双孢菇的品种类型及菌种质量

随着双孢菇栽培的普及和菌种选育技术的提高,其品种资源日趋丰富.不同的双孢菇品种类型需要不同的栽培管理技术;不同的生产区域,选用的菌株也不尽相同.明确品种类型,因地制宜的选择优良品种及使用高质量的菌种,是确保双孢菇高产优质的关键因素.     

MAGNETIC RESONANCE IMAGING OF THE CANINE BRAIN AT 7 T

The purpose of this study was to describe relevant canine brain structures as seen on T2-weighted images following magnetic resonance (MR) imaging at 7 T and to compare the results with imaging at 1.5 T. Imaging was performed on five healthy laboratory beagle dogs using 1.5 and 7 T clinical scanners. At 1.5 T, spin echo images were acquired, while gradient echo images were acquired at 3 T. Image quality and conspicuity of anatomic structures were evaluated qualitatively by direct comparison of the images obtained from the two different magnetic fields. The signal-to-nose ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared between 1.5 and 7 T. The T2-weighted images at 7 T provided good spatial and contrast resolution for the identification of clinically relevant brain anatomy; these images provided better delineation and conspicuity of the brain stem and cerebellar structures, which were difficult to unequivocally identify at 1.5 T. However, frontal and parietal lobe and the trigeminal nerve were difficult to identify at 7 T due to susceptibility artifact. The SNR and CNR of the images at 7 T were significantly increased up to 318% and 715% compared with the 1.5 T images. If some disadvantages of 7 T imaging, such as susceptibility artifacts, technical difficulties, and high cost, can be improved, 7 T clinical MR imaging could provide a good experimental and diagnostic tool for the evaluation of canine brain disorders.     

不同饲养方式对拜城油鸡生长、屠宰性能及肉品质的影响

[目的]探讨不同饲养方式对拜城油鸡生长、屠宰性能以及肉品质的影响,为拜城油鸡生产实际提供参考依据.[方法]试验选用1日龄的300只初生重相近的拜城油鸡雏鸡,随机分为散养、地面平养及网上饲养三个组,每组设4个重复,每个重复25只鸡,试验鸡饲喂相同的日粮.[结果]散养组鸡的末重及平均日增重显著低于地面平养组和网上饲养组(P＜0.05);散养组鸡的半净膛率显著低于网上饲养组与平养组(P＜0.05),腹脂率极显著低于网上饲养组(P＜0.01)和显著低于地面平养组(P＜0.05);散养组鸡胸、腿肌24、48h滴水损失率低于地面平养组和网上饲养组(P ＜0.05或P＜0.01);散养组鸡胸、腿肌剪切力显著高于地面饲养组和网上饲养组(P＜0.05);散养组鸡胸肌OD值高于地面饲养组和网上饲养组(P＜0.05);散养组鸡腿肌灰分含量高于地面平养和网上饲养组(P＜0.01);散养组鸡胸、腿肌肌内脂肪和腿肌肌苷酸含量均高于地面平养和网上饲养组(P＜0.05);网上饲养组胸肌及腿肌肌纤维直径均小于地面饲养组和散养组(P＜0.05),相反肌纤维密度小于地面饲养组和散养组(P＜0.05).饲养方式对拜城油鸡其它性能和肉质指标没有显著影响.[结论]三种饲养方式各有优缺点,生产者应根据自己的实际情况以及不同市场对鸡肉产品的不同要求选用适宜的饲养方式.     

县级气象站为新农村建设服务的策略探讨

对县级气象站为新农村建设服务的现状进行了分析,指出存在的问题,并提出相应的改进措施,以充分发挥气象服务为新农村建设的作用。     

温棚油桃梨小食心虫消长规律及不同诱捕器诱杀试验

【目的】为不同诱捕器在温棚油桃防治梨小食心虫提供依据。【方法】利用梨小食心虫性诱剂对新疆喀什地区叶城县温棚油桃梨小食心虫进行不同诱捕器(三角型粘胶式诱捕器、矿泉水瓶诱捕器、塑料桶诱捕器)诱捕效果的比较。【结果】温棚油桃梨小食心虫1年发生4代,分别出现在4月中旬、6月上中旬、7月上旬、8月上中旬。【结论】在三种诱捕器中,自制的矿泉水瓶诱捕器最佳,其次为三角型粘胶式诱捕器,塑料桶诱捕器较差,为诱捕器的研制工作提供科学依据。     

骨干玉米自交系抗病性改良研究

以大斑病鉴别寄主近等基因系、骨干自交系及二者杂交F1、F2代为材料,利用前期构建的分子标记技术体系,筛选与大斑病抗病基因紧密连锁的SSR分子标记,同时进行分子标记辅助选择改良玉米自交系的抗病性。结果表明：在大斑病抗病基因位点附近可以找到有效的SSR分子标记,利用这些标记可以对杂交、回交后代进行辅助选择。实验还发现,分子标记的有效性与材料本身的基因型有关,在利用分子标记辅助选择时应注意不同的材料,选择相应的有效分子标记。     

锯末木醋液对玉米种子萌发及幼苗影响的研究

The seeds of corn were socked in wood vinegar with different concentrations,aiming at researching the effect of wood vinegar on seed germination and seedling growth.The results showed that all treatments had obvious effect on the seed germination percentage,the seed germinating energy and the germinating index,and had effect on the seedling length.The regress curses were CUBICS.The every treatment also created effect on the germinating time and regular.It showed that all treatments had obvious effect on the seedling length and above ground dry weight F>F_0.05,F>F_0.01,but no obvious effect on the chlorophyll and root dry weight.     

单核细胞增多性李氏杆菌人工感染绵羊试验

将人从病羊脑分离纯化的单核细胞增多性李氏杆菌经列脉接种于健康得奴绵羊３只,结果被感染绵羊均表现出与自然感染绵羊相同的临床症状和病理变化,并从脑、心血、淋巴结中回收到了单核细胞增钨生李氏杆菌,从而证明了该分离株单核细胞增多性李氏杆菌具有较强的致病性。     

水稻超高产品种的产量潜力及产量构成因素分析

通过对我国近年育成的超高产水稻品种的研究结果表明,超高产水稻品种的产量水平,在福建龙海早、晚季栽培,１６个品种平均产量分别为９０９２ｋｇ．ｈｍ＾－２和９５２４ｋｇ．ｈｍ＾－２,比汕优６３（ＣＫ）分别增产５．７％和６．３％;在云南涛源栽培,１６个品种平均产量为１５７７９ｋｇ．ｈｍ＾－２,比汕优６３增产３．０％。超高产水稻的产量构成特征是在适应当地生态条件的足重穗基础上培育更大的穗子,具有较多的单位面     

伊维菌素在水产养殖中的应用及其水生态风险

伊维菌素是一种广谱抗寄生虫渔药,在国外被广泛用于鲑鱼、海鲷养殖中的海鲺防治.国内主要用于防治淡水鱼养殖中的各种寄生虫病,其在观赏鱼养殖中的应用也日益普遍.综述了目前国内外伊维茵素在水产养殖中的使用现状,并就其水生态风险进行评估.