Research on Propagating Tea Seedlings in Intelligent Greenhouses (Full Text)

      Improved varieties of tea trees are the basis for the high-quality and efficient production of tea. All tea producing countries in the world regard the promotion of improved varieties of clones as the primary measure to improve product quality and occupy the tea market. At present, the domestic tea plant asexual breeding technology generally adopts short ear cuttings, the seedling raising cycle is generally 13-18 months, the cycle is long, and the management cost is high. Facility agriculture is a new agricultural technology that has developed rapidly in recent years. It has been widely used in domestic and foreign vegetable, flowering and forest industries. Intelligent rapid propagation in greenhouse is one of the main ways to develop tea clones. Compared with the traditional tea tree short-ear cutting propagation, it has the advantages of artificial control of environmental factors, short reproduction cycle, fast speed, high efficiency, annual production, saving breeding materials, and maintaining the original excellent characteristics of tea trees. It can obtain a large amount in a short time. Plant strains with consistent genetic traits.
       Guizhou Tea Research Institute introduced tea plant intelligent rapid propagation technology in 2008. After more than two years of experimental research, preliminary results have been achieved, reaching two batches of tea seedlings in one year. The good results. In order to accelerate the popularization of tea plant intelligent rapid propagation technology and promote the popularization of improved tea varieties in Guizhou, the author summarized the intelligent rapid propagation technology in order to provide a fast propagation sharing platform for the development of Guizhou's characteristic tea industry.

1. Construction of intelligent greenhouse for tea seedlings
     The intelligent rapid propagation system for greenhouse is mainly composed of greenhouse, civil construction, and rapid propagation. Intelligent control systems Partial composition (Figure 1).



1.1 Greenhouse construction
       The multi-span sunlight greenhouse was built in September 2008, covering an area of ​​1000m2, and the open area of ​​the greenhouse 2000m2, the entire greenhouse material is made of hot-dip galvanized pipes and hollow organic solar panels to ensure durability and make the life of more than 20 years. Open windows on both sides of the shed, with automatic external shading system.

1.2 Civil Engineering
        There are 4 rapid propagation areas and 32 seedbeds in the shed, each with an area of ​​30m2. Each seedbed embedded line pipe is connected with the host. There are also cement floors, drainage ditches, and fan towers; outside the sheds are sheltered walls, side ditches, cement floors, and reservoirs.

1.3 Kaifan intelligent control equipment
      1.3.1 Kaifan intelligent control equipment consists of three parts: intelligent system, intelligent control auxiliary system and pipeline system constitute.
       Intelligent System The intelligent system consists of a fast propagation host, a sub-controller, an intelligent blade, a climate bar and a sensor. Among them, the fast propagation host and sub-controller are the intelligent computing systems of the fast propagation equipment, and the intelligent blades, climate rods and sensors are the signal data collection systems of the computer.
      1) Host. Composed of 4 fast-propagating computers, it is the operating platform of the entire fast-propagating intelligent computer, which is oriented to the entire fast-propagating area for control command output and signal data collection and processing.
      2) Sub-controller. The fast propagation computer has 4 sub-controllers, and each sub-controller only performs signal collection and processing and command output for each control zone. There are a total of 4 zones and 32 seedbeds.
      3) Smart blades. The intelligent blade is the signal acquisition equipment of the zone controller, which is installed in the seedbed of each zone and connected with each sub-controller to collect various climate factor data of the corresponding zone in the greenhouse for each sub-controller. The collected data include: temperature (the micro-environment temperature of the leaves in the seedbed of each zone), leaf water film (the thickness of the water film on the leaves in the seedbed of each zone), substrate temperature (the temperature of the substrate in the seedbed of each zone), substrate humidity (The humidity of the substrate in the seedbed in each zone), and the ambient light (the amount of natural sunlight in the seedbed in each zone). .
      4) Climate rods and sensors. The climate bar is the signal data collection equipment of the rapid propagation host. It is hung directly above the entire rapid propagation area in the greenhouse. The data collected by the climate rod includes: ambient temperature (the ambient temperature of the entire rapid propagation area) and ambient humidity (the entire fast propagation area) (Air humidity), ambient light (intensity of natural sunlight throughout the fast-growing area).
       The sensor is also the signal data acquisition equipment of the fast propagation host, which is divided into three types: nutrient EC liquid sensor, nutrient liquid water shortage sensor and clean water shortage sensor. The fast multiplication host is connected. The nutrient solution EC sensor collects and detects the EC value of the nutrient solution and the conductivity of the nutrient solution, that is, the concentration of the nutrient solution; the nutrient solution lacks water sensor collects the signal of the nutrient solution lack of water, and whether the nutrient solution barrel lacks water; the clear pool lacks water The sensor collects the water shortage signal of the clear water tank, and whether there is water shortage in the clear water tank.

