A method for constructing a germplasm resource bank of Sassafras tzumu from different regions

Abstract

The present invention discloses a method for constructing a non-native germplasm resource bank for Sassafras tzumu, which comprises the following steps: Step (1), site selection: determining the forest land for constructing the non-native germplasm resource bank for Sassafras tzumu; Step (2), forest land cleaning: cleaning the branches, shrubs and weeds in the forest land; Step (3), land preparation and zoning configuration; Step (4), afforestation; Step (5), tending and management. The present invention can solve the problems that the natural Sassafras tzumu forest has a small number of individuals, small genetic variation, and high investment in in-situ conservation.

Description

Technical Field

[0001] The present invention relates to the technical field of protection of Sassafras tsumu germplasm resources. Specifically, it is a method for constructing an off-site germplasm resource bank for Sassafras tsumu. Background Art

[0002] Sassafras tsumu (Hemsl.) Hemsl belongs to the genus Sassafras in the Lauraceae family. It prefers a warm and humid climate and is one of the main excellent fast-growing tree species for afforestation in southern timber forest bases. In existing research, it has been found that the natural forest individuals of Sassafras tsumu are sparsely distributed with very few individuals, and there is a large dispersion in the size and tree age of individuals within the population. In addition, the values of genetic diversity parameters of Sassafras tsumu are lower compared with the woody plants that have been investigated. This indicates that the small number of individuals and scattered distribution may be a genetic characteristic of Sassafras tsumu. Due to the characteristic of a small number of individuals in natural Sassafras tsumu forests, there may be the following defects in constructing a germplasm resource bank for Sassafras tsumu by in-situ conservation methods: the number of individuals within the population is too small, the forest area that needs to be protected in-situ is large, and the investment cost is relatively high. In addition, an off-site germplasm resource bank is a supplement to the in-situ germplasm resource bank and can effectively protect germplasm materials from different sources. Therefore, it is necessary to construct an off-site germplasm resource bank for Sassafras tsumu. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a method for constructing an off-site germplasm resource bank for Sassafras tsumu to solve the problems of large investment in in-situ conservation due to the small number of individuals and small genetic variation in natural Sassafras tsumu forests.

[0004] To solve the above technical problem, the present invention provides the following technical solutions:

[0005] A method for constructing an off-site germplasm resource bank for Sassafras tsumu, comprising the following steps:

[0006] Step (1), site selection: determining the construction forest land for the off-site germplasm resource bank of Sassafras tsumu;

[0007] Step (2), forest land cleaning: cleaning the branches, shrubs and weeds in the forest land;

[0008] Step (3), land preparation and zoning configuration;

[0009] Step (4), afforestation;

[0010] Step (5), tending and management.

[0011] In the above method for constructing an off-site germplasm resource bank for Sassafras tsumu, in step (1), select the lower-middle slope position of the logging slash of Chinese fir forest or broad-leaved forest with sufficient sunlight, gentle terrain, deep soil layer and sufficient water and fertilizer (constructing the germplasm resource bank at the lower-middle slope position grows better than at the upper slope position) as the construction forest land for the off-site germplasm resource bank of Sassafras tsumu.

[0012] For the above method for constructing a distant germplasm resource bank of Sassafras tzumu, the land preparation measures in step (3) include: adopting horizontal strip land preparation with a strip width of 2.6 m; digging hole pits with a size of 50×50×40 cm, and applying 1 kg of compound fertilizer as base fertilizer to each hole pit. The compound fertilizer is a nitrogen-phosphorus-potassium compound fertilizer, and the mass ratio of the three elements of nitrogen, phosphorus, and potassium is 1:1:1.

[0013] For the above method for constructing a distant germplasm resource bank of Sassafras tzumu, in step (3), single-tree planting is carried out in each horizontal strip, and the single-tree spacing is 4 m. If the spacing is greater than 4 m, the forest stand will be closed too late; if it is less than 4 m, the early growth of the plants will be affected.

[0014] For the above method for constructing a distant germplasm resource bank of Sassafras tzumu, in step (3), Chinese fir is mixed with Sassafras tzumu; the mixing mode is inter-plant mixing, that is, one Chinese fir is planted between two Sassafras tzumu; the planting ratio of Sassafras tzumu to Chinese fir is 1:1 - 2. Chinese fir is the main afforestation tree species in the south, and the crown of Chinese fir is relatively small, which is suitable for mixing; when there is no mixing with Chinese fir, the pure stand of Sassafras tzumu has no shade, and the bark is prone to sun cracking and death. Adopting the inter-plant mixing mode and controlling the planting ratio of Sassafras tzumu to Chinese fir to 1:1 - 2 can not only achieve the lateral shading of Chinese fir, but also be more conducive to the growth and hybridization of Sassafras tzumu compared with other modes such as star-shaped mixing and row mixing.

