1. 种子形态鉴定依据玉米种子的粒型、粒色、形状、大小、胚的大小、胚乳粉质多少等形态特征进行鉴别。鉴定时必须备有该品种的标准样品或图谱及有关资料，此法对于鉴定形态特征明显的品种比较有效，且快速、经济，但无法鉴别没有明显粒色差异的玉米杂交种中混有的自交系种子。（

1. Seed morphological identification is based on the morphological characteristics such as kernel shape, kernel color, shape, size, embryo size, and the amount of endosperm powder of corn seeds for differentiation. During identification, it is necessary to have the standard samples or illustrations of the variety as well as relevant information. This method is effective for identifying varieties with distinct morphological characteristics and is quick, economic, but it cannot differentiate the inbred line seeds mixed in corn hybrids without obvious kernel color differences.

2. 蛋白质（同工酶）电泳方法不同品种的种子因其遗传基础不同，因而合成的蛋白质（同工酶）的种类和数量不同，电泳分离后所形成的谱带也不同，与对照（标准）品种比较后可判断出其他品种的种子数量，最终达到鉴定种子纯度的目的。我国普遍采用“玉米种子蛋白质聚丙烯酰胺电泳（PAGE）法”：从每份样品中随机选取玉米种子100粒，单粒粉碎，分别加入样品提取液，置05小时以上，取上清液10微升在聚丙烯酰胺凝胶垂直板上进行电泳，电泳仪为DYY-Ⅲ6B型，电泳槽为DYY-Ⅲ型；电泳后，取下凝胶板，立即放入考马斯亮蓝和三氯乙酸的水溶液中染色4小时以上，观察电泳谱带，同时与本品种或其亲本种子进行对照，鉴定样品中各粒种子的谱带特征，计算品种纯度。蛋白质电泳方法准确、可靠、快速、实用、分辨率高、成本低、重演性好、易掌握，已逐步成为商品种子品种纯度的快速检测技术。但对于某些遗传组成非常接近的品种，不易找到特异蛋白，采用蛋白质电泳难以发现特征带，不容易鉴别。同工酶有器官及发育时期的特异性，误差较大，酶的提取和电泳条件较蛋白质要求严格，需在低温下进行，有时亲缘关系密切的品种也难以区别开。（

2. The electrophoresis method of proteins (isozymes) differs among different varieties of seeds due to their different genetic bases. Therefore, the types and quantities of proteins (isozymes) synthesized are different, and the resulting electrophoresis bands are also different. By comparing them with the control (standard) variety, the quantity of seeds from other varieties can be determined, ultimately achieving the goal of identifying the purity of seeds. In China, the "Corn Seed Protein Polyacrylamide Gel Electrophoresis (PAGE) method" is commonly used: from each sample, 100 corn seeds are randomly selected, single-seed milled, and separately added to the sample extraction solution. They are then placed for more than 0.5 hours, and 10 microliters of the supernatant are electrophoresed on a polyacrylamide gel plate. The electrophoresis instrument is of the DYY-III6B type, and the electrophoresis tank is of the DYY-III type; after electrophoresis, the gel plate is removed and immediately placed into a solution of Coomassie brilliant blue and trichloroacetic acid for staining for more than 4 hours. The electrophoresis bands are observed, and a comparison is made with the seed of the same variety or its parents to identify the characteristic bands of each seed in the sample, and to calculate the purity of the variety. The protein electrophoresis method is accurate, reliable, rapid, practical, with high resolution, low cost, good reproducibility, and easy to master, and has gradually become a rapid detection technology for the purity of commercial seed varieties. However, for certain varieties with very similar genetic compositions, it is not easy to find specific proteins, and it is difficult to discover characteristic bands using protein electrophoresis, making it difficult to distinguish them. Isozymes have specificity for organs and developmental stages, with larger errors. The extraction and electrophoresis conditions for enzymes are more stringent than for proteins, requiring低温 conditions, and sometimes closely related varieties are also difficult to differentiate.

