【作者】 李怡；

【导师】 刘发民； 李毅；

【作者基本信息】 甘肃农业大学 ， 林木遗传育种， 2008， 硕士

【摘要】 水分亏缺是制约树木生长的重要环境因子,尤其干旱、半干旱地区自然条件比较恶劣,干旱少雨,蒸发量大,影响树木的分布、生长和产量。因此,研究灌木植物在黄土高原干旱地区的生长、生理反应,探索这些地区植物的生理生态学特性,对区域植被的建设、保护和发展有重要的作用。本研究是在中国科学院寒区旱区环境与工程研究所皋兰生态农业研究站进行的,依据长期设立的试验观测场地,利用德国WALZ公司生产的GFS-3000便携式光合作用测定系统和德国WALZ公司生产的Mini-PAM光量子分析仪测定了供试植物的光合特性和叶子的叶绿素荧光,通过定期采样,研究了柽柳、拧条、红砂和珍珠叶子的水分生理特性,探讨了这几种灌木植物叶子的投影面积与其干重量之间的关系,对比研究了不同集雨方式对人工栽植的柽柳土壤水分及生理特性的影响,得出以下结论:(1)对自然条件下生长的柽柳和柠条光合速率、蒸腾速率和叶片的叶绿素荧光研究表明:柽柳的光合速率、蒸腾速率日变化都为一单峰曲线,水分利用效率变化曲线呈现双峰型。采用相关分析和多元逐步回归分析方法,得出了光合速率和蒸腾速率与大气CO2浓度、胞间CO2浓度、水汽压、水汽压亏缺等生理生态因子间的相关关系,并建立了相应的影响因子回归方程,与光合作用的相关系数分别可达0.99、0.95,与蒸腾速率的相关系数分别为0.998、0.994。(2)对不同集雨处理样地柽柳的光合速率、土壤含水量、水分特性和生长进行研究表明:柽柳在三种不同处理样地上的光合速率和蒸腾速率日变化都为一单峰曲线,但达到最大值的时间不同。且不同处理的集雨样地对柽柳的光合速率、蒸腾速率、土壤含水量、水分特性、叶片干重和面积的影响都不显著。地埂覆膜和水平沟铺砾石处理的样地表层土的土壤含水量大于对照,而水平沟和地埂均未覆盖处理样地与对照相差不明显。在不同的集雨及保墒处理中,柽柳生长增加比较显著。但在2004到2007年的三年时间,柽柳生长明显比2002到2004年的两年时间生长缓慢。(3)对柽柳和柠条叶片叶绿素荧光的研究表明:以太阳光为化学光,测定的叶绿素荧光参数日变化显示,柠条PSⅡ的非循环电子传递速率大于柽柳,柠条实际光化学量子产量与柽柳差异不大,日动态变化说明PSⅡ实际光化学量子产量对外界光强和气温条件的响应敏感。两种灌木光合机构在中午强光和高温下其光合活性受到了暂时的抑制。但未发生不可逆的光破坏,下午随着光强和温度的下降,其光合器官的功能得到恢复。柠条的光化学猝灭系数qP和NPQ非光化学猝灭系数的日变化可知,柽柳通过光化学猝灭转换光能的作用及非光化学猝灭方式耗散光能的作用都高于柠条。经充分暗适应后的柽柳、柠条的叶片叶绿素荧光参数初始荧光Fo随着光强的增加而增加,变化幅度较小,柠条比柽柳曲线变化平滑。光化学效率(Fv/Fm)随着光强上升而下降,到15:30左右降到最低值。之后,又随光强的减弱逐渐回升。在正常的生长条件下,经过一整夜充分暗适应后,柽柳、柠条叶片的FV/FM,即PSⅡ原初光能转换效率分别为0.76和0.77这一效率值明显低于过去许多研究中提到的0.80-0.85,对一些阳生植物而言,在光照强度远远未达到其光合所需能量时,FV/FM指标会下降。(4)对柽柳、拧条、红砂和珍珠的水分生理特性研究表明:四种植物中红砂和柽柳的抗旱性最强,柠条的最弱。(5)采用扫描图像与Photoshop图像处理软件结合的方法研究柽柳、柠条、红砂和珍珠的叶片投影面积与叶干重之间的关系,柽柳、柠条和红砂叶投影面积与叶干重呈线性相关,柽柳、柠条、红砂和珍珠的叶片投影面积与叶干重之间的关系,所得回归方程分别为:Y=0.055X+0.0085、R2=0.923,Y=0.0488X+0.0297、R2=0.80,Y=0.30X+0.0129、R2=0.53;珍珠的叶片是多浆汁叶,形状极不规则,不能利用目前的扫描仪计算出它的投影面积。(6)采用多元回归方法建立柠条生物量模型,得出了生物量和株高地径之间的关系,推算出每株柠条的生物量大约为:2383.7g。更多还原

