柳枝稷论文：黄土高原引种柳枝稷的生态适应性研究.doc

柳枝稷论文：黄土高原引种柳枝稷的生态适应性研究【中文摘要】本研究以10种不同基因型与生态型的柳枝稷品种(Alamo、Blackwell、Cave-in-Rock、Dakota、Forestberg、Illinois USA、Kanlow、Nebraska 28、Pathfinder和Sunburst)为受试材料,分别引种到黄土高原地区(陕西杨凌、陕西定边、宁夏固原),采用小区栽培试验和室内实验分析的方法,针对柳枝稷存活及生长情况、生理生态特征和形态学特征来鉴定柳枝稷的生态适应性。柳枝稷的存活情况在每年春天返青季节观测,主要观察每个品种是否顺利越冬;株高与地上部生物量于每个生长季节后期测定,通过烘干获得干物质量;柳枝稷光合速率、蒸腾速率以及水分利用效率的日变化通过LI-6400便携式光合仪测得,分析柳枝稷生物量积累及其在干旱地区生存、生长的内在机制;通过扫描式电子显微镜电镜(SEM)观察柳枝稷(根、茎和叶)的形态学特征,为柳枝稷引种、生理生态的进一步研究提供科学依据。低地品种Alamo和Kanlow可能成为杨凌示范区种植的优选品种,主要是由于品种能在杨凌稳定建立种群并生长,获得较高地上部生物量,Alamo地上部干物质年生产量高达44.22 t/ha。然而,Alamo与Kanlow在固原与定边不能忍受冻害而未存活。Illinois USA和Cave-in-Rock在固原生长五年后分别获得年地上部干物质重量10.59 t/ha和9.36 t/ha。Cave-in-Rock在定边的生长情况与固原相似,其产量为存活品种中最高。Cave-in-Rock和Nebraska 28光合速率较高,可能说明了这两品种积累较多有机物质的内在机制。品种间光合速率在一天当中的14:00点左右差异明显,大小依次为Cave-in-Rock Blackwell Sunburst Forestberg Pathfinder Nebraska 28 Dakota。蒸腾速率的峰值中Cave-in-Rock和Blackwell的值较大,Nebraska和Dakota的较小;蒸腾速率在14:00点左右达到最大峰值,较大的蒸腾速率品种为Cave-in-Rock和Blackwell,最小的为Nebraska 28和Dakota,此时,受试品种间蒸腾速率差异达极显著水平(P Blackwell Sunburst Forestberg Pathfinder Dakota Nebraska 28。Nebraska 28和Pathfinder表现出较强的抗旱能力,主要原因是这两个品种的水分利用效率(WUE)较高。Dakota在三个地区的生长情况较差,且属早熟品种,地上部生物量积累较少。优化牧草刈割制度对柳枝稷的地上部生物量影响较大, Illinois USA刈割后地上部生物量比对照增产61.7%,而Sunburst、Forestberg和Pathfinder两处理(刈割与非刈割)之间差异不明显。柳枝稷组织中硅细胞、液泡大小、叶片表皮毛以及其他特征的观测结果表明Cave-in-Rock和Pathfinder叶片的气孔面积最大,分别达到824.4m2和770.1m2。Pathfinder硅细胞长度最长,而Cave-in-Rock的硅细胞长度最短;Forestberg叶片硅细胞密度最大,而最小的硅细胞密度最低的为Cave-in-Rock和Pathfinder。植物茎秆及叶片中硅细胞多少与其坚韧程度相关;液泡的大小和植物的保水能力是植物减缓干旱胁迫的有效途径;柳枝稷叶片的表皮毛在电镜中可观察到(杨凌栽培的Blackwell和Cave-in-Rock与固原Dakota尤为明显),表皮毛的存在是柳枝稷自身在适应环境变化过程中形成的,对植物体水分蒸腾过程也起到抑制作用。固原四个供试柳枝稷品种(Nebraska 28、Pathfinder、Forestberg和Dakota)对生菜化感作用最强的为Nebraska 28,八倍体的Pathfinder对生菜的化感抑制作用最弱,而同为四倍体的Forestberg和Dakota抑制作用较强,且具有相似化感潜势。Forestberg、Nebraska 28、Dakota地上部蒸馏水浸提液对生菜的抑制作用均强于根系,而Pathfinder根系化感抑制作用强于地上部,品种间存在差异;柳枝稷甲醇浸提液对生菜的化感抑制作用较明显,与蒸馏水浸提液差异显著;高浓度对胚根的化感作用强于其它两个指标,而低浓度处理下,生菜胚芽的化感响应较为敏感。柳枝稷的形态学特征可能与其染色体倍性和适应干旱环境的生理机制有关,因此柳枝稷品种的生态型及本身特性是引种成功与否的关键,在种植地区,低地品种Alamo与Kanlow、中地品种Illinois USA、Cave-in-Rock、高地品种Nebraska等品种可在杨凌种植;而在固原地区,Cave-in-Rock、Illinois USA可能是优选品种;自然环境条件与固原相似的定边地区,Cave-in-Rock、Forestberg、Illinois USA和Pathfinder应为首选品种。【英文摘要】In the study, ten cultivars of switchgrass (Panicum virgatum L.) (Alamo、Blackwell、Cave-in-Rock、Dakota、Forestberg、Illinois USA、Kanlow、Nebraska 28、Pathfinder and Sunburst) were selected as the test materials. The field test and laboratory analysis of cultivation methods were conducted, and the growth traits, survival rate and ecological characters were observed to indentify their ecological adaptation. Exceptionally, photosynthesis and morphology characteristics of several cultivars of switchgrass have been assessed the yield potential and adaptability in diverse environments on the Loess Plateau of China (Yangling, Dingbian of Shaanxi Province, and Guyuan of Ningxia).The survival rate was observed in the second spring and identified which were the optimal cultivars to undergo the cold stress successfully. The height and biomass yield had been measured in the later growth period, then dried and measured the dry mater. The fully open leaves were selected, while switchgrass was in bloom, to survey photosynthesis rate (Pn) and transpiration rate (Tr) at 9:00, 10:00, 12:00, 14:00, 16:00, 18:00 and 20:00 respectively, using a Licor LI-6400 instrument. The internal mechanism of the biomass accumulation and drought tolerance were analyzed through the indicators mentioned above. Silica particles, vacuole size and other traits in switchgrass tissues (stem, leaf and root), as well as trichomes (leaf) were observed by the Scanning Electron Microscope (SEM), which should provide the proofs of the further researches of switchgrass on the physiological ecology.The results indicated that Alamo and Kanlow were the best adapted switchgrass cultivar for biomass production in Yangling with aerial parts dry matter (DM) yields of 44.22 t/ha per year due to it easily established and well grown; the lowland cultivars Alamo and Kanlow had not survived, probably owning to their sensitivity to the cold stress in Guyuan and Dingbian. Illinois USA and Cave-in-Rock grown at Guyuan had aerial