1. 广义的引种，是指把外地或国外的新作物、新品种或品系，以及研究用的遗传材料引入当地。狭义的引种是指生产性引种，即引入能供生产上推广栽培的优良品种。

1. In the broad sense, introduction of new species refers to the introduction of new crops, varieties, or strains from other regions or foreign countries, as well as genetic materials for research into the local area. In the narrow sense, introduction of new species refers to the production-oriented introduction, that is, introducing high-quality varieties that can be promoted and cultivated for production purposes.

2. 包括品种的选育历史、生态类型、遗传性状和原产地的生态环境及生产水平等，通过比较分析后，搜集与当地生育期，生态类型和生产要求相近的品种类型。

2. Including the breeding history of the variety, ecological type, genetic traits, as well as the ecological environment and production level of the original place, after comparative analysis, collect variety types that are similar to the local growth period, ecological type, and production requirements.

3. 引种是传播病虫害和杂草的一个重要途径，一定要严格遵守种子检疫制度，加强种子的检疫工作。

3. Introduction of new plant species is an important route for the spread of plant diseases, pests, and weeds. It is essential to strictly comply with the seed quarantine system and strengthen the quarantine work of seeds.

4. 一个品种引进新区后，由于生态条件的改变，往往会加速其变异，必须进行选择，保持种性或培育新品种。

4. After introducing a variety to a new area, due to the change in ecological conditions, it often accelerates its variation. Selection is necessary to maintain the strain or to cultivate a new variety.

5. 对新引进的品种，必须先在小的面积上进行试种观察，初步鉴定其对本地区生态条件的适应性和直接在生产上利用的价值。

5. For new varieties introduced, it is necessary to first conduct trial planting and observation on a small area to preliminarily assess their adaptability to the local ecological conditions and their direct value in production.

6. 对于表现符合要求的品种材料，进一步作更精确的比较鉴定，经

6. For variety materials that meet the required standards, further precise comparative identification should be conducted.

7. 三年评比试验后，选出表现突出的品种参加区域试验，再生产示范，繁殖、推广。

7. After a three-year evaluation and trial, outstanding varieties are selected to participate in regional trials, followed by production demonstrations, breeding, and promotion.

8. 对于初步肯定的引进品种，还应做好栽培试验，以明确适宜的栽培条件或关键性措施，做到良种结合良法进行推广。

8. For varieties preliminarily approved for introduction, it is also necessary to conduct cultivation experiments to clearly define suitable cultivation conditions or key measures, and to promote the combination of high-quality varieties with high-quality methods.

9. 品种审定是在几年多点科学试验结果上评定的，只有通过审定的品种，才能推广应用。没有正式审定的品种，不要乱引和随意大面积种植。购买种子要"三证一照"，并要发货票。

9. Variety approval is based on several years of scientific trial results, and only varieties that have passed the approval can be promoted and applied. Do not randomly introduce or arbitrarily plant a large area of varieties that have not been officially approved. When purchasing seeds, obtain the "three certificates and one permit" and ensure that a receipt is issued.

10. 优良品种的引、鉴、繁、推，一定要多点试验，试验目的在于看该品种是否适合当地的气候条件、生产特点、栽培模式和抗逆性、丰产性、优质性等。这样才易站住脚。

10. The introduction, identification, propagation, and promotion of high-quality varieties must involve more testing. The purpose of the testing is to determine whether the variety is suitable for the local climatic conditions, production characteristics, cultivation patterns, resistance to adverse conditions, high yield, and quality. Only in this way can it establish a firm footing.

11. 引种时要防止带进新的病、虫、草，必须按植保检疫程序办理。如果在疫区引种，一定要遵守检疫制度，防止属检疫对象的病害、虫害和杂草在本地蔓延。凡调出调入的种子包括南繁回来的种子，都要经过植物检疫员进行检疫，签登证书后方可发运。

11. When introducing new plants, it is necessary to prevent the introduction of new diseases, pests, and weeds, and it is mandatory to proceed according to the plant protection quarantine procedures. If introducing plants in an epidemic area, it is essential to strictly comply with the quarantine system to prevent the spread of diseases, pests, and weeds that are objects of quarantine locally. All seeds that are sent out or received, including those returned from the southern breeding areas, must undergo inspection by a plant quarantine officer and obtain a certificate of inspection before they can be transported.

