The seeds collected from the mother trees had better seed quality, seedling quality and afforestation effects than the ordinary stand seeds. (a) Seed quality In 1979, it was the seed year of Larix principis-rupprechtii. Northern Hebei Province is generally well-established. After the germination contrast test, the germination potential of the mother tree was 34.1 and 36% higher than that of the timber forest and commercially acquired seeds, respectively; the germination rate of the mother tree was 19.8 and 25.3% higher than that of the timber forest and the commercially purchased seeds, respectively (see 2- 4 tables). In addition, according to the sampling comparison of 5 forest farms in the Mengzi Forestry Bureau of Hebei Province, the germination potential of the mother tree seeds is 27 to 40% higher than that of general commodity seeds, and the germination rate is 18 to 36% higher. Table 2-4 Comparison of seed quality of Larix principis-rupprechtii Seed category Germinating% Germination rate% Goodness Note Mother tree seed Natural forest seeds 73.7 43.6 77.7 55.7 96.0 96.0 Produced in Longtoushan Forest Farm Timber seed Timber seed Timber seed average 34.3 45.7 38.7 39.6 53.7 64.7 55.3 57.9 98.2 98.8 94.8 97.3 Other forest farms Commodity seeds Commodity seeds Commodity seeds Commodity seeds average 33.6 47.7 36.7 33.3 37.7 47.7 59.3 41.7 60.7 52.4 93.9 99.6 95.0 98.2 96.6 Commercial acquisition (B) the quality of seedlings The base diameter and seedling height of seedlings cultivated from seedlings of mother trees were higher than those of ordinary seedlings by 10% and 32%, respectively. Table 2-5 Comparison of effects of different seedling seedlings Kinds of seedlings Base diameter (M) ratio(%) Seedling height (M) ratio(%) Mother trees offspring 0.49 110 32.5 132 Timbers 0.44 100 24.6 100 (3) Effect of afforestation In the late 1970s and early 1980s, multi-year and multi-site comparisons of seedlings and common seedlings established in the original Longtoushan Forest Farm and Yinhe Forest Farm showed that the genetic gain was greater than 10% when seedlings were planted with mother trees. The 5,000 mu of northern China larch mother trees at the base of improved seedlings at the Longtoushan seedlings plant produced 29,565 K of seed from 1980 to 2001, and afforested an area of ​​65,000 hectares, with a gain of 250 million yuan. The establishment and management of the second seed park I. The significance of establishing a seed park Orchard generally refers to the use of selected excellent trees as a material, and the use of a reasonable configuration of the forest land to produce superior seeds. The purpose of seed orchard management is to continuously improve the genetic quality of seeds, ensure the stable production of high yield seeds, and overcome the blindness in the production of forest seed. The 21st century is a period of fundamental transformation from traditional forestry to modern forestry and ecological forestry. Accelerating the construction of high-yield and high-yield forests is the only way to increase production per unit area, shorten production cycle of forest resources, improve wood quality, and reduce production costs. It is also a long-term plan for timber production in China. Forest seed is the material basis for the construction of high-quality fast-growing and high-yielding forests, and seed orchards are the main way to provide superior seeds for sexual reproduction. Seeds produced by the orchards have genetic gains greater than their mother trees or general seed production bases. If we correctly adhere to multi-generation cycle selection, the genetic quality of seed orchards will increase from generation to generation. Larix principis-rupprechtii is dominated by sexual reproduction. It is a fast-growing tree species with wide adaptability and strong cold resistance in northern China. It is also the main tree species for the establishment of fast-growing and high-yield forests. In addition to the normal growth of afforestation in mountainous regions such as Hebei and Shanxi Provinces, Larix principis-rupprechtii has been able to grow well in the entire “Three North†region after many years of regional afforestation tests, even exceeding the local tree species in the Fukang region of Xinjiang (see table). 2-6). Table 2-6 Comparison of growth of Larix principis-rupprechtii in different places Introduction area north latitude High pull m average temperature species Forest age Breast diameter cm Tree height m source East Longitude average The annual average average The annual average Xinjiang Fukang Tianchi Forest Area 43°51′～～ 87°50′ 1600 ~~ 1940 2～2.8°C Xinjiang Larch 12 4.3 0.36 5.2 0.43 Xinjiang Institute of Forestry and Soil Sciences Xingan Larch 12 1.2 0.11 2.5 0.22 Larix principis 12 4.4 0.37 5.0 0.4 Larix olgensis 12 5.1 0.42 6.1 0.5 The establishment of the Larix principis-rupprechtii orchard can provide high-quality seed for the afforestation industry, which is of great significance for advancing the pace of eco-environmental construction in the northern region and stimulating regional economic development. II. Conditions and zoning established by the orchard (A) Seed Park Site Selection: The orchard is a permanent breeding base and must be intensively managed. Therefore, the conditions of the site not only affect the yield and quality of seeds, but also increase operating costs due to poor conditions and inconvenient