赤霉素对非洲菊生长开花的影响研究

对非洲菊品种"洛斯"采用不同浓度的GA处理,研究其对非洲菊开花的影响。结果表明:赤霉素可使株高、叶片数、茎粗和叶绿素含量都有增长,不同浓度的赤霉素对花卉的品质影响不同,赤霉素以50 mg/L为最佳浓度处理。     

不同施氮水平对黄瓜产量和品质的影响

研究了青紫塥粘田上施用氮肥对黄瓜产量和品质的影响.结果表明,在磷、钾肥底肥的基础上.施用氮肥具有显著增产作用,但施氮量在450 kg/hm2以上产量极显著降低.施用氮肥对黄瓜卫生标准没有明显影响,黄瓜硝酸盐舍量符合生食标准(<432 mg/kg).施氮水平对黄瓜的品质影响很大,VC含量,可溶性蛋白质在一定范围内有所提高,但随氮肥的进一步增加呈下降趋势,可溶性糖舍量在450～600 kg/hm2 范围内有所增高.综合考虑作物产量、品质、生产成本、人体健康等因素,在本试验条件下,黄瓜氮肥施用量为300 kg/hm2左右为宜.     

西瓜、甜瓜果实品质及调控研究进展

西瓜甜瓜深受消费者喜爱,但是近年来品质呈现下降的趋势.西瓜甜瓜的品质包括外观品质、营养品质和风味品质,而品质的形成又受品种、土壤环境、肥料供应、水分供应、栽培方式、生长调节剂以及采收与贮运等因素的影响,所以要针对以上因素,从改进育种手段和栽培技术2大方面来改良和提高品质.     

药剂结合低温贮藏对青花菜品质的影响

研究了0℃包装贮藏条件下,化学药剂处理对单花球青花菜品质的影响.研究结果表明,赤霉素(GA3)、苯甲酸钠(SBN)、6-苄基腺嘌呤(6-BA):均能延缓青花菜的品质下降,其中以40 mg/kg 6-BA+0.2%SBN处理的效果最好,在药后30 d时,叶绿素含量仅下降9.8%,未表现出黄化,失水率仅为2.25%,花球形态紧密充盈,保持了较好的商品性.     

Potential for reintroduction of lake sturgeon in five northern Lake Michigan tributaries: a habitat suitability perspective

• 1. Conservation and rehabilitation efforts for lake sturgeon Acipenser fulvescens throughout the Great Lakes include the re‐establishment of self‐sustaining stocks in systems where they have been extirpated.
• 2. Information on the suitability of potential lake sturgeon habitat in tributaries is important for determining their capacity to support lake sturgeon stocking and to develop system‐specific rehabilitation strategies.
• 3. Geo‐referenced habitat information characterizing substrate composition, water depth, and stream gradient were applied to a life‐stage specific lake sturgeon habitat suitability index in a geographic information system to produce spatially explicit models of life‐stage specific habitat characteristics in five northern Lake Michigan tributaries from which lake sturgeon have been extirpated.
• 4. Habitat models indicated that high quality lake sturgeon spawning and staging habitat comprised 0 to 23% and 0 to 9% of the available habitat, respectively, whereas high quality juvenile lake sturgeon habitat was relatively ubiquitous throughout each river and comprised 39 to 99%.
• 5. Comparison of these data to lake sturgeon habitat availability in Lake Michigan tributaries currently supporting populations indicated that spawning and staging habitats may limit the ability of these systems to support spawning. Efforts to re‐establish lake sturgeon populations in these systems should consider the creation of spawning and staging habitat to increase reproductive and recruitment potential prior to the initiation of stocking efforts.

Copyright © 2007 John Wiley & Sons, Ltd.     

中小果型无籽西瓜新品种博帅的选育

博帅系湖南博达隆科技发展有限公司以9048为母本、M-2为父本杂交育成的中小果型黄瓤无籽西瓜新品种。该品种全生育期90d左右,雌花开放至果实成熟约需27d。植株生长势中强,抗病抗逆性强。果实短椭圆形,果形指数1.2。果皮浅绿底覆绿色齿条带,厚度0.9cm,硬韧,耐贮运。瓤色鲜黄,质脆爽口,纤维少,无籽性能好;中心可溶性固形物12%～13%,边部9%～9.5%。单果质量4kg左右,667m2产量2700kg左右。适应性广,全国各地均可栽培。2009年3月通过湖南省农作物品种审定委员会审定,审定编号:湘审西瓜2009002。     

数字图像处理在SEM空蚀图像定量分析中的应用

针对收缩-扩散型水洞中进行铝制翼型空蚀破坏试验时,传统度量不能准确量化翼型表面不同位置的空蚀程度,提出了数字图像检测的方法.获取试验翼型表面SEM空蚀图像,然后对图像进行模糊增强,并进行类间方差最大阈值分割,用二值形态学方法处理边缘,最后由统计特性计算出空蚀破坏表面积、蚀坑数量等.图像测量可得到空蚀对翼型表面破坏数值的定量结果.     

主成分分析法在长春市石头口门水库水环境质量评价中的应用

根据主成分分析法能够在保证原始数据信息损失最小的情况下,以少数的综合变量取代原有的多个变量的特点,对长春市石头口门水库汇水区的主要河流进行了水环境质量综合评价,并进一步对各个监测断面的水质优劣程度进行了排序.结果表明:该区水环境质量总体较差,以有机污染和农业非点源污染引起的水质污染为主.在空间分布上,石头口门断面水质相对较好,烟筒山断面和星星哨水库断面的水质次之,双阳河新安断面水质最差.     

阳城县农产品质量安全工作存在问题及对策

农产品质量安全越来越受到人们的普遍关注,农产品质量安全与否,直接关系到人民群众的日常生活和生命安全,关系到社会和谐发展和社会稳定。在分析阳城县农产品质量安全管理工作现状的基面上,指出了存在一些不容忽视的潜在问题．并提出了有针对性的对策建议。     

Effects of instream structures on Kirikuchi charr, southernmost population of genus Salvelinus, in a small mountain stream of Japan

ABSTRACT:   The changes in physical habitats and responses of fish, e.g. the Kirikuchi charr Salvelinus leucomaenis japonicus , were examined by placing instream structures in a stream on the upper drainage of the Totsu River system of the Kii Peninsula, Japan, over a two-year period. Instream structures created pools below the structures, and these pools have maintained their functions as fish habitats over two years. In two treatment sections, sections A and B (some red-spotted masu salmon were removed in advance in section B), mean water depth increased soon after placing the structures, but decreased over two years. Mean water velocity slowed after placing the structures in both sections. Total fish abundance has been relatively high at the two treatment sections compared with a control section after placing the structures. Age 1 Kirikuchi charr, however, increased only in section B. These results indicate that instream structures can serve as habitat enhancement for fish, including Kirikuchi charr, in the study area if other appropriate habitat factors for respective species are taken into consideration.