Ranta Hanna, Neuvonen Seppo
University of Turku, Department of Biology and Kevo, Subarctic Research Institute, FIN-20500 Turku, Finland.
New Phytol. 1994 Sep;128(1):63-69. doi: 10.1111/j.1469-8137.1994.tb03987.x.
Scots pine seedlings (1-yr-old) were inoculated either once, or three times, with the conidia of two saprophytic Honmmema species. After these inoculations, the seedlings were inoculated later with conidia of the pathogenic fungus Gremmeniella abietina (Lagerb.) Morelet. Seedlings received irrigation with simulated acid rain at pH 3, with water of pH 6. or no irrigation, during and after the inoculation treatments, The severity of the symptoms caused by G. abietina, and rhe isolation frequency of endophytic (symptomless) G. abietina and the saprophytes, were measured 11 months after G. abietina inoculation. The isolation frequencies of the two Hormunema species increased significantly in the seedlings inoculated three times with saprophyte conidia. Irrigation treatments did not affect the saprophytes. The disease symptoms caused by G, abietina were positively correlated with tree density. Symptomless G, abietina was isolated most often from the seedlings that had received irrigation at pH b. The isolation frequency was lowest in seedlings with acidic irrigation. The seedlings inoculated three times with conidia of Hormonema sp. 1 had a lower frequency of G. abietina isolations than other seedlings, but the difference was not statistically significant.
将1年生的苏格兰松幼苗分别接种1次或3次两种腐生的霍氏菌属菌种的分生孢子。接种这些之后，幼苗随后接种致病真菌冷杉叶枯病菌（Gremmeniella abietina (Lagerb.) Morelet）的分生孢子。在接种处理期间及之后，幼苗分别接受pH值为3的模拟酸雨灌溉、pH值为6的水灌溉或不灌溉。在接种冷杉叶枯病菌11个月后，测量由该病菌引起的症状严重程度，以及内生（无症状）冷杉叶枯病菌和腐生菌的分离频率。用腐生菌分生孢子接种3次的幼苗中，两种霍氏菌属菌种的分离频率显著增加。灌溉处理对腐生菌没有影响。冷杉叶枯病菌引起的病害症状与树木密度呈正相关。无症状的冷杉叶枯病菌最常从接受pH值为6的水灌溉的幼苗中分离出来。在酸性灌溉的幼苗中分离频率最低。用霍氏菌属1号菌种的分生孢子接种3次的幼苗，冷杉叶枯病菌的分离频率低于其他幼苗，但差异无统计学意义。