[0015] For the above method for constructing a distant germplasm resource bank of Sassafras tzumu, in step (3), the zoning and configuration method is as follows:

[0016] Sassafras tzumu seedlings are lifted according to provenances or families. Suppose there are N provenances or families in total; M Sassafras tzumu seedlings are randomly taken out from each provenance or each family respectively. The M Sassafras tzumu seedlings from the same provenance or family are bundled into one bundle every m plants, and a total of n bundles are made; corresponding provenance or family labels are hung on each Sassafras tzumu seedling; the n bundles of Sassafras tzumu seedlings from each provenance or family are transplanted into n plots respectively according to the randomized block experiment, so that each plot contains m×N Sassafras tzumu seedlings from N provenances or families at the same time, so that the Sassafras tzumu seedlings of the same provenance or family are replanted in different plots. This can not only effectively avoid the death of a certain provenance or family in a certain plot due to site conditions and other reasons, but also facilitate the observation of the adaptability of each provenance or family to different sites.

[0017] For the above method for constructing a distant germplasm resource bank of Sassafras tzumu, M, N, m, and n are all positive integers, and the value range of n is 5 - 10; evergreen tree species such as Schima superba and / or Cinnamomum chekiangense are planted between adjacent plots as isolation belts. Sassafras tzumu is a deciduous tree species, and Schima superba and Cinnamomum chekiangense are evergreen tree species, which are convenient for distinguishing the isolation belts during investigation.

[0018] For the above method for constructing an off-site germplasm resource bank of Sassafras tzumu, the afforestation method in step (4) is as follows: Afforestation is carried out before the germination of Sassafras tzumu seedlings. It is selected to plant in December to February when the soil is moist after rain. If the planting time of Sassafras tzumu seedlings is earlier than December, the seedlings have not yet shed their leaves at this time, making the planting difficult and the seedlings not easy to survive. If the planting is carried out later than February, the seedlings have already germinated at this time, and the planting survival rate is relatively low.

[0019] For the above method for constructing an off-site germplasm resource bank of Sassafras tzumu, when planting Sassafras tzumu seedlings, first backfill the topsoil; for bare-root seedlings, trim the roots and then dip them in mud before going up the mountain for planting; for container seedlings, remove the containers before afforestation, directly plant with the soil intact, and then tamp and cover with soil; when trimming the roots, use pruning shears to trim the main roots and lateral roots longer than 15 cm to 10 - 15 cm. If the roots are not trimmed, it may cause the phenomenon of coiled roots during planting and affect the growth of the plants. If the main roots and lateral roots are trimmed too short during root trimming, it may result in a low survival rate of the plants. In the present invention, the mud that the roots of bare-root seedlings are dipped in is a mud containing calcium magnesium phosphate fertilizer, which plays an important role in promoting the recovery and growth of the roots of Sassafras tzumu; this mud is made by mixing yellow heart soil with calcium magnesium phosphate fertilizer and adding water, and the volume ratio of yellow heart soil to calcium magnesium phosphate fertilizer is 99:1; the calcium magnesium phosphate fertilizer meets the standard GB20412 - 2006; the weight ratio of yellow heart soil to water is 1:3 - 5.

[0020] For the above method for constructing an off-site germplasm resource bank of Sassafras tzumu, in step (5), the tending method is as follows: Tending is carried out 2 times a year. The first tending is in April - May, removing miscellaneous shrubs and weeds, and fertilizing in combination with tending, applying 2 catties of compound fertilizer per plant; the second tending is in September - October, removing miscellaneous shrubs and weeds; the management method: In the first year of afforestation, set up wire meshes around the afforestation area to prevent animal damage; hang signs for each plot and conduct regular investigations.

