栗属分子生物学研究进展

壳斗科(Fagaceae)栗属(Castanea)植物的7个种分布广泛,不仅可用于木材生产,而且在坚果生产上也占有独特地位。基于形态学、同工酶、子叶储藏蛋白和RAPD数据,通过对分布于亚洲、欧洲和北美的栗属植物的遗传多样性研究表明中国板栗(Castaneamollissima)是世界栗属植物的原始种,长江流域是中国板栗的遗传多样性中心,土耳其是欧洲板栗的起源中心之一。在分子标记辅助育种方面,已发表了基于形态学、同工酶、RAPD和ISSR数据的两张栗属植物的遗传连锁图谱,其中一个是用欧洲板栗种内杂交后代F1全部单株构建的,另一张是用美洲板栗与中国板栗种间杂交后代F2单株构建的,并已经定位了3个假定的栗疫病抗性位点;并且证明在多年生木本果树上同工酶基因可通过连锁关系分析与形态基因整合为1个单一基因图而无需另外的杂交。从栗属植物中已分离纯化了包括可抑制HIV-1反转录酶活性的Mollisin在内的几丁质酶等抗真菌蛋白、胱氨酸蛋白酶抑制剂、热击蛋白、红血球凝集素、脱水素、花粉过敏原等功能蛋白质,并已经克隆了包括伤害应答基因在内的部分功能蛋白质相关基因。因此,作为具有独特性质的栗属植物,有必要开展更多的研究,就此本文对栗属植物遗传多样性、分子标记辅助育种和功能蛋白纯化和有关基因克隆等几方面的研究进展进行了总结,希望能位同行提供参考。     

杉木木质化过程特异表达基因文库的构建与分析

研究木质部木质化过程及其生物学特性对于了解木本植物水分和矿物质的吸收及运输机制、木材形成的遗传控制、改良材性及提高木材生长量具有十分重要的意义。为了获得杉木木质化过程中特异表达的基因,本研究利用抑制差减杂交技术,以杉木突变体独干杉无性系为测试方(Tester),正常的句容0号无性系为驱动方(Driver),构建了正向和反向两个差减文库,分别获得了618和409个克隆。利用通用引物T7和SP6进行PCR及EcoRⅠ酶切鉴定文库重组子,结果证明所构建的文库符合要求,具有代表性。该文库的成功构建为获得杉木木质化过程中特异表达的基因及深入了解木本植物木质化的机理奠定了基础。     

与大豆SMV3号株系抗性相关的分子标记的鉴定

对大豆花叶病毒SMV抗性的遗传研究一直是大豆抗病遗传研究的热点之一。本研究以哈91R3-301×黑农41组合构建了遗传群体,其F2分离单株的SSR标记基因型基本符合1:2:1的比例,说明这个群体没有偏分离。根据F3株系的病情指数分布推测SMV3的F2成株抗性似乎由多基因控制。根据SSR分子标记的基因型和F2:3株系对SMV3抗病性表型结果连锁分析,推测Satt296是与大豆花叶病毒(SMV)3号株系抗性主基因连锁的分子标记,应用Joinmap作图软件将该标记定位在D1b连锁群上,这一结果与部分文献报道的研究结果一致。本研究获得的与抗性基因连锁的分子标记在其他的RIL群体中的验证得到了初步证实,推测定位在D1b连锁群上的抗性座位可能是控制SMV3的主基因之一,该标记可望应用于大豆抗SMV3的分子标记辅助选择。     

山姜对益生芽孢杆菌体外抑菌活性试验研究

为研究中草药山姜粗提液对益生芽孢杆菌体外抑菌效果,特采用试管二倍稀释法和管碟法检测不同浓度的山姜煎煮液和乙醇提取液在体外对蜡样芽孢杆菌PAS38菌株和枯草芽孢杆菌Pab04菌株的最小抑菌浓度(MIC)和抑菌直径,并以肠毒性大肠杆菌(ETEC)、4μg/mL硫酸庆大霉素作阳性对照,生理盐水作阴性对照。结果表明,山姜煎煮液和乙醇提取液对两株益生芽孢杆菌和ETEC无抑菌作用,硫酸庆大霉素对蜡样芽孢杆菌PAS38和枯草芽孢杆菌Pab04菌株MIC均为1.25μg/mL,对ETEC的最低抑菌浓度MIC为0.625μg/mL。山姜煎煮液和乙醇提取液对受试菌株抑菌直径与生理盐水相比差异不显著(P>0.05),硫酸庆大霉素与其相比差异极显著(P<0.01)。山姜粗提液对两株益生芽孢杆菌无明显抑菌作用。     

