朱砂根化学成分的分析

通过系统提取法对朱砂根的根、茎、叶三部分分别提取,用化学反应法进行成分鉴定,结果表明:朱砂根中含有叶绿素、挥发油、三萜类、酚类、醌类、强心甙、有机酸、黄酮类、三萜皂苷、鞣质、氨基酸、糖类等多种物质.对朱砂根总皂苷进行定向提取,用紫外扫描测定分析,结果表明总皂苷在436nm和530nm波长具有吸收峰.     

Possible involvement of gibberellins and ethylene in Orobanche ramosa germination

Summary Six inhibitors acting at different stages of gibberellin biosynthesis, applied during conditioning of Orobanche ramosa seeds, reduced subsequent germination in the presence of GR₂₄ (a strigol analogue). Ethylene seems to be involved in the induction of germination of conditioned seeds by GR₂₄, as inhibitors of its synthesis or action, applied to conditioned seeds, also strongly reduced induction of germination by GR₂₄. Exogenous ethylene did not induce germination of conditioned seeds, but 2-chloroethylphosphonic acid was able to do so. When inhibitors of gibberellin biosynthesis were applied to conditioned seeds in the presence of GR₂₄, they inhibited germination. These same inhibitors also strongly inhibited germination of conditioned Striga hermonthica seeds in response to GR₂₄; this inhibitory effect was reversed by the addition of 2-chloroethylphosphonic acid. The effect of these inhibitors on S. hermonthica , in which ethylene is a necessary mediator of germination induction by GR₂₄, strongly suggests that ethylene synthesis is also required for the induction of O. ramosa seed germination by GR₂₄. These growth regulators, which inhibit the two steps of germination in O. ramosa , could be useful for the development of methods for early season control of this parasite.     

朱砂根群体遗传多样性RAPD分析

在对朱砂根形态变异系统观测的基础上,进一步采用RAPD标记技术在DNA水平上对其种内遗传多态性进行检测。结果表明,朱砂根5个群体平均等位基因数A为1.805 2,有效等位基因数Ne为1.460 0,Ne i氏基因多样度H为0.269 9,Shannon多样性指数I为0.406 7。总的群体基因多样性达0.270 6,其中群体间的基因多样性Dst为0.089 4,群体内的基因多样性Hs达0.181 2,群体内的基因多样性高于群体间的基因多样性。说明朱砂根群体间和群体内均存在着丰富的遗传变异,并以后者为主要变异来源。检测结果还表明,15个样本并不足以代表一个群体的遗传多样性,30个样本所代表的群体,其遗传多样性参数则相对一致和稳定。     

向日葵列当毛蕊花糖苷的提取工艺优化及其抗氧化活性

【目的】对向日葵列当（Orobanche cumana）毛蕊花糖苷提取工艺进行优化,并研究其抗氧化活性,为将其作为药材开发利用提供参考。【方法】从3株产木质素降解菌（雷斯青霉（Penicillium raistrickii）、产红青霉（Penicillium rubens）和霉菌（Fungal sp.））和2株产纤维素降解菌（白腐菌（Phanerochaetc chrysosporium）和黄孢原毛平革菌（Phanerochaete chrysosporium））中筛选最优复合菌剂对向日葵列当进行生物破壁发酵处理,通过气相色谱 质谱联用仪（GC-MS）分析复合菌剂降解后向日葵列当中的有效成分;以毛蕊花糖苷提取量为考察指标,以酵解温度、pH值和酵解时间为考察因素,设计单因素试验及响应面优化试验,优化毛蕊花糖苷提取工艺;体外检测毛蕊花糖苷对OH·自由基、DPPH自由基和超氧阴离子的清除能力,分析毛蕊花糖苷的抗氧化活性。【结果】在向日葵列当中共检测出207种化学物质,含量较高的药效成分为苯乙醇苷类物质毛蕊花糖苷,相对含量为2.470%。以雷斯青霉、白腐菌、黄孢原毛平革菌组合作为最优复合菌剂破壁酵解向日葵列当提取毛蕊花糖苷的最佳条件为：酵解温度27 ℃,酵解pH值7,酵解时间3.5 d,在此条件下,向日葵列当中毛蕊花糖苷的提取量为1 396 μg/mL。向日葵列当毛蕊花糖苷对OH·自由基、DPPH自由基和超氧阴离子有一定的清除能力,抗氧化活性明显,且呈剂量依赖性。【结论】向日葵列当中毛蕊花糖苷含量较高,通过复合菌剂发酵破壁处理能够有效提高毛蕊花糖苷的提取效率,且毛蕊花糖苷有明显的抗氧化活性。     