3. 幼苗形态鉴定依据幼苗芽鞘颜色（绿色、红色、紫红色、紫色）、叶色、叶形和生长势等进行鉴别。一般多以芽鞘颜色作为纯度鉴定的主要形态特征。鉴定途径有两种，一种是提供植株正常发育的条件（类似于田间小区鉴定，只是所需时间较短），当幼苗达到适宜评价的发育阶段时，对全部或部分幼苗进行鉴定；另一种途径是让植株生长在特殊的逆境条件下，测定其对逆境的反应来鉴别不同品种。该法简便、省时，比子粒形态法的使用范围明显扩大，但能用于鉴别的性状仍不够多，且受环境影响较大，准确性较差，对幼苗形态特征相近的品种很难鉴别其真伪。（

3. Seedling morphological identification is based on the color of the seedling sheath (green, red, purplish-red, purple), leaf color, leaf shape, and growth vigor for differentiation. Generally, the color of the seedling sheath is used as the main morphological characteristic for purity identification. There are two methods of identification: one is to provide the plants with normal development conditions (similar to field plot identification, but with shorter required time), and when the seedlings reach a suitable stage for evaluation, identify all or part of the seedlings; the other method is to allow the plants to grow under special stress conditions, and measure their response to the stress to differentiate between different varieties. This method is simple and time-saving, and its application range is significantly wider than that of the grain morphological method. However, the traits that can be identified are still not numerous enough, and it is greatly affected by environmental factors, leading to lower accuracy. It is difficult to distinguish the authenticity of varieties with similar seedling morphological characteristics.

4. 品种纯度包含真实性和纯度两重含义，品种真实性是指供检品种与文件记录（如品种说明书、标签等）是否相符，品种纯度是品种在特征、特性方面典型一致的程度，用本品种的株（穗或粒）数占供检本作物株（穗或粒）数的百分率来表示。品种的真实性和纯度是种子质量检验的必检项目，也是农业生产上最重要的种子品质之一。品种的真实性和纯度鉴定的常用方法有种子形态鉴定、幼苗形态鉴定、蛋白质（同工酶）电泳方法、DNA分子标记鉴定、田间小区种植鉴定。

4. Purity of variety includes two meanings: authenticity and purity. The authenticity of variety refers to whether the variety submitted for inspection matches the records in documents (such as variety descriptions, labels, etc.), while the purity of variety is the degree of typical consistency in characteristics and traits of the variety. It is represented by the percentage of the number of plants ( ears or grains) of the tested variety to the total number of plants (ears or grains) of the crop submitted for inspection. The authenticity and purity of variety are essential items in seed quality inspection and are one of the most important seed qualities in agricultural production. Common methods for identifying the authenticity and purity of varieties include seed morphological identification, seedling morphological identification, electrophoresis method of proteins (isozymes), DNA molecular marker identification, and field plot planting identification.

5. 田间小区种植鉴定此法是目前品种真实性和纯度鉴定最为可靠的方法，尤其适于对杂交种的鉴定，结果准确、可靠，是目前解决种子质量纠纷中最具有法律效力的检测方法。田间小区种植时是将种子样品与标准品种一起播种，单粒播种，不间苗、不定苗，在植株的不同发育时期与标准样品进行比较。主要根据株形、株高、叶片数、叶色、叶片宽窄、花药颜色等做出评判，从而对不同品种加以鉴别。田间小区种植鉴定方式多种多样，可在当地同季、当地异季或异地异季种植鉴定。该方法能够观察、比较的性状较多。缺点是费工、费时、鉴定周期长、费用高，而且此法受环境和人为影响较大，鉴定者的观察经验也制约着鉴定的准确性。因此，该法是在其他检验方法检验结果不确定或不可能鉴定时而不得不采用的方法。

