Protocol Establishment for Evaluation of Resistance of Garlic to White Rot (Sclerotium cepivorum Berk.)

A resistant garlic cultivar Hanzhong Red Skin(R)and a susceptible cultivar Gailiang(S)were employed to establish a protocol involved in evaluation of resistance of garlic to white rot(Sclerotium cepivorum Berk.). Results showed that at seedling stage the pathogen was able to infect garlic plants through both the wound and the natural orifices,while at flower bud differentiation stage it invaded the plants mainly through the wound. The plants with 6-week-leaf age were recognized as the best time for inoculation. In vitro inoculation was much simple and efficient,compared with in vivo inoculation. There was no significant difference in disease evaluation between leaf face inoculation and leaf back inoculation. The optimal incubation temperature and time for disease-resistant evaluation after inoculation was 18 ℃ and 7–8 days,respectively. The procedure developed from the present study was further applied to evaluate the resistant ability of other three garlic genotypes to white rot. Results obtained demonstrated that the established method was applicable to a wide range of garlic genotypes for testing their resistance to white rot.