氮素对短葶飞蓬生长和次生代谢产物积累的影响

以不同氮素供应对短葶飞蓬(Erigeron breviscapus)进行了人工栽培试验,探讨氮素对药用植物生长和次生代谢产物含量及产量的影响作用规律.结果显示:氮素施用量与短葶飞蓬植株生物量呈极显著的正相关;而与灯盏乙素和总咖啡酸酯含量则表现出显著的负相关;对总咖啡酸酯和灯盏乙素的产量没有显著的促进作用.植株灯盏乙素和总咖啡酸酯含量与生物量呈现极显著的负相关;与植株含氮量也存在极显著的负线性关系,变化规律与"碳素/营养平衡假说"预测的一致.研究表明,植株生长与次生代谢有效成分积累间存在一定的权衡关系,过多的施用氮肥提高药材产量时将会导致黄酮等酚类次生代谢有效成分含量下降.     

钾素对药用植物短葶飞蓬生长和有效成分积累的影响

在不同钾素供应下对药用植物短葶飞蓬（Erigeronbreviscapus）进行了人工栽培试验,探讨了钾素对其生长和次生代谢产物积累的影响。结果显示：在0～0．372g／株钾素施用量范围内,钾素供应量与短葶飞蓬单株生物量以及总咖啡酸酯和灯盏乙素的产量呈极显著的正相关;但植株总咖啡酸酯和灯盏乙素的含量则随钾素供应量增加先升高后降低;总咖啡酸酯和灯盏乙素含量与植株N含量呈显著的线性负相关,与碳素／营养平衡假说一致。0～0．248g／株钾素施用量范围内,短葶飞蓬地上生物量和总生物量与总咖啡酸酯和灯盏乙素含量都呈现出极显著的正相关。研究表明：当钾供应量不十分丰富时,适当增施钾可促进植株酚类次生代谢产物的积累,但高钾供应量则抑制积累。并不是只有在生长胁迫生境中才能得到高的酚类次生代谢产物积累,生长与次生代谢产物积累间不存在权衡关系。     

短葶飞蓬黄酮及咖啡酸酯的含量与土壤氮供应量的关系

通过对短葶飞蓬(Erigeron breviscapus)不同产地的44个种群植株的总黄酮、灯盏乙素和总咖啡酸酯含量与产地土壤全氮(N)和速效N含量的相关分析, 探讨了产地间土壤N含量变化在药用植物短葶飞蓬植株次生代谢有效成分含量变化中的作用机制。结果显示: 土壤全N含量与种群植株中总黄酮含量呈显著的负相关(r=-0.391, p＜0.01), 而与总咖啡酸酯和灯盏乙素关系不显著; 土壤速效N含量与种群植株中总黄酮(r=-0.528, p＜0.01)、灯盏乙素(r=-0.490, p＜0.01)和总咖啡酸酯含量(r=-0.471, p＜0.01)都表现出更高的极显著负相关关系。全部44个种群中, 有效N供应量变化只能解释次生代谢产物含量的17%~30%的变化。非石灰土壤与石灰土壤的种群分开进行线性回归, 可解释总黄酮含量产地间约80%的变化, 以及灯盏乙素和总咖啡酸酯含量约60%的变化。植株总黄酮、灯盏乙素和总咖啡酸酯含量都与植株含N量存在显著的负相关关系。研究表明: 土壤丰富的有效N供应不利于黄酮和咖啡酸酯的合成积累, 与“碳素/营养平衡假说”的预测一致; 土壤有效N对植物次生代谢产物的影响会受到植物体内外因素的影响。不同产地的短葶飞蓬的黄酮等酚类次生代谢产物含量的差异, 可能是产地间不同的土壤N供应量和其他生态因子及遗传变异共同作用的结果。     