     1.3.2 Intelligent control auxiliary system The intelligent control auxiliary system of the fast propagation computer is a means for the fast propagation computer to achieve control output. It is composed of mist control system, heating system, nutrition supplement system, lighting system and cooling system.
      1) Fog control system. It is controlled by the controllers of each zone, and feeds back to the expert system of the fast propagation host according to the information of the temperature, humidity, moisture evaporation coefficient, substrate temperature, and substrate humidity of the intelligent blade. The expert system intelligently controls the start and stop of peripheral equipment (solenoid valves, water pumps, etc.), so that water or nutrient solution can be supplemented and adjusted in a timely manner through the pipeline system. In addition, this pipeline system can also be used for fertilization and spraying in the "manual intervention" mode.
      2) Heating system. Controlled by each zone controller, heating wires are installed at the bottom of each seedbed. When the temperature changes, the computer will intelligently control and turn on the heating equipment.
      3) Nutritional supplement system. Controlled by the fast propagation host, the nutrient solution is sprayed on the entire fast propagation area. This system is mainly operated in the "manual intervention" mode. When spraying, first set the state of the rapid propagation host to the "manual intervention" mode, and then press "nutrition options" to realize the entire rapid propagation area Nutritional spraying.
      4) Lighting system. Controlled by the controller of each zone, the photosensitive material of the intelligent blade records the daily light time and cumulative amount of intensity, and compares it with the light time, intensity and the type of light required by the tea tree in the "parameter setting" in advance. Calculations promote the operation of control light equipment to achieve the best light measurement. The supplemental light system only operates from 19:00 to 4:00 am the next day.
      5) Cooling system. It is composed of two fans controlled by the Kuaifan host. When the climate bar detects changes in ambient temperature and humidity, the host automatically controls the start and stop of the two fans according to the "parameter setting" range.
      6) Pipeline compensation system. When the mist is filled, because the pipeline is too long, the beginning and end of the pipeline are affected by the speed, pressure, thickness of the pipeline and other parameters. When the water is not sprayed to the end, the system starts the water pump or solenoid valve. Has stopped. Therefore, the computer also has a pipeline compensation function, which is automatically controlled by the computer after it is set up.

       1.3.3 Piping system The piping system is divided into 2 parts, the clean water pipeline and the nutrition pipeline. The clean water pipeline is composed of a reservoir, a pressure pump, a filter, 4 solenoid valves, 4 check valves, a main water pipeline, a misting pipeline and a nozzle; the nutrition pipeline system is composed of water storage It is composed of tank, 1 nutrient solution bucket, 1 pressure pump, 1 filter, 4 solenoid valves, 4 check valves, nutrient main pipeline, misting pipeline and nozzle.
       The reservoir realizes the storage and purification of well water, and connects two systems of clean water and nutrition; the nutrient solution bucket is used to store the prepared nutrient solution; the pressure pump is to achieve the mist effect .The pressure of the water or nutrient solution in the pipeline is increased; the filter is used to filter out impurities in the water; the solenoid valve is the electric control pipe opening and closing connected to the computer; the check valve is to restrict the water flow in the pipeline to only one Directional flow; the main pipeline connects the pipeline that only flows clean water or nutrient solution to the misting pipeline on the seedbed; the misting pipeline is a pipeline laid on each acre bed and equipped with nozzles, which is a clear water pipeline system and a nutrient pipeline system Shared, each seedbed’s misting pipeline is equipped with a hand valve. You can manually close the front hand valve to control the misting of a single seedbed, or manually open the rear hand valve to clean the pipeline. The spray head realizes the fogging function.

