Research On The Effects Of Selenium On Selenium Accumulation And Quality Of Flue-cured Tobacco

The experiment was carried out in Enshi, Hubei province in 2009. The experiment set up 6 treatments with soil Se-supplement (3 levels), foliar application of Se (2 levels) and CK, the discipline of absorption, accumulation and distribution of selenium by flue-cured tobacco, the effect of selenium on flue-cured tobacco growing development and tobacco quality were studied in order to provide theoretic bases and practical direction for rich selenium cigarette. The primary results were as follows:1. The influence of different Se-supplement methods on Se accumulation and distribution were different. The methods of soil Se-supplement and foliar application of Se promoted dry matter accumulation of flue-cured tobacco, flue-cured tobacco dry matter accumulation increased with the fertilizer amount of Se. Effects of different organs of Se content varied with different Se-supplement methods, in soil Se-supplement treatment, the Se content increased in the order of stem, leaf, root while it did in the order of stem, root, leaf for the foliar application of Se. Different parts of leaves had different Se content, in soil Se-supplement treatment, the Se content increased in the order of bottom leaf, middle leaf, upper leaf while it did in the order of upper leaf, middle leaf, bottom leaf for the foliar application of Se. Se accumulation appeared as a "S" curve, the Se accumulation rate appeared as a single peak curve and the peak at 65d after transplanting in different treatments,the sequence of Se accumulation was leaf>root>stem in different treatments. Se utilization efficiency was different in different methods of Se-supplement, the Se utilization efficiency of the foliar application of Se (6.474%～7.466%) was several times of soil Se-supplement (0.169%～0.173%).2. In different Se content conditions, the influence of Se-supplement on the tobacco growth were different. In low-selenium soil conditions, selenium increased the stem girth and leaf area of flue-cured tobacco, selenium increased the yield of tobacco leaves, and it promoted growth and development of flue-cured tobacco slightly. In the natural high-selenium soil conditions, each treatment was in good condition and had a high output, it had no significant effect on growth and development of flue-cured tobacco in Se-supplement treatments.3. In different Se content conditions, the influence of Se-supplement on the tobacco quality was different. In low-selenium soil conditions, suitable selenium can increase the length, width and weight of leaves, and reduce the thickness of leaves; suitable selenium can reduce the reducing sugar and total sugar content, and increase the protein, nicotine, total nitrogen and K content of tobacco leaves; suitable selenium had no significant negative impact on sensory evaluation of tobacco leaves; In the natural high-selenium soil conditions, Se-supplement treatments had no significant effect on physical property and chemical composition of tobacco, and the sensory evaluation of tobacco leaves were reduced slightly.4. In low-selenium soil conditions, suitable selenium can increase non-volatile acids and neutral aroma components observably, and improve aroma quality of tobacco; suitable selenium can reduce harmful composition of smoke effectively, such as nicotine, tar and so on, to reduce the harmful results to human body.