| Seed quality plays a crucial role in seed production. Fake and shoddy seeds in market were often found, which brought great harm for high quality and high yield of agricultural production, and damage the benefits of farmers and seed enterprises. Nowadays, the anti-counterfeiting technologies of seed are mainly focus on seed packaging, which are easy to be reproducibility and immitigability. A new seed anti-counterfeiting technology, aiming at seed itself rather than the packing are barely reported at home and broad. Meanwhile, there were few studies on seed anti-counterfeiting by using fluorescent compounds. Therefore, fundamental research on fluorescence anti-counterfeiting methods was carried out in present study. Different types of crop seeds were marked by fluorescent compounds with seed treatment methods, and the suitable fluorescent dyes and methods were selected according the physiological changes and fluorescence of seedling. Film coating seeds with fluorescent compounds were stored for various time, their physiological effects of application and dynamics feature of fluorescence anti-counterfeiting were studied aiming at relationship of storage time and fluorescence effects. Moreover, the absorption and degradation of fluorescent compound in soil were also studied in order to provide theoretical basis for field reality. Thus, this study provides an effective anti-counterfeiting theory and a integrate technical system for different types of crop seeds, and the results fill up the vacant of fluorescent anti-counterfeiting for field crop seeds at home and abroad. Meanwhile, the results also supplied theoretical references for anti-counterfeiting of forest and forage seeds. Achieved main results were as follows:1. Suitable fluorescent compounds and their labling methods were selected. After treated with soaking and priming methods, the suitable soaking concentration0.1mg/ml for different types crop seeds was selected out. Seed vigor and seedling performance were not affected when seeds soaking in solution of0.1mg/ml Rhodamine B (RB), and the fluorescence of seed and seedling were both stronger than that of others and controls. The optimum fluorescence dyes for different crop seeds were:rape (RB. Lissamine RB. Safranine T); cauliflower (RB. Lissamine RB); chive (RB, Lissamine RB, Safranine T); onion (RB, Lissamine RB, Safranine T); rice (RB.3,6-Diamincacridine Hulmisulfate. Safranine T):maize (RB.3,6-Diamincacridine Hulmisulfate, Safranine T):pea (RB. Lissamine RB, Safranine T); broad bean (RB. Lissamine RB, Safranine T).2. The paths of fluorescent compound entering seeds were determined. The path of fluorescent compound enters seeds varied in crop seed, which were mainly affected by seed coat. Fluorescent compound entered into seeds of rape and cauliflower through micropyle; fluorescent compound penetrated into pea and maize seeds through seed coat; fluorescent dye entered broad bean seed through hilum and micropyle; fluorescent compound entered rice seed through lemma, apiculus and glume. Fluorescent compound was difficult to enter chive and onion seeds as their seed coats were really hard. In addition, fluorescence was observed obviously in root, stem, leaf and vain in some dicotyledonous such as rape, cauliflower, pea and broad bean.’Fluorescence was also observed obviously in root and stem of some monocotvledon such as chive and onion. Fluorescence was not observed in leaf and stem of some grass such as maize and rice.3. The feasibility of fluorescence anti-counterfeiting in coated seed was studied. RB was marked in different crop seeds by seed film coating, and the suitable doses of RB were selected according to the physiological changes and fluorescence during seed germination and seedling growth. The results showed that the seedling dry weight and height of rice, maize, chive, and onion seedlings were injured at the ratio of1:10(RB to seeds), and seed germination and seedling growth were not affected with the ratio of1:20and1:30. After seeds of rape, cauliflower and broad bean were treated with ratio of1:10,1:20and1:30. germination and seedling growth were not affected significantly. After treated with ratio of1:10and1:20. seedling dry weight, height. POD and SOD activity of pea decreased significantly, and1:30were no harm for seed germination and seedling growth. The fluorescence of seedling when seeds coated with RB were consistent to the result of seeds soaked with RB. indicating that the fluorescence of RB were not affected significantly by the coating materials, so,the results provide theoretical basis for fluorescence anti-counterfeiting of coated seeds.4. The relationship of storage time and the fluorescence of RB were researched. The content and fluorescence of RB marked on coated seeds were measured each mouth during six-month storage for studying the effect of RB fluorescence. The results showed that, for seeds of maize and pea coated with1:10and1:20. the RB content of seeds stored for5months was lower significantly than that of stored for1month, and the RB content from pea seeds coated with1:30had no differences among different storage times. The RB content of rice and chive seeds coated with1:10,1:20and1:30had no significant differences among different storage times. For broad bean seeds coated with1:10. the RB content of6month storage was lower significantly than that of stored for1month, and the RB content of seeds coated with1:20and1:30had no differences among different storage times. For cauliflower seeds coated with1:30, the RB content of seeds stored for6month was lower significantly than that of stored for1month, and the RB content of seeds coated with1:10and1:20had no differences among different storage times. The RB content of rice and chive seeds coated with1:10,1:20and1:30stored for6months were lower significantly than that of stored for1month. Meanwhile, the RB content of the same crop seeds coated with the same ratio had no signifigent difference between normal temperature and15℃, indicating that the content of RB were not affected significantly by the temperature, which supplied theoretical basis for field application of fluorescence anti-counterfeiting. Fluorescence of seeds coated with different ratio was significantly higher than that of the control seeds, and for seeds with the same ratio, the fluorescence had no obvious differences among different storage time. The seed fluorescence of pea. maize, rice and broad bean were stronger because of having light seed coat. For rape, cauliflower, chive and onion, the fluorescence was weak as the seed coat color was depth.5. Their physiological characteristics and the fluorescence in soil were researched after seeds coated with RB were stored for6months. The results showed that root length and seedling height of rape were higher significantly than those of the control after the seeds coated with1:20and1:30, and the root length, seedling height and chlorophyll content of cauliflower were improved significantly after seeds coated with1:20. After broad bean seeds coated with1:30, the root length, dry weight and height of seedling, germination percentage and germination energy of pea seeds were higher significantly than those of the control. The shoot length of chive and onion was significantly decreased. The root and shoot length of rice were decreased significantly after seed coated with1:10, however, the shoot length was increased significantly after seed coated with1:20. For maize seed coated with1:10. chlorophyll content and POD activity were lower significantly than those of the control, and shoot height increased significantly after seeds coated with1:30. When rape seeds coated with RB germinated for7days, the fluorescence was observed in root, leaf, vain and vascular of stern. When cauliflower seeds coated with RB germinated for10days, the fluorescence was observed in root, leaf, vain and vascular of stem. When chive and onion seeds with RB germinated for8,10days respectively, the fluorescence was observed in root and vascular of stem. When rice seeds coated with RB germinated for16days, the fluorescence was only showed in seeds and not found in stem and leaf. The fluorescence was only showed in seed and root, and not found in stem and leaf when maize seed coated with RB germinated for14days. For pea and broad bean seeds coated with RB, when germinated for16,15days respectively, the fluorescence was observed in root, leaf, vain and vascular of stem.6. The absorption and degradation of RB in soil were studied. The fluorescent compound of RB could be absorbed by field soil effectively and the absorption process in accordance with the Langmuir isotherm, in which the amount of saturated absorption was1.716mg/g and the adsorption equilibrium constant, was0.042L/mg. Then the adsorptive RB was degraded effectively under light-Fenton condition. There are similar conditions to light-Fenton in soil, therefore, RB absorbed by field soil can be degraded. Meanwhile, dose of RB in coated treatment was less, so the RB could not pollute soil and be used as an anti-counterfeiting marker for different crop seeds. |
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