大气二氧化碳倍增对短葶飞蓬生长和有效成分积累的影响

通过对人工倍增CO₂浓度（800±100） μmol·mol^-1与正常CO₂浓度（400±25） μmol·mol^-1条件下短葶飞蓬植株生物量、体内灯盏乙素和总咖啡酸酯含量及产量的比较,探讨了CO₂浓度升高对药用植物短葶飞蓬生物量、有效成分含量及产量的影响.结果表明：CO₂浓度倍增条件下,短葶飞蓬植株生物量增加了22%;总咖啡酸酯及灯盏乙素含量分别增加23%和26%,产量分别增加37.6%和45.3%.不同器官的生物量及有效成分含量对CO₂浓度升高的响应不同.在CO₂浓度倍增条件下,短葶飞蓬植株含氮量减少47.2%,与次生代谢有效成分含量的变化呈反比,符合“碳素/营养平衡假说”;植株生物量与次生代谢产物含量的变化呈正相关,植株生长与次生代谢产物积累之间没有表现出权衡关系.说明合理施用CO₂是可实现短葶飞蓬的优质高产.     

土壤类型对短葶飞蓬灯盏乙素和咖啡酸酯积累的影响

在相同栽培管理条件下,分别以黑色石灰土、红色石灰土、红壤、黄红壤、紫色土和腐殖土为生长介质对短葶飞蓬（Erigeron breviscapus）进行了人工栽培试验。结果显示,生长在不同土壤类型的短葶飞蓬植株体内总咖啡酸酯和灯盏乙素含量有显著的差异。红色石灰土、紫色土及黄红壤生长的植株总咖啡酸酯和灯盏乙素含量最高,黑色石灰土和腐殖土的最低。相同土类的不同亚类土壤生长植株间2种次生代谢产物含量的差异程度,会超过不同土类间的。植株总咖啡酸酯和灯盏乙素含量与土壤P和K含量没有显著相关关系,但与土壤速效N含量及植株含N量则都有极显著负相关关系。不同土壤生长植株叶片的最大光能转换效率（Fv／Fm）值与灯盏乙素和总咖啡酸酯含量都表现出极显著负相关关系。土壤类型对短葶飞蓬次生代谢影响规律与碳素／营养平衡假说（CNB）及资源获得假说（HA）的预测一致。     

短葶飞蓬总咖啡酸酯和灯盏乙素含量的空间变化

依据嵌套分层设计原理制定野外调查取样方案,以药用资源植物短葶飞蓬不同产地93个自然种群310份植株样品的灯盏乙素和咖啡酸酯含量的嵌套方差分析,探讨次生代谢有效成分含量在产区间的空间变化。结果表明:短葶飞蓬有效成分含量存在空间差异,最低含量产区的总咖啡酸酯和灯盏乙素含量分别只是最高含量产区的52.1%和41.8%,但不与产地间的空间距离远近完全一致;同一产地短葶飞蓬总咖啡酸酯和灯盏乙素含量有一定的年际差异,但高含量产地与低含量产地是相对稳定的;作为优质药材的基本产地单元,自然地理区划单元比行政区划单元更科学;短葶飞蓬总咖啡酸酯和灯盏乙素含量与植株含N量呈极显著负相关,符合"碳/氮营养平衡假说"的预测,但植株含N量的变化只能解释短葶飞蓬总咖啡酸酯和灯盏乙素含量不同产区间约30%的变异。植物药材有效成分含量的空间变化是药用植物地区间遗传变异和生长地环境生态因子变化共同作用的结果,用自然地理区划单元为产地单元更客观。确定药材的"优质产地"可作为保障药材有效性的科学管理途径之一。     

