【作者】 薄亚光；

【导师】 贾志宽； 韩清芳；

【作者基本信息】 西北农林科技大学 ， 生态学， 2008， 硕士

【摘要】 本研究比较分析了在关中地区栽培的三叶型与多叶型紫花苜蓿的生产性能及总黄酮含量差异,研究结果对苜蓿品种选育及合理开发利用苜蓿黄酮类物质具有重要的理论与实践意义。研究结果表明苜蓿品种的叶片和株高的生长发育关系相关性较弱,相关系数为0.705。主要结论如下:1.多叶型苜蓿在多叶表达方面存在差异,但差异不明显,平均多叶百分率均在11.3%～17.3%之间。株系间多叶枝率:牧歌>卫士>全能。株系间多叶节率:牧歌>全能>卫士。株系间多叶百分率:全能>牧歌>卫士,三个株系的多叶表达形式主要是四叶或五叶,六叶、七叶及七叶以上多叶数量相对较少。全能相对于牧歌与卫士两个株系在多叶性状的表达上不稳定,品种内部差异较大;牧歌与卫士两个株系间多叶性状差异不明显,与全能存在显著差异。2.不同茬次不同苜蓿品种株系净光合速率呈现出“单峰”、“双峰”两种不同的变化趋势,日变化曲线类型因品种而异。多叶型株系不同茬次净光合速率（Pn）日变化均表现为“单峰”趋势,而三叶型品种不同茬次净光合速率（Pn）日变化却表现为“双峰”趋势,且第2峰值均低于第1峰值,并出现光合午休现象。3.不同苜蓿品种株系各主要生物学特性指标,如株高、茎粗、叶面积、鲜干比、产量等,均表现为第一茬优于第二茬。多叶型株系与三叶型品种相比,在产量方面具有明显优势。不同茬次不同品种株系苜蓿在产量上存在较显著差异,第一茬牧歌多叶株系单位面积产量达3.715×10⁴kg.hm^-2,第二茬陕北苜蓿三叶品种产量仅为6.86×103kg.hm^-2,二者相差达5倍。研究初步表明,产量占优势的多叶型株系具备更大的黄酮类物质生产潜力。4.通过对6个品种、株系紫花苜蓿茎、叶中的总黄酮提取和测定,结果表明各品种、株系总黄酮含量均呈现先增高,后降低,而后缓慢升高的变化趋势。各品种、株系间总黄酮含量差异不明显,总黄酮平均含量最高的品种牧歌三叶型（AmeriGraze trifoliolate）为7.08 mg/g,含量最低的品种全能三叶型（Total trifoliolate）为6.32 mg/g。更多还原

【Abstract】 In this paper, the differences of productive performance and flavonoids of trifoliolate and multifoliolate Medicago sativa cultivars were analyzed. The results have the important theory and practice significances to variety breeding of alfalfa and flavonoids of rational exploitation and utilization. And the results showed that the correlation between the leaf area and the plant height was not significant. The correlation coefficient was 0.705. The main conclusions were as follows.There were not significant differences among different alfalfa （Medicago satival） varieties with the expression of multifoliate characters. The average percentage of the leaf with four or more leaflets was between 11.3% and 17.3%. The analysis results showed that the percentage of multifoliate stem ranked in the increasing order of AmeriGraze, AmeriGuard and Total. The percentage of multifoliate node ranked in the increasing order of AmeriGraze, Total and AmeriGuard. The percentage of the leaf with four or more leaflets ranked in the increasing order of Total, AmeriGraze and AmeriGuard. The primary form of expression of multifoliate characters was four or five leaflets, and the number of six or more leaflets was litter. AmeriGraze and AmeriGuard were consistent than Total on the expression of multifoliate characteristics and there was an internal difference. The differences between AmeriGraze and AmeriGuard were not obvious, but there were significant differences between the two varieties and Total.The Diurnal changes of net photosynthetic rate of different cultivars by different stubbles presented single or double apex pattern. The diurnal variation curve is different. The Diurnal changes of net photosynthetic rate of multifoliate varieties by different stubbles presented single apex pattern. The Diurnal changes of net photosynthetic rate of trifoliolate varieties by different stubbles presented double apex pattern. The second peak was always lower than the first peak. And the midday depression of photosynthesis was appeared.The first stubble was better than the second stubble on the main biological characteristics index of different cultivars alfalfa （Medicago sativa）, for example, the plant height, the stem diameter, the leaf area, the fresh/dry ratio and the fresh weight. The multifoliate varieties were better than the trifoliolate varieties on the fresh weight. There were significant differences among different alfalfa （Medicago satival） varieties by different stubbles on the fresh weight. The yield per unit area of AmeriGraze multifoliate by the first stubble was 3.715×104kg.hm^-2. The yield per unit area of Shanbei trifoliolate by the second stubble was 6.86×103kg.hm^-2. The yield per unit area of the largest was 5 higher than that of the least. The results showed that the flavonoid productive potential of multifoliate varieties was higher than that of the trifoliolate varieties.The content of flavonoids in stems and leaves of 6 different cultivars alfalfa （Medicago sativa） were extracted and determined. The dynamic variation rules of flavonoids content of different cultivars all presented increase-decrease-increase. The difference among cultivars in flavonoids content was not obvious. In the whole developmental stage, the highest level of flavonoids was“AmeriGraze trifoliolate”which average content was 7.08 mg/g. The lowest average content was“Total trifoliolate”with 6.32 mg/g.更多还原