[0021] The technical solution of the present invention has achieved the following beneficial technical effects:

[0022] When constructing the off-site germplasm resource bank of Sassafras tzumu in the present invention, the logging sites of Chinese fir forests or broad-leaved forests are used as the construction forest lands for the off-site germplasm resource bank of Sassafras tzumu. The mode of interplanting Chinese fir between plants is adopted to germplasm Sassafras tzumu. By controlling the planting density and the planting ratio of Chinese fir and Sassafras tzumu, and dividing the planting plots of different provenances or families of Sassafras tzumu according to the randomized block experiment method, the Sassafras tzumu seedlings of the same provenance or family are repeatedly planted in different plots, and Schima superba or Cinnamomum chekiangense isolation belts are planted between adjacent Sassafras tzumu plots. Finally, an off-site germplasm resource bank of Sassafras tzumu with good growth and good genetic resource stability is constructed, and the afforestation survival rate reaches more than 95%. Detailed implementation manners

[0023] The method for constructing an off-site germplasm resource bank of Sassafras tzumu in this embodiment includes the following steps:

[0024] Step (1), Site selection: Determine the construction forest land of the Sassafras tzumu off-site germplasm resource bank in the cut-over forest land of Chinese fir in Lishan Forest Farm, Yongfeng County, Jiangxi Province; Select the lower-middle slope position of the cut-over forest land of Chinese fir with sufficient sunlight, gentle terrain, deep soil layer and sufficient water and fertilizer as the construction forest land of the Sassafras tzumu off-site germplasm resource bank;

[0025] Step (2), Forest land cleaning: Clean the branches, miscellaneous shrubs and weeds in the forest land;

[0026] Step (3), Site preparation and zoning configuration;

[0027] The site preparation measures include: Adopt horizontal strip site preparation, with a strip width of 2.6 meters; Dig planting holes of 50×50×40 cm, and apply 1 kg of compound fertilizer (the compound fertilizer is nitrogen-phosphorus-potassium compound fertilizer, and the mass ratio of nitrogen, phosphorus and potassium is 17:17:17) as the base fertilizer for each planting hole; Plant single plants in each horizontal strip, with a single plant spacing of 4m; Adopt mixed planting of Chinese fir and Sassafras tzumu; The mixed planting mode is inter-planting, that is, plant one Chinese fir between two Sassafras tzumu; The planting ratio of Sassafras tzumu to Chinese fir is 1:1;

[0028] Dig out the seedlings of Sassafras tzumu according to provenance and family; Assume that the number of provenances or families of Sassafras tzumu in the Sassafras tzumu off-site germplasm resource bank is N, then each provenance or family of seedlings is bundled into one bundle every m plants, and a total of n bundles are bundled; Hang the labels of the corresponding provenance or family on each Sassafras tzumu seedling; Transplant the n bundles of Sassafras tzumu into n plots according to the randomized block experiment respectively, and plant m×N seedlings of Sassafras tzumu from different provenances or families in each plot. In this embodiment, the randomized block experiment is used to divide the seedlings of Sassafras tzumu of the same provenance or family and replant them in different plots. Specifically, in this embodiment, 50 seedlings of Sassafras tzumu are randomly selected from each provenance or family, bundled into one bundle every 5 seedlings, and the labels of provenance and family are hung. A total of 10 bundles of Sassafras tzumu seedlings of each provenance or family are bundled; Transplant the 10 bundles of Sassafras tzumu seedlings of a certain provenance or family into 10 different plots according to the randomized block experiment, then a bundle of 5 Sassafras tzumu seedlings of this provenance or family is planted in one plot; Transplant the seedlings of Sassafras tzumu of other provenances or families into the above 10 different plots in the same way, so that each plot contains the seedlings of Sassafras tzumu of all provenances or families, and at the same time, the seedlings of Sassafras tzumu of one provenance or family are replanted in 10 different plots, which can not only effectively avoid the death of a certain provenance or family due to site conditions and other reasons in a certain block, but also facilitate the observation of the adaptability of each provenance or family to different sites; Plant Schima superba or Cinnamomum chekiangense as an isolation belt between two adjacent plots;

[0029] Step (4), afforestation; Afforestation is carried out before the germination of Sassafras seedlings. Select December for planting when the soil is moist after rain. When planting Sassafras seedlings, first backfill the topsoil. In this embodiment, after trimming the roots of bare-root seedlings, dip them in mud and then plant them on the mountain. When trimming the roots, use pruning shears to trim the main roots and lateral roots longer than 15 cm to 10 - 15 cm. The mud that the roots of bare-root seedlings are dipped in is mud containing calcium magnesium phosphate fertilizer, which plays an important role in promoting the recovery and growth of Sassafras roots. This mud is made by mixing yellow heart soil, calcium magnesium phosphate fertilizer and adding water. The volume ratio of yellow heart soil to calcium magnesium phosphate fertilizer is 99:1. The calcium magnesium phosphate fertilizer meets the standard GB20412 - 2006. The weight ratio of yellow heart soil to water is 1:4.