12. （introduction of exotic trees）

12. Introduction of Exotic Trees

13. 将外区优良树种引入本区，通过试验，择其优良者加以繁殖推广的工作。每个树种在自然条件下都有一定的自然分布范围。当某一树种在该树种的自然分布区内生长时，称为乡土树种；当栽植到自然分布区外时，称为外来树种。从国内外引进有价值的树种，对于丰富树种资源，提高木材产量，提供新的林副产品，发挥森林保护自然和美化环境等都有很大的意义。

13. The work of introducing high-quality tree species from other regions into this area, selecting the superior ones through experiments, and propagating and promoting them. Each tree species has a certain natural distribution range under natural conditions. When a tree species grows within its natural distribution range, it is called a native species; when planted outside its natural distribution range, it is called an alien species. Introducing valuable tree species from home and abroad is of great significance for enriching tree species resources, increasing wood production, providing new forest by-products, and playing a role in protecting nature and beautifying the environment.

14. 英国引种工作开展较早，9世纪已引入许多外来树种。澳大利亚、新西兰和美国等都在19世纪50年代开始较大规模的引种。现在辐射松、花旗松、锡加云杉、桉树等已在许多国家广泛栽植，成为重要用材树种。原产中国的水杉、银杏等也为不少国家引栽。

14. The work of introducing species in Britain was carried out early on, with many exotic tree species being introduced as early as the 9th century. Australia, New Zealand, and the United States all began large-scale introductions in the 1850s of the 19th century. Now, radiata pine, sugar pine, Sitka spruce, eucalyptus, and other species are extensively planted in many countries and have become important timber species. Species native to China, such as Metasequoia and Ginkgo, have also been introduced and planted in many other countries.

15. 中国在20世纪初前后引进桉树、刺槐、三叶橡胶；30年代引进加勒比松、湿地松、火炬松等；1949年后，林木引种发展迅速。原产于澳大利亚等地的桉树在南方各省大量栽种，成为重要的用材、薪炭和绿化树种。原产澳大利亚、缅甸、马来西亚等地的木麻黄，在中国南起北部湾、北至浙江温州这一漫长的海岸线上，生长茁壮。长江以南广大地区引种的湿地松、火炬松、加勒比松生长快，干形好。欧美杨（欧洲黑杨与美洲黑杨的杂种）在华北、东北南部、西北东南部、长江下游江淮、江汉地区得到了大量的推广，成为重要的造林树种。刺槐原产美国东部阿帕拉契亚山区等地，现在已广泛栽植于华北、东北中部以南、西南、西北东南部、华东等地，成为这些地区水土保持、固沙造林、“四旁”绿化和薪炭林重要树种。此外，经济树种中的橡胶、油棕、咖啡、金鸡纳、油橄榄等在中国南方一些地区表现较好。与此同时，中国的不少优良树种在国内也得到推广。樟子松是大兴安岭及呼伦贝尔等地的乡土树种，现在辽宁章古台、内蒙古呼和浩特、陕西榆林等地都有引种，生长良好，很可能成为这一干旱地区的重要固沙造林和荒山造林树种。再如水杉、泡桐等树种的栽种区现已扩展到北京和山西等地。

15. At the beginning of the 20th century, China introduced eucalyptus, acacia, and three-leaf rubber trees; in the 1930s, species such as Caribbean pine, wetland pine, and torch pine were introduced; after 1949, the development of tree species introduction was rapid. The eucalyptus, native to Australia, was planted extensively in the southern provinces, becoming an important timber, fuelwood, and landscaping species. Casuarina, native to Australia, Myanmar, and Malaysia, grows robustly along the long coastline from the Beibu Gulf in the south to Wenzhou, Zhejiang in the north. Wetland pine, torch pine, and Caribbean pine introduced in the vast areas south of the Yangtze River grow fast and have good trunk shapes. Populus euramericana (a hybrid of European black poplar and American black poplar) has been widely promoted in the north of North China, southern South China, southeastern North China, the lower reaches of the Yangtze River and the Huai River region, becoming an important forestation species. Acacia, native to the Appalachian Mountains in eastern America, is now widely planted in the north of North China, central South China, southwest, southeastern North China, and East China, becoming an important species for soil and water conservation, sand fixation, peripheral greening, and fuelwood forests. In addition, rubber, oil palm, coffee, cinchona, olive, and other economic tree species have performed well in some southern regions of China. At the same time, many excellent tree species in China have also been widely promoted domestically. Larch, a native species in the Daxing'anling and Hulunbeier areas, is now introduced in Liaoning Zhanggutai, Hohhot, Inner Mongolia, Yulin, Shaanxi, and grows well, possibly becoming an important species for sand fixation and barren mountain afforestation in this arid region. For example, the planting areas of species such as Metasequoia and Paulownia have now expanded to Beijing and Shanxi.

