Etiology of oak decline in Spain
Etiology of oak decline in Spain
复制标题
西班牙橡木衰退的原因
DOI：
10.1046/j.1439-0329.1999.00128.x
复制
发表时间：
1999
期刊：
影响因子：
1.4
通讯作者：
R. Fernández
中科院分区：
文献类型：
--
作者：
F. Gallego;A. Algaba;R. Fernández
总结
在西班牙西部埃斯特雷马杜拉的不同地区，在表现出衰退症状的霍尔姆栎（Quercus ilex）树的底部采集了土壤样本。每个样品的一半被消毒，橡子被播种在消毒和未消毒的土壤样品。将所得幼苗用作分离真菌的诱饵。生长在自然的，非灭菌的基板上的幼苗的特点是具有较低的营养生长比生长在灭菌的土壤样品，他们中的大多数死亡。从它们的根中一致分离到疫霉。也分离出尖孢镰刀菌以及不同种类的腐霉，尽管程度较低。用5个不同的栗疫病菌分离物、F. chinnamomi、F.尖孢霉属、腐霉属以及这三种真菌的混合物。结果表明，接种后的幼苗均发生根腐病，生长缓慢，至试验结束时死亡率为35.7%。从根中始终分离出P. chinnamomi，表明这种真菌是霍尔姆栎衰退的致病因子。然而，F.尖孢霉在橡树幼苗上引起与P.chinnamomi相似的症状，并且也从根部分离，尽管其频率低于尖孢霉。肉桂
Summary
In different areas of Extremadura, Western Spain, soil samples were taken at the bottom of holm oak (Quercus ilex) trees that were showing decline symptoms. Half of each sample was sterilized, and acorns were sown in both sterilized and nonsterilized soil samples. The resulting seedlings were used as baits for the isolation of fungi. Seedlings growing on the natural, nonsterilized substrate were characterized by having a lower vegetative growth than the ones growing on the sterilized soil samples, and most of them died. Phytophthora dnnamomi was consistently isolated from their roots. Fusarium oxysporum was also isolated as well as different species of Pythium, although to a lesser extent. Pathogenicity tests were performed on holm oak seedlings with five different isolates of P. chinnamomi, with F. oxysporum, Pythium and with a mixture of the three fungi. All the inoculated seedlings with P. chinnamomi developed root rot and grew slowly, and 35.7% of them died up to the end of the experiments. P. chinnamomi was consistently isolated from their roots, indicating that this fungus is the causal agent of holm oak decline. However, F. oxysporum caused similar symptoms on oak seedlings as P. chinnamomi, and was isolated also from the roots, although its frequency was lower than that of. P. cinnamomi.