【Abstract】 Drought stress is an important environmental factor that affect survival plant and growth. Natural condition in the Semiarid Loess Region of China is badly, where is serious drought and wild evaporation. It is effect on plant distribution, growth and yield . Therefore, It,s play a very important role in ecological restoration and reconstruction, protecting and developing of regional vegetations.Growths and physiological responses and exploring ecophysiological characteristics was studied in the Semiarid Loess Region of China. This research basised for observation of long-term experiment field and made use of the GSF-3000 Portable Photosynthesis System and MINI-PAM Photosynthesis Yield .Analyzer were carried the research on water physiological characteristics of Tamarix ramosissma,Caragana microphylla, Reaumuria soongorica Maxim and Salsola passerina Bge by periodical sample. Studied the relationships between the leaf projection area and the leaf dryweight. Analied moisture physiology of shrubs and Comparative studied the soil water storage and moisture physiology under different environmental conditions in Ecological Agriculture Station Gaolan of Cold and Arid Regions Environmental and Engineering Research Istitute,China. On the basis of all above researches obtain conclusions as following:(1)Diurnal variations of photosynthesis of Tamarix ramosissma and Caragana microphylla were studied under natural conditions. The results indicated that the daily course of Tamarix ramosissima photosynthetic rate (Pn) and transpiration rate (E) were sing-peak curve. And the daily course of water use efficiency was two-peak curve. By the methods of correlation analysis and stepwise multiregression analysis, the correlations between them and environ mental factors were assessed. The related equations were also constructed in this paper, and the photosynthetic rate (Pn) correlation coefficients were 0.99 and 0.5, respectively.And ranspirationate (E) correlation coefficients were0.998, 0.994, respectively.(2)The photosynthesis characteristic, soil moisture content, water characteristics and plants growth of Tamarix ramosissima under different environments were researched. The results showed that the daily course of Tamarix ramosissima under different environments photosynthetic rate(Pn) and transpiration rate(E) were sing-peak curve. But the maximizing time was different. And it was not all significant differences in the photosynthesis characteristic of the special temporal pointers, soil moisture content, water characteristics and the relations between the leaf projection area and the leaf dry weight of Tamarix ramosissima under different environments. The moisture of surface soil was significantly higher for the C treatment than the control, but no significant differences in moisture of surface soil was found between B treatment and control treatment.Rainwater harvesting and moisture conservation treatments increased growth of Tramosissima, tree height was significantly higher for the rainwater harvesting and moisture conservation treatments than the control.It was obviously slow growth the in 2004 to 2007 than 2002 to 2004.(3) The measurement of daily chlorophyll fluorescence parameters with sunlight as the photochemical light indicated that the ETR of Cartagena microphylla was higher than that of Tamarix ramosissima but the qP and NPQ of the former was lower than that of the latter. The Yield was no significant difference between Caragana microphylla and Tamarix ramosissim.After sufficiently adapting to darkness, the chlorophyll fluorescence parameters such as Fo increasing along with the luminous intensity increase,and showed little change.The Caragana microphyll change was smoother than Tamarix ramosissim. The Fv/Fm of the two kinds of plants become lower with the increasing of light’s intensity and reached the lowest at 15:30, then it begins to increase as the light become weak.Under normal conditions,making full dark adaptiong by all-night showed that FV/FM is 0.76 and 0.77 of Tamarix ramosissima and Caragana microphylla.Its lower than 0.80～0.85.Perhaps this is FV/FM decreased in the light intensity far away the energy photosynthesis of sun plants.(4)Comparison of water physiological characteristics in four species, the results indicated that doughty resistance of four species Tamarix ramosissima and Reaumuria soongorica Maxim were the strongest, and Caragana microphyll was lowest.(5) The relationships between the leaf projection area and leaf dry weight of Tamarix ramosissima,Caragana microphylla,Reaumuria soongorica Maxim and Salsola passerina Bge were studied using scanning image processing system and image processing software Photoshop. The relations between the leaf projection area and the leaf dry weight of Tamarix ramosissima、Caragana microphylla and Reaumuria soongorica Maxi were linear. The regression equation were Y=0.055X+0.0085; R2=0.92; Y=0.0488X+0.0297,R2=0.80;Y=0.30X+0.0129,R2=0.53;respectively.The Salsola passé- rine Bge leaf is the multi- thick liquid juice leaf, and the shape is extremely irregular, so its projected area cannot be calculated using the present scanning technology.(6) By the methods of stepwise multiregression analysis to establish the biomass model of Caragana microphylla.The relations between the biomass and the high ground diameter had obtained. The biomass of Solola passerina Bge and Reaumuria soongorica Maxim were 135g, 43.5g, respectively. It was showed that the Solola passerina Bge capacity accumulated dry matter higher that Reaumuria soongorica.更多还原