Hermosa M R, Grondona I, Monte E
University of Salamanca, Spain.
Plant Dis. 1999 Jun;83(6):591. doi: 10.1094/PDIS.1999.83.6.591B.
Trichoderma spp. are associated with green mold of mushrooms. This fungal disease has caused severe losses in mushroom production in countries such as Ireland, the United Kingdom, Canada, and the United States. This disease is caused by two biotypes of T. harzianum (Th2, Europe; Th4, North America) (1,2). Both biotypes have not been detected in mushrooms or other material in Spain previously. However, during 1998, green mold was detected at facilities dedicated to produce compost, as well as in facilities used to produce Agaricus bisporus (Lange) Imbach. Three compost samples were isolated from commercial bags with mushroom substrate and three more samples were taken from mushroom yards. Several spores were isolated by the dilution plate method. Initial identification of the pathogenic fungi was made by examining cultures grown on potato dextrose agar. Morphological characteristics of all isolates coincided with the description of T. harzianum (3). The following amounts of CFU per g were found in commercial compost samples: 1.2 × 10, 5.5 × 10, and 1.4 × 10 per g; whereas 3 × 10, 12.4 × 10, and 2.2 × 10 were obtained from mushroom yards. The fragment containing the internal transcribed spacer (ITS1) was amplified and sequenced for each of the six samples obtained. The ITS1 sequence (201 bp) was identical in all samples, and the sequence was aligned, with Clustal W, with Th2 and Th4 biotype sequences of the EMBL data base. The ITS1 sequence showed 0.55% divergence from Th2 isolates and more distance, 3.3%, with Th4 isolates. The ITS1 sequence obtained with all Spanish samples studied, EMBL accession number AJ1321550, was identical to that described for the Irish isolate Th2I (#63), with accession number U78880 in the EMBL data base (1). This is the first description of the Th2 biotype in Spain. References: (1) M. D. Ospina-Giraldo et al. Mycologia 90:76, 1998. (2) D. L. Rinker et al. Mushroom World 8:71, 1997. (3) D. A. Seaby. Plant Pathol. 45:905, 1996.
木霉属真菌与蘑菇的绿霉病有关。这种真菌病害在爱尔兰、英国、加拿大和美国等国的蘑菇生产中造成了严重损失。这种病害由哈茨木霉的两种生物型（Th2，欧洲；Th4，北美）引起（1,2）。此前在西班牙的蘑菇或其他材料中未检测到这两种生物型。然而，在1998年，在专门用于生产堆肥的设施以及用于生产双孢蘑菇（Lange）Imbach的设施中检测到了绿霉病。从装有蘑菇基质的商业袋子中分离出三个堆肥样品，并从蘑菇种植场采集了另外三个样品。通过稀释平板法分离出几个孢子。通过检查在马铃薯葡萄糖琼脂上生长的培养物对致病真菌进行初步鉴定。所有分离株的形态特征与哈茨木霉的描述一致（3）。在商业堆肥样品中发现每克的CFU数量如下：每克1.2×10、5.5×10和1.4×10；而从蘑菇种植场获得的数量为3×10、12.4×10和2.2×10。对获得的六个样品中的每一个进行包含内转录间隔区（ITS1）的片段扩增和测序。所有样品中的ITS1序列（201 bp）相同，并且使用Clustal W将该序列与EMBL数据库中的Th2和Th4生物型序列进行比对。ITS1序列与Th2分离株显示出0.55%的差异，与Th4分离株的差异更大，为3.3%。所研究的所有西班牙样品获得的ITS1序列（EMBL登录号AJ1321550）与爱尔兰分离株Th2I（#63）的序列相同，其在EMBL数据库中的登录号为U78880（1）。这是西班牙首次对Th2生物型的描述。参考文献：（1）M. D. Ospina-Giraldo等人，《真菌学》90:76，1998年。（2）D. L. Rinker等人，《蘑菇世界》8:71，1997年。（3）D. A. Seaby，《植物病理学》45:905，1996年。
