小黑杨林分及林网内农作物水分生产率的研究

对嫩江中下游地区小黑杨片林及林网内农作物的水分生产率进行了研究,结果表明:嫩江流域中下游地区小黑杨林分的水分生产率为1.113,较全国农业平均水分生产率(0.8)相对提高39.13%;500 m×500 m的小黑杨农田防护林网,在树高达到10 m时,可使网内农作物的水分生产率提高12.9个百分点,效益十分显著,说明本地区的产业结构是科学的、合理的。     

Comparative Study on Fruit Volatiles of Different Day-Neutral Strawberry Cultivars in Autumn and Winter

【Objective】 Fruit volatiles of day-neutral strawberries harvested in autumn and winter were compared to clarify the effects of seasonal changes on volatile composition and odor activity value (OAV) of volatiles, aiming to provide theoretical basis for research on strawberry aroma and utilization of day-neutral cultivars. 【Method】 Matured fruits of day-neutral cultivars (including Albion, Monterey, Portola, and San Andreas) were harvested from high-tunnel in autumn and greenhouse in winter, respectively. Volatiles were extracted by using solid-phase microextraction (SPME), detected by gas chromatograph-mass spectrometer (GC-MS) and analyzed qualitatively and quantitatively. The numbers, contents, percentages and OAVs of volatiles were calculated. Principal component analysis (PCA) was employed to analyze the differences in volatiles content between autumn and winter strawberries. Clustered heatmap was used to classify the samples depending on the volatiles with OVA higher than 1. 【Result】 A total of 88 individual volatiles were identified and the OAVs of 57 volatiles were calculated. It was found that there were 30 components with OAV higher than 1. Effects of seasonal changes on the number of each chemical category and the total content of volatiles varied among cultivars. Compared to the autumn fruits, the content and percentage of esters in winter fruits were significantly higher, while terpenes were remarkably lower. The result of PCA indicated that, compared with other cultivars, volatiles pattern of Portola showed less variation, whereas San Andreas showed the highest variation between two seasons. Ethyl butanoate was very important for these tested cultivars since its average OAV was the highest in all volatiles. The OAVs of butyl acetate and methyl butanoate in winter fruits were noticeably higher than that in autumn fruits. However, compared with autumn fruits, the winter fruits of each cultivar had a lower sum of terpene OAVs that were higher than 1. Ethyl butanoate, butyl butanoate, 4-methoxy-2, 5-dimethyl- 3(2H)-furanone, ethyl hexanoate and linalool played an important role in the aroma differences between fruits of different seasons. The eight tested samples were classified into 3 groups using clustered heatmap. The group I included Albion autumn, Albion winter and Monterey autumn, of which total OAVs and the OAVs of ethyl butanoate were significantly higher than other groups. 【Conclusion】 Seasonal change had a remarkable impact on esters and terpenes in fruit volatiles of day-neutral strawberry cultivars. It was showed that the content and percentage of esters in winter fruits were significantly higher than autumn fruits, while the percentage of terpenes was remarkably lower in winter fruits. Among the 4 tested cultivars, Portola showed the least variation in volatile content between autumn and winter. Albion was the cultivar with intense aroma and its aroma performance presented the least changes when season changed, however, San Andreas was the one with the largest volatile variation both in volatile content and fruit aroma.     

土霉素在奥尼罗非鱼体内的药动学研究

在(21±1)℃的水温条件下,以50 mg/kg的单剂量,分别给奥尼罗非鱼(Oreochromis aureus×O.niloticus)水剂口灌和混饲口灌土霉素,用高效液相色谱法(HPLC)检测给药后各个时间点的血药浓度。结果显示:最低检测限为0.005μg/mL,线性范围为0.005~4μg/mL。水剂口灌组和混饲口灌组的药时数据均符合具时滞的二室开放动力学模型,水剂口灌组的动力学方程为:Ct=0.231e-0.028(t-0.010)+0.353e-0.011(t-0.010)-0.584e-0.468(t-0.010),混饲口灌组动力学方程:Ct=0.839e-0.057(t-0.459)+0.442e-0.013(t-0.459)-1.281e-0.282(t-0.459)。水剂口灌组及混饲口灌组主要药动学参数分别为:吸收半衰期(t1/2ka)为1.481 h,2.458 h;分布半衰期(t1/2α)为24.834 h,12.193 h;消除半衰期(t1/2β)为60.312 h,51.533 h;达峰时间(Tmax)为7.230 h,8.221 h;最大血药浓度(Cmax)为0.494μg/mL,0.796μg/mL;血药浓度-时间曲线下面积(AUC)=37.74μg.h/mL,43.075μg.h/mL。这些参数表明,水剂口灌比混饲口灌吸收快,分布和消除慢,在血液中达到峰浓度的时间更短,但峰浓度值比混饲口灌低。     

