一种一品红细菌性疫病病原菌的鉴定

采用一系列指标对一种一品红细菌性疫病病原菌进行了鉴定研究。描述了近年来海南省儋州市某花圃一品红植株上发生的一种细菌性疫病的症状，测定了病原菌的形态、染色反应、培养性状、生理生化特性以及寄主范围，将病原菌鉴定为野油菜黄单胞菌一品红致病变种[Xanthomonas campestris pv．poinsettiicola(Patel Bhatt et Kulkami 1951)Dye 1978]。猩猩草(Euphora heterophylla)、铁海棠(Euphorbia millii)和木薯(Manihot esculenta)为国内新报道的接种寄主，橡胶Hevea brasiliensis)和蓖麻(Ricinus communis)为国内外新报道的接种寄主。     

Molecular characterization of melanin-concentrating hormone (MCH) in <Emphasis Type="Italic">Schizothorax prenanti</Emphasis>: cloning,tissue distribution and role in food intake regulation

Melanin-concentrating hormone (MCH) is a crucial neuropeptide involved in various biological functions in both mammals and fish. In this study, the full-length MCH cDNA was obtained from Schizothorax prenanti by rapid amplification of cDNA ends polymerase chain reaction. The full-length MCH cDNA contained 589 nucleotides including an open reading frame of 375 nucleotides encoding 256 amino acids. MCH mRNA was highly expressed in the brain by real-time quantitative PCR analysis. Within the brain, expression of MCH mRNA was preponderantly detected in the hypothalamus. In addition, the MCH mRNA expression in the S. prenanti hypothalamus of fed group was significantly decreased compared with the fasted group at 1 and 3 h post-feeding, respectively. Furthermore, the MCH gene expression presented significant increase in the hypothalamus of fasted group compared with the fed group during long-term fasting. After re-feeding, there was a dramatic decrease in MCH mRNA expression in the hypothalamus of S. prenanti. The results indicate that the expression of MCH is affected by feeding status. Taken together, our results suggest that MCH may be involved in food intake regulation in S. prenanti.     

Petri网逆网在主轴故障诊断中的应用

比较了成熟期27个梨品种的果胶含量、半乳糖醛酸含量、果肉硬度和可溶性固形物含量,并分析果胶含量与果实品质特性的相关性。结果表明,不同梨品种间的果肉硬度、可溶性固形物、果胶、半乳糖醛酸含量4个指标的差异性都达到极显著水平(P0.01),果肉硬度均值为2.76 kg·cm-2,F值为47.03;半乳糖醛酸含量为0.64%~1.73%,F值为89.24,品种间差异最大;可溶性固形物含量为9.41%~15.19%,F值为17.66,品种间差异最小;果胶含量为0.23%~1.02%,与可溶性固形物和半乳糖醛酸含量呈极显著正相关(P0.01),Pearson相关系数分别为0.618和0.680。     

高松香思茅松无性系的选育

对40个思茅松（Pinus kesiya var．langbianensis）高产脂无性系的松香产量进行了测定分析。结果表明：所有无性系的松香产量均大于对照,较对照松香产量平均提高192．4％;无性系间松香产量存在极显著差异。无性系松香产量的遗传力为0．68。初步选择出20个高产脂的优良无性系。入选无性系松香产量的对照遗传增益为178．8％。     

Schizothorax prenanti corticotropin-releasing hormone (CRH): molecular cloning,tissue expression,and the function of feeding regulation

Corticotropin-releasing hormone (CRH) is a potent mediator of endocrine, autonomic, behavioral, and immune responses to stress. For a better understanding of the structure and function of the CRH gene and to study its effect on feeding regulation in cyprinid fish, the cDNA of the CRH gene from the brain of Schizothorax prenanti was cloned and sequenced. The full-length CRH cDNA consisted of 1,046 bp with an open reading frame of 489 bp encoding a protein of 162 amino acids. Real-time quantitative PCR analyses revealed that CRH was widely expressed in central and peripheral tissues. In particular, high expression level of CRH was detected in brain. Furthermore, CRH mRNA expression was examined in different brain regions, especially high in hypothalamus. In addition, there was no significant change in CRH mRNA expression in fed group compared with the fasted group in the S. prenanti hypothalamus during short-term fasting. However, CRH gene expression presented significant decrease in the hypothalamus in fasted group compared with the fed group (P < 0.05) on day 7; thereafter, re-feeding could lead to a significant increase in CRH mRNA expression in fasted group on day 9. The results suggest that the CRH may play a critical role in feeding regulation in S. prenanti.     

