Phytopathology. 1999 Jul;89(7):555-63. doi: 10.1094/PHYTO.1999.89.7.555.
ABSTRACT Rain simulation studies were performed to compare splash dispersal of three Colletotrichum species: C. acutatum (C. acutatum-O isolate from Ohio and C. acutatum-M isolate from Mississippi), C. fragariae (isolate from Mississippi), and C. gloeosporioides (isolate from Florida). Conidial dispersal was assessed by counting colonies formed from spore-bearing splash droplets deposited in sheltered petri plates containing a selective medium. Colonies were converted to number of conidia based on germination rates of spores on the media. The interpolated total number of dispersed conidia over a 61 min rain and 72 cm from the point source (Sigma) was calculated. For all species, a rain intensity of 30-mm/h resulted in significantly greater dispersal than an intensity of 11-mm/h. C. fragariae had the lowest amount of spore dispersal, and C. acutatum-O had the highest dispersal. C. acutatum-M and C. gloeosporioides were intermediate in magnitude of conidial splash dispersal. However, differences were directly attributed to differences in spore density per fruit at the source. When Sigma was corrected for source strength (Sigma(r)), the species were very similar, with only C. acutatum-M having a mean Sigma(r) significantly less than the others. Proportions and rates of spore removal (per minute) from source fruits were higher for C. acutatum-O and C. gloeosporioides than for other isolates. Wash-off rates of conidia deposited on healthy fruits were the same for all species. Deposition flux density of spores that had been uniformly sprayed over the entire soil surface of the experimental area was affected by species. A significant difference in means was observed between C. acutatum and C. fragariae-the latter had a somewhat lower flux density. This is the first demonstration that closely related species infecting the same plant species are similar in terms of splash dispersal.
为了比较三种炭疽菌的飞溅散布情况，进行了雨水模拟研究：炭疽菌（来自俄亥俄州的 C. acutatum-O 分离株和来自密西西比州的 C. acutatum-M 分离株）、草莓炭疽菌（来自密西西比州的分离株）和胶孢炭疽菌（来自佛罗里达州的分离株）。通过计数在含有选择性培养基的庇护 Petri 板中沉积的带有孢子的飞溅液滴中形成的菌落，评估了分生孢子的散布情况。将菌落转换为基于培养基上孢子萌发率的分生孢子数量。计算了从点源（Sigma）61 分钟降雨和 72 厘米处散布的分散分生孢子的插值总数。对于所有物种，雨强为 30-mm/h 时的散布量明显大于雨强为 11-mm/h 时的散布量。草莓炭疽菌的孢子散布量最少，炭疽菌-O 的散布量最大。炭疽菌-M 和胶孢炭疽菌的分生孢子飞溅散布量居中。然而，差异直接归因于源果上孢子密度的差异。当 Sigma 校正为源强度（Sigma(r)）时，这些物种非常相似，只有炭疽菌-M 的平均 Sigma(r)显著低于其他物种。从源果上去除的孢子的比例和速率（每分钟）对于炭疽菌-O 和胶孢炭疽菌比其他分离株更高。沉积在健康果实上的分生孢子的洗脱率对于所有物种都是相同的。在整个实验区域的土壤表面上均匀喷洒的孢子的沉积通量密度受到物种的影响。在炭疽菌和草莓炭疽菌之间观察到均值的显著差异-后者的通量密度略低。这是首次证明感染同一植物物种的密切相关的物种在飞溅散布方面相似。
