沪农灵芝1号全基因组分析和演化比较

对“沪灵芝”(Ganoderma lucidum SH)等23个真菌物种进行全基因组系统发生分析,进一步选取其中具有代表性的物种进行比较基因组学分析.全基因组系统发生分析和分子钟估计结果显示,沪灵芝分化时间(8.75百万年前)明显晚于灵芝属分化时间(180百万年前);基因家族尺寸和直系同源基因数目分析显示,与另外参试灵芝菌种相比沪灵芝基因家族具有一定的收缩趋势;进一步对基因家族数目进行比较的结果显示,沪灵芝逆转录酶家族发生了显著扩增.GO功能分析提示沪灵芝逆转录酶家族的功能富集主要为核酸结合功能和酶的催化活性.     

紫色黄秋葵转录组功能基因测序及分析

黄秋葵为药食兼用型植物,富含花青素、多糖、黄酮及萜类等活性成分。为探讨黄秋葵次级代谢过程中这些活性物质合成的遗传基础,以紫色黄秋葵嫩茎叶为材料,采用Illumina Hi Seq 2500高通量转录组测序技术获得23 026 500个短读序,经组装获得42 484个Unigene,平均长度877 bp。31 931个和21 926个Unigene分别在Nr和Swiss Prot数据库有同源比对信息;Unigene与COG、KOG数据库进行比对,根据其功能各分为24类和25类;通过Pfam数据库,所注释到的20 031个Unigene分属于7 277类蛋白结构域;GO注释到18 602个Unigene分为细胞组分、分子功能及生物学过程等三大类的51个功能组,其中大量Unigene与细胞部分、细胞、催化活性、结合活性、代谢进程及细胞进程相关;根据KEGG数据库,可将7 619个Unigene定位到119个代谢途径分支,其中有1、3、35、61、13和70个Unigene分属于花色素苷、黄酮、类黄酮、N-多糖、二萜类和萜类骨架生物合成路径,它们可能参与这些活性物质的生物合成。本研究结果为后续深入开展黄秋葵花青素、黄酮类等物质代谢合成途径及相关功能基因研究奠定了基础。     

Physicochemical and Gel Properties of Myofibrillar Protein from Sin Croaker (Johnius dussumieri) Fish During Ice Storage

The physicochemical and gel properties of myofibrillar protein (MFP) from sin croaker fish were studied during ice storage for 18 days. Significant changes in the trends of solubility, Ca²⁺ ATPase enzyme activity, surface hydrophobicity, and water holding capacity of extracted MFP were observed by the 6th day of storage. The Ca²⁺ ATPase enzyme activity reduced significantly (p < 0.05) by the 6th day of storage. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) did not show a remarkable change in the concentration of myosin heavy chain. Surface hydrophobicity increased almost four times from its original value of 18.98 µg; whereas, water holding capacity showed a fluctuating trend during storage. The emulsion capacity of the MFP was in the range of 0.89- to 1.92-mL oil/mg protein during storage. The gel strength value (313.45 g.cm) of heat-induced gel prepared from fresh minced meat decreased significantly (p < 0.05) by the 6th day of ice storage. Texture profile analysis revealed that changes in hardness and gumminess were concurrent to steeply reducing breaking force up to the 6th day. The histological observation showed gradually increasing gaps between muscle fibers. The histological observations and physicochemical quality indicated that the sin croaker fish can be used for producing good quality surimi when stored for up to 6 days in ice.     

Taxonomic versus functional diversity metrics: how do fish communities respond to anthropogenic stressors in reservoirs?