Second, the technical process and technical points of the intelligent and rapid propagation of tea trees in greenhouse

2.1 Technical process
     Tea Mother Garden—Sui Retention and management of strips — rapid propagation materials collection, production and processing—inoculation in intelligent seedbed—computer automatic control (fertilization, pest control)—the promotion and application of mature seedlings and improved tea seedlings.

2.2 Technical points
      2.2.1 Cutting time Cutting time should be controlled before the first ten days of August or after mid-November, to ensure that the seedling cycle is 47 months.
      2.2.2 The substrate is mixed with perlite and acidic soil as the substrate. The perlite has good permeability and good moisture retention characteristics, which will quickly produce explosive roots, and there are various nutrients in the soil. The elements are used for the growth of tea seedlings. The root system of the cultivated rapid propagation seedlings is more developed and grows robustly (Figure 2).

      2.2.3 Panicle cutting morphology: One bud and 1 leaf, two buds and 2 leaves, three buds and 3 leaves, etc. Different panicle cutting forms can produce burst roots, two buds and 2 leaves or Three buds and three leaves form two-story roots around the buds. From the perspective of saving breeding materials, the effect of one bud and one leaf is better.

3. The effect of intelligent and rapid propagation of tea trees in greenhouse
     In the autumn of 2009, spring and summer of 2010, experiments on rapid propagation of tea trees were carried out in intelligent sunlight greenhouse, and the results were better The rapid propagation effect.

3.1 The cuttings have a large amount of rooting. Shorten the seedling cycle
       The cuttings are inoculated on the seedbed in the smart sunlight greenhouse, 1520d callus begins to form, 3040d more than 80% Short ear wounds healed, roots extended, axillary buds differentiated and grew, and a large number of explosive roots formed in 60 days (Figure 3). The seedling raising cycle is 45 months in spring and summer, and 5 6 months in autumn and winter. The seedling raising time is 50% shorter than that of conventional short-ear cuttings. Fast propagation technology shortens the seedling cycle, realizes two seasons of tea seedlings out of the nursery a year, and improves land utilization.


 
3.2 ​​The refining process is scientific and reasonable, and the operation is simple.
       Intelligent fast propagation technology is controlled by computer program settings , It can simulate the transition to the natural environment on the seedbed, and realize in-situ planting, saving a lot of tedious operations and special planting land. In an intelligently controlled environment, planting planting is a transition process in a natural state and also a root system The process of continuously forming secondary roots and tertiary roots. Generally, when the third roots are opened and developed, the seedlings already have a developed root system and strong adaptability. At this time, the root-to-shoot ratio is also large, which can adapt to the nature of low humidity and less water. Environment, transplanting and planting can be carried out at this time. In an intelligently controlled environment, a new model of high-quality tea seedling propagation with rapid annual propagation and annual transplantation can be formed.

3.3 Fast-propagating seedlings transplanting has a high survival rate
      The tea seedlings bred by intelligent fast-propagating technology are more developed than the tea seedlings produced by conventional short-ear cuttings, because Under the most suitable environment and nutrient regulation, the root primordium is fully expressed, and the root system is explosively rooted. The root system of fast-propagating seedlings is several times larger than that of conventional short-spike cuttings. Therefore, the survival rate of transplanting to the field is high. The survival rate of fast-propagating seedlings after transplanting can reach more than 95%.

4. Advantages of tea tree intelligent rapid propagation technology
       Intelligent rapid propagation technology integrates temperature, humidity, light, carbon dioxide concentration, evaporation coefficient, and nutrient solution concentration It is a high-tech technology that realizes the rapid propagation of seedlings and is an organic combination of computer intelligent control technology and biological technology through the computer control system to create the best growth ecological environment for the in vitro material of the plant. A brand-new seedling technology.

