Poplar seedling raising technology

Red Populus is a species of American black poplar bud found in the spring of 2000 in the Provincial Academy of Forestry. In 2005, it was certified by the Henan Provincial Forest Variety Affirmation Committee, and in 2006, it obtained the new breed protection right of the State Forestry Administration. At present, there is a large gap in the market of red poplar seedlings, and the production management is not standardized. In order to improve the level and quality of red poplar breeding, guarantee the promotion of improved varieties and production of strong seedlings, we combine the breeding experience of the past few years and the technical specifications for the breeding of red poplars are as follows:

First, hardwood cuttings breeding

The cutting diameter of the cuttings is 0.8 to 1.6 cm, and the length is 10 to 15 cm. The upper cut is 1 to 1.5 cm from the bud, and the lower cut is 0.5 cm from the bud. The incision should be smooth to avoid chapped and protect the buds. body. The cuttings should be coarsely subdivided, one bundle per 50 roots. For the cuttings stored using the outdoor wet sand storage method, attention should be paid to check and prevent the cuttings from heating when the temperature in early spring rises.

Cutting time and methods Hardwood cuttings are mostly done in the spring and can also be done in the fall. Spring cuttings should be early, generally before the buds sprout; autumn cuttings should be carried out before soil freezing. The cutting density is generally 4000~4500 per mu. Cuttings before cutting is best soaked in water, soaking time is generally 4 to 8 hours. There are two kinds of straight inserts and oblique inserts. The depth of cuttings is preferably 1 bud on the ground. When the cuttings are inserted, the cuttings can all be inserted into the soil, the upper end is level with the ground, and the surrounding is compacted, and after watering, one bud at the top of the cuttings naturally appears on the ground. When cutting in the fall, pay attention to covering the cuttings with a layer of soil or film.

Second, grafting and breeding In order to speed up the breeding process, save breeding materials and achieve rapid promotion, grafting can be used for breeding.

Rootstock selection Because red poplar with their parents maternal 2025 grafting survival rate is the highest, the largest amount of growth, it should be selected robust, no pests, annual 2025 poplar cutting seedlings as rootstock.

Grafting from March to May, the full shoots with no pests and diseases on the strong shoots of Chinese red poplar were taken and grafted with xylem-embedded buds. Scion with the use of mining, unfinished scion timely storage with wet sand in a cool ventilated place, so as not to affect the graft survival rate. Grafting should try to avoid rainy days.

Ventilator block diagram
One. Main mechanical ventilation modes
(1) Intermittent Positive Pressure Ventilation (IPPV): positive pressure in the inspiratory phase and zero pressure in the expiratory phase. 1. Working principle: The ventilator generates positive pressure in the inspiratory phase and presses the gas into the lungs. After the pressure rises to a certain level or the inhaled volume reaches a certain level, the ventilator stops supplying air, the exhalation valve opens, and the patient's thorax Passive collapse of the lungs and exhalation. 2. Clinical application: Various patients with respiratory failure mainly based on ventilation function, such as COPD.
(2) Intermittent positive and negative pressure ventilation (IPNPV): the inspiratory phase is positive pressure and the expiratory phase is negative pressure. 1. How it works: The ventilator works both in the inspiratory and exhaled phases. 2. Clinical application: Expiratory negative pressure can cause alveolar collapse and cause iatrogenic atelectasis.
(3) Continuous positive pressure airway ventilation (CPAP): Refers to the patient's spontaneous breathing and artificial positive airway pressure during the entire respiratory cycle. 1. Working principle: Inspiratory phase gives continuous positive pressure air flow, and exhalation phase also gives a certain resistance, so that the airway pressure of inhalation and exhalation phases are higher than atmospheric pressure. 2. Advantages: The continuous positive pressure airflow during inhalation is greater than the inspiratory airflow, which saves the patient's inhalation effort, increases FRC, and prevents the collapse of the airway and alveoli. Can be used for exercise before going offline. 3. Disadvantages: great interference to circulation, large pressure injury of lung tissue.
(4) Intermittent command ventilation and synchronized intermittent command ventilation (IMV / SIMV) IMV: There is no synchronization device, the ventilator air supply does not require the patient's spontaneous breathing trigger, and the time of each air supply in the breathing cycle is not constant. 2. SIMV: There is a synchronization device. The ventilator gives the patient a commanded breath according to the pre-designed breathing parameters every minute. The patient can breathe spontaneously without being affected by the ventilator. 3. Advantages: It exerts its ability to regulate breathing while offline; it has less influence on circulation and lungs than IPPV; it reduces the use of shock medicine to a certain extent. 4. Application: It is generally considered to be used when off-line. When R <5 times / min, it still maintains a good oxygenation state. You can consider off-line. Generally, PSV is added to avoid respiratory muscle fatigue.
(5) Mandatory ventilation per minute (MMV) When spontaneous breathing> preset minute ventilation, the ventilator does not command ventilation, but only provides a continuous positive pressure. 2. When spontaneous breathing is less than the preset minute ventilation volume, the ventilator performs command ventilation to increase the minute ventilation volume to reach the preset level.
(6) Pressure Support Ventilation (PSV) Definition: Under the prerequisite of spontaneous breathing, each inhalation receives a certain level of pressure support, increasing the patient's inhalation depth and inhalation volume. 2. How it works: The inspiratory pressure begins with the patient's inspiratory action, and ends when the inspiratory flow rate decreases to a certain level or the patient attempts to exhale hard. Compared with IPPV, the pressure it supports is constant, and it is adjusted by the feedback of the inspiratory flow rate. Compared with SIMV, it can get pressure support for each inhalation, but the level of support can be set according to different needs. 3. Application: SIMV + PSV: used for preparation before off-line, can reduce breathing work and oxygen consumption Indications: Exercise the ventilator; prepare before going offline; the ventilator is weak due to various reasons; severe flail chest causes abnormal breathing. 5. Note: Generally not used alone, it will produce insufficient or excessive ventilation.
(7) Volume Supported Ventilation (VSV): Each breath is triggered by the patient's spontaneous breathing. The patient can also breathe without any support and can reach the expected TV and MV levels. The ventilator will allow the patient to be truly autonomous Breathing also applies to preparations before going offline.
(8) Capacity control of pressure regulation
(IX) Biphasic or bilevel positive pressure ventilation How it works: P1 is equivalent to inspiratory pressure, P2 is equivalent to breathing pressure, T1 is equivalent to inspiratory time, and T2 is equivalent to exhalation time. 2. Clinical application: (1) When P1 = inspiratory pressure, T1 = inspiratory time, P2 = 0 or PEEP, T2 = expiratory time, which is equivalent to IPPV. (2) When P1 = PEEP, T1 = infinity, P2 = 0, T2 = O, which is equivalent to CPAP. (3) When P1 = inspiratory pressure, T1 = inspiratory time, P2-0 or PEEP, T2 = desired controlled inhalation cycle, equivalent to SIMV.

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