多花黑麦草品种比较试验

通过对现行生产中常用的4个多花黑麦草品种在昆明地区的物候期、株高、草产量、生长率、净同化率等指标的规定表明,在生长初期,特高的生产性能比其余3个品种都好,但生长一段时间后,邦德的生产性能明显超过特高(P<0.05),抗锈王略高于特高(P>0.05),旺饲的生产性能最差(P<0.05)。因此,邦德是一个在生产中值得推广应用的品种。     

外来入侵种的危害与防治对策

外来入侵种对当地的自然生态系统结构和功能以及生物多样性都有着深远的影响,而且可能对地方的生态环境和经济造成严重危害。四川已经成为遭受外来入侵种威胁的省份之一,全省现有20多个外来入侵种。为了防止外来入侵种的泛滥,应当建立外来物种的引入评价机制,慎重进行有意引种;加强口岸管理,防止外来入侵种通过贸易途径无意引入,同时采取措施控制已经产生危害的外来入侵种。     

优质牦牛肉肉质的综合评价

2000-2002年对大通牛场40头6月龄不同性别的全哺乳牦牛的肉质进行了综合评价。对供试牦牛肌肉pH、嫩度、肌纤维细度、系水率、肉的贮存损失、肉的煮熟时间、熟肉率和烹饪损失率及肉色等进行了评价，分析了肌肉的化学成分，氨基酸及微量元素含量。结果表明该牦牛肉系水率强，肉的煮熟时间短，肉的贮存损失及烹饪损失较小，肌纤维较细，肉色深红。并具有蛋白质含量高，脂肪含量低及富含各种氨基酸的特点。     

营养液浓度及pH值对山葵生长及光合速率的影响

 探讨了0.5、1.0、1.5 倍日本园试营养液3 种浓度(以清水为对照) 和5.4、6.0、6.6、7.2 等4 种pH 值对山葵生长和光合速率的影响。结果表明, 在营养液1.0 倍和pH 6.0 条件下, 山葵平均根茎鲜质量为42.75 g , 且叶绿素含量和净光合速率显著高于其它处理。     

采收成熟度对牛肝菌保鲜贮藏的影响

不同成熟度的食用菌子实体采后生理、病理及贮藏品质有不同的变化规律 ,本文通过对美柄牛肝菌(BoletusspeciosuFrost)三种不同成熟度的子实体的呼吸强度、呼吸商的测定分析 ,及贮藏过程中菌体外观品质变化综合评定的产生及发展进行分析 ,为牛肝菌采集及贮藏中的原料标准的制定提供依据。     

高压电击法防治黄斑星天牛的研究

对黄斑星天牛虫害木(毛白杨)施以高压电击的实验结果表明,高压电击法对杀灭黄斑星天牛1～3龄幼虫效果明晃,死亡率达70%～80%;各龄幼虫停止取食率80%～90%.高压电击法在防治木材害虫、树木蛀干害虫及木材检疫上具有广阔的开发应用前景.     

半自然条件下几种赤眼蜂及品系对亚洲玉米螟卵寄生能力比较

在半自然条件(田间网罩)下,将人工饲养的玉米螟卵按4、8、16块/株3个处理分别固定在网罩内的玉米植株中上部叶片上,然后每网罩分别引入供试赤眼蜂20头,24 h后更换玉米螟卵块,连续3 d。7 d后调查供寄生的玉米螟卵被寄生率及羽化率。结果表明:在半自然条件下广赤眼蜂伊朗1-1品系虽寄生能力高于其他供试品系,但到第2、3天明显降低;玉米螟赤眼蜂北京6-2-2品系每天均维持一个较平稳的寄生能力,产卵量在时间上的分配比较分散,并在第2、3天显示出比其他品系较高的寄生潜能。广赤眼蜂伊朗1-1品系的卵块寄生数量可随卵块密度的增加而增加,而其他品系则在各处理密度下,寄生数量基本没有变化;从卵粒寄生率看,广赤眼蜂伊朗1-1和吉林1-2两个品系的寄生数量随卵块密度的增加而大幅度提高,其他品系增加幅度较小。     

采收时间对蜡蚧轮枝菌分生孢子的萌发及致病力的影响

将蜡蚧轮枝菌Vp菌株在PDA培养基上23℃黑暗培养,分别于第5、15、20、25、30天后采收。将不同时间采收的分生孢子置于2％葡萄糖培养液内培养,16 h后检测其萌发率,结果表明,采收于第5天和第15天的分生孢子萌发率分别达到89.76％和94.98％,显著高于采收于第25天(30.27％)和第30天(6.12％)的孢子的萌发率;在PDA培养基培养5 d和15 d的分生孢子在相同浓度下对温室白粉虱的致病力分别达到83.40％和74.44％,显著高于培养了30 d的分生孢子的致病力(8.76％)。     

Effects of area and isolation of woodland patches on herbaceous plant species richness across Great Britain

Richness of Ancient Woodland Indicator plant species was analysed in 308 woodland patches that were surveyed during the Countryside Survey of Great Britain carried out in 1998. The Countryside Survey recorded vegetation plots and landscape structure in 569 stratified 1 km sample squares and developed a remotely-sensed land cover map of the UK. Using these datasets, we tested the hypothesis that Ancient Woodland Indicator species richness in woodland fragments was limited by patch area, shape and spatial isolation and that woodland patches located in the lowland region of Great Britain would respond differently than those in the upland region. The variation in Ancient Woodland Indicator species richness in the British lowlands (n = 218) was mainly explained by patch area and two measures of connectivity, the length of hedgerows and lines of trees in the 1 km square and the area of woodland within 500 m of the vegetation plot. By contrast, variation in Ancient Woodland Indicator species richness in the British uplands (n = 90) was related to Ellenberg scores of the vegetation communities sampled – a surrogate for habitat quality – and no significant effect of spatial structure was detected. It therefore appears that the degree of fragmentation of woodland in the British lowlands limits the distribution of Ancient Woodland Indicator species, while in the uplands, failed colonisation is a matter of habitat quality rather than a result of landscape structure.This revised version was published online in May 2005 with corrections to the Cover Date.     

Role of vascular NAD(P)H oxidase in vascular remodeling

NAD(P)H oxidase was initially found in phagocytes and it participates in the generation of reactive oxygen species(ROS). Recent researches have showed that NAD(P)H oxidase also expresses in other tissues including blood vessels and it plays a critical role in vascular remodeling through ROS which are important signaling molecules in vascular cells.This article reviews the biochemical characterization, activation paradigms, structure, and function of this enzyme.