16. 一个树种的自然分布范围，是和种的发生历史、适应能力和传播条件密切相关的。南北半球树种很不一样。松科树种，包括松、云杉、冷杉、黄杉、落叶松、金钱松、铁杉、雪松、油杉、银杉等各属，在北半球分布广泛，是许多地区植物群落中的优势种群。在松属中除南亚松稍稍跨越赤道，到达印度尼西亚的苏门答腊岛以外，其他树种在南半球没有自然分布。但是，针叶树中南洋杉科的南洋杉和贝壳杉两属中，除个别种稍稍北跨赤道，到达印度尼西亚、菲律宾和马来半岛外，都分布在南半球。引种实践证明，原产北半球的多种松树引栽到南半球后，完全能适应该地区的气候土壤条件，生长茂盛。这表明一些树种不能超越现有分布区，很可能是受海洋、山岭阻隔的结果。在一些地区没有某些树种分布，也可能是历史上气候变迁的结果。如水杉，现在的自然分布区仅局限于中国湖北、四川、湖南三省交接的狭窄地带。但据化石分析，水杉在白垩纪曾广泛分布于北美、西欧、格陵兰、苏联西伯利亚、日本等地，可是在冰期这些地区的水杉被灭绝了。1945年中国发现水杉后，曾分送给一些国家。现在亚洲、美洲、欧洲不少国家引种的水杉生长正常，有的已结实。

16. The natural distribution range of a tree species is closely related to its historical occurrence, adaptability, and conditions for dispersal. Tree species in the Northern and Southern Hemispheres are quite different. Conifer species, including pine, cedar, fir, yellow cedar, larch, golden larch, hemlock, cedar, cypress, silver fir, etc., are widely distributed in the Northern Hemisphere and are dominant populations in many regional plant communities. Among the pine genus, except for the South Asian pine which slightly crosses the equator to reach the island of Sumatra in Indonesia, other species do not have a natural distribution in the Southern Hemisphere. However, in the conifers, the genera of Araucariaceae, such as Araucaria and Agathis, are distributed in the Southern Hemisphere, with only a few species slightly crossing the equator to reach Indonesia, the Philippines, and the Malay Peninsula. The practice of introducing species has proven that many pine species native to the Northern Hemisphere can fully adapt to the climate and soil conditions in the Southern Hemisphere after being introduced, growing luxuriantly. This indicates that some tree species cannot exceed their current distribution areas, which is likely due to the barriers of oceans and mountains. The absence of certain tree species in some regions may also be the result of climatic changes in history. For example, Metasequoia, whose current natural distribution is limited to a narrow area where Hubei, Sichuan, and Hunan provinces intersect in China. However, according to fossil analysis, Metasequoia was widely distributed in North America, Western Europe, Greenland, Siberia of the Soviet Union, and Japan during the Cretaceous period. But during the ice age, Metasequoia was extinct in these areas. After the discovery of Metasequoia in China in 1945, it was sent to some countries. Now, Metasequoia introduced in many countries in Asia, America, and Europe is growing normally, and some have already started to bear fruit.

17. 树木种类繁多，经济性状和社会效益各异，生态习性也各不相同，在引种时要有一定依据。①根据引种目的，即引种地区对树种的要求，了解外来树种在原产地的表现，作初步筛选。引种实践表明，引种成功的外来树种，在新地区的性状表现都是和原产地相似的。②要考虑外来树种适应新环境的可能性。树木是多年生植物，一个轮伐期，少则十几年，多则几十年，生长环境又不易人为控制。所以原产地和新地区生态因子的剖析，特别是气候因素的剖析是重要的。1906年德国林学家马依耳（HMayr），提出了气候相似论，认为引栽地和原产地气候条件必须相似，引种才能成功。但事实上，在世界范围内，不可能存在条件完全一致的地区。同时，许多引种试验表明，分布区大致相同的树种，有时引种后的表现却很不一样：有的适应性强，能在大范围内推广；有的却只能局限于小范围内栽种。挑选的外来树种，能否在新地区生长推广，需有引种试验来检证。

