Detailed Explanation of the Technology for Rapid Propagation of Virus-Free Potato Test-Tube Plantlets
Potato is the fifth-largest crop in Heilongjiang Province, ranking only after rice, @#@245@#@, corn, and soybean. It is a crop that can be used for multiple purposes such as food, vegetables, and industrial raw materials. Potato is still an emerging industry in Heilongjiang Province, with a history of only about twenty years. The formation and development of this industry was born alongside the research and development of virus-free potato technology. Through the smooth implementation of the "institute-county joint development" poverty alleviation and development project, and under the guidance of experts and professors from the Provincial Academy of Agricultural Sciences, Huanchuan County established virus-free potato propagation bases mainly in Sujiadian Town and Lifeng Township, greatly improving the county's potato cultivation technology level and yield and quality level. The average yield per mu reached about 2000 kg, and the starch content reached about 20%. In order to further improve the production level of virus-free seed potatoes, we studied the rapid propagation technology of virus-free potato test-tube plantlets. The main techniques are as follows:
1. Selection of virus-free plantlets
The virus-free test-tube plantlets used for rapid propagation must undergo strict virus testing. They must indeed contain no viruses or viroids. The virus-free test-tube plantlets should be robust in growth, 5-6 cm in plant height, with medium internodes, thick stems, and large leaves.
2. Preparation of culture medium
MS culture medium is used for the rapid propagation of virus-free test-tube plantlets. An appropriate amount of agar is added. Since the agar currently sold on the market varies in content, a test must be conducted before preparation. The approximate dosage is 6-13 g/L. Heat the culture solution to boiling, and while hot, pour it into test tubes, filling each test tube with 6-7 mL. After filling, plug with cotton plugs and place into a sterilization pot. A sterilization pressure of 15 pounds (121°C) maintained for 20 minutes can thoroughly kill pathogens. After sterilization, remove and cool. Once solidified, it can be used for rapid propagation.
3. Rapid propagation equipment
Units with the means may use a sterile operating bench. We focused on exploring the technology of using a simple inoculation box for rapid propagation. In addition to the operating box, an alcohol lamp, a planting hook, an iron tray, matches, and a cup containing 1/3 alcohol are also needed.
4. Disinfection
One day before rapid propagation, thoroughly disinfect the room with 3-5% Lysol. Before disinfection, wipe the disinfection box clean with 75% alcohol. Take sterilized culture medium in an amount equivalent to 5-6 times that of the virus-free plantlets (for each rapid propagation), and after disinfection, place it into the operating box. Disinfect the inside and outside of the operating box again.
During rapid propagation, put your hands into the operating box, dip the planting hook and scissors in alcohol, ignite them on the alcohol lamp, and immediately place them on the iron tray to cool naturally. At the same time, take 5-6 tubes of culture medium and remove the cotton plugs. While burning the mouth of one test tube of plantlets over the alcohol lamp, remove the cotton plug. Use the planting hook to pull the plantlet out until most of it is exposed from the test tube, then use scissors to cut 2-3 segments into each tube of culture medium, with each node bearing one leaf. After cutting, use the planting hook to insert each cut segment vertically (must not be inserted upside down) into the culture medium in each tube. After planting, hold the mouth of the test tube over the flame while plugging in the cotton plug.
After all planting is completed, take out the empty tubes and the newly planted test-tube plantlets.
5. Culturing
The planted test-tube plantlets need to be placed under conditions of room temperature 22-24°C, light intensity 1000-3000 LUX, and guaranteed 16 hours of light per day. If sunlight is insufficient, fluorescent lamps can be used to supplement light. Under normal conditions, rooting occurs in about 3-5 days, and after about 25 days, the next rapid propagation can be carried out.
Using the above techniques, the number of virus-free test-tube plantlets can be expanded nearly 700-fold in 3 months during winter, greatly shortening the production cycle of virus-free seed potatoes.