栗树芽内酚类物质含量与抗栗瘿蜂的关系

栗树芽内酚类物质含量与抗栗瘿蜂性状有极显著的相关性．在所测的7个栗树品种中，阳山油栗芽内酚类物质含量最高，其栗瘿蜂虫瘿百分率为最低．而日本栗芽内酚类物质含量最低，其栗瘿蜂虫瘿百分率也就最高．     

朱砂根组织培养防褐化探讨

探讨了朱砂根继代培养中抗氧化剂(维生素C、L-半胱氨酸、硫代硫酸钠)和吸附剂(活性炭、聚乙烯吡咯烷酮)对外植体褐化的影响。结果表明:培养基中添加活性炭3 g.L-1,继代周期控制在30 d之内,平均褐化率可控制在18.89%,效果最理想;培养基中添加维生素C 0.2 g.L-1也能有效控制褐化,但整体效果不如活性炭。     

Genetic differentiation and host preference reveal non‐exclusive host races in the generalist parasitic weed Phelipanche ramosa

We developed 20 microsatellite markers to genotype over 100 populations of the parasitic weed Phelipanche ramosa, which covers a wide host crop and geographic range. A representative core collection of 15 populations was also used in cross‐infestation assays to study host preference during germination, attachment and shoot formation. We observed low genetic differentiation within most of the populations, but high genetic differentiation between populations partitioned into 3 genetic groups with different host preferences and geographic distributions. Genetic group 1 is detected exclusively in western France and on various host crops, notably winter oilseed rape (WOSR) and not hemp. Cross‐infection assays confirmed its incompatibility with hemp and showed its preference for WOSR and tobacco in terms of germination and attachment success. The group 2 populations share a large geographic distribution in France and Europe, low germination success with WOSR and high germination success, attachment success and shoot formation with hemp, tobacco or tomato. The subclades 2a and 2b include most of the French populations in hemp crops in eastern France and in tobacco fields in several European countries respectively. The genetic analyses revealed the potential of the three groups to increase their geographic range in the future. Intermediate genetic groups showed higher intrapopulation diversity and represent potential stocks for new host race emergence. Those findings argue in favour of the existence of host races in P. ramosa and should be considered for appropriate management strategies, notably in breeding programmes for resistance against this parasitic weed.     

一种检疫性寄生杂草——小列当

小列当为检疫性寄生杂草,原产欧洲和中东地区,已在世界各地造成了严重的经济损失,本文阐述了其分类学历史、形态特征、生物学特性、地理分布、传播途径、传播历史及危害性,描述了小列当与其近似种在形态特征上的区别及其防治方法,为小列当的检疫鉴定和综合防治提供理论依据。     

不同处理对朱砂根坐果及生长的影响

探讨了物理和化学方法对朱砂根坐果及生长的影响。物理方法设3个水平:ck、环剥、摘心;化学方法设4个水平:ck、0.1 mg.L-1赤霉素2、mg.L-1硼砂、5 mg.L-1尿素。结果表明,经环剥处理的植株果子较大,且大果率明显提高,但会影响朱砂根整体观赏效果。摘心法能显著提高朱砂根的坐果数,果子相对较小;化学方法对于坐果数和特殊花枝数没有显著性差异,但对果子大小、新梢生长量和特殊花枝长却有极显著差异,经赤霉素处理的植株果子变小、枝条变长、变细、株型松散,严重影响朱砂根的观赏价值。证明在提高朱砂根的坐果数方面摘心法是较为理想的方法,不提倡使用环剥法,慎用赤霉素。     

Fenugreek root exudates show species-specific stimulation of Orobanche seed germination

Various Orobanche species are weedy and cause severe reduction in the yields of many important crops. The seeds of these parasitic weeds may remain dormant in the soil for many years until germination is stimulated by the release of a chemical signal from a host plant. In order to determine the effects of fenugreek root exudate on the induction of Orobanche crenata, Orobanche ramosa and Orobanche foetida seed germination, root exudate was collected from hydroponically grown fenugreek seedlings. Fractionation patterns obtained from column and thin layer chromatography of the fenugreek root exudate showed a set of metabolites differing in their polarity with stimulatory activity on Orobanche seed germination. The crude root exudate stimulated both O. ramosa and O. crenata seed germination to the same level caused by the synthetic germination stimulant GR24 at 10 mg L^?1. It also stimulated O. foetida seed germination which did not respond to GR24. Active fractions of root exudate stimulated the germination of Orobanche species differentially.