17. There are many species of trees, with various economic characteristics, social benefits, and ecological habits. When introducing new species, there must be certain bases for the decision. ① According to the purpose of introduction, that is, the requirements of the introducing region for tree species, understand the performance of the introduced species in their original habitats and conduct an initial screening. Introduction practice shows that successfully introduced alien species exhibit similar characteristics in the new region to those in their original habitats. ② It is necessary to consider the possibility of the alien species adapting to the new environment. Trees are perennial plants, with a rotation period of at least a few decades and up to several decades, and the growth environment is not easily controlled by humans. Therefore, the analysis of ecological factors in both the original and new regions is important, especially the analysis of climatic factors. In 1906, German forester H. Mayr proposed the theory of climatic similarity, which suggests that the climate conditions of the introducing site and the original habitat must be similar for successful introduction. However, in reality, it is impossible for there to be regions with completely consistent conditions worldwide. At the same time, many introduction experiments have shown that tree species with similar distribution areas may exhibit very different performance after introduction: some have strong adaptability and can be widely spread; while others can only be planted in a limited area. Whether the introduced alien species can grow and spread in the new region needs to be verified by introduction experiments.

18. ①温度：尤其是低温和绝对低温，往往是一个树种分布的主要限制因子。林木引种中，对几年甚至几十年难遇的低温以及低温持续期也应考虑。高温和绝对高温对林木的损害没有低温显著，但高温配合干旱却能产生严重不良影响。此外，季节交替特点也往往是北树南移受害的原因之一。②降水：是决定引栽外来树种成败的重要因子之一。雨量的季节分配类型，称为雨型，与引种关系密切。中国东部亚热带地区，属夏雨型，引种地中海地区和美国西海岸冬雨型树种，如油橄榄、海岸松、辐射松等很少成功，而引进夏雨型的加勒比松、湿地松等生长良好。③光：日照长度和光的性质随着纬度和海拔的不同而变化，影响到植物生长和发育。植物的正常生长和发育，需要一定昼夜比例的交替，即所谓光周期。对多年生高大树木来说，除发育大周期外，每年还有越冬问题，所以对日照长度的反应比一年生植物要复杂。例如南树北移时，生长季节内日照延长，使生长期延长，影响封顶，妨碍组织木质化和入冬前保护物质的转化，降低了抗寒性。而当北树南移时，日照长度变短，促使提早封顶，缩短生长期，影响树木正常的生理活动，有时会引起二次生长。④土壤：土壤化学特性、物理结构和肥力状况深刻影响到树木生长。其中土壤含盐量和酸碱度对引种成败有决定性作用。柳科、藜科、蒺藜科及部分蓼科为喜盐植物。榆、柳、刺槐、紫穗槐等对土壤酸碱度的适应范围较广。松、云杉、冷杉、落叶松等针叶树种适宜在中性和酸性土上生长。土壤结构与土壤通气、排水性有关。松等多数树种适宜在排水良好的土壤上生长；毛白杨、泡桐等不仅要求排水良好，还需土层深厚。但落羽杉、池杉、水杉等适宜在水湿地上生长，特别是池杉极耐水湿。⑤病虫害：它的发生发展，涉及病原、寄主、环境三者间的复杂关系和相互影响，有的病虫害在原产地就已存在，但并不构成重要威胁，当在新环境条件下却成了严重危害因素；有的是新地区的病虫害找到了更适于侵染的新寄主，使外来树种不能占有新的领地。松、赤杨和豆科一些种的根部组织与菌类共生，成为树木正常生长的必要生物条件，在引种中对此也应有所考虑。

