China is one of the oldest agricultural countries in the world. It is rich in cultivated and wild plant resources and is considered to be one of the centers of genetic diversity of cultivated plants. According to preliminary statistics, there are more than 600 kinds of important crops in China, including more than 30 kinds of food crops, about 90 kinds of cash crops, more than 120 kinds of vegetables, more than 140 kinds of flowers, about 150 kinds of fruit trees, about 50 kinds of pastures, and about 20 kinds of green manures. . There are 237 species that have originated in our country or have been cultivated in prehistoric crops. However, due to rapid population growth and other reasons, China’s agricultural plant resources have suffered serious human damage and erosion. For example, wild rice, wild soybeans, and wheat close wild plants have been difficult to find in their original habitats; the number of plant species that indigenous species invade and grow is long. The decrease, coupled with the reduction of a large number of natural enemies of pests and diseases, aggravated crop diseases and pests; large-scale popularization of agricultural mechanization and improved varieties led to the elimination of a large number of local breeds. The germplasm foundation of the backbone varieties of many crops grown in production is becoming increasingly narrow, and there are hidden dangers of genetic fragility and sudden devastating diseases. For this reason, in the past 20 years, as a source of broadening the genetic basis of breeding, the collection, preservation and research of germplasm resources have been highly valued by relevant departments and have made remarkable achievements. The instrument used in the preservation of germplasm resources is an automatic counting instrument.
Nowadays, the preservation and utilization system of crop germplasm resources has been initially established. According to the biological characteristics of crop reproduction methods, the conservation strategy of combining the in-situ conservation of germplasm resources with ex situ conservation is implemented. In situ conservation refers to the establishment of protected areas or protected areas in the original ecological environment of plants, so that important crop wild species and wild relatives self-proliferate in situ to preserve germplasm. Ex situ conservation, ie preservation of germplasm outside the origin of the plant, including preservation of seed bodies in low-temperature germplasm banks, plant preservation in germplasm nurseries, tissue culture in in vitro genebanks Things such as preservation.
There are many kinds of seed preservation technologies, such as cryogenic storage technology. The use of low-temperature germplasm banks to preserve seeds, in addition to the low storage temperature, as seeds for germplasm preservation, must also be subjected to a series of storage pretreatments such as viability testing, drying and dehydration, and sealed packaging. In addition to the in vitro germplasm conservation technology, many plant germplasm resources cannot be conserved through seed storage for the purpose of resource conservation. For example, coconuts, oil palms, and coffee are recalcitrant seeds that may not be able to tolerate dry dehydration and cryogenic storage, or crops. Without seeds, this kind of plant cannot be stored in the low-temperature library. It can only be preserved in the field through plants or roots, tubers and other live methods through the germplasm nursery. It includes tissue culture techniques and ultra-low temperature preservation techniques.
With the constant recognition of the protection of germplasm resources, the state has continued to deepen its research on germplasm resources. Since the 7th Five-Year Plan period, collection and preservation of crop germplasm resources have been included in national scientific and technological research projects and were completed in 1984 in China. The National Germplasm Bank No. 1 Library (later changed to the National Germplasm Distribution Exchange Bank) was designed and constructed by itself. In 1986 and 1992, the National Long-term Bank and the Qinghai Fufang Long-term Bank were built. It can be seen that the state attaches importance to the preservation of germplasm resources. Through the country's scientific and technological research, China has entered a new stage in research on the conservation of seed quality and resources, and has established a set of advanced management and seed pre-processing technology in the country's library. Through systematic research, the safe and effective drying conditions and methods for various crops have been solved. Research on the viability testing methods for more than 80 varieties of crops cultivated and seeds of wild relatives provided an effective life force detection technique for the storage of wild resources and difficult-to-sprout seeds. In order to ensure the long-term safe storage of 300,000 stored seeds in the national repository, a follow-up monitoring study of stored seeds was conducted.
In the past 20 years, despite the rapid development of the conservation of crop germplasm resources in China, it should be noted that there are still many gaps in the conservation of germplasm compared with foreign countries, and the following countermeasures must be taken.