不同施氮量对乌龙茶生长和生理的影响

以武夷肉桂为研究对象,研究不同施氮量对乌龙茶幼龄茶树生长和生理的影响。结果表明,幼龄茶树对氮肥的需求不强烈,其新梢生物量、根生物量和总生物量以及茶叶产量随施氮量的增加而下降。茶树新梢全氮、叶绿素、游离氨基酸、茶多酚和咖啡碱的含量随施氮量的增加而增加,而茶树碳氮比随着施氮量增加而下降;但施氮并没有影响茶树总碳含量。老叶叶绿素含量、根全氮和硝态氮含量、新梢总糖含量与施氮量呈二次曲线回归关系,适度施氮促进根对氮的吸收、老叶叶绿素合成和新梢总糖代谢,过度施氮则相反。新梢生物量与其硝态氮含量和游离氨基酸总量显著负相关;根生物量与根碳氮比和新梢咖啡碱含量显著负相关;茎叶生物量和总生物量与根含氮量显著正相关,但与新梢硝态氮和氨基酸含量显著负相关。过度施氮造成茶树生产力下降的主要原因是因为过度施氮极显著提高了茶树氨基酸代谢水平,使用于茶树生长的碳代谢产物（如总糖）减少,进而影响茶树的生长。     

Separation of scutellarin from crude extracts of Erigeron breviscapus (vant.) Hand. Mazz. by macroporous resins

Scutellarin, a flavone glycoside, popularly used in the treatment of heart disease, has been efficiently separated using macroporous resins from crude extracts of Chinese medicinal plant Erigeron breviscapus (vant.) Hand. Mazz. HPD-800 resin offered the best adsorption and desorption capacity for scutellarin among the eight macroporous resins tested, and its adsorption data at 25 degrees C fit best to the Langmuir isotherm. The dynamic adsorption and desorption experiments have been carried out on a HPD-800 resin packed column to optimize the separation process of scutellarin from the crude extracts of E. breviscapus. After one run treatment with HPD-800 resin, the scutellarin content in the product was increased 15.69-fold from 2.61% to 40.96% with a recovery yield of 95.01%. The preparative separation process via adsorption-desorption method developed in this study provides a new approach for scale-up separation and purification of scutellarin for its wide pharmaceutical use.     

大穗型小麦叶片性状、养分含量及氮素分配特征

采用田间试验研究了8个大穗型小麦新品系和西农979不同生育期比叶面积(SLA)、叶干物质含量(LDMC)与养分含量的差异性,并对其不同器官氮素积累和分配情况进行了探讨。结果表明,大穗型小麦的SLA和LDMC平均值小于西农979;小麦叶片养分含量由大到小依次为全氮(N)、全钾(K)和全磷(P);成熟期大穗型小麦品系各器官平均氮素积累能力都高于对照,氮素积累量及分配比例的大小顺序为籽粒>茎+鞘>穗草(穗轴+颖壳)>旗叶>倒二叶>余叶;大穗型小麦平均转移率和贡献率较西农979低;抽穗期旗叶SLA和LDMC呈负相关关系,SLA和N含量呈不显著的正相关,和P、K呈极显著的负相关。小麦叶片结构性状与养分含量影响体内有机物质的积累与转运,通过水肥调控措施来提高大穗型小麦养分利用效率的研究需进一步加强。     

氮、磷、钾施用对灯盏花产量和主要提取物收获量的影响

通过设置N、P、K不同施肥量处理,研究了施肥量差异对灯盏花（Erigeron breviscapus（Vant.）Hand.-Mazz.）的生长指标、产量、3种主要提取物（野黄芩苷、总咖啡酸酯和总黄酮）含量及单位面积收获量的影响。结果表明,增施N、P肥对植株生长指标具有促进作用。随着N、P、K肥施用量的增加,植株产量逐渐升高,且以施N肥的增产幅度最大。一定范围内施用N肥可导致灯盏花3种主要提取物含量降低,而P、K肥的施用则对此没有影响。3种主要提取物单位面积收获量与产量之间呈极显著正相关,N、P、K肥的施用可以提高灯盏花的产量从而增加3种提取物的收获量。N、P、K肥施用量分别为103.5、126.0、112.5 kg/hm²时获得的提取物单位面积收获量最大。     

