Method of quickly identifying bacterial wilt resistance in tobacco varieties in seedling stage

Abstract

A method of quickly identifying bacterial wilt resistance in tobacco varieties in seedling stage comprises the main steps of A, raising seedlings of a tobacco variety under test in nutrient pots according to a floating seedling raising method; B, subjecting tobacco plants infected by bacterial wilt and collected from a field to isolation purification culture for 3-5 days via a TTC (triphenyl tetrazolium chloride) medium to obtain purified Ralstonia solanacearum; inoculating the Ralstonia solanacearum subjected to purification culture to NA (nutrient agar) medium, and culturing for 12 h to obtain an inoculation bacterial liquid; C, sucking the inoculation bacterial liquid with an injector, selecting tobacco seedlings growing with 3-4 true leaves in the nutrient pots in step A, and injecting 2-4 mu L of the inoculation bacterial liquid obliquely into a stalk of each selected tobacco seedling from its axil; D, culturing the inoculated tobacco seedlings in a sunlight culture room for 10 days, observing and recording disease attack conditions of the tobacco seedlings on 10th day of culture, calculating a disease index, and judging the bacterial wilt resistance of the tobacco variety under test. The method is simple to perform, high in measuring speed, good in results accuracy and good in result uniformity.

Description

technical field [0001] The invention relates to a method for identifying tobacco variety bacterial wilt resistance. Background technique [0002] Tobacco is an important economic crop in my country and even in the world. Tobacco bacterial wilt caused by Ralstonia solanacearum (Ralstonia solanacearum) is one of the main diseases of tobacco, and the annual yield loss caused by it is about 20%, and the severe one can reach 50%, or even no harvest, which seriously affects the yield and quality of tobacco leaves. quality. The infection sources of tobacco bacterial wilt mainly include soil with bacteria, diseased residues, and pathogenic bacteria invade from tobacco wounds. In recent years, due to continuous cropping of tobacco, the incidence and area of ​​soil-borne diseases such as bacterial wilt have increased year by year. At present, chemical control methods are mainly used to control bacterial wilt in production. However, the long-term and large-scale application of chem...

AI Technical Summary

Problems solved by technology

Natural infection identification has the advantage of easy operation, but it is greatly affected by environmental factors, the incidence is uneven, and the identification takes a long time; artificial inoculation identification is characterized by its standard method, rapid onset, short identification time, and accurate identification results. Widely used by researchers and plant protection workers

[0005] However, in the existing identification method of artificial inoculation of tobacco bacterial wilt disease, the tobacco seedlings need to be cultivated in MS medium, and before the identification, the roots of the tobacco seedlings need to be cut with scissors one by one, and after inoculation, sterilized filter paper is required to absorb the excess bacterial liquid , and the tobacco seedlings need to be replanted in the culture medium

The identification cost is still high and the identification conditions are harsh, so it is difficult to promote and apply on a large scale