1. Properly solve the operating expenses of the germplasm bank (pen) and stabilize the germplasm conservation team
The collection and preservation of germplasm resources is a great cause for future generations. The collection of resources for storage (reservoir) is a precious material asset of our country and can be regarded as a strategic resource for the sustainable development of agriculture in China in the next century. However, it is understood that the vast majority of genebanks (plants) currently have no fixed special operating expenses, and there are also poor operating expenses. Therefore, it is recommended that the state-level germplasm bank (garden) be responsible for the central government's finances, and that the local medium-term bank should be responsible for the local fiscal affairs, and properly handle the funding for the operation of the genebank. It needs to be emphasized that the operating expenses should include not only the hydroelectric and refrigerant charges for the chiller units, but also the costs for seed storage, monitoring, distribution and renewal, and data management, as well as the basic research costs for necessary safety preservation technologies. Because the preservation of germplasm is a systematic foundation work, any problems in that link may lead to the risk of loss of germplasm resources.
2. Establish a systematic plan for the preservation and utilization of germplasm resources in China
The preservation of germplasm is not a goal. The important thing is how to make full use of it to serve our agricultural production. Therefore, on the one hand, it is necessary to establish an authoritative agency for germplasm resources to coordinate the organization of the conservation of plant genetic resources throughout the country and to reduce unnecessary duplicated construction of conservation facilities. On the other hand, it is necessary to establish several comprehensive resource workstations for species resources in regions of different climatic and ecological types as in the United States, India, and other countries. The workstation is not only responsible for the medium-term preservation and distribution center of some crop germplasm resources, but also responsible for the newly introduced, newly-collected germplasm evaluation and appraisal, breeding superiority, and updating of stored materials. This will not only be beneficial to stabilizing the team, but also build China's germplasm preservation and utilization operating system on the basis of these preservation facilities and workstations, so that various excellent resources can be fully utilized.
3. Strengthen germplasm resources legislation and policy research
Although China has formulated some policies on the exchange of germplasm resources, the parents are still weak in legislation and policy research. Therefore, it is necessary to strengthen the formulation of legislation and policies for germplasm resources, which can make full use of germplasm resources and ensure that strategic resources are not lost to foreign countries. In addition, it is necessary for the state to formulate relevant laws and regulations requiring that resources introduced must be sent back to the state for long-term storage; for breeding units funded by the state, they should also request that their parental materials be sent back to the state for long-term storage. At the same time, it should promote the voluntary resources of the relevant units to the national long-term storage, because this is an important principle for the safe preservation of resources.
4. Research on germplasm safety preservation techniques and methods
The preservation of germplasm resources in storage (gardens) can only be said to temporarily avoid man-made or natural disaster damage and be protected in other places. However, during the preservation of germplasm in the germplasm pool, the seed viability will still decline and genetic changes will be induced. Therefore, to strengthen the monitoring of vitality and genetic changes, as well as germplasm renewal standards and methods of breeding, in order to ensure the long-term safe preservation of germplasm resources. For China's unique and precious wild relatives, such as wild rice, wild soybeans, wild rhesus monkeys, and wild vegetables, consideration should be given to the construction of wild relatives, conservation sites, or protected areas. At the same time, research on strong cryogenic preservation techniques should be conducted to form the original germplasm resources for crops. A set of safety preservation strategic plans for conservation in the environment, heterotopia and ex situ conservation.
5. Speed ​​up the construction of germplasm information network
Although the China Crop Germplasm Resources Information System (CGRIS) has been completed, due to the lack of national networking, germplasm information can only be transmitted via floppy disks or mail, and the scope of application is limited. Therefore, a nationwide germplasm information network system should be established in the near future with various crop germplasm resources, genetic breeding, biotechnology research units, conservation centers, germplasm exchange, seed companies, and production departments to expand germplasm resources information. Use the range to increase the utilization efficiency of germplasm information. At the same time, the research of germplasm information application technology, such as data acquisition technology, image automatic identification technology, data analysis model and method, and network technology, should also be strengthened to promote the full use of germplasm resources.