Tobacco wildfire germ separation method

Abstract

The invention discloses a tobacco wildfire germ separation method. A typical tobacco wildfire infected plant is selected, a dry and clean infected leaf is obtained, and a disease spot is cut off along the junction of the health part and the infected part of the leaf; the center of the disease spot is cut into a '+' or 'double-cross' shaped incision, the disease spot is arranged on the edge of a groove of a concave slide, the cut is arranged in the 1 / 3-1 / 2 depth of the groove; 150-300mu l of a sterilized water is dropped into the groove, a cover glass covers the groove, the concave slide with bacteria exudation phenomenon is selected and the bacteria exudation solution is collected; the bacteria exudation solution is diluted to five or ten times in gradient under the sterile conditions, and 100-200mu l of 53-5 or 103-5 times of diluted solution is coated on a KMB medium, and the medium is cultured at 24-28 DEG C for 48-72 hours; green fluorescent single colonies are selected under UV light, and the pathogenicity of the single colonies is measured, thus the single colony with brown withered dead disease spots and a yellow halo is the object colony. The separation, purification, and identification are integrated, the separation efficiency of the tobacco wildfire germ is high, the separation accuracy is also high, the tobacco wildfire germ separation method is suitable for timely separating the tobacco wildfire germ on field samples, the purity of the separated germ is high, and the wild type characteristics of the germ are kept.

Description

technical field [0001] The invention belongs to the technical field of separation of agricultural microorganisms, and in particular relates to a method for isolating tobacco wildfire pathogens which is simple and quick to operate and suitable for collecting pathogens under field operation conditions. Background technique [0002] Tobacco wildfire is one of the most serious bacterial diseases in tobacco production in the world, and it is also one of the main diseases of tobacco in my country. Wildfire disease primarily affects leaves but can also attack flowers, capsules and seeds. Symptoms on the leaves are small water-soaked circular discolored spots at first, and later the spots expand, and the center turns brown, surrounded by a wide yellow-green halo, which is most obvious at the seedling stage or when the climate is humid, with a diameter of up to 1~ 2 cm. After tobacco is damaged, the general incidence rate is 10-30%, and the incidence rate in severe plots is 70-100%...

AI Technical Summary

Problems solved by technology

This method not only effectively removes saprophytic microorganisms on the surface of diseased tissue, but also kills a large number of target bacteria, which makes it difficult to isolate bacteria from a large number of diseased samples, and the separation efficiency is relatively low, which wastes a lot of specimens