【作者】 吕梅；

【导师】 方炎明；

【作者基本信息】 南京林业大学 ， 植物学， 2008， 博士

【摘要】 红桤木(Alnus rubra)为非豆科共生固氮速生、先锋树种,主要分布在北美太平洋西北部。该树种能改良土壤,是良好的伴生树种,具有很好的商业价值。以引种到我国南京及周边地区的红桤木为材料,本文系统地研究了红桤木的扩繁技术、生长规律、光合生理、根瘤固氮活性及氮磷营养生理,进行了根瘤超微结构观察和Ca2+-和ATPase的细胞化学定位,对放线菌根瘤内生菌进行了分离、培养和观察,进一步比较研究了两个菌株生长特征及生理特性。主要结果如下:播种育苗的技术关键包括播种时间与深度、苗床覆盖、苗期水分管理等。试验表明,红桤木幼苗能在南京地区安全过暑和越冬。在研究嫩枝和硬枝扦插技术的基础上,分六次测定了扦插生根过程中内源激素的含量,其初终值为:IAA 106.66和162.02 ng/g,GA1/3,16.62和25.37ng/g,ZR 8.2和22.23ng/g,均呈“上升-下降-上升”趋势,谷值出现在第37天。ABA(176.54和150.02ng/g)呈“下降-上升-下降”,峰值也出现在第37天。通过两地四年的连续观察证实:在安徽南陵,4年生苗木高1.5～7.0 m,地径2.130～9.456 cm;在南京六合,4年生苗木高2.1～5.3 m,地径2.682～10.2cm;并且呈现更加快速生长的趋势;在两试验地第四年普遍开花结实。两年生苗木季节性生长规律观察表明,苗高和地径生长曲线均呈“S”形。这些结果说明红桤木速生,适合两地生长,引种成功。二年生苗光合特性测定结果表明:净光合速率日变化单峰型,出现在4月24日(13.94μmol/m2?s)、10月10日(16.64μmol/m2?s)和11月20日(10.28μmol/m2?s),或呈双峰型,出现在6月11日11:00和15:00时(13.7和12μmol/m2?s)和8月9日9:00和15:00时(17.7和16.85μmol/m2?s)。蒸腾速率也具有明显季节性变化,日变化曲线均呈单峰曲线,最高值出现在10月10日,峰值为4.921μmol/m2?s。作者还对净光合速率和蒸腾速率与光量子密度等气象因子和气孔导度等生理生态因子间的关系,进行了相关和回归分析。与未结瘤对照相比,结瘤苗木显著地提高了组织中叶绿素含量、硝酸还原酶(NR)活性、谷氨酰胺合成酶(GS)活性、可溶性蛋白含量和硝态氮含量,也显著提高了生长量和生物量;结瘤植株叶面喷施无氮Hoagland营养液,与未结瘤植株喷施含混合氮或硝态氮Hoagland营养液相比,表现出更好的生理和生长状态;施加磷肥也促进了红桤木的生长。这些结果显示红桤木表现出良好的固氮活性。透射电镜观察表明,Ca2+和H+-ATPase反应颗粒在根瘤细胞中的定位具有一致性。在根瘤无菌细胞中,主要沉积在细胞质膜和淀粉粒周围,以及内陷的质膜和壁内突上。在含菌丝的根瘤细胞内,反应颗粒的定位与菌丝发育的时期有关。从放线菌根瘤中分离出菌株33个,对其中的23株包括红桤木8个(LH001～LH005,NL001～NL003)、四川桤木7个(SM003～SM004和SM006～SM010)、江南桤木4个(ZP1,ZP3,ZP4,ZP6)和杨梅4个(ZY1～ZY4),进行了结构观察和生长状况的分析。LH002和NL001两菌株具有以下特点:适应性强,可利用多碳源,适生pH范围分别为6.0-12.8和4.0-12.0,耐盐能力强,NaCl浓度达到5%时仍能生长。这些特性显示两菌株具有很高的潜在应用价值。更多还原

