【作者】 伏兵哲；

【导师】 米福贵；

【作者基本信息】 内蒙古农业大学 ， 草畜种质资源学， 2010， 博士

【摘要】 串叶松香草（Silphium perfoliatum L.）,属菊科松香草属多年生草本植物。原产于北美洲中部潮湿高草原地带,1979年引入中国。其蛋白质含量高,富含各种氨基酸,是一种优质青饲料。本研究对引种到呼和浩特地区的串叶松香草进行了抗寒敏感性,引种驯化世代遗传规律以及施肥效应研究,其目的是为在呼和浩特地区大面积推广应用和新品种选育提供技术体系和理论基础。研究获得以下结果:1在自然越冬过程中,串叶松香草侧根的电导率,可溶性糖,可溶性蛋白和脯氨酸含量随温度的变化均呈先增加后减少的变化趋势;根颈的电导率和脯氨酸含量也呈先增加后减少变化趋势,但根颈的可溶性糖和可溶性蛋白含量随温度的变化逐渐减少;根颈和侧根组织中的含水量随温度变化呈先降低后升高趋势。根颈的电导率和组织含水量明显高于侧根,可溶性糖,脯氨酸和可溶性蛋白含量均低于侧根。2串叶松香草侧根的初生结构由表皮、皮层和中柱三部分组成,初生木质部呈束状,与初生韧皮部相间排列;次生结构主要由周皮、次生韧皮部、维管形成层和次生木质部组成,在次生韧皮部中有分泌腔。根部淀粉颗粒含量较少,呈圆球型,主要分布在表皮和皮层细胞中。随着温度的降低淀粉颗粒逐渐水解,到翌年3月份温度回升又开始淀粉的积累。蛋白颗粒呈卵圆型,主要存在于初生韧皮部和皮层中,随温度的降低蛋白颗粒在细胞内会大量积累。3根颈入土较浅,对低温敏感,根颈中积累的渗透调节物质较少,1月份地表温度低是串叶松香草在呼和浩特地区受冻害致死的主要原因。入冬前浇水和返青前水可以使串叶松香草的返青期提前。入冬前根际覆土和浇水可以明显提高越冬率、根蘖芽数和产草量。4串叶松香草经自然选择和人工驯化后,越冬率由原始群体的59.21%提高到驯化2代的86.36%。不同驯化世代在根颈长、根颈粗、茎生叶宽、基生叶长、株高和千粒重6个表型性状有明显的变异,且随着世代的推移逐渐变小;在光合日动态曲线,光响应曲线,净光合速率,蒸腾速率和水分利用率等光合因子方面具有较大差异,随驯化世代的推移串叶松香草净光合速率有变大趋势。5从串叶松香草4个世代的3个等位酶系统中,共检测出5个等位酶位点,14个等位基因,平均多态位点的百分率为64.29%。6对AFLP引物扩增总共产生265个基因位点,各世代的平均多态性位点数为203个,平均多态性达76.6%。Nei’s基因多样性指数和shannon’s信息指数分析显示,串叶松香草具有较高的遗传多样性,且遗传多样性随世代的增加呈减小趋势,世代内的遗传变异大于世代间,遗传变异主要发生在世代内。6增施氮磷钾肥能够显著提高串叶松香草产草量、鲜干比、种子产量和品质,其中草产量最高的施肥组合为:N 90kg/hm²,P2O5 60kg/hm²,K2O 25kg/hm²;种子产量和质量最高的施肥组合为:N 90kg/hm²,P₂O₅ 90kg/hm²,K₂O 50kg/hm²。更多还原

【Abstract】 Silphium perfoliatum is a perennial herb belongs to Silphium genus of Compositae. It originated in humidity high grassland areas of central north America, introduced into China in 1979. It has high protein content,rich in inamino acid, high quality green fodder. Sensitivity of cold resistance, inheritance of domestication generation and fertilization effect of S. perfoliatum were researched to provide the theoretical and technical bases for new variety breeding and extension utilization of the species in Hohhot area in this paper. The main results were as follows:1 The conductivity, the soluble sugar content, the soluble protein content and the proline content of lateral root of S. perfoliatum increased at the beginning and then decreased following with temperature changes. The conductivity and the proline content of root crown also increased at the beginning and then decreased, but the soluble sugar concent and soluble protein content decreased with temperature changes. Tissue water content of lateral root and root crown decreased at the beginning and then increased following with temperature change. The conductivity and tissue water content of root crown were significantly higher than lateral root, but the soluble sugar content, the proline content and soluble protein content were lower than lateral root.2 The primary structure of lateral root of S. perfoliatum were composed of epidermis, cortex and stele. Primary xylem was fascicular alternated with primary phloem. The secondary structure were mainly composed of periderm, secondary phloem, vascular cambium and secondary xylem, secretory cavity was in the middle of secondary phloem . There were little starch granules in root of S.perfoliatum, which showed spheroidal, mainly existed in the epidermis and cortex cells. Starch granules were hydrolyzed gradually with the temperature decreased, and accumulated with the temperature increased until March next year. Protein particles showed ovoid and single grain, mainly existed in the primary phloem and cortex. Protein particles were accumulated with the temperature decreased.3 The low temperature of soil surface in January in Hohhot areas, the sensitivity to low temperature, the root crown situated nearly to the soil surface, and the little accum- ulateed osmotic regulation substances before winter was the main reasons caused the free -zing injury of S. perfoliatum. Returning green stage of S. perfoliatum could be advanced by irrigation before winter and returning green. Overwintering rate, overwintering buds and forage yield production were increased significantly by covering soil and irrigation before winter.4 The root crown length, root crown diameter, stem leaf width,basal leaf length, plant height and 1000-grain weight were varied significantly in different generations. Overwintering rate of S. perfoliatum was improved from 59.21% of original generation to 86.36% of second generation through natural and artificial selection in Hohhot area The variation degree of 6 phenotypic traits were smaller along with the generations alternation. The photosynthesis factors such as diurnal variations of photosynthetic curve, light response curve,net photosynthetic rate, transpiration rate and water use efficiency had also significant variation, and net photosynthetic rate had increased with the generations increasing.5 14 alleles and 5 loci were detected from 3 enzymes of 4 generations, and the percentage of average polymorphic loci was 64.29%. 265 loci and 203 polymorphic loci were detected by 6 AFLP primers, average polymorphic loci percent was 76.6%. Nei’s gene diversity and Shannon’s information index showed: S. perfoliatum had great genetic diversity, and genetic diversity was decreased with the increasing of generations. Genetic variation within generations was larger than that among generations, and mainly occurred within generations.6 Forage production, fresh and dry matter ratio, seed yield and seed quality of S. perfoliatum were improved significantly by fertilize N、P、K fertilizers. The maximal fertilizer combination for forage production, yield and quality of seed was the N 90kg/hm²,P2O5 60kg/hm²,K2O 25kg/hm² and N 90kg/hm², P₂O₅ 90kg/hm², K₂O 50kg/hm² respectively.更多还原