桑黄残渣黄酮提取工艺研究

利用桑黄提取多糖后的残渣,采用乙醇回流法提取桑黄黄酮,实现桑黄高值化。首先对提取温度、提取时间、料液比、乙醇体积分数进行单因素试验,然后通过正交试验优化提取黄酮的工艺条件,并通过与VC的对比研究桑黄黄酮粗提液对·OH和DPPH·的清除能力,以探讨其抗氧化活性。研究表明,最佳工艺条件为提取温度90℃,提取时间4 h,料液比1∶30,乙醇体积分数60%,在此条件下黄酮的提取率为5.12%,所得到的桑黄黄酮粗提液对·OH的清除能力比VC高,对DPPH·的清除能力比VC稍弱。     

沙棘木腐病菌的新记录种——沙棘针层孔菌

本文报道了中国多孔菌一新记录种，沙棘针层孔菌Ｐｈｅｌｌｉｎｕｓ ｈｉｐｐｏｐｈａｅｉｃｏｌａ，根据中国的材料进行了详细描述，并与模式产地的标本和近似种进行了异同比较，该菌为青藏地区沙棘林的重要病原菌。     

桑黄新菌株“桑-S”经济性状的研究

为了更好地了解桑黄新菌株"桑-S"的综合经济性状,以国内生产使用的其他桑黄菌株桑-H、桑-R、桑-Z、桑-JT、桑-AJ为对照,通过对杨凌示范区大棚栽培的桑黄新菌株桑-S的经济性状进行分析比较。结果表明,桑黄新菌株"桑-S"对绿霉菌抵抗力强,生物转化率最高达5%,子实体主要活性成分桑黄多糖含量高,达4.76%,黄酮含量为4.34%,粗三萜含量为1.85%,总氨基酸含量为9.73%。表明该桑黄新菌株具有很高的食用和药用价值,丰产性良好。     

鲍氏层孔菌以固体培养基为基质的人工培养技术研究

试验目的在于探索出鲍氏层孔菌子实体人工培养的发酵培养基的最佳配方。配方设计采用3因素3水平的正交试验设计，找出适于鲍氏层孔菌生长的最佳氮源、碳源及木屑种类，以及3者的最佳组合配方。     

秦巴山区野生桑黄人工栽培技术研究

采用代料栽培对秦巴山区野生桑黄进行人工驯化研究,比较了不同温度、湿度、光照、通气等条件对桑黄子实体生长的影响,确定了出菇期的管理关键技术。结果表明,桑黄人工栽培子实体生长最适温度为25℃～30℃,湿度90％一95％,光照300lx,早中晚各通风10min,平均每袋产桑黄干品36g。     

部分稀土元素对桑黄液体发酵的影响

研究了5种稀土元素（镧、铈、钕、镨、铒）对桑黄液体发酵的影响。实验结果表明,不同的稀土元素在适宜浓度时对桑黄生物量以及多糖、三萜和黄酮等活性物质的合成,均具有一定的促进作用。其中稀土元素铈和铒有利于桑黄生物量的积累,并分别在浓度0.01 mmol.L-1和0.1 mmol.L-1时使生物量达到最大值（5.85±0.14）g.L-1和（5.34±0.45）g.L-1,比对照提高了23%和13%。而稀土元素铈、钕和镧则对桑黄胞外多糖、胞内多糖和胞内三萜的合成具有明显促进作用,其中铈在浓度0.01 mmol.L-1、钕在浓度0.1 mmol.L-1、铈在0.01 mmol.L-1时分别使胞外多糖、胞内多糖和胞内三萜产量达到最大值（610.36±0.31）mg.L-1、（789.09±2.09）mg.L-1和（106.70±2.92）mg.L-1。本文所考察的5种稀土元素都在一定程度上促进了桑黄胞外三萜和黄酮的合成,但稀土元素镧、钕和镨对胞外三萜诱导效果相对较好,而钕、铒和铈则对黄酮诱导效果相对较好。综合来看,稀土元素对桑黄液体发酵的影响,与稀土元素的种类和浓度密切相关,体现出一定的选择性和特异性。     