18. ①Temperature: Particularly low temperatures and absolute low temperatures are often the main limiting factors for the distribution of a tree species. In the process of introducing tree species, the low temperatures that occur once in several years or even decades, as well as the duration of low temperatures, should also be considered. The damage caused by high temperatures and absolute high temperatures to trees is not as significant as that caused by low temperatures, but when combined with drought, it can produce serious adverse effects. In addition, the characteristics of seasonal alternation are often one of the reasons for the damage to trees that are moved from the north to the south. ②Precipitation: It is one of the important factors that determine the success or failure of introducing exotic tree species. The type of seasonal distribution of rainfall, known as the rainfall pattern, is closely related to the introduction of species. In the eastern subtropical region of China, it belongs to the summer rainfall type. The introduction of Mediterranean and western coastal U.S. tree species such as olive, coast pine, and radiata pine has rarely been successful, while the introduction of summer rainfall type species such as Caribbean pine and swamp cypress has grown well. ③Light: The length of daylight and the nature of light vary with latitude and altitude, affecting plant growth and development. The normal growth and development of plants require a certain alternation of day and night ratios, known as the photoperiod. For perennial tall trees, in addition to the large development cycle, there is also the problem of wintering every year, so their response to daylight length is more complex than that of annual plants. For example, when trees are moved from the south to the north, the extension of daylight during the growing season prolongs the growing period, affects the final growth, hinders the lignification of tissues, and the conversion of protective substances before winter, reducing cold resistance. When trees are moved from the north to the south, the shortening of daylight length promotes early closure of the growing season, shortens the growing period, affects the normal physiological activities of trees, and sometimes causes secondary growth. ④Soil: The chemical properties, physical structure, and fertility of the soil have a profound impact on tree growth. Among them, the salt content and pH of the soil play a decisive role in the success or failure of introducing species. The Salicaceae, Chenopodiaceae, Zygophyllaceae, and some species of Polygonaceae are halophytes. Elm, willow, acacia, and caragana have a wide range of adaptability to soil pH. Coniferous tree species such as pine, spruce, fir, and larch are suitable for growing on neutral and acidic soils. Soil structure is related to soil ventilation and drainage. Most tree species, such as pine, are suitable for growing in well-drained soils; white poplar and Paulownia require not only good drainage but also deep soil layers. However, bald cypress, pond cypress, and Metasequoia are suitable for growing in waterlogged land, especially pond cypress is very tolerant of waterlogging. ⑤Diseases and pests: Their occurrence and development involve the complex relationships and interactions among pathogens, hosts, and the environment. Some diseases and pests already exist in the original habitat but do not constitute an important threat; however, under new environmental conditions, they become serious factors of harm. Some diseases and pests in new regions have found new hosts more suitable for infection, preventing the exotic tree species from occupying new territory. The root tissues of pine, alder, and some species of legumes symbiotically associate with fungi, which become necessary biological conditions for the normal growth of trees. In the process of introducing species, this should also be taken into consideration.

19. 树木引种成功的标准是：不需要特殊的栽培、保护措施，能够正常地生长和发育；提供的产品数量和品质能达到原产地的平均水平。为保证引种成功，必须注意以下事项：①引种必须坚持长期试验、逐步推广的原则。一个树种在生产中推广是长期引种试验工作的结果。如果不经过试验就在生产中推广，势必要冒风险，有时会遭到重大损失，浪费人力物力。一个外来树种不经过几个世代的长期自然考验，也很难说引种已完全成功。为兼顾试验和生产的需要，在经几轮试验后初步确认有希望发展的外来树种，可逐步扩大试验面积，向生产推广过渡。②要重视引进外来树种的种内差异。过去引种时由于忽视树种种内的变异，往往达不到引种的最佳效果。同一外来树种中不同种源在生长和适应性方面存在差异。没有种源选择，便不可能有效地引种，这是引种工作中的一条重要经验。③在同一地区中要选多种立地条件作试验。不同的地形和坡向会造成温度、土壤湿度等方面的显著差别，对引种成败有重要影响。适地适树（见树种选择）对引种外来树种同样是适用的。④加强引进种苗的检疫工作。从外地或外国引进树种，一定要严格按照种子检疫制度，做好检疫工作，严防带进检疫对象。对引进已受检疫对象感染的树种，或从感染地区引种时，工作宜特别审慎。⑤采取最适于外来树种的栽培措施。如南树北移时，施肥宜在每年生长早期，后期不宜施肥和灌溉，对1～2年生的南方树苗，冬季可设置风障或埋土；北树南移，夏季宜设置荫棚，对杉类宜接共生菌等。

