条斑紫菜基因组Fosmid文库构建

高分子量基因组文库是开展条斑紫菜基因组学研究的必备工具。构建了由23 040个Fosmid克隆组成的条斑紫菜孢子体无偏倚基因组文库。检测分析表明：文库克隆重组率为100%;插入DNA片段长度为28~40 kb,平均长度为35 kb,文库覆盖率约为条斑紫菜基因组的2.78倍;从超级池中筛查条斑紫菜18S rRNA、atpA、h2A、rbcL基因,至少能得到一个阳性克隆,印证了计算所推测的文库覆盖率;随机选取6个Fosmid克隆经100代传代后插入DNA片段未发生丢失或长度变化,表明克隆传代的稳定性。该文库的构建为开展条斑紫菜基因组特性分析和基因克隆奠定了基础。     

配合饲料中添加玉米DDGS对刺参(Apostichopus japonicus)生长、体组成及免疫指标的影响

在基础饲料中分别添加0、10％、20％、30％、40％的玉米干酒精糟及其可溶物(Dried distiller's grains with solubles,DDGS),配制成5种等氮等能的实验饲料(DDGS0、DDGS10、DDGS20、DDGS30 和DDGS40),饲喂初始体重为(9.69±0.28)g的刺参56 d,研究玉米DDGS作为替代蛋白源对其生长、体成分及免疫指标的影响.结果显示,随着玉米DDGS添加水平的升高,刺参增重率和特定生长率略有下降,但各组间差异不显著(P＞0.05).各实验组刺参体壁指数、肠道指数、肠长比以及体壁水分、粗蛋白、粗脂肪和粗灰分含量均不受玉米DDGS添加的影响(P＞0.05).体腔液中溶菌酶的活性呈先上升后稳定的趋势,其中,DDGS20和DDGS40组显著高于DDGS0和DDGS 10组(P＜0.05),DDGS30组与其他各组无显著差异(P＞0.05).酸性磷酸酶的活性呈先上升后下降的趋势,在DDGS20组达到最大值,其中,DDGS20组显著高于其他各组(P＜0.05),DDGS40组显著高于DDGS0组(P＜0.05),其他各组间无显著差异(P＞0.05).酚氧化酶的活性随着DDGS添加量的增加呈上升趋势,各添加组均显著高于DDGS0组(P＜0.05),DDGS40组显著高于DDGS 10组(P＜0.05),其他各组间无显著差异(P＞0.05).饲料中添加玉米DDGS对体腔液中碱性磷酸酶和超氧化物歧化酶的活性无显著影响(P＞0.05).本研究表明,饲料中添加0-40％的玉米DDGS均不影响刺参的生长和体壁成分,且添加20％-40％的玉米DDGS能提高刺参体腔液中免疫酶的活性.     

Effect of dietary chitosan oligosaccharide complex with Ce (IV) on growth,immunity and disease resistance against Vibrio splendidus of sea cucumber,Apostichopus japonicas

An 8‐week feeding trial was conducted to investigate the effects of dietary chitosan oligosaccharide complex with cerium (Ce IV) (COS‐Ce) on growth performance, nonspecific immunity and disease resistance of sea cucumber, Apostichopus japonicas. Five isonitrogenous (18.6%) and isolipidic (1.1%) practical diets were formulated with graded level of COS‐Ce (0, 150, 300, 600 and 1200 mg kg^?1 dry feed), which were named as COS‐Ce/0, COS‐Ce/150, COS‐Ce/300, COS‐Ce/600, COS‐Ce/1200 respectively. Each diet was allocated to four replicates of sea cucumbers (Initial weight: 6.72 ± 0.02 g). Sea cucumbers were fed to apparent satiation once daily (19:00 hours) for 56 days. During the experiment, water temperature was kept at 16 ± 0.5°C, pH 7.8–8.2, dissolved oxygen beyond 5 mg L^?1, ammonia nitrogen below 0.5 mg L^?1 and salinity from 30‰ to 31‰. Results showed that the specific growth rate of sea cucumbers was significantly higher in COS‐Ce/600 than that in other four treatments. Activities of phagocytosis, respiratory burst, acid phosphatase and alkaline phosphatase in COS‐Ce/600 were significantly higher than that in COS‐Ce/0 (P < 0.05) respectively. On the contrary, cumulative mortality was the lowest in COS‐Ce/600 following 14 days exposure to Vibrio splendidus (P < 0.05). In conclusion, these results confirmed that dietary COS‐Ce had beneficial effects on growth performance, nonspecific immunity and disease resistance of sea cucumber.     