operations and management. In order to cultivate good seeds better, seed orchards are best placed in places where natural conditions are relatively good and are easy to operate and manage. At the same time, they must have environmental conditions that are conducive to the normal growth and flowering of the tree species, and ensure that the seeds produced are adapted. Afforestation in the area. The selection of the North China larch orchard garden mainly considers the following factors: 1. Temperature and altitude conditions: The annual average temperature is above 1°C, the growth period is not less than 100 days, the accumulated temperature above 10°C is 2500°, and the altitude is about 1000-1200m. 2. Topography and soil conditions: The terrain with open terrain, sunny leeward, water source, and irrigation area should be selected. The soil layer is deep, the soil is fertile, and the air permeability and drainage are good. The slightly acidic soil is most suitable. If you choose a mountainous area, the slope should be below 20o, and you need to build terraces; require concentrating and connecting, larger area, easy to intensive operations and mechanized operations. 3. Pollen segregation conditions: There are no common stands or similar species within 200 meters around the site. It is best to have good natural isolation conditions, and other species of evergreen conifers can also be used as a barrier, with a bandwidth of 10 to 20 meters. 4, convenient transportation, easy management and protection. (II) Division of the Seed Garden The establishment of a seed orchard should not only consider the yield and quality of seeds, but also consider the application, promotion scope, and objective evaluation of expected benefits in the future. To this end, the establishment of a seed orchard should be based on the management objectives of the system zoning. The base of improved seedlings of Larix principis-rupprechtii in the Longtoushan seedlings and nursery is divided into the following functional areas: 1, breeding resources collection area: Resource collection is one of the important contents of the construction of seed gardens, and its purpose is to collect and preserve excellent germplasm resources. Its main function is to prevent the original germplasm from being damaged and lose its potential for reuse by transferring the excellent foreign germplasm resources to local preservation and storing the local excellent germplasm resources; according to genetic information and seed orchards To meet the needs of development, timely adjust the storage of the target resources, and use the nearest available resources once they are used, so as to ensure timely and sufficient input of excellent germplasm resources into the seed production area. Up to now, the Mengzi Forestry Bureau has collected nearly 600 excellent resources, and each resource has preserved 5-10 strains. These resources mainly come from Hengshan in Shanxi Province, Xiaowutai in Zhangjiakou, Hebei Province, Fuping County, Fengning County, Fuping County, Dagushan in Liaoning Province, Chifeng in Inner Mongolia, and Linkou County in Heilongjiang Province. Among them, Larix principis-rupprechtii is the main one, and some Larix olgensis, Larix gmelinii, Larix gmelinii and hybrid larch are also found. These germplasm resources provide material guarantees for broadening the breeding channels and promoting the development of seed orchards to higher generations. 2. Grafting preparations: Grafting and supplementing areas are places where clonal plants or cuttings are provided for the establishment of a garden, and are part of the orchard. The purpose is to transfer the grafted plants directly from the graft preparation area to the production area by serial number when the grafted mother tree in the production area is dead or vacant. It is also possible to collect the seedlings from the grafted seedlings in the seed production area. . According to the need of production, grafting can also be carried out on the grafted preparation area according to the serial number. In the following year, the grafted plants that have survived can be directly used to establish the seed production area according to the configuration map. In addition, the patching zone also has the function of saving resources. Since the grafted preparation area does not belong to the seed production area, the density of planting can be slightly larger, 50×50M or 50×100 cm. Because it can be reused, the area does not need to be too large. The Yonglongshan seedlings plant improved seedlings area is 37.5mu, and the planting density is 50×50cm, which is a good guarantee for achieving uniform and uniform seed production areas. 