氮肥形态和用量对藏东南地区烤烟产量和质量的影响

在藏东南地区进行了氮肥用量和形态对烟产量与质量影响的田间试验。结果表明,在施N量0－150kg·hm^-2范围内,施N量与烘烤后烟叶产量、产值、氧化钾及总N含量呈显著或极显著正相关,与上中等烟比例、还原糖含量则呈显著负相关,糖／碳比显著下降,氮肥用量75kg·hm^-2时,产量、质量最佳。无机氮肥对烟产量与质量的效应极显著优于有机氮肥。铵态氮、硝态氮、硝铵态氮肥处理间除上中等烟比例,其它各项指标仅略有差异,但均极显著优于酰胺态氮肥。铵态氮对烤烟产量与质量的影响略优于硝态氮,主要在于烟株吸收和同化过程的差异。     

Influence of Elevated CO2 Concentration and Nitrogen Source on Photosynthetic Traits in the Invasive Species Eupatorium adenophorum (Asteraceae)

Increases in the concentration of atmospheric CO2 and plant invasion are two important problems that face humans worldwide. In some plants, exposure to a short term elevated concentration of CO2 (SE［CO2］) promotes photosynthesis, but the promotion of elevated ［CO2］ (E ［CO2］) to photosynthesis might disappear after long term treatment (so called “CO2 acclimation”); this might result from the associated inhibition of nitrate assimilation. The present study investigated the physiological effects of short term (8 days) and long term (40 days) exposure to E［CO2］ when these were combined with different forms of inorganic N (full N; nitrate (NO3-) N) in the invasive species Eupatorium adenophorum. Exposure to E［CO2］ increased the biomass of Eadenophorum, regardless of the duration of exposure to E［CO2］ and the type of inorganic N that was supplied. E［CO2］ could promote the photosynthesis of Eadenophorum seedlings fertilised with non depleted Hoagland solutions (full N). For plants fertilised with NH4+ depleted Hoagland solution (NO3- N), LE［CO2］ treatment promoted the photosynthesis of Eadenop horum, but the promotion of photosynthesis by E［CO2］ disappeared under SE［CO2］ conditions. Photosynthetic pigments contents were determined to estimate potential changes in the photosynthetic capacity of Eadenophorum. For plants fertilised with non depleted Hoagland solution, there were no significant differences in chlorophyll among the three ［CO2］ treatments, but the treatment of SE［CO2］ increased the levels of chlorophyll in leaves. The apparent promotion of biomass accumulation and photosynthesis at LE［CO2］ without a decrease in chlorophyll indicates that Eadenophorum might not acclimate to long term exposure to E［CO2］. NH4+ depletion did not affect the capacity of LE［CO2］ to promote the photosynthesis of Eadenophorum. Thus, considering some plants fertilised with NO3- acclimating to LE［CO2］, Eadenophorum might be more competitive in areas where the soils are relatively poor in NH4+ as levels of atmospheric CO2 continue to rise.     

Effects of N application on N accumulation of two Erigeron breviscapus populations from different altitudes under enhanced ultraviolet-B radiation

To study intraspecific differences in N utilization in response to enhanced UV-B radiation, field experiments were conducted on two Erigeron breviscapus populations (Huguo and Cangshan), which were respectively obtained from low altitude (UV-B sensitive) and high altitude (UBV-B resistant).The effects of soil nitrogen (N) application (0, 15, 30, 45 g m²) on free amino acid content, the activities of nitrate reductase (NR) and glutamine synthetase (GS), total nitrogen content and N mass in leaves were determined under enhanced UV-B radiation (5 kJ m²) for both populations. The results showed that under enhanced UV-B radiation: (1) increases in total N contents in leaves of the Huguo and Cangshan populations correlated with the amount of N applied. Additionally, leaf biomass of Huguo treated with 15 g m^?2 N application and Cangshan with 30 g m^?2 N application were higher than that of other treatments. Leaf N masses were highest in both E. breviscapus populations treated with 30 g m^?2 N; (2) increases in contents of free amino acids in leaves of both E. breviscapus populations correlated with the amount of applied nitrogen; (3) increases of NR activity in leaves correlated with the amount of applied nitrogen; (4) GS activity in leaves of the Huguo and Cangshan E. breviscapus populations were highest with respective N applications of 15 g m^?2 N and 30 g m^?2 N. In general, under enhanced UV-B radiation, N application might affect NR and GS and change free amino acid content, resulting in changes in total nitrogen content, biomass and N mass. The optimal amount of supplemental N for N accumulation in E. breviscapus was 30 g m^?2 N under enhanced UV-B radiation.     

