为明确烟草黑胫病(Phytophthora parasitica var.nicotianae Tucker)抗性鉴定方法,采用粗毒素浸种法、粗毒素浸根法、孢子悬浮液浸根法及田间病圃接种法,研究烟草革新3号(抗病品种,R)、G28(R)、金星6007(中抗品种,MR)、小黄金1025(感病品种,S)、红花大金元(S)等对烟草黑胫病的抗性,并对其抗性鉴定效果进行相关性分析。结果表明,孢子悬浮液浸根法的鉴定结果与粗毒素浸种法的鉴定结果呈显著负相关,与田间病圃接种法的鉴定结果呈显著正相关。粗毒素浸种法不受季节限制,可以对烟草材料黑胫病的抗性进行大批量筛选。粗毒素浸根法和田间病圃接种法有一定的缺陷,可以作为粗毒素浸种法和孢子悬浮液浸根法的辅助鉴定方法。在整个抗性鉴定过程中,孢子悬浮液浸根法可观测到烟株病情指数和发病率的动态变化,较其他3种方法更能准确、合理地评价品种抗性。
In order to determine the reasonable and effective method for the identification of resistance to tobacco black shan disease(Phytophthora parasitica var. nicotianae Tucker),using four identification methods:Toxins soaked seed soaking method,root method, spore suspension dipping root method and field disease nursery inoculation method,the tobacco resistant of fluecured tobacco cv. Gexin 3(resistant,R),G28(resistant,R),Jinxing 6007(medium resistance,MR),Xiaohuangjin 1025(susceptible,S) and Honghuadajinyuan(susceptible,S) were researched. And its resistance identification effects for correlation analysis were conducted. The results showed that there were negatively correlation between the identification results of the immersing seeds method and the identification results of immersing root in spore suspension. There were significantly positive correlation between the identification results of the immersing root in spore suspension and the results of inoculating in disease nursery. The immersing seeds with liquid toxin was unaffected by seasonal factors, which could be used to screen tobacco varieties with black shank disease resistance in a large scale all the year round. There were somewhat defects in immersing immersing roots with liquid toxin and inoculating in disease nursery methods had flaws, which could be used to assist the methods of immersing seeds with liquid toxin and immersing root in spore suspension to evaluate disease resistance level of different tobacco varieties. Immersed the root with pore suspension could be applied to observe dynamic change of the disease index and the incidence rate of the tobacco during the whole inoculating process. Compared with other three methods, immersing the root with pore suspension could be more accurate and reasonable to evaluate disease resistance of different tobacco varieties.