3, genetic determination of forest area: Genetic determination of forests is an important part of the construction of seed gardens. It can be said that without the determination of forests, there is no way for the development of seed orchards. Without the determination of forests, there will be no seed orchards. The two are inextricably linked. The test forests are mainly progeny test forests and clonal test forests. The test forest established with the seedlings of the clones to be tested is called the progeny test forest; the test forest established with the clonal seedlings of the test clones is called the clone test forest. The genetically determined forests of Larix principis-rupprechtii are mainly progeny-determined forests, and some of them are clonal forests. In the progeny assay, it can also be subdivided into different forms such as open pollination progeny assays, multi-lineage pollination progeny assays, diploid hybrid assays, and cross-line assays. The main purpose of progeny measurement is to identify the hereditary and genetic advantages such as parental adaptation and productivity through the performance of offspring. As of 2002, the base of fine seedlings for the Longtoushan seedlings plant had established nearly 1050 acres of various types of forests in the forest management area of ​​Mengzi. In addition, in the period from the early 1980s to the 1990s, the Yongjiashan Seedlings Planting Base of Larix principis-rupprechtii had been under the unified organization of the Hebei Provincial Academy of Forestry and successively in the paddock of Bashang, Chengde County, Yanshan Mountain and Taihang Mountainous Area. Pingxian County has set up multi-point forests, involving five state-owned forest farms and two villages in four counties with a total of 13 test sites, accumulatively afforesting 253.5 hm2. After investigation and analysis, the gains can reach 15% or more in 10 years after afforestation. Level. These measurable forests are the material basis and information platform for the development of this elite seed base for high generations. Over time, these forests will play an even more important role. In each progeny measurement, open pollination progeny measurement, multi-lineage pollination progeny measurement, double-row hybridization assay, and side-crossing line assay were included. These progeny assays have been used by Lin You to establish a modified garden. With the continuous improvement of the construction materials, these determination forests will play an important role. In order to assess the clones that have been put into construction, the first batch of excellent seedlings bases of the Longtoushan seedlings plant established the first batch of Larix principis-rupprechtii half-sib and the full compatriot progeny forest in 1980, and many investigations and analyses have been conducted so far. The progeny test results showed that both the free pollination progeny and the pollination progeny of the Larix principis-rupprechtii seed orchards will gain significant genetic gain. Among them, the open-pollinated progeny were born at 17 years old, and the obtained DBH, tree height, and volume gain were about 9%, 13%, and 27%, respectively, and the yield increase was significant (Table 2-7). Table 2-7 Analysis Results of Excellent Tree Progeny Measurement Results Categories and indicators 138 families (17 years old) 30 hybrid combinations (11 years old) Family average Control For control% Family average Control For control% Breast diameter M 10.2 9.38 108.7 5.94 5.2 114 Tree height m 10.16 8.99 113 5.32 5.06 105 Volume m3 49327.76 38769.12 127.2 7362.71 5581.08 132 Note: The results of the 1995 and 1989 surveys were 138 families and 30 cross combinations. In order to explore the genetic control model for the growth traits of Larix principis-rupprechtii and provide a theoretical basis for the future orientation improvement, the Longtoushan seedling plant improved seed base was selected in the seed garden of the 1977, 1984 and 1993 grafted type in 2000. A male paternal clone, 10 female clones, were designed according to the test line mating and obtained 50 full-sib family seeds, using the open pollinating seeds of the paternal clone as a control (see the figure below). ♀♂ 205 98 55 120 49 59 44 43 52 53 1 × × × × × × × × × × 2 × × × × × × × × × × 3 × × × × × × × × × × 4 × × × × × × × × × × 5 × × × × × × × × × × Crossbreds Sowing in 2001, in 2002 to create a descendant test forest. The field is designed to be 5-10 strains of different strains of the plot and repeat six times. At the same time, it also created the hybrid larch cedar forest introduced by the Provincial Academy of Forestry from Qingshan Forest Farm in Linkou County, Heilongjiang Province, and the progeny forest of 40 fine families in the orchard, accounting for more than 90 acres. This batch of offspring Lin will certainly provide important genetic information to broaden the genetic improvement of L. principis-rupprechtii and advance genetic improvement. 4, scion: Whether it is the use of asexual seedlings for afforestation or the establishment of seed orchards, it requires a large number of species. In order to continuously provide a large number of high-quality cuttings, the main approach is to establish a scion plot. The scion nursery is a place for providing vegetative propagation materials with high efficiency and scale. Together with the seed orchards, it constitutes the main form of propagation of improved varieties of forest trees. Scion nursery has the following advantages: V1w facilitates intensive management, good quality of cuttings, high yield, and low cost. V2w is built with selected fine materials and genetic quality is guaranteed. Because v3w is a centralized plant, the operation is convenient and the reproductive survival rate is high. V4w is easy to control pests and diseases. Storage Nets For Toys,Corner Net For Toys,Teddy Storage Net,Hanging Storage Net Suzhou Yitengjia Extruded Net Packaging Co., Ltd. , https://www.ytjextrudednet.com
"The cultivation technology of fast-growing and high-yield forest of North China larch"
IV. Analysis of Management Effects of Mother Trees