宜宾烟区烟草根黑腐病发病条件及品种抗性评价

The Epidemic Condition and Resistance of Cultivars of Thielaviopsis basicola on Yibin Tobacco Area

为摸清烟草根黑腐病的发生特点,有效控制烟草根黑腐病的发生,通过室内盆栽试验,研究pH、土壤含水量、接种体浓度、施氮量4个因素对烟草根黑腐病发病情况的影响;同时以云烟87、云烟97、云烟85、K326、中烟100为试验对象,明确不同栽培品种间的抗病性差异。结果表明,当土壤偏弱酸性和碱性,有利于根黑腐病的发生;土壤湿度越大,烟草根黑腐病的发生越严重,土壤含水量80%时,病株率和病情指数均最高,分别为88.9%、60.2;接种体浓度高于104个孢子/mL后,浓度越高,病株率越高,病情越严重;氮肥的施加会加重烟草根黑腐病的发生,不利于控制烟草根黑腐病的发生;云烟87属高感品种,云烟97属感品种,云烟85、K326属中抗品种,中烟100属抗病品种,未筛选出高抗品种。

In order to investigate the characteristic and effectively control the occurrence of Thielaviopsis basicola, the influence of pH value, soil moisture content, inoculum concentration and nitrogen application rate on the incidence on Thielaviopsis basicola of tobacco was studied through the indoor pot experiment.At the same time, the differences of disease resistance between different cultivars were determined by the subjects of Yunyan 87, Yunyan 97,Yunyan 85, K326 and Zhongyan 100.By investigating the disease strain rate and disease index, the pathogenesis of black rot of tobacco root was preliminarily determined.The results showed that when soil pH was weakly acidic and alkaline, it was beneficial to the occurrence of root black rot.The higher the soil moisture content, the more serious the occurrence of the black rot of tobacco root, the highest in the soil moisture content and the disease index, 88.9% and 60.2 respectively.The higher the concentration of inoculation, the higher the incidence and the more serious the disease.The application of nitrogenous fertilizer could aggravate the occurrence of tobacco root black rot, which was not conducive to controll the occurrence of black rot of tobacco root.Yunyan 87 belonged to high susceptible;Yunyan 97 belonged to susceptible;Yunyan85 and K326 belonged to moderate resistant varieties;Zhongyan 100 belonged to resistant varieties, without high resistance varieties.