不同地区稻虾综合种养系统的微生物群落结构分析

为研究不同地区稻虾综合种养系统的环境及克氏原螯虾肠道的细菌群落结构差异,为改进不同地区稻虾综合养殖策略提供依据,采用Illumina Miseq高通量测序技术,研究了武汉、永州和韶关地区稻田养殖克氏原螯虾的水体、底泥及虾肠道细菌群落结构,并对水体、肠道菌群与环境因子之间的关系进行了分析。结果显示,武汉地区稻虾综合种养系统的水体、底泥及克氏原螯虾肠道细菌群落的多样性均大于永州地区和韶关地区。武汉地区的稻虾综合种养系统的水体及底泥的细菌群落结构与永州地区和韶关地区均相似,其中水体的优势菌门均为放线菌门、蓝细菌门、变形菌门和拟杆菌门;底泥的优势菌门均为变形菌门。武汉地区的克氏原螯虾肠道的优势菌门为变形菌门、厚壁菌门和拟杆菌门;优势菌属为柠檬酸杆菌属(Citrobacter,10.85%)、气单胞菌属(Aeromonas,9.88%)和[Anaerorhabdus]＿furcosa＿group (8.43%)等。永州地区的克氏原螯虾肠道的优势菌门为厚壁菌门和放线菌门;优势菌属为ZOR0006 (9.78%)、拟杆菌属(Bacteroides,5.41%)和[Anaerorhabdus]＿fur...     

不同产地绿茶主要成分含量及质量指标的差异分析

为了客观地评价不同主产地绿茶品质的差异性,统计分析了四川、湖北、福建的16个绿茶样品的茶多酚、茶多糖、茶氨酸、灰分、水分、重金属、农药残留含量的差异。结果表明,四川产绿茶的茶氨酸含量显著高于湖北,3个省份的茶多酚、茶多糖含量差异不显著;茶多酚、茶多糖、茶氨酸含量最高的产地分别为宜宾市、峨眉山市、眉山市(编号3)。湖北产绿茶的灰分含量显著高于四川和福建,水分含量显著低于四川;不同主产地绿茶的重金属含量和农药残留量均符合食品安全国家标准。研究结果将为绿茶原料的产地选择、品质评价等提供技术依据。     

PEG介导的玉米弯孢叶斑病菌遗传转化

为了探索不同酶系组成对玉米弯孢叶斑病菌原生质体制备的影响,建立该病菌原生质体遗传转化系统,采用酶系混合物裂解菌丝体制备原生质体,采用PEG介导方法进行原生质遗传转化,通过PCR和Southern blotting技术对转化子进行验证。结果表明:1%溶壁酶+1%蜗牛酶+1%纤维素酶混合酶系为玉米弯孢叶斑病菌原生质体制备的最佳酶系,可以产生原生质体6.78×106 cfu/mL。用PEG介导方法转化共获得16个稳定的转化子,从中随机挑取5个转化子发现质粒pV2已被成功整合到基因组中。本研究获得了制备玉米弯孢叶斑病菌原生质体的最佳酶系,建立了PEG介导的原生质体遗传转化体系,为开展该菌致病相关基因克隆和基因功能研究提供了一种手段。     