19. The standard for successful introduction of trees and shrubs is that they do not require special cultivation or protection measures to grow and develop normally; the quantity and quality of the products they provide can reach the average level of their original habitat. To ensure the success of introduction, the following matters must be noted: ①The introduction must adhere to the principles of long-term trials and gradual promotion. The promotion of a tree species in production is the result of long-term introduction trials. If it is promoted in production without trials, it is bound to take risks, and sometimes it may result in significant losses, wasting human and material resources. It is also difficult to say that the introduction of an alien species has been completely successful without several generations of long-term natural tests. To meet the needs of both trials and production, after several rounds of trials, it is possible to gradually expand the trial area and transition towards production promotion for alien species that have been preliminarily confirmed to have the potential for development. ②Attention should be paid to the intraspecific differences of the introduced alien species. In the past, due to neglect of the variations within tree species, the best effects of introduction were often not achieved. Different sources of the same alien species show differences in growth and adaptability. Without source selection, it is impossible to effectively introduce species, which is an important experience in the work of introduction. ③It is necessary to select multiple site conditions for trials in the same region. Different topography and slope directions can cause significant differences in temperature and soil humidity, which have an important impact on the success or failure of introduction. The principle of suitable trees for suitable sites (see tree species selection) is also applicable to the introduction of alien species. ④Strengthen the quarantine work of introduced seedlings. When introducing species from other places or countries, it is necessary to strictly follow the seed quarantine system, do a good job of quarantine, and strictly prevent the introduction of quarantine objects. When introducing species that have been infected by quarantine objects or when introducing from infected areas, the work should be particularly cautious. ⑤Adopt the cultivation measures most suitable for alien species. For example, when moving southern trees to the north, fertilization should be done in the early stage of growth each year, and it is not advisable to fertilize or irrigate in the later stage; for 1 to 2-year-old southern seedlings, wind barriers or soil burial can be set up in winter; when moving northern trees to the south, it is advisable to set up shade shelters in summer, and for cedar trees, it is advisable to graft symbiotic fungi, etc.

20. 吴中伦等编：《国外树种引种概论》，科学出版社，1983。

20. Wu Zhong Lun et al., "Introduction to the Introduction of Tree Species from Abroad," Science Press, 1983.

21. 为了保证引种成功，在具体引种时，还须注意以下事项：

21. In order to ensure the success of seedling introduction, the following matters should also be paid attention to during the specific introduction of seedlings:

22. 引种必须有明确的目的和要求。引种前要针对本地生态条件、生产条件及生产上的需要，根据引入品种的温光反应特性、两地生态条件和生产条件的差异程度研究引种的可行性，确定引进品种的类型和引种的地区，切不可盲目乱引，以免造成不应有的损失。

22. The introduction of new varieties must have clear objectives and requirements. Before introducing, it is necessary to study the feasibility of the introduction based on the local ecological and production conditions, as well as the needs for production. This should take into account the temperature and light response characteristics of the introduced variety, the differences in ecological and production conditions between the two places, and determine the type of introduced variety and the region for introduction. It is imperative not to introduce blindly and arbitrarily to avoid unnecessary losses.

23. 要做好引种试验。虽然引种有其规律，属于同一生态区的品种相互之间引种一般都可以成功，但不同品种之间的适应性也有一定的差异。在引种实践中也有从较远的地区引种获得成功而从较近的地区引种反而不成功的特殊事例。所以在大量引种前，一定要多点进行小规模的试验观察，并与本地推广品种相比较，以确定引入品种的推广使用价值和适宜推广的范围。

23. It is necessary to conduct seed introduction trials. Although seed introduction has its own laws, the seed introduction among varieties belonging to the same ecological zone generally succeeds. However, there are also certain differences in adaptability among different varieties. There are also special cases in the practice of seed introduction where successful introductions were made from relatively distant regions, while introductions from relatively close regions failed. Therefore, before large-scale seed introduction, it is essential to carry out multiple small-scale trials and observations, and compare them with locally promoted varieties to determine the promotional value and the appropriate scope for the introduction of new varieties.

24. 加强检疫工作，防止检疫性病、虫、杂草的引入和传播。对外地，特别是国外引进的种子，一定要按国家要求严格进行检疫，否则可能造成严重后果。以前在这方面有许多严重教训，如棉花的枯黄萎病、水稻的白叶枯病、甘薯的黑斑病、野燕麦等，都是随引种传入我国的。

24. Strengthen the quarantine work to prevent the introduction and spread of quarantine pests, diseases, and weeds. For seeds introduced from other places, especially from abroad, it is essential to strictly carry out quarantine according to national requirements, otherwise it may cause serious consequences. There have been many serious lessons in this regard in the past, such as the wilt and yellowing disease of cotton, the white leaf blight of rice, the black spot disease of sweet potatoes, and wild oat, etc., which were introduced into our country along with the planting of new varieties.