parts DM yield of 10.59 t/ha and 9.36 t/ha, respectively. Similarly, Cave-in-Rock in Dingbian performed better than others except the lowland cultivars (Alamo and Kanlow), which could not overcome cold stress at Guyuan and Dingbian. Moreover, Cave-in-Rock and Nebraska 28 has the highest photosynthesis rate which reflects its high productivity. At 14:00, was the time-point of most significant difference among different cultivars in the photosynthesis rate, which displayed the pattern of Cave-in-Rock Blackwell Sunburst Forestberg Pathfinder Nebraska 28 Dakota. Maximum transpiration peak appeared in Cave-in-Rock and Blackwell, while the minimum was observed in Nebraska 28 and Dakota. The rate exhibited the most significant difference at 14:00, following Cave-in-Rock Blackwell Sunburst Forestberg Pathfinder Dakota Nebraska 28. In addition, Nebraska 28 and Pathfinder had shown stronger drought tolerance due to their higher WUE. Dakota showed its most weak adaptability in the Loess Plateau areas; its productivity was the lowest among the cultivars. Optimal mown management seems to enhance the growth and productivity of switchgrass, the aerial parts biomass yield of Illinois USA mown had increased 61.7% than the control (not mown), and there was no significant difference between the two treatments (mown and not mown) the cv. Sunburst, Forestberg and Pathfinder. Morphological characteristics were further studied using light-and scanning electron microscopy (SEM). Silica particles, vacuole size and other traits in switchgrass tissues (stem, leaf and root), as well as trichomes (leaf) were observed and showed that Cave-in-Rock and Pathfinder had larger stoma area, up to 824.4m2 and 770.1m2, respectively. Silica particle length was the longest in Pathfinder and shortest in Cave-in-Rock. There was a highest density of silica particles in cv. Forestberg, and lowest in Cave-in-Rock and Pathfinder. Silica particle in plant stems and leaves was associated with degree of tenacity; vacuole size and water capacity of the plant is an effective way to overcome drought stress; switchgrass leaf trichomes were visible clearly through SEM (especially in the leaves of Blackwell and Cave-in-Rock, and Dakota in Guyuan), the trichomes formed in the process of adapting the environment and had play an important role on transpiration process.The four varieties of switchgrass Pathfinder, Forestberg, Nebraska 28 and Dakota were investigated in the experiment. The results indicated that Nebraska 28 had the strongest allelopathy while Pathfinder shown the weakest allelopathy. The allelopathy of Pathfinder root was higher than that of aerial part which was different from others. The allelopathic effects of methanol extracts were higher than that of aqueous extract in diluted treatments. The radicle length of Lettuce was shown significant influence at high concentration while the coleoptile length was displayed a significant influence at lower concentration.The morphological characters seemed to be associated with their ploidy levels and the arid habitat from which they were selected. Therefore, if switchgrass is to be introduced and extended on the Loess Plateau of China, Lowland cultivars Alamo and Kanlow, intermediate cultivar Illinois USA、Cave-in-Rock would be the optimal choices in cultivating in Yangling, and Cave-in-Rock、Illinois USA maybe the good cultivars grown in Guyuan; Cave-in-Rock、Illinois USA、Forestberg and Pathfinder exhibited better than others, and the optimal choice seem to be them.【关键词】柳枝稷 黄土高原 地上部生物量 光合作用 形态学特征 化学生态适应性【英文关键词】Switchgrass the Loess Plateau biomass yield of aerial parts photosynthesis morphology characters Chemical ecological adaptability【目录】黄土高原引种柳枝稷的生态适应性研究摘要5-7ABSTRACT7-8第一章 文献综述12-191.1 柳枝稷及其生物学特征121.2 柳枝稷主要功能121.3 生态适应性12-141.4 国内外研究进展14-171.4.1 国内研究进展141.4.2 国外研究进展14-171.4.2.1 优质牧草14-151.4.2.2 生物质能源15-161.4.2.3 柳枝稷的生态适应性161.4.2.4 柳枝稷的肥料管理16-171.5 研究目的和意义17-19第二章 不同品种柳枝稷存活适应性研究19-222.1 引言192.2 材料和方法19-202.2.1 试验材料192.2.2 研究区概况19-202.2.3 实验步骤与方法202.3 结果分析20-212.4 讨论212.5 小结21-22第三章 不同品种柳枝稷地上部生长差异研究22-323.1 引言223.2 材料和方法22-233.2.1 试验材料223.2.2 实验方法22-233.2.3 数据处理233.3 结果与分析23-313.3.1 杨凌栽培的柳枝