施氮水平影响蚯蚓介导的番茄生长及抗虫性

过量施用氮肥不仅导致严重的生态环境问题, 还会限制土壤生物驱动的生态系统服务功能。蚯蚓的取食和掘穴等活动可以促进土壤肥力和植物生长, 进而影响植物与病虫害的关系。了解氮肥与害虫作用下蚯蚓对植物抗虫性的影响, 有助于揭示土壤动物的生态功能调控机制。采用蚯蚓(威廉腔环蚓Metaphire guillelmi)、西花蓟马(Frankliniella occidentalis)和氮肥用量的三因子完全交互设计, 利用番茄(Lycopersicon esculentum)盆栽实验探索了不同氮水平下蚯蚓对番茄生长及对植食者抗性的影响。结果表明, 在低氮条件下蚯蚓显著降低了番茄茎叶干生物量、根系干生物量及茎叶可溶性糖含量, 而茎叶的茉莉酸和水杨酸含量分别是无蚯蚓对照的6倍和3倍, 且伴随着西花蓟马数量下降了58%。在高氮水平时, 蚯蚓未影响番茄茎叶茉莉酸、茎叶水杨酸含量及西花蓟马数量。蚯蚓介导的番茄营养物质(茎叶可溶性糖和茎叶全氮)和防御信号物质(茎叶茉莉酸和茎叶水杨酸)含量分别与西花蓟马数量呈显著的正相关和负相关。总之, 氮肥施用改变的土壤氮有效性通过改变植物资源和防御物质含量转变了蚯蚓介导的植物抗虫性响应; 全面了解土壤生物对植物生长的影响需要综合考虑土壤管理-土壤动物-植物病原物三者之间的关系。     

Root responses to nitrogen pulse frequency under different nitrogen amounts

Responses of morphology and biomass allocation of roots to frequency of nitrogen (N) pulse potentially influence the fitness of plants, but such responses may be determined by root size. We grew 12 plant species of three functional groups (grasses, forbs, and legumes) under two N pulse frequencies (high vs. low supply frequency) and two N amounts (high vs. low supply amount). Compared to low-amount N supply, high-amount N supply stimulated biomass accumulation and root growth by either increasing the thickness and length of roots or decreasing the root mass fraction. Compared to low-frequency N supply, high-frequency N supply improved biomass accumulation and root growth in forbs or grasses, but not in legumes. Furthermore, the magnitude of the response to N frequency was significantly negatively correlated with root size at the species scale, but this was only true when the N amount was high. We conclude that root responses to N frequency are related to plant functional types, and non-legume species is more sensitive to N frequency than legume species. Our results also suggest that root size is a determinant of root responses to N frequency when N supply amount is high.     

盐城海滨湿地盐沼植被对土壤碳氮分布特征的影响

在盐城海滨湿地不同植被带下采集土壤样品,研究了土壤有机碳和全氮的空间分布特征,分析了盐沼植物对湿地土壤碳、氮分布的影响.结果表明：在盐城海滨湿地,表层土壤中有机碳和全氮含量分别介于1.71～7.92 g·kg^-1和0.17～0.36 g·kg^-1之间,变幅较大,不同植被带之间存在显著差异,且各植被带表层土壤中有机碳、全氮含量均高于光滩.垂直方向上,各植被带土壤中有机碳、全氮的分布均呈自表向下逐渐降低的趋势,15 cm以下其含量基本保持稳定.土壤有机碳与全氮、碳氮比呈显著正相关,但全氮与碳氮比无显著相关性.     

