大蒜紫斑病抗性鉴定方法的研究

Studies on Identification Method of Garlic Resistance to Violet Leaf Spot

以G087(抗病)、G064(中抗)、G073(感病)大蒜为鉴别品种,对大蒜紫斑病的侵染途径,抗性鉴定的接种叶龄、接种浓度、接种部位,接种后培养温度及调查时期等进行了研究。结果表明,苗期紫斑病菌通过伤口和自然孔口均可浸染大蒜植株,而花芽鳞芽分化期只可通过伤口侵入。抗病性鉴定最适接种叶龄为5叶期;最适接种浓度为1×106个.mL-1;离体接种法较活体接种法更简便快捷。离体接种鉴定时,叶面接种和叶背接种鉴定结果无显著性差异;接种后最适培养温度为21℃;最适调查时期为接种后第6天。以G057(抗病)、G103(中抗)、G083(感病)大蒜为验证品种,离体接种鉴定结果显示,建立的大蒜紫斑病抗病性鉴定方法可行,能如实反映品种的真实抗性。

The infection path of garlic violet leaf spot [ Alternaria porri （ELL.） Cif. ] and resistance identification of inoculation leaf stages, inoculation spore concentration, inoculation position, culture temperature after inoculation and time to survey etc were studied by using the identification cuhivars G087 （ R）, G064 （MR）, and G073 （S）. The results show that, the pathogen of violet leaf spot infects garlic plants through both the wound and the natural orifices at seedling stage while at flower bud differentiation stage it only invades through the wound. For disease resistance identification, the optimal leaf stage is 5-leaf stage, the optimal spore concentration is 1 × 10^6 cfu · mL^-1 ; Inoculation in vitro is more simple and rapid compared to inoculation in vivo. For in vitro inoculation, there is no significant difference between leaf face inoculation and leaf back inoculation; The optimal culture temperature after inoculation is 21 ~C ; The optimal time to survey dis- ease index is the 6th day after inoculation. Using G057 （R）, G103 （MR）, and G083 （S） as the verification cultivars, the results show that the established method is practicable to reflect the true resistance of garlic cultivars to violet leaf spot.