中文摘要：

为了解烟草赤星病（Alternaria alternata）在大田空间分布情况及对不同品种烟草的危害程度,通过田间系统调查,从寄主生态位、空间生态位角度系统分析了赤星病病菌的生态位特征。结果表明：烟草赤星病在试验烟草品种中的寄主生态位宽度大,发病率的生态位宽度为0.918 7,病情指数的生态位宽度为0.931 4。各品种对该病的抗性大小依次为闽烟35〉翠碧1号〉C2〉红花大金元,说明赤星病病菌基本上可以侵染各个参试品种;各品种赤星病的空间生态位宽度也较大,赤星病对各品种的发病率空间生态位宽度大小依次为闽烟35〉C2〉红花大金元〉翠碧1号,对各品种的病情指数空间生态位宽度大小依次为闽烟35〉翠碧1号〉红花大金元〉C2。说明赤星病病菌可以较充分地占据烟株上、中、下各空间部位而全面危害烟株。因此,掌握烟草赤星病的空间分布和不同品种对该病的抗性,有利于烟草赤星病的有效防治。

英文摘要：

In order to know the spatial distribution of Alternaria alternata（A. alternata） and the damage it caused to flue-cured tobacco of different varieties, field investigation trials were carried out systematically, and its niche characteristics in Longyan tobacco growing areas were analyzed from the points of host niche and spatial niche. The results showed that the host niche breadth of A. alternata was quite large to the trial tobacco varieties with the incidence and disease index niche breadths of 0.918 7 and 0.931 4, respectively. The varieties in the order of resistance against A. alternata were Minyan 35CB-1C2Honghuadajinyuan, which indicated that the germs basically infected all the trial varieties. Moreover, its spatial niche breadth was also large. The varieties in the order of the spatial niche breadth of A. alternata incidence were Minyan 35C2HonghuadajinyuanCB-1, while in the order of the spatial niche breadth of disease index were Minyan 35CB-1HonghuadajinyuanC2. It suggested that the germs could fully occupy the upper, middle and lower parts of tobacco plant and cause damage to whole plant. Knowing the distribution of A. alternata and the resistance of different varieties would be helpful to its effective control.