| Chuanxiong Rhizoma comes from umbrelliferae. Its dried foot has functions of invigorating the circulation of blood and qi, preventing wind-evil and relieving pains. It mainly used for patients who have angina pectoris, chest pains, sores, abnormal menstruation, amenorrhea dysmenorrheal, lump abdominal pains, headache, and rheumatic arthralgia.In recent years, it is a common phenomenon that Chuanxiong contains overproof heavy metal cadmium content, which has seriously affected its safety usage and export. This thesis aims to provide a scientific basis to solve Chuanxiong's overproof heavy metal cadmium content, and studies the key factors that affect heavy metal cadmium and Chuanxiong absorption and accumulation pattern, so as to discuss the prevention and control measures. Followings are the main research contents:At first, absorption and accumulation study of Chuanxiong heavy metal cadmium.By making a comparison analysis of two different parts Chuanxiong and contents of cadmium in soil in its corresponding soil cultivated land:Aoping, Pengzhou and Yongshou, Meishan, we make a primarily research of how Chuanxiong assimilate and accumulate cadmium. Results show that averge cadmium content of underground is higher 77.21% than overground. Cadmium enrichment coefficient and cadmium transfer coefficient of the different parts were greater than 0.5, and enrichment coefficient of underground were 64.75% higher than overground part. Showed that Chuanxiong has a certain capacity to absorb and transfer cadmium, It turns that most cadmium elements enrich in medicinal roots of Chuanxiong.Secondly, the main factors influences on Chuanxiong heavy metal cadmium exceeds and prevention MeasuresThrough field and pot experiment, we made an investigation on how region, soil, germplasm, growth cycle, etc, influences on herbicide on Chuanxiong heavy metal cadmium content, and we also plans to a further research on the sources of heavy metals in Chuanxiong.The Major Factors Analysis(a) Region:Different region and its cadmium content of Chuanxiong have significant differences (n=30, p<0.01) among Aoping, Pengzhou,Yongshou, Meishan.Hongya Meishan and Wenjigang, Chengdu. Among these, the cadmium content of Aoping was 0.63 mg·kg-1,2.1 times higher than the industry standard (?0.3 mg·kg-1), and its percent proficiency just was 6.67% while Wenjiang is 90%.(b)Soil:AoPing, Pengzhou, Yongshou, Meishan, and Wenjigang, Chengdu, the three different cultivation area soil cadmium content of Chuanxiong are differ (n=8. p<0.01). Meanwhile 3 origins and its production in the soil cadmium content in Rhizoma Chuanxiong medicinal materials has significant positive correlation (r= 09993,p<0.01). That is to say the higher soil cadmium background values, the higher Chuanxiong cadmium content. Taking an example of AoPing, its cadmium pollution soil is serious, more than 3.2 times standard of the national secondary standard of soil environment (0.30 mg kg-1), so it is urgent to be management; The soil pH value and different regions of cadmium content in medicinal materials of Chuanxiong from the soil and has certain relevance, which characterized by a high pH, lower cadmium content in the soil and medicinal materials.Herbs cultivation medium application of farmyard manure cadmium content was 1.97-7.75 times higher than without fertilization, which shows that fertilizer has a certain influence in Chuanxiong cadmium content.(c) Germplasm:small fish hole, white river, Shuimo town, Aoping Ba, Jiunong shan and Jiunong Gou, the cadmium content of 6 different germplasm from its corresponding Chuanxiong has high cadmium content of 1.03-7 times. Both correlation analysis results show that there is no significant correlation (p= 0.223), show that:three kinds of cadmium content in the high and low has no effect on the cultivation of medicinal materials cadmium content.Different germplasm and corresponding medicine biological yield and content in grey correlation degree and the cadmium content of sorting results show that the lofty state and the Jiunong Mountain. GaoMiao Town, Ba and Shuino's germplasm and corrsesponding medicinal materials quality is better.Growth cycle:different growth stages (March to May) cadmium content in Chuanxiong are different. The cadmium content of Aoping's Chuanxiong is relatively low in mid-April (59.46%); Yongshou reached to the lowest level (range is from 59.50%) in mid-March. These data turn out that growing Chuanxiong in different growth cycle has certain affects on cadmium's absorption and transference.Herbicide:Results show that the use of'herbicide Cadmium content in Chuanxiong herbs is 1.59 times higher than those not applying herbicide. It is turned out that the applying of herbicide of Chuanxiong has a certain influence on cadmium content.Smmarizing above factors, we could learn that different regions Chuanxiong have great effects on cadmium of Chuanxiong medicinal materials, and germplasm which impact is smallest.Prevention measures:according to the major affecting factors, we put forward the following measures:(a) Choose regions where cadmium content can reach the standards:high quality soil, good atmosphere and irrigation water as a developing green Chuanxiong planting bases; (b) Choose both high quality and low cadmium content Chuanxiong in Middle March as the best harvest time, (c) Apply physics weed control mode to control the use of herbicides, (d) The use of farmyard manure should consider the heavy metal pollution situation, Choose organic fertilizer such as uncontaminated farmyard manure or the use of green manure cake fertilizer plants.At least, control measures for heavy metal cadmium exceedsIn the area of soil pollution is relatively serious; we should choose suitable chemical soil improvement measures.Study found that different ecological environment and soil conditioner effect are differing. When the cadmium content exceeds bid, we should combined the local ecological environment with appropriate control measures to take effective prevention measures. The followings are some effective measures:AoPing, Pengzhou(1) Humic acid is 8 kg per hectares, cadmium content in Chuanxiong herbs was reduced by 24%;(2) Activated carbon is 150kg per hectares, cadmium content in Chuanxiong herbs was reduced by 10% to 44%;(3) Quicklime is 100kg per hectares, starch is 100kg per hectares and potassium dihydrogen phosphate 20kg per hectares, cadmium content in Chuanxiong herbs was reduced by 28%.(4) Quicklime is 100kg per hectares, potassium dihydrogen phosphate is 20kg per hectares, activated carbon 150kg per hectares and sodium polyacrylate 150kg per hectares, cadmium content in Chuanxiong herbs was reduced by 18.6%.YongShou, Meishan(1) Quicklime is 100kg per hectares, Cadmium content in Chuanxiong herbs was decreased by 2.32% to 47.37%.(2) Quicklime is 100kg per hectares, and potassium dihydrogen phosphate is 20kg per hectares, Cadmium content in Chuanxiong herbs decreased by 20% to 30%.(3) Quicklime is 100kg per hectares, and potassium dihydrogen phosphate is 30kg per hectares, Cadmium content in Chuanxiong herbs decreased by 20% to 30%.(4) Quicklime is 100kg per hectares, starch is 100kg per hectares, Cadmium content in Chuanxiong herbs decreased by 22.50%.(5) Humic acid is 8kg per hectares, and sodium polyacrylate 150kg per hectares, Cadmium content in Chuanxiong herbs decreased by 22.5%.(6) Quicklime is 100kg per hectares, potassium dihydrogen phosphate is 20kg per hectares, starch is 100kg per hectares, cadmium content in Chuanxiong herbs was reduced by 34.21% to 42.5%.To sum up, in the process of Chuanxiong planting, we should combine prevention measures with governance tool to solve the problem of Chuanxiong medicinal materials in heavy metal cadmium content exceeds bid, which will create important practical significance. |
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