4.1 Strong practicability, easy to learn and easy to operate
      Simple to operate, only need to pass 12d technical training to operate and produce. Take only one bud and one leaf of the plant, insert it into the seedbed, and implement rapid propagation under the supervision of the computer intelligent system to simulate the best conditions for plant growth. The cuttings can generally be transplanted after 46 months of cultivation.
4.2 High seedling raising efficiency
      Each batch of tea seedlings can propagate 400,600 plants/m2, and every 667m2 can produce 26.4 million plants. 2 batches per year, 1 year 500,000 seedlings 800,000 plants/667m2. It is 45 times higher than conventional short ear cuttings (about 150,000 tea seedlings/667m2 per year under normal conditions). Intelligent fast propagation technology application planThe computer simulates the growth factors of the rapid propagation of plants, which can intelligently control the growth environment of the plants, without being restricted by seasons, and can propagate throughout the year. Through the intelligent computer system, it can perceive the humidity, temperature, light, carbon dioxide, substrate humidity, nutrient EC value, etc. of the environment, and digitize various environmental factors. Through the calculation of the computer, the plant growth mode and environmental parameters set by people Comparing operations, issuing execution signals, directing seedbed facilities such as fogging, heating, lighting, and aeration, etc., so that the entire seedling process can be intelligent and automated, saving a lot of management labor.
4.3 Tea tree genetic stability
      Tea tree intelligent rapid propagation is asexual reproduction, also known as plant cloning. It is genetically stable and generally does not undergo mutations and mutations. It is widely used for rapid breeding.
4.4 Speed ​​up the breeding speed of new materials
       Intelligent rapid propagation in greenhouse is suitable for the rapid propagation of less breeding materials, newly selected strains or rare varieties. For example, according to the current method, it takes about 10 years to expand the original seed of a new tea variety after it is bred to form a certain scale of seedling breeding ability and reach the stage of large-scale production and application. However, using intelligent rapid seedling breeding technology only requires 34 The work that could only be completed in the past 10 years can be completed within one year, which plays an important role in accelerating the promotion and application of new varieties.
4.5 Multifunctional equipment
       Plant rapid propagation simulation computer is a kind of agricultural intelligent computer system, using professionally designed hardware and software to realize remote control, online control and centralized group Control, etc., and support function expansion and upgrades, computer control systems for rapid propagation, in addition to rapid propagation of substrates, it is also suitable for plant air propagation, water propagation, plant hydroponic cultivation, tissue culture test tube  Rooting and smelting seedlings, intelligent soil irrigation, soilless cultivation and greenhouse environment control and management, etc.

Fifth, Guizhou tea plant rapid propagation technology application prospects
      Intelligent rapid propagation technology has outstanding advantages and is suitable for the rapid propagation of various plants. The application of intelligent rapid propagation technology to the propagation of tea seedlings with Guizhou characteristics will definitely play its positive role. In the short term, it can increase the reproduction speed of Guizhou's characteristic and excellent varieties, speed up the breeding progress, promote the establishment of Guizhou's characteristic tea tree mother garden, and promote the formation of Guizhou's characteristic tea advantages. The application of intelligent rapid propagation technology will definitely change the small scale of Guizhou characteristic tea planting, speed up the process of localization of excellent varieties of characteristic tea trees, improve the scientific and technological content of the breeding of improved varieties of tea trees, in order to adapt to the new situation of tea development in Guizhou and meet the expansion of tea in Guizhou Province Planting area Demand for high-quality tea seedlings.
    In addition, in tea breeding research, through the annual multi-generation cycle and rapid propagation, it can shorten the breeding time of improved tea varieties, timely launch excellent varieties of tea trees that meet the needs of production and market, and increase the planting ratio of excellent varieties in Guizhou , To promote the sustainable development of Guizhou tea.