濒危植物毛柄小勾儿茶生境特征研究

通过对小勾儿茶Berchemiella wilsonii的变种毛柄小勾儿茶Berchemiella wilsonii(Schneid.)Nakai var.pubipetiolata H.Qian的实地调查,对其分布概况、生境特性以及种群生存概况等方面进行了分析。结果表明:(1)毛柄小勾儿茶主要分布于安徽省霍山县马家河、舒城县万佛山和浙江省临安市湍口乡、临安市马啸乡等地。常见分布于沟边、路边、悬崖峭壁的向阳面。(2)毛柄小勾儿茶对水分及光照的要求较高,喜温暖湿润气候,成年植株主要分布在群落最高层,其幼苗耐荫性差,难以在郁闭度高的林内生长。(3)毛柄小勾儿茶种子大都落在树旁,缺乏有效传播方式,且种子未熟先落,95%无活性,导致极其缺乏幼苗。毛柄小勾儿茶生态位十分狭窄,是群落的伴生种或偶见种,缺乏群落竞争力。毛柄小勾儿茶数量已极其稀少,建议加大保护力度,加快对种子成熟生理机制的研究,提高种子活性。或是探索有效的规模化繁育技术,进行人工抚育小苗,扩大种群数量。     

RTK技术解析及在工程测量中的应用

GPS（RTK）改变了传统的测量方式,使原本复杂、费时、费力的工作变得简单,它的出现是测绘行业发展的重大里程碑,对测绘行业的发展起到巨大的推动作用。     

浸渍用三聚氰胺树脂固化时间影响因素的研究

分析了浸渍用三聚氰胺树脂的性能指标、固化剂种类及用量、环境温度等对其固化时间的影响。研究发现：浸渍MF原胶的性能（pH、固含量、游离甲醛等）均不同程度影响树脂的固化速度;不同种类的固化剂及其添加量,浸渍MF固化反应存在明显差异;原纸的pH值和环境温度影响MF树脂的固化反应。     

氮磷亏缺条件下杨树幼苗根系分泌酚酸的动态

采用循环收集装置收集杨树幼苗根系分泌物,采用超高压液相色谱法(UPLC)对根系分泌物中的酚酸含量进行测定。结果表明:在正常、缺N、缺P处理下杨树幼苗根系均能分泌对羟基苯甲酸、香草醛、苯甲酸和肉桂酸等酚酸类物质,养分缺乏显著促进杨树根系分泌酚酸。在缺N条件下,杨树幼苗较正常培养条件下酚酸分泌增加量为对羟基苯甲酸125%～263%、香草醛201%～316%、苯甲酸230%～332%、肉桂酸138%～188%,且根系分泌的各酚酸量随着胁迫时间的延长呈明显增加趋势,但3个培养时间段内(0～5天,6～10天,11～15天)酚酸分泌量差异未达显著水平(P>0.05);在缺P条件下,杨树幼苗较正常培养条件下酚酸分泌增加量为:对羟基苯甲酸96%～124%、香草醛58%～156%、苯甲酸222%～734%、肉桂酸99%～328%,其中,苯甲酸和香草醛的分泌量随胁迫时间的延长呈明显增加趋势,而苯甲酸和肉桂酸呈现先升后降的趋势。缺N、缺P处理下,杨树幼苗根系分泌酚酸的平均速率也存在一定差异,对羟基苯甲酸和香草醛在缺N条件下的平均分泌速率高于缺P培养,而苯甲酸和肉桂酸的平均分泌速率低于缺P培养。杨树幼苗在N,P缺乏条件下根系分泌酚酸...     

几种天牛纤维素酶的来源

测定３种常见天牛：桑粒肩天牛（ＡｐｒｉｏｎａｇｅｒｍａｒｉＨｏｐｅ）、星天牛（ＡｎｏｐｌｏｐｈｏｒａｃｈｉｎｅｎｓｉｓＦｏｒｓｔｅｒ）和桔褐天牛（ＮｅｄｅｚｈｄｉｅｌｌａｃａｎｔｏｒｉＨｏｐｅ）消化道纤维素酶活性，发现几种天牛幼虫均有完整的纤维素酶体系，即Ｃ１酶、Ｃｘ酶和β－葡萄糖苷酶，能真正消化利用食物中的纤维素成分；以微晶纤维素（ＭＣ）和羧甲基纤维素钠（ＣＭＣ－Ｎａ）为碳源的选择性培养基培养几种天牛肠液，未发现纤维分解真菌及能分解ＭＣ的细菌；肠道解剖及肠组织切片未发现特殊的共生菌囊及含菌细胞；比较天牛的纤维素酶与常见真菌纤维素酶的性质相差甚远。因而认为所研究的几种天牛其纤维素酶均为其自身分泌的内源性酶而不是来源于其它生物。     

