Does waste feed from salmon farming affect the quality of saithe (Pollachius virens L.) attracted to fish farms?

Salmon farms attract large amounts of wild fish, which prey on uneaten feed pellets. The modified diet of the wild fish aggregating at salmon farms may reduce the flesh quality of the fish, influencing the local fisheries. We compared the quality of saithe (Pollachius virens) captured near (farm associated—FA) or more than 5 km away (un‐associated—UA) from salmon farms in Norway. The fish were captured during summer, autumn and spring using two commercial fishing methods (jigging and bottom nets). Overall, the fillet quality of FA saithe was good, although it was clearly reduced for almost 10% of the catch. Moreover, the quality of the FA saithe was significantly reduced compared with UA saithe, but the differences were small. Our results also showed that fish caught with jigging had better quality than fish caught with nets, and that fish that died in the nets were of lower quality than fish that were alive after hauling. There was no clear variation among seasons in fillet quality. Although no major and overall differences in quality were found between FA and UA saithe, reduced quality for even a modest proportion of the fish may influence the value of the total catch.     

樟子松无性系种子园种子生产及其苗木培育

樟子松种子园无性系间的花粉量、种子产量均存在着差异,这种差异,是由樟子松无性系本身的遗传基因决定的。种子园中,往往少数无性系控制着园内50%以上的花粉量和种子产量。由于部分无性系种子产量低,育苗、造林时这些家系容易丢失。为减少家系的丢失数量,育苗时,应改善圃地的环境条件,增加土壤肥力,加强除草等抚育措施,提高育苗水平。     

Aripuanin, a megastigmane skeleton from Ficus aripuanensis

The isolation and NMR spectra of aripuanin (1), a sesquiterpene from Ficus aripuanensis, are reported.     

Gastrointestinal activity of Ficus sur

The gastroprotective effects of some extracts of the dried leaves of Ficus sur in animals were investigated in order to validate the use of the plant in traditional medicine. The water and methanol extracts showed antiulcer activity, the hot water extract being the most effective. These extracts had also spasmolytic effects on the rabbit jejunum. LD₅₀ values ranged from 900 to 1200 mg/kg in mice. These results show that F. sur has potential in the treatment of ulcers.     

稻曲病菌分离技术的初探

用7种培养基和2种分离方法对稻曲病菌的培养及分离技术进行了研究。结果表明,胁本哲氏培养+抑制细菌生长的氯霉素(50 μg/mL)是分离稻曲病菌最适宜的培养基。稻谷是厚垣孢子产生的理想培养基。厚垣孢子悬液法可用于稻曲病菌的快速分离,而稻曲球不同层次组织块分离法可从保存长时间的稻曲球分离到稻曲病菌。     

稻曲病的接种技术研究

 探索在田间条件下进行稻曲病的人工接种技术。通过比较3种接种体发现,上年保存于-20℃的厚垣孢子不能引起发病;用PS液体培养获得的薄壁分生孢子可引起发病,孢子浓度越高引起病穗率越高;菌丝片段-分生孢子混合液接种发病最严重。病原菌的培养菌龄对接种效果有影响。在水稻的3个时期接种,以抽穗破口前6~9d的效果最好。在一天的3个时段接种,以下午4~6时的病情最重。在接种液里添加马铃薯煮汁可显著提高接种发病率。本文的接种技术能高效引发稻曲病,最高穗发病率100%,最大病情指数93.96,最多穗病粒数110粒。该接种技术可鉴别出品种抗病性的差异。     

西双版纳热带雨林聚果榕小蜂季节性变化规律

聚果榕是西双版纳热带雨林生态系统中的一个优势树种。聚果榕和它的传粉媒介昆虫聚果榕小是一种高度协同进化,互相依赖才能繁殖各自后代,互惠共生的生物。聚果榕必须依靠聚果榕小蜂的传粉才能获得有性繁殖;而聚果榕小蜂又必须依赖聚果榕的短柱头雌花作为繁殖后代的场所,才能获得种群的繁衍。研究结果表明,聚果榕小蜂的种群随季节变化而变化,雨季种群数量高,干季种群数量低,但进入同一榕果内繁殖产卵的雌蜂数量则相反,雨季数     

无花果试管苗解剖学观察及移栽成活原因分析

以无花果扦插苗和试管苗为材料,用石蜡切片法进行解剖观察,结果表明:无花果不定根的起源与移栽成活无关,只与试管苗叶片特殊适应性改变有关,因此需要逐步恢复叶片的瓶外正常结构,才能提高移栽成活率.     

NaCl胁迫对普陀樟叶绿素荧光参数的影响

设置不同盐浓度,对盐胁迫下普陀樟生长、叶片叶绿素荧光参数、叶绿素含量进行研究,以期弄清盐胁迫下普陀樟的生理变化,为我国沿海防护林建设,特别是沿海滩涂盐碱地防护林建设开发选育适生植物提供科学依据。     

银杏与叶籽银杏枝丫材管胞径向变异趋势

以泰山老君堂1300年生银杏和中国发现的第1株800年生叶籽银杏木材为试材,对其管胞性状指标的径向变异趋势进行研究。结果表明：叶籽银杏枝丫材的管胞双壁厚、径向直径、弦向直径、管胞长度均大于银杏,而银杏的壁腔比大于叶籽银杏,两者的微纤丝角相差不大;两者枝丫材自髓心向树皮的径向变异规律为：双壁厚、径向直径、弦向直径、管胞长度均呈增长趋势,应压木壁腔比为增长趋势,对应木壁腔比则为下降趋势,微纤丝角为下降趋势。