桑黄漆酶的发酵条件研究初报

采用液体深层培养方法通过不同碳源、氮源、pH值、温度等因素对桑黄产酶量的影响,研究桑黄合成漆酶的最适发酵条件。采用L9(34)正交设计法对桑黄合成漆酶发酵培养基进行了优化,初步筛选出了桑黄合成漆酶发酵培养基。结果表明,培养基为玉米粉1%、麦麸1%、葡萄糖2%、蛋白胨0.5%、酵母膏0.5%、磷酸二氢钾0.1%、硫酸镁0.05%、添加Cu2+浓度60μmol.L-1,维生素B1 1 mg.100-1.mL-1,漆酶产量最高,为7 666 U.L-1。     

桑黄黄酮的超声波辅助醇提工艺优化及其体外抗氧化活性测定

黄酮是桑黄的重要活性成分,具有多种药理作用。在对料液比、提取温度、提取时间3个因素进行单因素试验的基础上,应用响应面法对桑黄黄酮的超声波辅助乙醇回流提取工艺进行优化,并测定其还原力及对DPPH自由基、羟基自由基的清除作用。结果显示,桑黄黄酮提取的最优工艺条件为料液比1∶40、提取温度100℃、提取时间5 h,在此最优工艺条件下的桑黄黄酮提取得率为4.41%,达到回归模型预测值的98.44%;3个因素对桑黄黄酮提取得率的影响从大到小依次为提取温度、提取时间、料液比,并且料液比与提取时间之间存在交互作用;提取的桑黄黄酮具有较强还原力以及对DPPH自由基和羟基自由基的强清除作用,表现出明显的体外抗氧化作用。     

Evaluation of dazomet as fumigant for the control of brown root rot disease

BACKGROUND: Brown root rot disease caused by Phellinus noxius is widespread in approximately 216 tree and plant species in tropical and subtropical countries. No direct means of protection against P. noxius infection have thus far been developed. Therefore, in this field survey, a method was developed for preventing and controlling brown root rot disease using fumigation with dazomet. RESULTS: Tracers were used to monitor the effect of dazomet fumigation. The results from field surveys and phytotoxicity tests showed that dazomet is able to kill P. noxius without any side effects on plants. CONCLUSION: The use of an environmentally friendly agent to control brown root rot disease is needed, and prevention of the disease is more important than treatment. Hence, chemical fumigation with 60 g m^?2 of 98% dazomet may be a possible means of preventing P. noxius incursion in agriculture, gardening and agroforestry. Copyright © 2012 Society of Chemical Industry     

Long-term effects of post-harvest stump removal and N-fertilization on understory vegetation in Western USA forests

Intensive forest management practices often disturb understory vegetation, and the recovery of these plant communities may depend on the type and severity of the disturbance. We examined the effects of stump removal and N-fertilization on understory plant communities and functional group (shrubs, graminoids, forbs, and introduced species) cover and diversity at five study areas in the Pacific Northwest of North America 24–28 years after treatment. Treatments at each study area included stumped and non-stumped controls as well as four levels of broadcast ammonium nitrate (0, 336, 672, and 1345 kg N ha⁻¹) in all combinations. Stumping had significant effects on community composition at all sites, and several plant species were associated (p < 0.05) with either controls or stumped plots. Diversity of graminoids, forbs and introduced species increased in stumped areas region wide. Stumping reduced cover and diversity of shrubs at some sites. Cover of graminoids and forbs also increased in stumped plots at some study areas. Forbs like Viola sempervirens were often indicators of stump removal while shrubs such as Acer circinatum tended to be associated with non-stumped plots. N-fertilization affected community composition at only one study area, and had no effects on cover or richness of functional groups. Stump removal has lasting impacts on plant communities and may make them more vulnerable to colonization by introduced species.