CURRENT STATUS OF ANTELOPES IN CHINA

UpliftingofQinghai-TibetanPlatcausincemidTertiary'caused-climaticdifferc11tia-tionbetWeenwesternandeasternChina.Ontheotherhand,thestrongmonsoonsincelatePleistoccnehasenhancedtheenvironmentalchanges,westernChinaundersuchenviron-mentalchangeshasbecomedrier'andstepPeanddesertvegetationshavedeveloPedinthesearidAsianinlandwhereasshortalpinevegeta-tionshavedeveloPedontheQinghai-TibetanPlateau.Thus'theenvironn1entalchangesinrecent3million\'earscreated\'asthabitatforUngulatespecies,particularly"…     

干热河谷和干旱山地人工混播造林试验

干热河谷和干旱山地的人工混播造林试验，于１９９１～１９９２年在永胜大龙潭、猫猫山和水平水泄３个造林困难的地区进行。选用车桑子、山毛豆、银合欢、滇合欢、银荆、黑荆等树种进行人工混播造林试验。还分别进行了云南松与车桑子、银荆、黑荆、滇合欢、红木荷、金合欢的混播造林试验。经３、４年的试验，通过对各参试树种的种质评价，落种状况、出苗率、成苗率和各成苗期，苗木生长状况的观测。得出以车桑子、山毛豆、银合欢作为干热河谷和干旱山地的混播造林种较好。可在今后形成多树种，多层次的林分环境。     

Ectomycorrhizal fungus (Paxillus involutus) and hydrogels affect performance of Populus euphratica exposed to drought stress

? Mycorrhizal fungi and hydrogels (water-absorbing polymers) can improve water availability for trees. The combination of both factors for plant performance under water limitation has not yet been studied.

? To investigate the influence of the ectomycorrhizal fungus Paxillus involutus, hydrogel and the combination of both factors, a drought-sensitive poplar, Populus euphratica, was examined in this study.

? After 16 weeks of inoculation, no ectomycorrhizas were found. Nevertheless, P. involutus-inoculated poplars displayed increased concentrations of soluble sugars and osmolality, leading to an improved water status. Growth was diminished compared with non-inoculated P. euphratica. The presence of hydrogels in the rooting medium resulted in increased biomass and higher plant water content and decreased the osmolality of plant tissues. Drought markedly decreased water contents in rooting medium and plants, and leaf chlorophyll fluorescence, and stimulated the root growth, concentrations of soluble sugars and osmolality in plants. Under drought conditions, P. euphratica exhibited osmoregulation by accumulation of low-molecular-weight carbohydrates.

? These data indicate that adding hydrogels to soils may improve the plant performance. The reasons for improved osmoregulation by fungi and hydrogels were probably related to their stimulating influence on the formation of soluble carbohydrates under drought conditions.

     

Dammarane-type saponins from Panax quinquefolium and their inhibition activity on human breast cancer MCF-7 cells

A new compound, named quinquefoloside-L_c (1), together with nine known compounds, was isolated from leaves of Panax quinquefolium, and its structure was elucidated as 3β,12β,20S-trihydroxy-25-methoxydammar-23-ene 3-O-β-d-glucopyranosyl (1 → 2) β-d-glucopyranosyl-20-O-β-d-xylopyanosyl (1 → 6) β-d-glucopyranoside (1), on the basis of MS, 1D-and 2D-NMR experiments as well as by chemical degradation. The cytotoxicity of these compounds against human breast cancer MCF-7 cell line was also tested by MTT method.     

配方施肥对白桦不同家系苗期生长的影响

选择7个白桦半同胞家系种子分别播种育苗,在苗木生长过程中配制T1、T2、13 3种配方的氮磷钾混合营养液定期进行叶面施肥,系统地研究配方施肥对白桦不同家系苗期生长的影响对每个家系内3种施肥处理与非施肥处理的苗木苗高、高径比、茎根比进行方差分析和多重比较,确定各个家系的最佳施肥配方.结果为:家系1、家系3、家系4和家系5的最佳施肥配方均是T2,该施肥处理能够使白桦苗高提高13.43%～35.74%;家系6和家系7的最佳施肥配方均是T3,该施肥处理能够使白桦苗高提高24.93%和26.46%;家系2的最佳施肥配方是T1.3种施肥配方均能改善白桦苗期的生长,对7个家系总体而言,T2为最佳施肥配方.