EDC/NHS crosslinked electrospun regenerated tussah silk fibroin nanofiber mats

The tussah silk fibroin (TSF) nanofibers with 611 nm diameters were prepared by electrospinning with the solvent hexafluoroisopropanol (HFIP). And then, the TSF nanofibers were crosslinked by 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide/N-Hydroxysuccinimide (EDC/NHS) crosslinking agent. The morphology and microstructure of the crosslinked TSF nanofibers were characterized by scanning electron microscopy (SEM), Fourier transforms infrared analysis (FTIR), X-ray diffraction, Instron electronic strength tester, and cell culture. After treatment with EDC/NHS crosslinking agent, the TSF nanofibers swelled and its average diameter increased from 611 to 841 nm. FTIR and X-ray diffraction results demonstrated that random coil, ??-helix, and ??-sheet co-existed in the TSF nanofiber mats, but the content of ??-sheet increased from 25.26 to 45.34 %, and the random coil content decreased from 32.47 to 24.94 %. Compared with the electrospun pure TSF nanofiber mats, the crosslinked TSF nanofiber mats exhibited a lower breaking tenacity and initial modulus, which were 5.51 MPa and 9.86 MPa, respectively. At the same time, the extension at break of the crosslinked TSF nanofiber achieved 109.38 %. In cell culture evaluation, the crosslinked TSF nanofibers were found to support cell adhesion and spreading fibroblast L373 and bone marrow mesenchymal stem cells (BMSCs), which had potential utility in a range of tissue engineering.     

乌兰布和沙区紫花苜蓿建植与萌发预测模型

研究乌兰布和沙区紫花苜蓿种子发芽与温度的关系及环境因素对种子萌发的影响,探讨不同播种期和播种技术对出苗和保苗的影响。结果表明,适宜播种期为5月中、下旬。种子发芽所需热量累积为22℃以上。在沙区特殊环境条件下,初步建立紫花苜蓿种子萌发预测的动态模型,验证结果表明,该模型可用以预测类似条件下紫花苜蓿种子的萌发。     

秋水仙素处理下蓝蓟花期叶片净光合速率(Pn)日变化的研究

本研究采用不同浓度的秋水仙素和诱导时间不同的蓝蓟种子,大田播种,在蓝蓟不同生长时期使用美国LI-COR公司产LI-6400XT便携式光合仪系统测量蓝蓟叶片的光合日变化,测试结果:叶片净光合速率(Pn)具有"两峰一谷"的不对称双峰曲线,但随着秋水仙素浓度增加和处理时间延迟呈现单峰曲线,浓度0.6%处理24h时净光合速率达到最佳效果,双峰曲线,高峰值为:"24.1μmol·m~(-2)·s~-";秋水仙素浓度0.6%浸泡36h气孔导度(Gs)、胞间二氧化碳浓度(CI)达最高值;秋水仙素浓度0.2%浸泡24h,水分利用率(WUE)最大;不同秋水仙素处理蓝蓟叶片蒸腾速率(Tr)呈"双峰曲线",通过不同处理整体表现为浓度大蒸腾速率较大,但规律性不明显。光合速率日变化与气孔导度呈极显著正相关,与蒸腾速率呈显著正相关。说明秋水仙素浓度大小和处理时间长短对蓝蓟花期光合日变化有直接影响,浓度大、处理时间长光合影响最大,最适合的浓度是0.6%处理,时间是24h。但高浓度、处理时间长抑制了光合作用出现"午休"现象。     

中国水牛血红蛋白多态性及命名研究

采用醋酸纤维薄膜法首次系统分析了中国１２个水牛地方类群１０７１头水牛的血红蛋白多态性。结果表明，中国水牛血红蛋白受Ｈｂ＾Ａ，Ｈｂ＾Ｂ，Ｈｂ＾Ｃ３个等位基因控制，其频率分别为０．０７６１，０．８８５２和０．０３８７，Ｈｂ＾Ｃ基因系首次命名。聚类分析表明，中国水牛名地方类群间亲缘关系较近。