驼绒藜等8种耐旱灌木持水力分析

采用切枝自然脱水法测定了驼绒藜等8种耐旱植物的持水力及几个相关参数。结果表明,随着脱水时间的延续,植物间失水率的差异先是由小增大,后又趋于缩小,规律性十分明显。分析表明,个体间失水率差异与植物间失水率差异具有相同的消长模式,且二者峰值的时间进程基本吻合,从而导致植物间差异显著性峰值向右偏移。提出Logistic方程拟合法,认为方程拐点是植物种类间和个体间生理活性变化最大时期的客观标志之一。拐点是失水率曲线上多点信息的综合体现,且具有动态性质,因而相对于其他点状体系或静态标准,拐点用于持水力的判断表现出最高效率。依据以拐点为核心的失水率体系,将8种灌木的耐旱性分为3组。特别针对华北驼绒藜所表现出的超强的耐旱性参数,对华北驼绒藜与驼绒藜相对旱生地位的传统认识提出了质疑。     

从梭梭的土壤条件谈它的恢复和发展

梭梭是我国西北干旱荒漠地区抗旱、耐盐碱、抗风沙的优良防风固沙林、薪炭林和饲料林树种。共有二种,即梭梭柴和白梭梭,二者皆系旱生抗风沙植物。其中梭梭柴生态幅度较宽,可在沙质、砾质、土质和盐土荒漠生长,分布较广;而白梭梭生态幅度较窄,天然分布仅限于准噶尔盆地的沙质荒漠。因此,应分别采种育苗,分别造林。解放以来,梭梭林受到严重破坏,面积减少,不少地区生态条件恶化,向沙漠化发展,影响沙漠前沿绿洲的安全。因此,保护,恢复和发展梭梭林是十分必要的。行之有效的主要措施有:封育,人工造林(包括直播、植苗、径流造林、灌溉造林等)。     

旱生观赏植物资源及其开发利用价值

本文在阐述了27种旱生观赏植物的生长特性和观赏特点的基础上,总结了我区旱生观赏植物所共有的观赏特点及其观赏价值,提出应大力开发、利用这类资源以促进干旱地区园林绿化事业发展的观点。     

柄扁桃幼苗的水分生理特征研究

对乌兰察布市察右后旗人工造林地土壤含水量及柄扁桃幼苗水分生理特征进行研究。结果表明,由于长期干旱,样地土壤含水量降到7.24%以下,柄扁桃自然含水量为68.41%,束缚水与自由水比值为1.01,其自然饱和亏缺为17.94%。持水力测定表明,柄扁桃持水力曲线斜率大。PV曲线分析表明,Ψπ100和Ψπ0值为7.08 MPa。蒸腾速率日进程变化分析表明,柄扁桃的＂午休＂现象不很明显。     

Na compound fertilizer stimulates growth and alleviates water deficit in the succulent xerophyte Nitraria tangutorum (Bobr) after breaking seed dormancy

Nitraria tangutorum (Bobr), a typical succulent xerophyte with high level of seed dormancy, is one of the few shrubs found to date that can develop and form fixed dunes in desert regions. Our studies have demonstrated that the strong drought tolerance of the succulent xerophytes was strongly linked to high sodium (Na⁺) accumulation in the photosynthesizing branches (PB) as well as leaves. The study is to explore a method that can rapidly promote the seed germination of N. tangutorum, and then investigate the positive effects of Na compound fertilizer (NaCF) on the growth and drought tolerance of N. tangutorum and ecological environment by short-term pot experiment in a greenhouse and long-term field and pot experiment in a desert environment. The results indicate that the germination rate of seeds obtained a maximum by 69% when seeds were treated with 150 mg L ^?1 gibberellic acid (GA₃) for 48 h followed by soaking in concentrated sulfuric acid (98% H₂SO₄) for 55 min, and then germinated (25/5°C) in darkness for 8 d. After breaking seed dormancy, the NaCF significantly stimulated growth of N. tangutorum and, concomitantly, improved its ability to cope with water deficit (30% of field water capacity) by increasing Na⁺ more than Potassium (K⁺) accumulation for osmotic adjustment in greenhouse and desert conditions. The contribution (take the pot experiment in the desert, for example) of Na⁺ to the osmotic potential (compared with control) varied from 13.9% in plants subjected to diammonium phosphate [(NH₄)₂HPO₄] to, surprisingly, 63.9% in plants grown in the presence of NaCF under water deficit. The distribution characteristics of the total Na⁺ (1620 mg) in the NaCF indicate that 691.2 mg (42.7%) is absorbed by plants, 848.8 mg (52.4%) remained in the pot and 80 mg (4.9%) leached, which accounted for 2.2% of the nursery soil, respectively. The positive effect of NaCF on the drought resistance of N. tangutorum and the ecological environment were also confirmed in the field experiments. These findings suggest that the rapid seed germination technology of N. tangutorum combined with the popularization and application of NaCF can shorten the seed germination period and make the seedling establishment much easier, which may be an effective strategy to restore and reconstruct degraded vegetation in many desert regions.     

大棚蔬菜土壤盐渍化治理技术研究

针对大棚蔬菜土壤次生盐渍化问题,通过进行水旱轮作、灌水洗盐、不同改良荆改良等一系列试验,比较得出水旱轮作降盐增产效果明显,灌水洗盐也有一定效果,可推广应用.     

我国旱生植物的形态解剖学研究

干旱威胁世界农业的生存和发展，是人类所面临的最严重问题之一。植物的抗旱性研究历来受到各国学者的重视，是当前植物学研究的热点，本文概括和总结了我国旱生植物的形态解剖学研究历史和进展，并对其进行评述，阐明植物抗旱性研究的发展趋势。