25. 办理引种手续。经过引种试验确定了引入品种的推广价值和适宜推广的范围后，在进行生产推广前，一定要到引入地省级农业行政主管部门办好引种手续。只有办理了引种手续的品种才能进行推广应用。

25. Handle the seed introduction procedures. After the seed introduction test has determined the promotional value and the appropriate scope of promotion for the introduced variety, it is essential to handle the seed introduction procedures properly at the provincial-level agricultural administrative authority of the introduction location before proceeding with production promotion. Only varieties that have completed the seed introduction procedures can be promoted and applied.

26. 加强引入后的选择工作。由于原产地与引进地区自然条件的差异，新引进的品种容易产生变异个体。因此，为了保持引入品种的优良种性和纯度，延长其使用年限，在生产种植过程中要注意进行去杂去劣，或提纯更新。

26. Strengthen the selection work after introduction. Due to the differences in natural conditions between the place of origin and the introduced area, the newly introduced varieties are prone to produce variant individuals. Therefore, in order to maintain the excellent quality and purity of the introduced varieties, and extend their service life, attention should be paid to the removal of杂种和劣质个体, or to purification and renewal during the production and planting process.

27. 任何植物都是在一定自然条件下生存和发展的，在引种之前，应先了解清楚自然地理条件，对比一下有多少异同，如果有差距能否采取措施弥补。一旦生长停滞，不但好花不能常开，而且会出现夏眠。如果相似处多，又有办法弥补差距，引种成功的可能性就会增大。

27. Any plant survives and develops under certain natural conditions. Before introducing a new species, it is essential to understand the natural geographical conditions clearly, compare the similarities and differences, and determine whether any gaps can be bridged through measures. Once growth stagnates, not only will beautiful flowers not bloom frequently, but there may also be summer dormancy. If there are many similarities and there are ways to bridge the gaps, the likelihood of successful introduction will increase.

28. 植物的引种有其本土化过程。一般引种的植物至少要到当地有3年的引种试验。除了考察抗逆性，观赏性以外，还要观察物候期是否跟引种地一致。引种植物在种植过程中总有些不适应，尤其是夏冬。为了促进其逐步适应，可适当降温和遮阴、喷水和埋土，搭设风障等，减低温度对苗木的侵害，使其能达到基本生存能力并且逐步被同化，等到苗木长大之后，抵抗不良环境因子的能力也就会增强，易于习惯当地的生长条件，引种成功的几率也就会得到大大的提高。

28. The introduction of plants has its process of localization. Generally, the introduction of plants requires at least 3 years of trial planting in the local area. In addition to examining their resistance to adversity and ornamental value, it is also necessary to observe whether the phenological periods of the introduced plants are consistent with those of the introduction site. During the planting process, introduced plants always experience some degree of maladaptation, especially during summer and winter. To promote their gradual adaptation, it is appropriate to lower the temperature, provide shade, spray water, bury soil, set up windbreaks, and so on, to reduce the damage to seedlings from temperature. This allows them to achieve basic survival capabilities and gradually become assimilated. As the seedlings grow larger, their ability to resist adverse environmental factors will also increase, making it easier for them to adapt to local growing conditions. The chances of successful introduction will also be greatly improved.

29. 土壤的适生条件主要指土壤的酸碱度，例如樟科植物、杜鹃花科植物及竹柏类等比较适应在酸性土壤中生长，在南方是很好的常绿树种，引进北方以后很多都会出现黄化病，这主要是因为土壤碱性不适。

29. The suitable conditions for soil mainly refer to the soil's pH level. For example, plants from the Lauraceae family, Ericaceae plants, and bamboo-pine trees, etc., are more adaptable to growing in acidic soil. They are excellent evergreen species in the south. However, after being introduced to the north, many of them will develop yellowing diseases, which is mainly due to the unsuitable alkalinity of the soil.

30. 植物都有自己的生物特性，它们的生长发育有一定的节律，这种节律是对各种气象因子的反应。植物种类多，在一个地区长期生存，当地的各种自然条件就被它同化，久而久之形成了遗传性，这种遗产性是相对保守的，如果引种后得不到基本的满足，很容易就会失败。

30. Plants have their own biological characteristics, and their growth and development have a certain rhythm, which is a response to various meteorological factors. With a wide variety of plant species surviving in a region over a long period of time, the local natural conditions are assimilated by them, and over time, they develop hereditary traits. This hereditary nature is relatively conservative; if the introduced plants do not receive the basic requirements, they are prone to fail.