Field ecology of the ochratoxin A-producing Penicillium verrucosum:: Survival and resource colonisation in soil
Field ecology of the ochratoxin A-producing Penicillium verrucosum:: Survival and resource colonisation in soil
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DOI：
10.1023/a:1007003106343
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发表时间：
1999-01-01
期刊：
影响因子：
5.5
通讯作者：
Hestbjerg, H
中科院分区：
文献类型：
--
作者：
Elmholt, S;Hestbjerg, H
通过田间试验，研究了疣状拟青霉在侵染土壤(T1)和秸秆侵染土壤(T2)中的存活情况。在1994年10月至1996年3月期间，将侵染土壤和参照土(T3)填充到钢质圆柱体中，埋藏并取样13次。在选择性和诊断性培养基(DIG)上用稀释平板法测定了疣状假单胞菌和土生真菌的丰度。在T2进行籽粒侵染检查。根据我们的研究结果，疣状假单胞菌似乎很好地适应了在耕地土壤中的生存，几乎不受本土真菌的影响。在第一个秋冬季，谷粒引起了疣状疫霉的繁殖，而其在土壤中的丰度较稳定，但在95年2月有所下降，这归因于霜冻/融化交替。在T2期，疣状疫霉最初侵染超过50%的籽粒，但在最初的几个月里，它被其他真菌赶走了。因此，认为废弃谷物是田间真菌的自然生态位的假设被部分否定了。T1和T2的土壤中疣状芽孢杆菌丰度在春季逐渐降低，夏季干旱时死亡，第二年冬季增殖。我们的结果不能提供第二个冬季期间增加的原因。但总体而言，这些研究表明，疣状假单胞菌可以在田间存活，在土壤有机质上繁殖，并可能成为土壤生态系统的组成部分。在适当的环境条件下，这可能会构成粮食污染的风险。
A field experiment was conducted to elucidate the survival of P. verrucosum in infested bulk soil (T1) and infested soil with waste grain (T2). The infested soil and reference soil (T3) was filled into steel cylinders, which were buried and sampled 13 times during a period from October 1994 to March 1996. The abundance of P. verrucosum and indigenous soil fungi were assessed by dilution plating on a selective and diagnostic medium (DYSG). Kernel infection was examined in T2. According to our results, P. verrucosum seems well adapted to survival in arable soil and little affected by indigenous fungi. During the first autumn and winter the grain caused a proliferation of P. verrucosum while its abundance in bulk soil was more constant except for a decrease in February 95, which is ascribed to frost/thaw alternations. In T2, P. verrucosum initially infected more than 50% of the kernels but during the first few months it was ousted by other fungi. A hypothesis regarding waste grain as the natural niche for the fungus in the field was therefore partly rejected. A gradual decrease in the abundance of P. verrucosum in soil during spring, a die-off in the dry summer and a proliferation during the second winter were found in both T1 and T2. Our results cannot provide the reason for the increase during the second winter. On an overall basis, however, they show that P. verrucosum can survive in the field, proliferate on soil organic matter and probably become an integral part of the soil ecosystem. This may constitute a risk of grain contamination when given appropriate environmental conditions.