施用城市污泥对小叶黄杨光合特性和生长的影响

城市污泥作为有机肥料施用于园林植物已备受关注.本研究利用温室盆栽试验,分别设置不同用量城市污泥［低量（LC）、中量（MC）和高量（HC）］处理和无机肥（IF）处理,并以不施肥料和污泥为对照（CK）,研究不同用量城市污泥对小叶黄杨幼苗光合特性和生长的影响.结果表明：施用城市污泥可以提高小叶黄杨幼苗叶片叶绿素和氮素含量,但随污泥施用量的增加,叶片净光合速率（P_n）呈下降趋势.在生长季的8月,与IF处理和CK相比,LC、MC处理的叶片P_n均提高,而HC处理却较IF和CK分别降低了25.9%和8.9%;至10月,LC、MC和HC处理的叶片P_n均低于IF处理,但LC处理的P_n仍高于CK,而MC、HC处理的P_n均低于CK,其中HC处理的P_n较IF处理和CK分别降低了48.4%和29.2%.IF处理小叶黄杨植株的株高、地径和根长最大,LC处理次之,且地上生物量最大;MC处理除了株高和地上生物量高于CK外,根长和地径均低于CK;而HC处理则严重抑制了根系的生长.小叶黄杨幼苗的城市污泥施用量应限制在30 t·hm^-2以内.     

长白山阔叶红松林不同深度土壤水分特征曲线

采用露点水势仪对长白山阔叶红松林不同深度（0～10 cm的壤土、20～30 cm的白浆土、50～60 cm的黄土）土壤水分特征曲线进行分析.结果表明：不同土层土壤水分特征曲线整体趋势均表现为快速下降-缓慢下降-基本平稳;用Gardner等提出的幂函数方程可较好地反映该区土壤含水量与土壤水势之间的数量关系,拟合方程的相关系数在0.9239～0.9400;不同土层土壤的持水能力大小依次为黄土>壤土>白浆土,土壤含水量随土壤水势降低而减小的速度依次为壤土>白浆土>黄土.不同土层脱湿过程的土壤水分特征曲线位于吸湿过程之下,说明土壤水分存在滞后现象,且滞后时效依次为壤土>黄土>白浆土.     

不同冬季覆盖作物对稻田甲烷和氧化亚氮排放的影响

采用静态箱-气相色谱法对不同冬季覆盖作物处理［免耕直播黑麦草-双季稻(T₁)、免耕直播紫云英 双季稻(T₂)、翻耕移栽油菜-双季稻(T₃)、免耕直播油菜-双季稻(T₄)和冬闲-双季稻(CK)］下稻田甲烷（CH₄）和氧化亚氮（N₂O）排放进行观测,分析了不同冬季覆盖作物对稻田CH₄和N₂O排放的影响.结果表明：在冬季作物生长期,不同冬季覆盖作物稻田CH₄和N₂O总排放量与对照（CK）的差异均达到极显著水平（P<0.01）;T₃和T₁处理的稻田CH₄和N₂O排放量最高,其CH₄排放量分别为0.88 和0.60g·m^-2,N₂O排放量分别为0.23 和0.20 g·m^-2;冬季作物还田后,各处理早、晚稻田CH4排放量均明显高于对照.早稻田CH₄排放量最高的为T₁和T₂处理,分别达21.70和20.75 g·m^-2;晚稻田CH₄排放量最高的为T₃和T₄处理,分别为58.90和54.51 g·m^-2.各处理早、晚稻田N₂O总排放量均显著高于对照,T₁、T₂、T₃和T₄处理的早稻田N₂O总排放量分别比对照增加53.7%、12.2%、46.3%和29.3%,晚稻田分别比对照增加28.6%、3.8%、34.3%和27.6%.     

Antitumor Diterpenoids from Hedychium yunnanense and Their Photosensitized Oxidation

Two antitumor active diterpenoids, yunnancoronarin C and yunnancoronarin A, were isolated from the rhyzome of Hedychium yunnanense Gagnep. The former is a new compound, whose structure was deter- mined by spectra and chemical methods. Yunnancoronarin C could also be obtained from photosensitized oxidation of yunnancoronarin A as a minor product.     