常用抗生素在鸡体内消除和鸡蛋中残留的规律研究进展

抗生素类药物在蛋鸡养殖过程中起着非常重要的作用,但一直以来抗生素的使用缺乏科学的指导,致使抗生素残留在动物性食品和环境中,给生态系统和人类健康带来了巨大的威胁。从21世纪初开始,全球各个国家和相关国际组织采取相应的措施控制动物性食品中抗生素的残留,并逐渐加大了监察力度。文章对蛋鸡饲养过程中常用抗生素在鸡体内的消除和在鸡蛋中的残留规律进行综述,并根据我国部分省市鸡蛋中抗生素残留现状,综述影响鸡蛋抗生素残留的因素,拟为抗生素的合理使用和休药期的制订提供参考。     

售种凭证存在的问题及对策

种子经营者在销售种子时,应当向购种者开出有效凭证,这是种子销售过程中的一个重要环节。是解决种子质量纠纷的重要依据。何为售种有效凭证？由于《种子法》及配套法规都无明文规定,因而所产生的凭证是五花八门,弊端诸多。现就市场上出现的售种凭证进行分述和探讨。     

主要热带果树煤烟病的为害性及病原菌种类研究

在海南等地的调查、测定结果表明,煤烟病对热带果树有一定为害性。在特别重病的情况下,芒果产量损失９．８％;芒果品种间对煤烟病抗病性有明显的差异。经鉴定,芒果、荔枝、柑桔、人心果、油梨、番石榴的煤烟病有８种;其中Ｍｏｌｉｏｌａ ｓｐｐ。,Ｔｒｉｐｏｓｐｅｒｍｕｍ ｓｐｐ．,Ｃａｐｎｏｄｉｕｍ ｓｐｐ．为优势种群。     

应用Triton WR-1339测定产蛋鸡血脂分泌量的方法研究

通过研究不同剂量Triton WR-1339(TWR)对产蛋鸡血液脂肪(血脂)浓度的影响,探讨测定血脂分泌量的方法.选用15只24周龄、平均体重1.5 kg的罗曼粉壳产蛋鸡,按单因子设计,分别从翅静脉注射4 mL TWR,浓度分别为0、100、200、300 mg/kg或400 mg/kg体重(缓冲液为生理盐水).每只产蛋鸡在注射TWR之前及注射后0.5、1、2、4、8、12、24、36 h和48hAk翅静脉采血,测定血清甘油三酯(TG)含量.结果表明:8h后注射TWR产蛋鸡的TG含量均显著高于注射生理盐水的产蛋鸡(P<0.05),但36 h后不同注射剂量下的TG含量又无显著差异(P>0.05).注射TWR产蛋鸡在0～8 h的TG积累曲线均呈线性增加,到8 h达最大值,此后逐渐下降.采食产蛋鸡血脂分泌量为0.1216mmol/(min·kg体重).静脉注射TWR200～300 mg/kg体重是研究产蛋鸡血脂分泌量的有效方法.     

腐烂茎线虫rDNA-ITS序列分析

利用一对通用引物rDNA1/rDNA2扩增6个腐烂茎线虫供试群体的rDNA-ITS区域,获得序列长度不等的片段.Des-1、Des-2和Des-3群体扩增片断长度均为1 130 bp.而Des-5、Des-6和Des-7群体的扩增片段长度均为942 bp,与以上群体相比,在ITS区具有一个188 bp的缺失片段.序列比对后确定缺失片段位于ITS1区,而且该片段含有多个可重复小片段,这可能是造成碱基缺失的原因.根据遗传进化分析可将供试线虫分为两个大的群体.