香菇病毒快速检测

应用十二烷基磺酸钠聚丙烯酰胺(SDS-PAGE)凝胶电泳分析香菇菌丝蛋白质,根据能否检出22 000道尔顿的34nm香菇病毒外壳蛋白带作为菌株是否带病毒的指标。在生长不正常香菇菌株和对照的带病毒菌株中均检测出了34nm香菇病毒外壳蛋白带。这一结果表明,应用SDS聚丙烯酰胺凝胶电泳可对香菇病毒进行简单、快速的早期检测。     

大坡度山前人工草场灌溉工程及效益研究

在大坡度山前天然草场上进行了人工草场灌溉工程的研究,其实例是新疆昭苏县秦力松人工灌溉草场,建成后牧草连年获得高产,取得了明显的经济效益和生态效益.     

乡土观赏竹在重庆北碚城市景区中的应用

重庆北碚乡土竹类植物共有11属51种,其中35种已在园林中得到应用。该文分析了各竹种的观赏特性及应用前景,对竹子在北碚区城市景区中的应用进行了探讨,为市区丰富园林绿化树种,增添园林景观,为类似城市旅游景区提供一定的参考。     

小场地足球对抗赛在足球训练中的应用

阐述了小场地足球对抗赛的特点和作用,对小场地足球对抗赛在足球训练(技术训练和战术训练)中的应用进行了研究,并对训练过程中应注意的问题进行分析。说明小场地足球对抗赛作为一种训练手段,应该被合理地应用到教学训练中去,因为这既是提高技战术水平和发展足球意识的需要,也是基本和重要的教学训练内容。     

2006年贵州省赫章县秋季小麦条锈病调查

为了解中国新发现的小麦条锈病菌越夏区贵州省赫章县小麦条锈病秋季发生情况,2006年秋季笔者主要对该县古基乡、野马川镇、六曲河镇进行了调查,共调查119块地,自生麦病田率为55%,秋播小麦病田率为20.20%。古基乡发病较多,自生麦苗上有多个发病中心,有的秋播小麦田块亦呈现病叶较集中现象。在海拔1660-1910m范围内,都有小麦条锈病发生,说明当地越夏菌源能够为本地区秋苗发病提供充足菌量。对进一步研究内容进行了讨论并提出了赫章县小麦条锈病治理措施。     

Effects of Dietary Binders on Survival and Growth Performance of Postlarval Tongue Sole, Cynoglossus semilaevis (Günther)

A 30‐d feeding experiment was conducted in tanks to investigate the effects of four different binders (2% in microdiet) on the survival, growth performance, and specific activity of digestive enzymes in tongue sole, Cynoglossus semilaevis Günther, postlarvae (24 d after hatching, with initial average wet weight of 22.4 ± 6.65 mg [mean ± SD]). Five approximately isonitrogenous and isoenergetic microbound diets were formulated with carrageenan (Car), sodium carboxymethylcellulose (CMS), sodium alginate (SA), and gelatin (Gel) as binders, and a diet with no special binder as a control. A commercial diet (RQ Com., manufactured by Marubeni Nisshin Feed Co., Ltd., Chita, Japan) was used as another tested diet, and Artemia nauplii was used as live prey control. The results showed that the survival of the fish fed SA diet (31.3%) was significantly higher than that of fish fed CMS (21.8%), Car (10.8%), and control (21.8%) diets (P < 0.05), but significantly lower than that of the fish fed the live prey (54.5%) diet (P < 0.05). The results of growth followed the similar pattern as that of survival, although there were no significant differences in specific growth rate (SGR) among fish fed SA, CMS, Gel, the control, and RQ diets (7.2, 6.8, 7.0, 6.9, and 7.3% per day; P > 0.05). However, fish fed Car diet had a significantly lower SGR (5.9% per day) than fish fed other diets. Percentages of secreted amylase in fish fed artificial diets were not significantly different, but fish fed artificial diets had significantly higher (P < 0.05) secreted amylase than live prey group. Percentage of secreted trypsin in fish fed SA diet (54.9%) was relatively higher compared with other binders, and not significantly different from RQ Com. and live prey treatments. However, trypsin in fish fed Car diets (29.3%) was significantly lower than in other groups. Specific activities of alkaline phosphatase (AP) in the intestine and AP and leucine aminopeptidase N in brush border membranes in fish fed SA diet (264.6, 1882.8, and 187.2 mU/mg protein) were relatively higher compared with other binders. These results indicate that SA is one of suitable binders compared with carrageenan, CMS, and gelatin in microdiet of postlarval tongue sole.     