In vitro propagation of Hedychium coronarium Koen. through axillary bud proliferation

This report describes an efficient and reproducible protocol for large-scale multiplication of Hedychium coronarium plantlets. Axillary bud explants were cultured on Murashige and Skoog medium supplemented with 3 mg/l benzylaminopurine, 3 mg/l kinetin (KIN), and 0.2 mg/l thidiazuron, yielding a maximum of 13.2 ± 0.3 number of shoots. Sub-culturing of shoots every 4 weeks on fresh multiplication medium yielded a consistent proliferation rate. Shoot clusters containing three to five shoots were successfully rooted in KIN (3 mg/l) and indole acetic acid (0.5 mg/l), yielding a maximum of 6.3 ± 0.5 number of roots. Plantlets grown in vitro were acclimatized and subsequently transferred to the field for phenotypic evaluation. Random amplified polymorphic DNA and inter-simple sequence repeat analysis has confirmed the genetic uniformity of in vitro plantlets up to 2 years. After 2 years, these plantlets were transplanted to field, and evaluation of phenotypic characteristics was done. This study is of high significance as these could be commercially utilized for large-scale production of true-to-type plantlets.     

In vitro plant regeneration of Hedychium roxburghii blume through rhizome-meristem culture

Full grown plants have been raised successfully in vitro by culturing meristems excised from rhizome of Hedychium roxburghii Blume on Murashige and Skoog's medium supplemented with NAA and kinetin. Zeatin associated with IAA stimulated the development of buds on the basal region of the stem. A low concentration of NAA (0.2 mg.1^-1) enhanced the root formation on young excised buds.     

箬叶多糖及其化学修饰物、亚硒酸钠和GSH对Cu~(2+)诱导的LDL氧化修饰的保护作用

研究了箬叶多糖ＦⅢ－ａ及其化学修饰物、亚硒酸钠和ＧＳＨ对Ｃｕ２＋诱导的低密度脂蛋白氧化修饰的保护作用．其结果表明箬叶多糖、硫酸酯多糖、硒酸酯多糖可显著抑制脂质过氧化产物（ＴＢＡＲＳ）及荧光物质的生成,彼此之间无明显差异．但对ＶＥ的消耗有着不同的保护作用,其顺序是ＦⅢ－ａ＞Ｓ－ＦⅢ－ａ＞Ｓｅ－ＦⅢ－ａ,并且具有明显的量效关系．硒或ＧＳＨ对Ｃｕ２＋诱导的ＬＤＬ氧化修饰无明显的抑制,但联合使用在０．１２５ｍｍｏｌ／ＬＮａ２ＳｅＯ３和０．２ｍｍｏｌ／ＬＧＳＨ及１２．５μｍｏｌ／ＬＮａ２ＳｅＯ３和０．０２ｍｍｏｌ／ＬＧＳＨ的浓度下能强烈地抑制ＴＢＡＲＳ的生成,甚至比正常的ＬＤＬ还要低．但是对ＶＥ的消耗只有较弱的保护作用,硒酸酯多糖与此相似．Ｎａ２ＳｅＯ３在０．１２５ｍｍｏｌ／Ｌ时可以明显抑制荧光物质的生成．     

接种刺状无梗囊霉对番茄生长及psy1与psy2基因表达的影响

本研究利用前期筛选获得的丛枝菌根真菌(AMF)刺状无梗囊霉XJ27侵染矮化观赏型番茄品种“小汤姆”,分析番茄植株生物量、叶绿素含量以及果实番茄红素含量等相关指标,并采用半定量RT-PCR与实时PCR检测对番茄红素合成相关基因psy1与psy2的表达情况.结果表明：与对照组相比,刺状无梗囊霉处理组番茄的生物量显著增加,增产效果明显;番茄红素合成相关基因psy1与psy2表达增强,果实中的番茄红素含量显著提高.表明刺状无梗囊霉XJ27是一株很有应用潜力的AM真菌.