水稻品种栽培密度的确定方法浅议

水稻品种栽培密度是生产中可控因素之一,对产量和品质有较大影响。栽培密度的确定一方面反映了对品种和栽培条件的认识程度,另一方面也是实施计划栽培的基础,以往栽培密度多根据品种的个别性状进行确定,如株高、分蘖能力等。但从生产的实际应用效果看,以单因素或个别因素为依据     

Seasonal Variation of Plasminogen Activator Activity in Spermatozoa and Seminal Plasma of Boar,Buck, Bull and Stallion

Plasminogen activators (PA) are proteolytic enzymes present in the spermatozoa and seminal plasma of various species. They play a role in the binding of the spermatozoon and its penetration through the layers surrounding the oocyte. Plasminogen activator activity (PAA) is modulated by hormones that have a seasonal variation, such as testosterone and melatonin. The present study investigates the seasonal variation of PA activity in sperm extracts and seminal plasma of four farm animal species: boar, buck, bull and stallion. Semen samples were collected every second week during a 12‐month period and PAA was determined. With respect to sperm enzyme activity, the boar showed a peak from late January until the beginning of April, whereas the activity in the bull was at the highest levels from April until October and gradually declined during autumn and winter period. Plasminogen activator activity of stallion spermatozoa peaked during March and April, and remained low throughout the rest of the year, whereas in the buck sperm, PAA increased from late October until the end of January. No biologically significant variation was detected regarding the seminal PAA activity in any of the species studied. While seasonality of reproduction is typically studied from the female perspective, the present data provide compelling information about a factor that may affect the reproductive ability of the male.     

广西药用大型真菌资源概况

通过查阅大量文献资料,掌握药用大型真菌研究现状及前景,明确广西药用大型大型真菌资源,为广西药用大型真菌开发及应用提供参考依据。     

纤维素分解微生物复合菌剂降解固态物料特性研究

为提高纤维素类碳源物质降解能力,通过试验驯化得到可降解玉米秸秆微生物复合菌剂。将复合菌剂添加到以纤维素类物质（滤纸、打印纸、秸秆、报纸）作为培养基碳源物质的液体培养基中,分析菌剂反应前后培养基中碳源物质减重率。结果表明,滤纸、打印纸、秸秆、报纸减重率分别达到93.7%、83.2%、75.4%、61.3%。玉米秸秆横截面扫描电镜观察表明,复合菌剂处理前后,细胞结构变得疏松,产生裂缝和空洞,有效证实驯化微生物复合菌剂有助于降解纤维素碳源物质能力。为分离复合菌剂中的单菌株,利用功能菌培养机上产生的透明圈及颜色变化,分离出降解蛋白质、脂肪、纤维素及产酸菌株,利用16S rRNA序列分析,鉴定出4个菌属8种菌株,分别为Chryseobacterium indologenes Dan121、Chryseobacterium indologenes Dan191、Acinetobacter bereziniae Zhi71、Acinetobacter bereziniae Zhi77、Acinetobacter bereziniae Zhi111、Lactococcus garviae S36、Bacillus cereus M7、Bacillus cereus MP310。     

不同样品保存液和保存条件对动物细胞体外培养的影响

本研究取矮脚油鸡7日龄胚胎作为试验材料,用MEM、全培养基和PBS 3种不同的液体对鸡胚组织进行保存,同时在不同保存温度条件下按不同保存时间梯度,采用组织块贴壁培养法进行体外细胞培养。对细胞的保存液变化,细胞形态、细胞生长等情况进行研究,分析样品保存条件对细胞体外培养和细胞系构建的影响。结果发现,4 ℃保存的组织块培养效果明显优于室温保存;无论在4 ℃或常温,基础培养基保存的组织块培养效果明显优于保存液,全培养基效果最好。常温保存48 h以内3种保存液培养效果差别甚微,48 h后培养效果均急剧下降,96 h后保存在PBS中的组织失活,未长出细胞。本研究结果为建立细胞系采集样品的保存提供了一定的参考。     

内蒙古大青山主要植被类型综合生态效益的评价

【目的】对内蒙古大青山主要植被类型综合生态效益进行评价。【方法】应用层次分析法(AHP)建立内蒙古大青山主要植被类型综合生态效益的评价指标体系和评价模型,对3种森林类型(油松林、白桦林、落叶松林)的20个指标进行测定,对各指标进行无纲量化处理后计算各自的权重,然后计算大青山油松林、落叶松林、白桦林3种森林类型的综合生态效益指数。【结果】3种森林类型6种评价指标的生态效益排序中,就生态系统结构与功能而言,白桦林>落叶松林>油松林;就涵养水源而言,落叶松林>白桦林>油松林;就改良小气候、水土保持和改良土壤而言,白桦林>落叶松林>油松林;就固碳放氧而言,落叶松林>油松林>白桦林。【结论】内蒙古大青山3种森林类型综合生态效益大小依次为:白桦林(1.067)>落叶松林(1.036)>油松林(0.742)。