【Abstract】 As a lowland species, red alder (Alnus rubra) is most often observed along the northern Pacific coast. This species is desired for soil nutrient enhancement, good associated species, and the major commercial hardwood tree species. Thereby we carefully studied the species, focusing not only on introduction, cultivation, propagation, growth, and photosynthesis under field conditions, but also on effects of nodulation on nitrogen forms and phosphorus levels, and on activities of nitrogen fixation. The ultrastructure and cytochemical localization of calcium and ATPase activities in the root nodules from red alder was also investigated in detail. Isolation and culture characteristics of the endophyte Frankia from root nodules of A. rubra and other nitrogen fixing trees were observed in this study. Moreover, we compared the differences of growth, morphology and physiological characteristics of two endophyte frankia strains from A. rubra and A. cremastogyne. The conclusions are as follows:Key technologies of sowing and seedling raising of red aler were recognized including the following aspects: depth and time, coverage of nursery bed, management of moisture, and so on. Field Experiments indicated that seedlings of red alder had capacity to survive in hot Summer and cold Winter in Nanjng.Based on the cutting techniques of epicomic branches and mature branches, we determined the contents of endogenous hormones at different time points (0d, 20d, 30d, 37d, 42d, 45d) during rooting process of mature branch cutting. Initial and final values of different endogenous hormones in the cuttings within the period were listed here: 106.66 and 162.02 ng/g for IAA, 16.62 and 25.37 ng/g for GA1/3, and 8.2 and 22.23 ng/g for ZR. The full data demonstrated that the levels of IAA、GA1/3、ZR presented a tendency towards“up-down-up”, with the valley value at the 37th day. The ABA levels, 176.54 and 150.02ng/g for the initial and final values, showed an opposite tendency towards“down-up-down”, with the peak value at the 37th day.A four-year successive observation on red alder growth in two experiment fields indicated that significant growth was achieved and sexual maturity was mostly reached within four years. At the end of the fourth year, growth increment, measured by stem height and ground diameter, of red alder was highly variable, e.g. 1.5～7.0 m for height and 2.13～9.45 cm for diameter in Nanling, Anhui, while 2.1～5.3 m for height and 2.68～10.20 cm for diameter in Liuhe, Nanjing. The growth data of two-year old red alder showed that the seasonal growth rhythms of height and diameter increment both took on a curve of“S”-form. These results demonstrated that as a fast-growing species, red alder was successfully introduced and seemed to grow well in the two places.The seasonal and diurnal variations of net photosynthetic of two-year-old seedlings in red alder fields were characterized by the following two patterns, a variation curve of single peak on Apr.24 (13.94μmol/m2?s), Oct.10 (16.64μmol/m2?s) and Nov.20 (10.28μmol/m2?s), as well as a variation curve of double peaks at 11:00 am and 15:00 pm on Jun.11 (13.7 and12μmol/ m2?s ) and at 9:00 am and 15:00 pm on Aug.9 (17.7 and 16.85μmol/m2?s). The transpiration rates varied dramatically among seasons. The diurnal variation curves showed a single-peak pattern with a peak value of 4.921μmol/m2?s. By means of correlation analysis and stepwise multi-regression analysis, the multi-correlation among net photosynthetic rate (Pn) and transpiration rate (Trmnol), with meteorological factors, for example, quanta flux density (QFD) and physio-ecological factors such as conductance to water (Cond), were also assessed. The relation equation was established in this paper.Compared to the control of non-nodulation, red alder nodulation significantly improved growth rate and biomass. Remarkable increase was found in the contents of chlorophyll and soluble protein, and nitrate nitrogen, as well as activities of nitrogen reductase and glutaminase. With the application of foliage fertilizer of non-nitrogen Hoagland nutrition, the red alder with nodule roots had better effects on physiological and growth state than the non-nodulation plants spraying mixed or nitrate nitrogen Hoagland fertilizer. Phosphorus liquid fertilizer without nitrogen also promoted growth of red alder. These data supported good activities of nitrogen fixation in red alder.Observation of transmission electron microscopy (TEM) demonstrated that reaction grains of calcium and ATPase had identical location in nodule root cells. These grains were generally located on the cytoplasm membrane, starch periphery, plasmalemma invagination, and wall ingrowth in the non-endophyte cells. In the endophyte cells, however, the positions of reaction grains were different, depending on development stages of endophytes.Thirty three strains were obtained from root nodules of five species, and twenty three strains of them were studied focusing on structure observation and growth state analysis. These observed strains were eight strains from A. rubra, seven from A. cremastogyne, four from A. trabeculosa and four from Myrica rubra.The strains of LH002 and NL001 had characters as follows: strong adaptability, multiple utilization approaches of carbon sources, broad ranges of pH value (6～12.8 for LH002 strain and 4～12 for NL001 strain). On the other hand, these strains could survive at a high concentration (5%) of sodium chloride. Therefore, both strains had high potential application value.更多还原