Biological indicators are frequently used to assess the effects of anthropogenic stressors on freshwater ecosystems. The structure of fish communities and their response to stressors have been commonly described by taxonomic richness, diversity and evenness. More recently, functional structure of communities has also been suggested to be a reliable indicator of disturbance. This article aimed at testing whether taxonomic and functional diversity metrics can provide comparable or complementary information on the response of fish communities to eutrophication and abundance of non‐native species in reservoirs. Comparison of the responses of taxonomic and functional diversities to biogeography, habitat and stressors was made in 112 French reservoirs. Widely observed effects of biogeographic and habitat variables on taxonomic and functional diversities were identified. Taxonomic and functional richness metrics notably increased with lake area and temperature respectively. Taxonomic diversity metrics did not respond to any stressor, while all functional diversity metrics were found to be impacted by non‐native species. Eutrophication was further found to decrease the impact of non‐native species on two functional diversity metrics: evenness and divergence. Our study therefore reveals that functional metrics are more sensitive than taxonomic metrics to anthropogenic stressors in the studied reservoirs. Still, the multiple linear regressions tested had overall low explanatory power. Further refinements will thus be needed to use this type of metrics in an impact assessment scheme.     

欧李番茄红素β–环化酶基因ChLCYb的分离与功能鉴定

利用RACE技术和RT-PCR相结合,从欧李[Cerasus humilis(Bge)Sok]果实中克隆获得长度为1798 bp的番茄红素β–环化酶(lycopeneβ-cyclase)基因ChLCYb的cDNA全长序列,开放读码框为1515 bp,编码503个氨基酸。序列分析发现,ChLCYb具有植物LCYb保守区(Plant LCYb conserved region)、FAD/NAD(P)结合区(Dinucleotide-binding signature)、"Cyclase motif 1"、"Cyclase motif 2"和"lycopeneβ-cyclase motif"等典型结构特征,在N–端存在1~84个氨基酸残基组成的转运肽信号序列,在85~106、209~227、373~391和460~480氨基酸区域包含4个跨膜结构域。荧光定量PCR结果表明,ChLCYb在叶中表达量最高,其次是幼果,在根中最低;在欧李果实发育过程中,果皮中ChLCYb表达量高于果肉,果皮中ChLCYb表达量先升高,在花后90 d左右表达量最高,然后呈缓慢下降趋势,而果肉中ChLCYb表达量相对平稳。ChLCYb表达模式与果皮和果肉中β–胡萝卜素含量的积累呈显著正相关(r=0.824和r=0.712,P0.05)。利用大肠杆菌工程菌体系诱导表达了ChLCYb蛋白,并证实其可催化工程菌株中番茄红素向β–胡萝卜素转化,其转化效率达71.22%。在番茄中超量表达ChLCYb促进果实中番茄红素向β–胡萝卜素的转化和积累,转基因株系L-11号果实中的β–胡萝卜素含量高达692.18μg·g~(-1) DW,是非转基因对照的4.42倍。     

蠋蝽对小菜蛾幼虫的捕食作用

本试验在室内研究了蠋蝽3～5龄若虫及成虫对小菜蛾幼虫的捕食能力,采用HollingⅡ功能反应模型和Hassell模型,以明确蠋蝽对小菜蛾的捕食潜能以及蠋蝽自身密度对小菜蛾捕食作用的影响。结果表明,蠋蝽3～5龄若虫及成虫对小菜蛾幼虫的捕食模型均符合HollingⅡ模型;蠋蝽3～5龄若虫和成虫瞬时攻击率由大到小依次为1.461(3龄若虫)1.322(4龄若虫)1.086(5龄若虫)0.803(雌成虫)0.734(雄成虫);蠋蝽5龄若虫的日最大捕食量最高,为83.33头。随着小菜蛾幼虫密度增大,蠋蝽的搜寻效应逐渐降低,5龄若虫的搜寻效应明显大于其他虫态。蠋蝽3～5龄若虫及成虫自身密度对其捕食作用的干扰效应明显,其中蠋蝽3龄若虫的竞争参数最大,为0.862。本研究表明蠋蝽对小菜蛾具有较好的捕食潜力,尤其是蠋蝽5龄若虫。     

Osteomorphological features of the hind limb bones of Saiga antelope (Saiga tatarica)

