【作者】 刘睿；

【导师】 王正银；

【作者基本信息】 西南大学 ， 植物营养学， 2007， 硕士

【摘要】 荞麦属蓼科荞麦属双子叶禾谷类作物，以其丰富的营养、独特的保健功能被国际农业营养及卫生组织认为是21世纪具有前途的绿色食品。荞麦在重庆市某些城区有较大规模种植，但因品种老化混杂，种植零星分散，栽培管理落后，而使荞麦产量低、用途单一、效益不高，没能发挥我市荞麦生产的区域优势。当前我国对荞麦的研究也仅停留在产品加工的层面上，对荞麦施肥等基础性研究还不多，将微量元素肥料施用于荞麦以优化其营养结构的研究更甚。而硒是人体必需的微量元素之一，我国72％的地区为缺硒低硒地区，缺硒导致多种地方性疾病。荞麦硒含量较高，因此从营养调控的角度上研究硒对荞麦营养效应的生理机制，对更进一步提高荞麦产量和优化产品营养结构、开发富硒荞麦具有非常重要的意义，必将赋予荞麦这一绿色食品更强的保健功能和市场活力。本文以重庆市合川地方种黄荞一号为材料，采用土壤盆栽试验和化学分析方法，设4个不同施硒水平，系统研究了硒对苦荞生长发育、营养效应和土壤性状的影响，主要研究结果如下：1．施硒后苦荞早期生长受到抑制，表现为株高、干重下降，但成熟期时施硒浓度为0.5mg／kg的处理株高高于对照，施硒浓度为0.5和1.0mg／kg的两个处理干重超过对照，说明硒对苦荞后期生长有促进作用。施硒促进苦养地上部生长，但抑制苦荞根部的生长，使根冠比变小。从产量性状来看，施硒浓度为0.5和1.0mg／kg的两个处理株穗数、株粒数、产量和百粒重都较对照增长显著，其中每盆产量分别增加132％和41％，增产效果明显。施硒浓度为2.0mg／kg时，苦荞整个生育期的生长发育均受到严重抑制，产量降低，表现为中毒现象。从生长发育来看，施硒量在0.5-1.0mg／kg范围内适宜苦荞生长，0.5mg／kg为最佳浓度。2．施硒显著提高了苦养的硒水平，但各器官的硒含量随生长期不同而有差异。苗期硒在苦荞各器官含量顺序为：根＞叶＞茎。花期硒在苦荞各器官中的含量顺序为：花＞根＞叶＞茎。成熟期时花的硒含量最高，茎最低。硒在苦荞植株体内转运的规律是从地下部向地上部各器官转移，从营养器官向生殖器官转移。从分布来看，叶、茎是苦养主要的贮硒器官，成熟期施硒处理的苦荞叶部和茎部硒积累量占整株的72-79％。作为人类直接食用部位的籽粒，贮硒量占全株比例的大小随施硒水平而异，4个硒水平的作用大小顺序为：T2＞T3＞T4＞T1。3．苦荞干物质的积累主要发生在生长的中后期，60天时积累速率达到峰值。施硒可以使苦荞生长后期干物质积累速率下降幅度降低，即延长了苦荞的生长周期。硒在苦荞整个生育期都在不断积累，低硒浓度时成熟期硒积累速率最高。不同处理各器官的硒积累过程差异较大，说明硒在植物体内的转运过程比较复杂，但在施硒0.5-1.0mg／kg范围内变化规律较一致，成熟期硒积累量大小顺序是：叶＞茎＞籽粒＞根＞花。施硒0.5-1.0mg／kg既可以提高苦荞干物质积累量，也可以提高苦荞硒积累量，在此浓度范围内，苦荞干物质积累量和硒积累量呈极显著正相关(r=0.9748*)。4．施硒使苦荞籽粒硒含量提高了8.8-11.5倍，同时提高了苦荞籽粒中氮、磷、钙、镁、锌、锰等元素的含量，但降低了铜、铁的含量。苦荞籽粒硒含量与磷、钙含量呈显著正相关，与锌含量达到极显著正相关，与铜、铁含量呈显著负相关。施硒使苦荞籽粒淀粉含量下降，粗脂肪、粗蛋白含量升高，施硒0.5-1.0mg／kg苦荞籽粒淀粉、粗脂肪、粗蛋白产量均有显著提高。表明，施硒改善了苦荞籽粒的营养结构，提高了品质。5．施硒后土壤有效硒含量呈抛物线形式增加，植株硒含量与土壤有效硒含量相关性显著(r=0.950*)。施硒可以提高土壤有效磷、钾的含量，对有效氮含量影响无规律。更多还原