Immune Responses and Resistance against Vibrio parahaemolyticus Induced by Probiotic Bacterium Arthrobacter XE-7 in Pacific White Shrimp, Litopenaeus vannamei

A 63-d feeding experiment was conducted to determine the effects of dietary supplementation of probiotic bacterium Arthrobacter XE-7 on immune responses and resistance against Vibrio parahaemolyticus in the Pacific white shrimp, Litopenaeus vannamei . The probiotic bacteria were administered orally at four different doses of 0, 10⁶, 10⁸, and 10¹⁰ colony-forming unit (CFU)/g feed for shrimp. On Day 50, the shrimp were challenged with Vibrio parahaemolyticus by bath. On Days 7, 21, 49, and 63, six shrimp per tank were sampled to take intestine and hemolymph. With increasing dietary supplementation of probiotic bacteria, shrimp mortality decreased from 63.16% (the control) to 55.9% (10⁶ CFU/g feed), 51.75% (10⁸ CFU/g feed), and 51.78% (10¹⁰ CFU/g feed), respectively. Vibrio counts in intestine of shrimp fed probiotic bacterium Arthrobacter XE-7 was generally lower than that in the control shrimp ( P  < 0.05). The probiotic bacteria generally increased the immune parameters in shrimp, that is, total hemocyte counts, percentage phagocytosis, respiratory burst activity, and serum phenoloxidase activity. The results showed that probiotic bacterium Arthrobacter XE-7 can be used as probiotic in shrimp feed.     

温度胁迫下沙葱萤叶甲小热激蛋白基因GdHsp20.6的克隆及表达分析

为明确小热激蛋白在沙葱萤叶甲Galeruca daurica应对温度胁迫中的作用，采用PCR方法克隆沙葱萤叶甲小热激蛋白基因Hsp20（GdHsp20.6）完整的开放阅读框（open reading frame，ORF）序列，应用在线软件对GdHsp20.6基因进行生物信息学分析，通过原核表达技术诱导表达及纯化其编码蛋白，并通过实时荧光定量PCR（real-time quantitative PCR，RT-qPCR）技术分析不同温度胁迫下GdHsp20.6基因的表达量。结果显示，GdHsp20.6基因ORF序列长度为543 bp，编码180个氨基酸，预测分子量为20.6 kD，无跨膜区和信号肽。GdHsp20.6氨基酸序列有高度保守的α-结构域。GdHsp20.6氨基酸序列与其它鞘翅目昆虫的Hsp20氨基酸序列有较高的一致性，其中与花绒寄甲Dastarcus helophoroides的Hsp20.99氨基酸序列的一致性最高，为63%。GdHsp20.6基因在大肠杆菌Escherichia coli BL21（DE3）细胞系中成功表达，经异丙基-β-D-硫代吡喃半乳糖苷（isopropyl-β-d-thiogalactoside，IPTG）诱导后GdHsp20.6蛋白成功表达，十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electrophoresis，SDS-PAGE）和Western-blot分析表明融合蛋白大小与预测大小一致，并纯化获得了纯度较高的目的蛋白GdHsp20.6。低温（-10~5℃）和高温（35~40℃）处理1 h以及处理后25℃恢复30 min均能诱导GdHsp20.6基因表达上调，并且0℃处理30~120 min也能诱导GdHsp20.6基因表达上调。表明GdHsp20.6基因在沙葱萤叶甲应对低温和高温胁迫中可能起着重要作用。