Selection of tissue Culture, cultivation sites and cultivation facilities of Dendrobium candidum

Selection of tissue Culture, cultivation sites and cultivation facilities of Dendrobium candidum

I. tissue culture technique of Dendrobium candidum

Dendrobium candidum seeds will be affected by many factors in the process of germination, if these factors can not be effectively controlled to change the germination rate of Dendrobium seeds, and then affect the yield and quality of Dendrobium candidum. After studying the relationship between seed age and germination, some scholars can find that the seeds of 2-6 months old are selected to culture separately when using tissue culture technology, and the older seeds show obvious advantages in the culture operation. both the germination time and the germination rate show that the older the seed age is, the shorter the germination time is, and the higher the germination rate is. Thus it can be seen that the older seeds should be given priority in tissue culture. In addition, the proper addition of NAA, IAA and IBA hormones to the culture medium can promote the root growth of test-tube plantlets. Therefore, in order to improve the root growth rate of seedlings in the process of tissue culture, hormones can be properly added to the medium according to the actual culture conditions, so as to achieve the purpose of increasing income and yield.

2. Cultivation and management techniques of Dendrobium candidum.

1. Seedling refinement and bottle production

Seedling refinement refers to the whole process of transplanting the cultivated test-tube plantlets to the seedling-refining room for about 3 weeks, during which time the test-tube seedlings adapt to the natural environment. After a period of cultivation, the leaves of the seedlings are dark green and the roots can be planted in bottles after growing to a certain length.

After the test-tube plantlets were cultivated in the seedling training room for 2-3 weeks, the growth status of the seedlings was observed. When the value-added algebra was less than 10 generations, the seedlings grew to 3cm, grew more than 3 fleshy stems, and the number of leaves reached about 5, and the bottle could only be produced when the color was normal. In addition, there are certain requirements for the growth state of the root system, such as that the root epidermis should be white and greenish, the root length is more than 3cm, and the number is more than 5, and there are no black roots and abnormal roots.

The specific operation mode of the bottle is as follows: in order to reduce the damage to the seedlings caused by improper bottle operation, it is necessary to take out the culture medium and the seedlings at the same time, and then separate the well-developed seedlings from the contaminated seedlings and the seedlings with fewer roots. After taking out the normally developed seedlings, the Agar on the surface should be washed off with tap water to avoid root rot caused by Agar residue. After the Agar on the surface is cleaned, rinse again with clean water. For the seedlings with poor root development, it is necessary to soak with rooting powder, and the next stage of planting operation can not be carried out until the root system is fully developed. For contaminated seedlings, carbendazim needs to be used for sterilization treatment and then planted separately to avoid adverse effects on other healthy seedlings due to incomplete sterilization treatment.

2. Selection of cultivation land and cultivation facilities in order to ensure the yield and quality of Dendrobium candidum, it is necessary to study the biological characteristics of Dendrobium candidum and select the appropriate planting area. Generally speaking, the area with wild distribution of Dendrobium candidum is more suitable for the cultivation of Dendrobium candidum. If there is no wild Dendrobium candidum in the planting area, it is necessary to comprehensively consider the temperature, humidity, light and ventilation to determine the final planting area. When the conditions of the planting area are not consistent with the growth conditions of Dendrobium candidum, manual intervention can be taken to provide a suitable growth environment. Generally speaking, it is necessary to build a greenhouse and do a good job of ventilation and shading. The construction scale of the greenhouse needs to be determined according to the actual planting quantity to ensure that the distance before the plant is set reasonably, which can achieve good ventilation effect and growth requirements. In addition, a sunshade net is set at the top of the greenhouse, a vent is set around the greenhouse, and the bottom needs to be closed, and an anti-insect net is set up at the same time to avoid the impact of mosquitoes on crop growth.

3. Matrix selection.

In the cultivation techniques of Dendrobium candidum, the selection of substrate is directly related to the survival rate, growth status, propagation degree and final yield of Dendrobium candidum. For this reason, we need to pay enough attention to the selection of substrates. After years of development, many types of substrates have been obtained, and the appropriate substrates can be selected according to the specific conditions in the actual cultivation work. After comparing and analyzing the culture conditions of many kinds of substrates, it was found that Dendrobium candidum grew best and the yield was the highest when the limestone gravel filter layer 5cm + sawdust 8cm + live moss 2cm was used as the substrate.

4. Transplanting time and method

As the planting of Dendrobium candidum has higher requirements for temperature, therefore, the choice of planting time is particularly important, too high or too low temperature will affect the growth state of Dendrobium candidum. Generally speaking, for the southern region, it can be planted except for the extremely cold weather in January-February and the higher temperature in July-August, but the best planting time is between April and May.

The specific method of transplantation is to dig a shallow hole in the substrate with a depth of 2-3cm, and gently place the root of the seedling in the hole. It is necessary to pay special attention to the fact that the root is not easy to bend, and finally apply the substrate. In order to facilitate the follow-up planting management, the normally developed seedlings, polluted seedlings and few root seedlings can be planted in different areas.

5. Cultivation and management

Light. Zheng Yongping et al thought that the light intensity of 30000 lx was the most suitable for the growth of tissue culture seedlings of Dendrobium candidum; temperature and humidity. The tissue culture seedlings of Dendrobium candidum grew in cool, moist and unobstructed air, and the suitable temperature for growth was 20-30 ℃. When the temperature is high in summer, the greenhouse should be ventilated and cooled and kept humid by spraying at the same time; when the temperature is low in winter, it can be controlled at about 10 ℃ by heating. The air humidity should be kept at about 90% within 1 week after transplanting, and 70% to 80% after 1 week.

III. Harvesting of Dendrobium candidum

Dendrobium candidum can be harvested after planting for 2-3 years, and the suitable harvest time is from "the Beginning of Winter" to "Qingming Festival". At this time, Dendrobium has stopped growing, and the stems and branches are solid, full and dry. In order to make sustainable use of the limited resources of Dendrobium candidum, we should generally adopt "go three and leave two", that is, to harvest the stem of Dendrobium candidum for 3 years or more, leaving less than 3 years old Dendrobium candidum for growth and reproduction. After harvest, attention should be paid to timely spraying protective fungicides to prevent the occurrence of diseases.

According to the current development form of Dendrobium candidum culture, shortening the growth cycle and expanding reproduction are still the key contents. Although it can improve the yield and efficiency of Dendrobium candidum production to a certain extent, the quality can not be guaranteed. This rapid culture method is difficult to ensure the medicinal value of Dendrobium candidum. In view of the above problems, it is suggested that in the future cultivation technology research, we should pay more attention to the quality control and strengthen the study on the biological characteristics of Dendrobium candidum in order to provide a more suitable growth environment.