辽宁地区稻谷粮堆真菌分布及演替规律的研究

以东北地区辽宁省抚顺直属库高大平房仓储藏一年的稻谷为实验材料,研究平房仓内稻谷粮堆不同位置的温度、含水量变化对真菌种类分布及演替规律的影响。研究结果表明,稻谷低温条件储藏一年后,粮堆中各位点真菌数量均在10~3 CFU/g数量级以内,整仓稻谷储存安全。但由于稻谷粮堆不同深度温度和含水量的变化,稻谷真菌种类及数量会发生变化。稻谷在储藏期间,粮堆中层和下层平均温度低于10℃,优势菌为稻谷收获期间携带的田间真菌,低温有利于田间真菌孢子活性的保持;粮堆上层夏季平均温度达到20℃左右,含水量为14.5%左右,储藏真菌逐渐替代了稻谷收获时携带的田间真菌成为优势菌,高温是储藏真菌孢子萌发生长的主要原因。稻谷粮堆不同位置温度和含水量的变化,对稻谷真菌种类及生长有重要的影响,优势菌的演替可以用来表征粮堆局部微环境的变化。

Research on Distribution and Succession Law of Fungi in Grain Bulk of Liaoning Area

The rice was used as the test material which had been stored for one year from the big warehouse in Fushun Grain depot, Liaoning Province, Northeast China. The effects of temperature and moisture changes on the distribution and succession law of fungi from different positions of grain bulk in the big warehouse were investigated in this work. The experimental results showed that the number of fungi from each point in the grain bulk was all about 103 CFU/g after one year of low temperature storage, which showed that the grain in the bulk was safe during storage period. However, the kind and number of rice fungi changed due to the difference of temperature and moisture at different depths of the grain bulk. During the whole storage period, the average temperatures in the middle and lower layers of the grain bulk were lower than 10 °C, and the dominant fungi were the field fungi which carried by the rice at harvesting stage, which indicated that the low temperature was beneficial to maintain the spore activity of the field fungi. The average temperature of the upper layer of the grain bulk was about 20°C and the moisture was nearly 14.5% in summer, and the storage fungi gradually replaced the field fungi to become the dominant fungi, which showed that the high temperature was one of the main reasons for the spore germination and growth of the storage fungi. The changes of temperature and moisture in different positions of grain bulk have important influences on the species and growth of rice fungi, and the succession of dominant fungi can characterize the change of local micro-environment of the grain bulk.