在产CO2特性方面，昆虫密度与产CO2量具线性关系（r＞0.99），而真菌产CO2呈明显的加速现象，在储藏初期带菌量没有显著增加（p＞0.05）时，产气速率已提高5.96倍。在大型粮仓储藏中的试验也表明，昆虫的产气量恒定，粮堆4 m深度昆虫活动部位25 d的CO2浓度变化幅度为13％，而离霉变点0.5 m的CO2浓度变化高达37倍。因此，利用检测CO2气体浓度变化的方法可以灵敏地发现小麦储藏中昆虫和真菌的危害活动。

Abstract:

In the present work, the characteristics of carbon dioxide (CO2) produced by insects and fungi were studied under different wheat storage conditions with varying temperatures and moisture contents. The findings could be useful for determining the storage safety of wheat. The results showed that storage temperature had the most dramatic effects on the rate of CO2 production by fungi during growth. When the storage temperature rose from 20 ℃ to 25 ℃, the CO2 production rate increased by ten-fold. Gas was mainly produced by insects in wheat with moisture in the safe range, while fungi were the main producers in high-moisture wheat. In terms of CO2 production characteristics, there was a linear relationship between insect density and CO2 production quantity (r > 0.99), and gas production by fungi appeared accelerated. The gas production rate increased by 5.96-fold when fungal counts in wheat did not change significantly (p > 0.05) during early storage. In large-scale wheat warehouse experiments, the gas production rate of insects was stable, and the CO2 concentration fluctuation rate was 13% at 25 days in the 4-m-deep area of the wheat bulk, at which insects carried out their activities. In comparison, the changes in CO2 concentrations were 37-fold at locations 0.5 m from mold spots. Therefore, the harmful activities of insects and fungi in stored wheat could be sensitively monitored by CO2 detection.