[0030] In some other embodiments, container seedlings can also be used for afforestation. Remove the containers before afforestation with container seedlings, and tamp and cover the soil after planting.

[0031] Step (5), tending and management; The tending method is: tend 2 times a year. The first tending is in April - May, remove miscellaneous shrubs and weeds, and apply compound fertilizer at 2 catties per plant in combination with tending. The second tending is in September - October, remove miscellaneous shrubs and weeds. The management method: In the first year of afforestation, set up mesh sheets around the afforestation area to prevent animal damage. Hang signs for each plot and conduct regular investigations.

[0032] Using the method for constructing Sassafras germplasm resources in different places of this embodiment, the afforestation survival rate reaches 97.3%, and finally a constructed Sassafras germplasm resource bank with good growth and good genetic resource stability is constructed.

[0033] Obviously, the above embodiments are merely examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or alterations derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A method for constructing a germplasm resource bank of Sassafras tzumu from different regions, characterized in that, It includes the following steps: Step (1), site selection: Determine the forest land for constructing the off-site germplasm resource bank of Sassafras tzumu. Step (2), forest land cleaning: Clean the branches, shrubs and weeds in the forest land. Step (3), site preparation and zoning configuration; The method of zoning configuration is as follows: Lift Sassafras tzumu seedlings according to provenance or family. Assume there are N provenances or families in total; Randomly select M Sassafras tzumu seedlings from each provenance or each family. Bundle the M Sassafras tzumu seedlings from the same provenance or family into one bundle every m plants, and a total of n bundles are made; Hang the labels of the corresponding provenance or family on each Sassafras tzumu seedling; Transplant the n bundles of Sassafras tzumu seedlings from each provenance or family into n blocks respectively according to the randomized block experiment, so that each block contains m×N Sassafras tzumu seedlings from N provenances or families at the same time; M, N and n are all positive integers, and the value range of n is 5-10; Plant Schima superba or Cinnamomum chekiangense between adjacent two blocks as an isolation belt. Step (4), afforestation Step (5), tending and management 2. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 1, wherein In step (1), select the lower slope position of the clear-cut area of Chinese fir forest or broad-leaved forest with sufficient sunlight, gentle terrain, deep soil layer and sufficient water and fertilizer as the forest land for constructing the off-site germplasm resource bank of Sassafras tzumu.

3. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 1, characterized in that, The site preparation measures in step (3) include: Adopt horizontal strip site preparation, with a strip width of 2.6 meters; Dig planting holes with a size of 50×50×40 cm, and apply 1 kg of compound fertilizer as base fertilizer for each planting hole. The compound fertilizer is nitrogen-phosphorus-potassium compound fertilizer, and the mass ratio of nitrogen, phosphorus and potassium is 1:1:

1.

4. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 3, characterized in that, In step (3), plant single plants in each horizontal strip, and the single plant spacing is 4m.

5. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 1, wherein, In step (3), mix Chinese fir with Sassafras tzumu; The mixing mode is interplanting, that is, plant one Chinese fir between two Sassafras tzumu; The planting ratio of Sassafras tzumu to Chinese fir is 1:1-2.

6. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 1, wherein The afforestation method in step (4) is: Afforest before the germination of Sassafras tzumu seedlings, and select to plant in December to February when the soil is wet after rain.

7. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 6, wherein When planting Sassafras tzumu seedlings, first backfill the topsoil; For bare-root seedlings, trim the roots and then dip them in mud before going up the mountain for planting; For container seedlings, remove the containers before afforestation, directly plant them with the soil and then tamp and cover the soil; When trimming the roots of bare-root seedlings, use pruning shears to trim the main roots and lateral roots with a length greater than 15 cm to 10-15 cm; The mud for dipping is made by mixing yellow heart soil with calcium magnesium phosphate fertilizer and adding water; The volume ratio of yellow heart soil to calcium magnesium phosphate fertilizer is 99:1; The weight ratio of yellow heart soil to water is 1:3-5.

8. The method for constructing a Sassafras tzumu germplasm resource bank in different regions according to claim 1, wherein, In step (5), the tending method is: Tend 2 times a year. The first tending is in April-May, remove shrubs and weeds, and apply fertilizer in combination with tending, applying 2 catties of compound fertilizer per plant; The second tending is in September-October, remove shrubs and weeds. Management method: Build wire meshes around the afforestation land in the first year of afforestation to prevent animal damage; Hang signs on each block and conduct regular investigations.