【作者】 李鑫；

【导师】 陈雅君；

【作者基本信息】 东北农业大学 ， 园林植物与观赏园艺， 2013， 硕士

【摘要】 早熟禾属于多年生草本植物，其叶色浓绿、叶形和株形优美，形成的草皮结实而富有弹性，是优良的、世界广泛利用的冷季型草坪草。本研究在现有的试验条件下，以西伯利亚早熟禾作为供试材料，与引进的美国‘午夜’早熟禾进行比较。研究早熟禾叶片喷施不同浓度的硅肥后，通过连续干旱及复水处理的方法，测定形态特征和生理特性指标，旨在为培育国内的早熟禾乡土资源及其品种开发和利用提供理论依据。研究结果如下：（1）外源性硅有助于维持2种早熟禾正常生长状况，降低干旱胁迫下叶长、叶宽以及色泽出现的变化，从而维持早熟禾正常的观赏价值，其中叶片喷施400mg/L Na2SiO3·9H2O缓解效果最好。西伯利亚早熟禾叶长、叶宽以及色泽指标来说，其坪用性低于午夜早熟禾。较高的硅浓度增加地下地上生物量比，促进早熟禾根系的生长。（2）叶片喷施硅肥对2种早熟禾水分生理变化具有积极的作用，可以有效提高水分含量，维持蒸散量，增加对土壤中水分的利用以降低干旱胁迫带来的损伤，提高复水后的恢复速度，同时硅对降低2种早熟禾细胞膜损伤、膜脂过氧化作用具有积极的作用，电导率和丙二醛含量减少，其中西伯利亚早熟禾施加800mg/L，‘午夜’早熟禾施加400mg/L的Na2SiO3·9H2O效果最好。（3）干旱胁迫下叶片喷施硅肥，可以减缓2种早熟禾可溶性蛋白下降的速度，促进脯氨酸积累，其缓解效果依次为400mg/L>800mg/L>200mg/L。同时硅肥可以延缓可溶性糖含量的升高，降低对光合作用抑制，西伯利亚早熟禾施加800mg/L，午夜早熟禾施加400mg/L的Na2SiO3·9H2O效果最好。（4）硅肥对2种早熟禾叶绿素含量、净光合速率、气孔导度、蒸腾速率、胞间CO2浓度及Rubisco酶活性的影响基本一致，降低干旱胁迫对早熟禾光合作用的影响。其缓解效果依次为400mg/L>800mg/L>200mg/L。（5）干旱胁迫下，不同浓度硅肥有效减缓2种早熟禾谷氨酰胺合成酶、蔗糖合成酶及蔗糖磷酸合成酶下降速度。400mg/L缓解效果最好，800mg/L缓解效果次之，而200mg/L虽有缓解但效果最小。（6）干旱胁迫下叶片喷施不同浓度硅肥后，2种早熟禾C/N与未施加硅肥相比均降低，其减缓胁迫损伤的效果依次为400mg/L>800mg/L>200mg/L。更多还原

【Abstract】 Bluegrass is a perennial herb, which have dark green leaves, beautiful leaf and plantmorphology. The turf formed by the bluegrass is strong and elastic, thus making it the world’sexcellent and extensive use of cool-season turfgrass. In this study, with the present experimentalconditions, Siberia bluegrass to was used as the test material, compared with ’midnight’ bluegrassintroduced from the United States. After applications for different concentrations of siliconfertilizer to bluegrass foliar, with drought and complex water treatment method, the morphologicaland physiological characteristics of indicators were measured, aiming at providing a theoreticalbasis for the cultivation of domestic bluegrass country development and utilization of resourcesand their varieties. The results were as follows:1.Exogenous silicon helped maintain the two bluegrass varieties’ normal growth conditions,reduce the variations of the leaf length, leaf width, and color change under drought stress in orderto maintain the bluegrass normal ornamental value, and the foliar application400mg/LNa2SiO3·9H2O alleviated the best. According to Siberian bluegrass leaf length, leaf width andcolor indicators, its turf application value was lower than midnight bluegrass. The higher siliconconcentration increased underground and aboveground biomass ratio, and promoted the growth ofbluegrass roots.2.Foliar applications of silicon fertilizer had a positive effect on the twp bluegrass’s moisturephysiological changes, including effectively improved water use efficiency, maintainedevapotranspiration, increased use of water in the soil in order to reduce the damage caused bydrought stress, improved rehydration speed of recovery, meanwhile, the silicon had a positiveeffect on membrane damage and membrane lipid peroxidation of the bluegrass two varieties, andthe conductivity and MDA content decreased. Among the different concentrations of siliconfertilizer,800mg/L Na2SiO3·9H2O applied to the Siberian bluegrass and400mg/L Na2SiO3·9H2O to’midnight’ bluegrass were the best.3.Under drought stress, foliar applications of silicon fertilizer could slow the rate of decline ofthe two kinds of bluegrass soluble protein, and promote the accumulation of proline and themitigating effects sequentially were400mg/L>800mg/L>200mg/L. The silicon fertilizercould delay the soluble sugar content increasing, reduced the inhibition of photosynthesis. Siberia bluegrass under800mg/L Na2SiO3·9H2O and midnight bluegrass under400mg/L Na2SiO3·9H2Owere the best.4.Silicon fertilizer on two varieties of bluegrass had similar results, including chlorophyllcontent, net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO2concentration, Rubisco enzyme activity, reducing the impact of drought stress on bluegrassphotosynthesis. Mitigation effects sequentially were400mg/L>800mg/L>200mg/L.5.Under drought stress, different concentrations of silicon fertilizer could effectively slow downthe bluegrass glutamine synthetase, the rate of decline of sucrose synthase and sucrose phosphatesynthase.400mg/L alleviated with the best results,800mg/L with the second, and200mg/L couldease, but with minimal effects.6.Under drought stress, after the foliar applications for different concentrations of siliconfertilizer, the two bluegrass C/N reduced, compared to the samples with no silicon fertilizerapplied. And the mitigate stress damage effect followed by400mg/L>800mg/L>200mg/L.更多还原