Studies on identification method of garlic resistance to violet leaf spot.

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 cultivars 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 1×106 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 ℃;The optimal time to survey disease 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.