盐碱胁迫对青山杨光合特性的影响

青山杨(Poplars pseudo-cathayana×P.deltodides)是抗性良好的速生杂交杨,文章对其在盐碱胁迫下一个生长期内的光合生理特性进行了研究。结果表明,盐碱地和对照地上的青山杨在整个生长期内,净光合速率日变化都先后呈"双峰"、"单峰"和"平缓"型曲线。5～7月是青山杨全年光合作用最旺盛的时期,盐碱地青山杨日最大净光合速率为13.20μmol.m-2.s-1,对照地为14.53μmol.m-2.s-1,同比下降了9.15%。盐碱地和对照地蒸腾速率的日变化都呈"单峰"曲线,一年内5～7月蒸腾速率逐渐升高,7月15日达最大值后逐渐下降,在13:00左右蒸腾速率最大。盐碱地与对照地的气孔导度变化都呈双峰曲线,与光合速率变化相一致。盐碱地与对照地胞间CO2浓度与光合速率呈负相关。     

转Bt基因南林895杨抗虫性及对土壤微生物影响分析

以转Bt基因南林895杨株系B1、B4、B17、B21扦插苗为试验材料,分析其在室内和野外自然条件下对靶标害虫杨小舟蛾幼虫的抗虫性。结果表明:转Bt基因杨树4个株系均有一定的杀虫活性,其中株系B21对杨小舟蛾1龄幼虫12 d校正死亡率高达95.3%;虫试表明转Bt基因杨树各株系扦植苗在野外自然条件下的12 d幼虫校正死亡率8月份为35.0%88.8%,9月份为40.5%95.3%。用转Bt基因杨树叶片饲养杨小舟蛾,对照植株杨小舟蛾幼虫化蛹率为83.3%96.0%,而转Bt基因株系幼虫化蛹率为8.0%76.7%,二者有显著差异。转Bt基因杨树对杨小舟蛾幼虫的生长发育有抑制作用,饲喂8 d后害虫取食量、体质量增长速率显著低于对照。此外,为了解转Bt基因杨树对土壤微生物的影响,对转Bt基因杨树株系及对照进行了根际土壤微生物可培养类群的分析,初步结果显示:转Bt基因杨树根际土壤微生物中细菌、真菌、放线菌的数量与对照比较无显著差异。     

过氧化物酶UTLIEF电泳对苏丹草、高粱及其杂交种品种的真实性鉴定研究

本试验采用超薄层等电聚焦电泳(UTLIEF),检测了苏丹草、高粱以及高粱苏丹草杂交种3个种共15个品种的幼苗、幼根以及萌发种子和干种子的过氧化物酶同工酶。结果表明:采用pH范围为4～5的载体两性电解质制备凝胶进行电泳得到的过氧化物酶电泳图谱谱带数目多且清晰度高,易于鉴定;萌动种子和干种子的过氧化物酶电泳后没有谱带出现,幼苗幼根均出现一定数目的谱带,其中以14d幼苗的过氧化物酶电泳图谱最适宜用作参试品种的鉴定。     

不同尾巨桉木屑处理对毛木耳产量及品质的影响

研究尾巨桉木屑培育基质不同处理方式对毛木耳产量、厚度和泡发直径、营养成分和氨基酸含量等指标的影响,结果表明:不同处理间毛木耳产量、厚度和大小、营养成分和氨基酸等存在一定差异.淋洗与不淋洗不能成为产量和营养成分的决定影响因子,粗细木屑进行混合的处理方式可提高毛木耳产量和生物学效率,细木屑淋洗处理后产量略有下降的同时品质有所提升,粗木屑则呈现相反的规律.尾巨桉粗、细及混合木屑均可不淋洗用于栽培毛木耳,但以混合木屑产量更高.     

3种肥料处理对尾细桉生长的影响研究

在总养分含量相同条件下研究了有机-无机复混肥A（包括基肥、追肥）、有机-无机复混肥B（包括基肥、追肥）、无机肥C 3种肥料处理对尾细桉生长的影响。结果表明施用有机-无机复混肥A的处理在苗木生长17个月的时候长势最好,与其他3种处理差异达到极显著水平。在生长30个月时,施用有机-无机复混肥A处理与B处理生长均较好,两者差异不显著,但是均与C处理差异显著。说明肥料和施肥方式会对尾细桉的生长有影响;添加有机质会提高桉树尾细桉的产量。     

杂交马褂木人工林生长规律及趋势研究

[目的]研究杂交马褂木人工林在冲击沙壤土地区的生长规律和趋势。[方法]在标准地调查基础上,采用标准木解析法研究杂交马褂木人工林胸径、树高和材积生长规律,采用Logistic方程模拟生长并推测生长趋势。[结果]杂交马褂木生长迅速,6年生林分平均胸径、树高和材积分别为22.9 cm、20.6 m和0.206 6 m3;杂交马褂木生长具有阶段性,速生期为造林后4～8年,速生期生长量占总生长量60%以上。[结论]为杂交马褂人工林经营管理提供理论依据。     

家蚕荧光茧色判性品种“苏·雄×荧晓”的选育

根据家蚕茧荧光色的遗传机制,将现行普通家蚕品种转育成荧光茧色判性蚕品种苏.雄×荧晓。该品种孵化齐一、发育快、好养,荧光判性准确率达到100%,茧丝纤度细(2.539 dtex),生丝匀度好,茧丝长1 300 m,解舒率在71%以上,适宜在华东蚕区推广饲养。