不同玉米象感染度的小麦储存环境中二氧化碳浓度变化研究

摘要

在模拟储存环境中研究了小麦感染不同玉米象Sitophilus zeamais Motschulsky后不同时间的二氧化碳浓度变化,试验环境温度分别为20℃和25℃,试验中设置的玉米象成虫密度分别为0头/kg、2头/kg、5头/kg、10头/kg.主要结果为:初始成虫密度为0头/kg的小麦样品中,20℃4个月内二氧化碳浓度从0.046％增长到了0.752％,25℃时二氧化碳浓度从0.44％增加到0.820％；2头/kg的样品中,20 ℃二氧化碳浓度增长到5.638％,25℃浓度增加到7.505％；5头/kg成虫密度的样品中,20C二氧化碳浓度增长到8.702％,25℃时浓度增加到10.474％；害虫密度为10头/kg的样品中,20℃二氧化碳浓度增长到17.381％,25℃时浓度增加到18.244％.主要结果显示:对于感染害虫的粮食环境,二氧化碳的累积浓度明显随时间增加而上升,且同比条件下,温度为25℃的环境中二氧化碳浓度显著大于20℃时的环境.密闭无害虫感染的粮食中,粮食及微生物也能使二氧化碳浓度有很小变化.当小麦中有害虫感染后,密闭10 d后即可检测到明显的二氧化碳浓度增加,且增加速率与害虫密度、环境温度和储存时间呈正相关.试验结果表明,在密闭的储粮环境中,二氧化碳浓度变化可在一定程度上反映储粮害虫的发生状态.%In this paper, we studied the concentration change of carbon dioxide in simulated storage environment of wheat which was infested by Sitophilus zeamais Motschulsky adults for different periods, wherein the environment temperature was set to 20 ℃ and 25 ℃ ,and three samples with 0,2,5 and 10 adults per kilogram wheat were selected in the experiment. The results showed that: in the sample without adults,the concentration of carbon dioxide increased from 0.046% to 0.752% at 20 ℃ in four months,and increased from 0.44% to 0.820% at 25 ℃ in four months; in the sample with 2 adults per kilogram wheat, the concentration of carbon dioxide respectively increased to 5.638% at 20 ℃ and to 7.505% at 25 ℃; in the sample with 5 adults per kilogram wheat,the concentration of carbon dioxide respectively increased to 8.702% at 20 ℃ and to 10.474% at 25 ℃; and in the sample with 10 adults per kilogram wheat,the concentration of carbon dioxide respectively increased to 17.381% at 20 ℃ and to 18.244% at 25 ℃. The results showed that the accumulated concentration of carbon dioxide in the wheat infested by insects increased as the storage time prolonged, and the concentration of carbon dioxide at 25 ℃ was significant larger than that at 20 ℃ under the same condition. In the closed wheat sample without insects, the concentration of carbon dioxide might also change slightly due to the grain and microorganism. When the wheat was infested by insects,the concentration of carbon dioxide increased significantly after the closed storage for 10 days,and the increasing rate was in positive correlation with the insect density,the temperature and the storage time. Therefore,the concentration of carbon dioxide in the sealed grain storage environment could reflect the infection state of wheat to some extent.