Establishment of the three-level citrus virus-free propagation scheme

  The “Study on the Establishment of Technology for Virus-free Citrus Plants System in Chongqing” was awarded the second prize of the Sci-Tech Progress Achievements of Chongqing City in 1996. The “Molecular Detection of Citrus Viruses and Quarantine Diseases, and Techniques for the Three Levels Virus-free Propagation System” passed the achievement authentication in 2006.

  This achievement was involved in systematic studies on the occurrence and distribution of main citrus viruses and virus-like diseases in both domestic and abroad-introduced varieties, construction of the virus-free elite variety bank of citrus and conservation of more than 200 virus-free varieties. “Identification of occurrence and distribution of citrus viruses and virus-like diseases and construction of the virus-free elite variety bank of citrus” has already passed the achievement authentication by the Ministry of Agriculture.

  The viruses have been excluded for 25 single strains of the main cultivated varieties and introduced elite varieties in Chongqing: the main objective was to exclude the Exocortis viroid, Tatter Leaf Virus and Atrophy of Wenzhou Citrus and serological techniques in combination with the indication plants was used to detect Citrus virus and virus-like diseases.

  In recent years, the National Citrus Virus Exclusion Center has obtained a breakthrough in the rapid identification technology in molecular biology, including construction of the rapid identification system for citrus viruses and virus-like diseases. Following the overseas experiences and experiences in our own country, we firstly proposed the idea of a technique strategy for the Three Levels Propagation System of the Virus-free Elite Citrus Varieties in order to provide a scientific basis for the improvement of citrus plant quality in our country. Based on the overseas advanced experiences, the standardized container plant propagation system was established, and the propagation demonstration base for the virus-free citrus was built: these propagation techniques have caught up with the international advanced level.

  Using the rapid molecular identification techniques established, we have achieved the rapid identification of citrus viral diseases in the candidate mother trees in the transition period of Project for a Million Tons of Citrus Production in Chongqing, which promoted the development of the project. Meanwhile, within the support of “The Span Plan” of the Ministry of Agriculture, the Three Levels Propagation System was constructed by integrating techniques in molecular detection and container plant propagation, along with other techniques. This has resulted in more than ten thousand plants and more than one million budwoods of virus-free citrus for Chongqing and other citrus producing areas.

  The proposed technique strategy for the Three Levels Propagation System of the Three Levels Propagation System of the Virus-free Elite Citrus Varieties was agreed upon and accepted by the authorizing organizations such as the Ministry of Agriculture, and has provided an important reference standard for the construction of propagation systems for other crops such as fruits and tea. This achievement has caught up with the international advanced level. For the prominent achievement in the construction of the propagation system and the standard technical regulations, the principal, Dr. Zhou Changyong, was invited by the Department of Agriculture, Fisheries and Forestry of Australia to attend the conference for the constitution of the standard for citrus Huanglongbing diagnosis in 2003. Dr. Zhou was also invited to give a special report at the National Convention for Exchanging Experience of the Construction of Propagation Stations of Elite Fruit and Tea Varieties by the Crop Cultivation Bureau of the Ministry of Agriculture, and was invited as the convener of the Citrus Group at the 15th International Plant Protection Conference.