Edwardsiellosis in farmed turbot,Scophthalmus maximus (L.), associated with an unusual variant of Edwardsiella tarda: a clinical,aetiological and histopathological study

During 2005 and 2010, a survey of edwardsiellosis on eight turbot, Scophthalmus maximus (L.), farms was conducted in China. This report presents the detailed results of the study on this disease. Diseased turbot displayed two distinct types of gross signs: black discoloration of the dorsal skin on the posterior portion of the body; and red cutaneous foci on the ventral side. Internally, the most pronounced clinical signs in all fish examined were enlarged kidneys. The causal agent of the disease was finally proved to be one species of bacterium that was identified as Edwardsiella tarda by physiological and biochemical tests, API 32E and 16S ribosomal RNA sequence analysis. It is noteworthy that unlike the commonly described E. tarda strains, the isolates in this study were non‐motile strains without flagella. A histopathological study revealed that E. tarda infection was systemic in turbot and that kidney showed the most significant pathological changes, including acute focal necrosis, an influx of macrophages and formation of granuloma. The most common histopathological characteristics of this disease are the proliferation of macrophage in various organs and formation of granuloma. In addition, this article also gave background information on the disease and presented the results of virulence tests with the E. tarda strain identified in this study.     

Comparison of food selection and growth performance of koi carp, Cyprinus carpio L., and goldfish, Carassius auratus (L.) in mono- and polyculture rearing in tropical ponds

To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.     

胡椒预处理方式对胡椒脱皮的影响

通过改变胡椒的预处理方式来解决固态发酵脱皮时间短与固态发酵脱皮白胡椒色泽差之间的矛盾。结果表明：不同条件下沸水热烫处理得到的胡椒脱皮率虽能达到100 %,但色泽不理想;而在室温条件下,经不同水处理后脱皮得到的白胡椒的色泽明显比沸水热烫的好,但脱皮率未能达到100 %;用热水浸泡预处理后的实验组不仅胡椒脱皮率能达到100 %,而且色泽也较为理想,已达到市售的水平。所以,选择胡椒脱皮的最优预处理方式为50 ℃热水浸泡20 min。     

数值分类法在玉米品种资源上的应用

本文应用主成分分析法对湖北省201份玉米品种资源的28个性状进行分析,结果表明,前7个主成分对变异的累计贡献率达79.5%,以前7个主成分为综合指标进行系统聚类,在遗传距离D²=1.50水平上聚成7大类;不同类群间的性状具有明显差异,而类群内特征相似;其中Ⅲ、Ⅴ、Ⅵ类为综合性状较好的种质类群。     

几个籼稻品种的成熟胚愈伤组织植株再生体系的建立

组织培养技术在作物改良上的成功应用需要合适的植株再生体系。本试验以7个籼稻成熟胚为材料，通过优化激素配比，建立适合于水稻遗传转化的高频植株再生体系。研究结果表明，NB 2mg／L2，4-D适合于供试品种的成熟胚愈伤组织的诱导，诱导率达90％以上；在分化培养基中添加3．0-3．5mg／L KT，0．5～1．0mg／L NAA和5．0mg／L ABA的激素配比，明恢81、N175、航1号的最高分化率分别达72．7％、80．0％和78．0％；移栽成活95％以上。     

离体培养条件下半夏叶柄形成珠芽过程中内源激素的变化

为了探讨半夏试管珠芽形成的生理生化机制,以半夏无菌叶柄为材料,倒置在MS基本培养基上,对半夏珠芽形成过程中5种内源激素(IAA、GA3、ABA、ZR、JA)的动态变化进行了研究。结果表明:倒置半夏叶柄的珠芽无一例外地出现在叶柄形态学上端;ELISA方法测定显示,半夏叶柄形成珠芽的过程中叶柄上端IAA、ABA、ZR和JA的含量呈上升趋势,GA3在的珠芽形成初期急剧下降。随着珠芽的形成,GA3与其它各激素的平衡关系发生变化,IAA/GA3、ABA/GA3、ZR/GA3和JA/GA3的比值先呈下降趋势,15 d后开始上升;在珠芽快速形成期(10~20 d)IAA/GA3、ABA/GA3和JA/GA3维持在高的水平,其中JA/GA3的比值20 d后又呈上升趋势。