Effects of ecological factors on secondary metabolites and inorganic elements of Scutellaria baicalensis and analysis of geoherblism

This study analyzed the effects of ecological factors on secondary metabolites of Scutellaria baicalensis using two sources: 92 individual roots of S. baicalensis from all over China, and secondary metabolites, medicinal materials and inorganic element contents obtained from the testing of 92 S. baicalensis rhizosphere soil samples. The study used environmental data from the Genuine Medicinal Material Spatial Analysis Database. Most of the chemical constituents of S. baicalensis were negatively correlated to latitude and positively correlated to temperature; generally, the contents of 21 chemical constituents were higher at low latitudes than that at high latitudes. By gradual regression analysis, it was found that the content of baicalin in S. baicalensis was negatively correlated to latitude and generally the content of inorganic elements in soil was excessively high (excluding Mg and Ca), which has a negative effect on the accumulation of chemical constituents in S. baicalensis. Based on the cluster analysis of 21 constituents, S. baicalensis from different places of origin was divided into two groups, and S. baicalensis was not genuine only in a specific small region. Within the zone from Chifeng, Inner Mongolia to Taibai, Shaanxi is suitable for accumulation of secondary metabolites of S. baicalensis and such a zone represents a suitable distribution and potential genuine producing area.     

闽江河口湿地植物氮磷吸收效率的季节变化

以闽江河口湿地土著种芦苇与入侵种互花米草为研究对象,测定了二者地上生物量和氮、磷吸收效率.结果表明：芦苇和互花米草地上生物量的季节变化呈典型的单峰值曲线,芦苇夏季地上生物量最大,达到2195.33 g·m^-2,互花米草则秋季最大,达到3670.02 g·m^-2;不同季节芦苇和互花米草氮、磷吸收效率均呈单峰值曲线,芦苇氮、磷吸收效率分别在夏季和秋季达到最高(21.06 和1.12 g·m^-2),互花米草均在秋季达到峰值(26.76和3.23 g·m^-2);芦苇和互花米草的氮吸收效率极显著大于磷(P<0.01),且互花米草的氮、磷吸收效率显著大于芦苇(P<0.05);植物N/P、C/N和C/P对植物氮、磷吸收效率有一定指示意义.     

盐城海滨湿地盐沼植被对土壤碳氮分布特征的影响

在盐城海滨湿地不同植被带下采集土壤样品,研究了土壤有机碳和全氮的空间分布特征,分析了盐沼植物对湿地土壤碳、氮分布的影响.结果表明：在盐城海滨湿地,表层土壤中有机碳和全氮含量分别介于1.71～7.92 g·kg^-1和0.17～0.36 g·kg^-1之间,变幅较大,不同植被带之间存在显著差异,且各植被带表层土壤中有机碳、全氮含量均高于光滩.垂直方向上,各植被带土壤中有机碳、全氮的分布均呈自表向下逐渐降低的趋势,15 cm以下其含量基本保持稳定.土壤有机碳与全氮、碳氮比呈显著正相关,但全氮与碳氮比无显著相关性.     

猪场废水施用对直播稻磷素吸收利用与氮磷生态化学计量的影响

以直播稻为对象,在上海农场进行了猪场处理废水基肥和穗肥不同用量组合的田间试验,研究猪场废水对水稻磷养分吸收利用与氮磷生态化学计量的影响。结果表明:施用猪场处理废水对直播水稻干物质积累、植株磷含量有显著影响。水稻拔节期、齐穗期和成熟期干物质积累量以及产量随废水施用量增加而增加;拔节期、齐穗期和成熟期植株、秸秆及籽粒含磷量与废水用量皆呈显著正相关;不同施肥处理在整个生育期水稻植株N∶P为3.13～5.10,在拔节期、齐穗期、成熟期分别为3.13～4.83、3.42～4.35、3.98～5.10,总体上以齐穗期N∶P值较低;成熟期秸秆N∶P值变动较大(4.30～6.57),而籽粒变化较小(3.85～4.37);齐穗期植株、成熟期秸秆、籽粒和植株的N∶P值与废水施用总量皆呈显著正相关,表明废水施用对直播稻氮素吸收的促进作用大于磷素。