【Abstract】 The buckwheat is dicotyledonous polygonaceae plant, which is considered as the best organic food in the 21st century by the International Agricultural Nutrition and the Health Organization. The buckwheat is widely grown in some places in Chongqing, but because of the aged and combination variety, fragmentary and disperser planter and backwardness management, the output of the buckwheat is low. The regional advantages of buckwheat production in Chongqing can not be displayed well. The research of buckwheat in our country concentrates in the product processing now, but basic research, such as applying fertilizer is lacking and little research is considered on applying trace elements fertilizer of buckwheat to optimize the nutriments structure. Selenium is an essential trace element. Selenium in 72% areas of China is low or deficient, which lead to various kinds of endemic diseases. Buckwheat contains higher selenium, so studying the selenium nutritional effects of physiological mechanism from the perspective of nutritional control has a very important significance and will increase the yield, optimize the nutritional structure and improvement the development of buckwheat. It will give the green food stronger health function and market vitality. In this paper, the NO. 1 golden buckwheat, a kind of local species in Hechuan zone of Chongqing, was employed. Pot experiments in four selenium levels and chemical analysis methods were adopted to study the effect of selenium on buckwheat growth, nutritional effects and character of soil. The main results were as follows:1. Early growth of buckwheat was restrained after applying Se, and plant height and dry weight all dropped. However, plant height under the 0.5mg/kg treatment and dry weigh under the 0.5 mg/kg and 1 mg/kg treatments were all higher than those of the control. The results showed that selenium improved growth in the late period. Applying Se could improve growth of overground part, but root growth was restrained and made root/canopy ratio little. Compared with the control, kernel number head, yield, weight and 100-kernel weight all increased markedly under the 0.5 mg/kg and 1 mg/kg treatments, which respectively increased 132% and 41%. When the concentration of Se was 2.0mg/kg, the growth and development of buckwheat were seriously restrained and the yield decreased, and the buckwheat seemed to be poisoned. It was suitable for buckwheat growth when the concentration of Se was 0.5mg/kg or 1.0mg/kg, and 0.5 mg/kg concentration range was considered the optimum density scope.2. Selenium level of buckwheat was significantly improved after applying Se, but the content of selenium was different in the buckwheat organ at different growth stage. Order of content of Se in the buckwheat organ at the seedling stage was as follow: roots＞leaves＞stems. The order of the selenium content in the organs of buckwheat at the flowering stage was: flowers＞roots＞leaves＞stems. The highest and lowest selenium content was respectively in the flower and the stem. Transfer law of selenium in the buckwheat was from the underground to the organs of the ground and from nutrition to the genital organ. Leaves and stems were the main storage organs of selenium in the buckwheat. Selenium contents in the leaves and stems almost were 72-79% of the whole plant., the storage proportion of selenium in the grain which was a direct use part for humans was different under different Se level and the order was as follow:T2＞T3＞T4＞T1.3. Accumulation of dry matter in buckwheat mostly happened at the middle and late stage of buckwheat development, and the peak value of accumulation rate was on the 60th Day. After applying Se, the accumulation rate of dry matter reduced slowly at the middle and late stage, which meant that the growth period of buckwheat was extended. Selenium accumulated constantly in the whole growing period of buckwheat. The accumulation rate of selenium was maximum at the mature stage of buckwheat at the low selenium concentration. There were great differences on the accumulation rate of selenium in organs among different treatments. It showed that the transport process of Se in plants was complex. However, the law of change was approximate at 0.5-1.0mg/kg selenium concentrations. The accumulation concentration of Se in the different organs was leaves＞stems＞seeds＞roots＞blossoms. Employing Se at 0.5-1.0mg/kg concentration could enhance dry matter accumulation of buckwheat, and it could also enhance Se accumulation of buckwheat. Within this concentration range of Se, the extra significant positive correlation(r=0.9748^**) was observed between dry matter accumulation and Se accumulation.4. The Se content of the Buckwheat seeds increased by 8.8-11.5 times after applying Se. Applying Se also increased the content of N, P, Ca, Zn and Mn, while decreased the contents of Cu and Fe. Se content of buckwheat seeds had significant positive correlation with the P and Ca content, extremely significant positive correlation with the Zn content, and it had significant negative correlation with the Cu and Fe content. The starch content of buckwheat seeds decreased, while the crude fat and crude protein content increased after employing Se. The starch, crude fat and crude protein contents were all increased remarkably after applying Se at 0.5-1.0mg/kg concentrations. Generally speaking, applying Se improved the nutrition structure of buckwheat seeds and its quality.5. Available Se content in soil increased at parabola after applying Se. Relativity between plant selenium content and the soil available selenium content was remarkable （r=0.950^*）. Simultaneously, applying Se could increase the content of available P and available K, but the influence to available N was not orderly.更多还原