5. Field Plot Cultivation Identification This method is currently the most reliable method for品种 authenticity and purity identification, especially suitable for the identification of hybrid varieties. The results are accurate and reliable, and it is the most legally effective testing method for resolving seed quality disputes. In field plot cultivation, seed samples are sown together with standard varieties, single-seed planting is performed, without thinning or marking seedlings. The plants are compared with standard samples at different stages of development. The assessment is mainly based on plant shape, plant height, number of leaves, leaf color, leaf width and thickness, anther color, etc., thereby distinguishing different varieties. There are various field plot cultivation identification methods, which can be conducted in the same season, different seasons in the same location, or different seasons in different locations. This method can observe and compare many traits. The缺点 is that it is labor-intensive, time-consuming, has a long identification cycle, and is expensive. Moreover, this method is greatly influenced by the environment and human factors, and the observer's experience also limits the accuracy of the identification. Therefore, this method is used when the results of other testing methods are uncertain or impossible to determine.

6. DNA分子标记鉴定DNA分子标记鉴定以品种DNA片段作为检测对象，运用电泳方法检测品种基因组DNA结构与组成，通过对品种DNA的多态性即DNA碱基序列的差异进行分析，从而鉴别不同品种。目前在品种真实性和品种纯度鉴定上所用的DNA分子标记主要有以PCR扩增为基础的SSR、AFLP、RAPD技术和以分子杂交为基础的RFLP技术。在实际应用中各种分子标记方法也各有优缺点。RFLP和AFLP操作复杂、技术要求高、精密仪器设备需要多、投入大，一般实验室、种子生产、经营部门难以普及使用。RAPD技术简单、方便、快速、成本低，但其重复性和准确性差；RAPD标记大多为显性标记，难以区分杂合型和纯合型；同时玉米单交种的RAPD图谱与其双亲图谱吻合性差，F1代RAPD图谱除双亲型外，还会出现偏父型、杂种型、缺失型。SSR标记技术DNA用量少、技术要求低、多态性水平高、成本低廉，为共显性标记；PCR扩增时退火温度在56℃左右，保证了PCR扩增的准确性。截止2000年3月克隆合成的玉米SSR引物已达到1147对，引物序列已公布，因此SSR技术是当前最有潜力的玉米品种纯度检验方法之一。利用SSR标记建立玉米品种的指纹图谱档案，将被鉴别品种的SSR指纹与标准图谱作对照，可进行品种真实性和种子纯度检验。SSR标记技术将成为今后解决玉米品种产权纠纷、种子纯度责任事故的仲裁技术依据之一。（

6. Identification of DNA Molecular Markers The identification of DNA molecular markers is based on the use of DNA fragments of varieties as the object of detection. It employs electrophoresis methods to examine the structure and composition of the genomic DNA of the variety. By analyzing the polymorphism of the variety's DNA, which is the difference in DNA base sequences, it is possible to differentiate between different varieties. Currently, the DNA molecular markers used for the identification of variety authenticity and purity mainly include SSR, AFLP, and RAPD techniques based on PCR amplification, and RFLP techniques based on molecular hybridization. In practical applications, each type of molecular marker method has its own advantages and disadvantages. RFLP and AFLP are complex to operate, require high technical skills, necessitate a lot of precision instruments and equipment, and are costly, making them difficult to be widely used in general laboratories, seed production, and business departments. RAPD technology is simple, convenient, fast, and cost-effective, but it has poor reproducibility and accuracy; most RAPD markers are dominant, making it difficult to distinguish between heterozygous and homozygous types. Additionally, the RAPD profiles of single-cross corn varieties do not match their parental profiles well, and in the F1 generation RAPD profiles, in addition to parental types, there may also be paternal, hybrid, and missing types. SSR marker technology requires little DNA, has low technical requirements, high polymorphism levels, and is cost-effective, being a codominant marker; the annealing temperature during PCR amplification is around 56°C, ensuring the accuracy of PCR amplification. As of March 2000, 1147 pairs of corn SSR primers have been cloned and synthesized, and the primer sequences have been published, making SSR technology one of the most promising methods for current corn variety purity testing. By using SSR markers to establish a fingerprinting database for corn varieties, the SSR fingerprints of the identified varieties can be compared with standard profiles for variety authenticity and seed purity testing. SSR marker technology will become one of the arbitration technologies for resolving corn variety property disputes and seed purity responsibility accidents in the future.