The intralimb indices and calcaneal linear metrics are known as the reliable predictors of locomotor adaptation in artiodactyls. The osteological features of hindlimb in adult Saiga (Saiga tatarica) were described, and its correlation with cursoriality and habitat adaptation was discussed. Gross anatomy data showed Saiga owned the deep acetabulum as a broad lunate surface, the large acetabular anteversion, the well-developed ischiatic tuberosity and the prominent gluteal lines. It also presented the robust rough line and the strong gluteal tuberosity. A proximodistally elongated eminence located on the cranially distal tibia, which had not been found in goat. The tibial extensor groove was deep. The calcaneal tuberosity was robust. Digital anatomy data showed Saiga owned the higher metatarsal-femur ratio than forest musk deer and sheep. Comparing with wild bovids and sheep, Saiga presented a transitional variation in calcaneal form. The mean greatest length of the calcaneus (GLC) and the height of the sustentacular facet (HSF) in Saiga were shorter than that in sheep and longer than that in wild bovids respectively (F = 587.492; F = 10.264, p < .05). The wild bovids had longer cubonavicular facets than the other two groups (F = 18.587, p < .05). The great metatarsal–femur ratio of Saiga implied a superior cursorial ability and high conservation confronting the different habitats. The calcaneal linear metrics might shed light on lifestyle-related functional adaptation over decades of short-term evolution in the semi-free range environment.     

国家热带农业科学中心建设的几点思考

本文在系统梳理国内相关综合性国家科学中心建设情况的基础上,形成对建设国家热带农业科学中心的经验启示,即强化基础支撑、优化资源布局、创新体制机制,进而从功能定位、重点任务和体制机制等方面对推进国家热带农业科学中心建设提出设想。     

休眠期后板栗混合花芽的转录组分析

板栗是中国重要的木本粮食作物,具有极高的经济价值,但板栗雄花比例远远高于雌花,是限制板栗产量的主要因素。为了从分子水平上探讨板栗雌雄花的发生机制,本研究利用高通量测序技术对休眠期后板栗的两种混合花芽的转录组进行比较分析。总计获得了3 772个差异表达基因,其中2 173个基因上调,1 599个基因下调。这些差异基因经过GO分类和KEGG pathway富集分析分别归类于47个GO term和251条代谢途径。从转录组数据中获得了春化、光周期、赤霉素(GA)等途径的开花相关基因,还鉴定多个开花相关内源激素途径的基因。将基因VIN3,GAI,ELF3,GID1的qPCR检测结果与其转录组测序结果进行比对,发现虽然两种检测结果在差异倍数上存在差别,但4个基因的表达量的总体变化趋势一致,说明转录组测序结果有较高的可信性。本研究结果为揭示板栗雌雄花性别比例调控机制和花期人工调控提供了一定的科学参考。     

施用生物菌肥对桃园土壤养分及微生物功能多样性的影响

以不同施肥处理下的桃园土壤为试验材料，设置不同梯度的生物菌肥 T1（200 kg·667m^-2）、T2（300 kg·667m^-2）、T3（500 kg·667m^-2）及T4（1 000 kg·667m_-2）4个处理，以鸡粪为 CK（2 000 kg·667m^-2），研究生物菌肥对桃园土壤养分及微生物功能多样性的影响。结果表明：随生物菌肥施用量的增加，桃园土壤pH值、有机质、铵态氮、速效钾、有效磷含量、微生物单孔颜色平均变化率(AWCD)、微生物多样性指数及微生物对六类碳源的利用强度先增加后降低，硝态氮含量下降。生物菌肥200 kg·667m^-2处理下，0~20 cm土层有效磷含量较CK提高53.98%（P＜0.05），而与生物菌肥300 kg·667m^-2处理差异不显著。生物菌肥300 kg·667m^-2处理下，土壤微生物对羧酸类化合物利用强度最高，较CK提高22.67%(P＜0.05)。生物菌肥300 kg·667m^-2处理下20~40 cm土层的土壤有效磷、速效钾含量、微生物多样性指数（Simpson 优势度指数）及微生物对碳水化合物利用强度较CK分别提高33.49%、129.61%、0.22%和18.06%（P＜0.05）。冗余分析表明，土壤微生物对氨基酸化合物利用强度与有机质显著正相关，相关系数为0.68。主成分分析中，生物菌肥300 kg·667m^-2处理对土壤微生物多样性指数、碳源利用强度及土壤养分影响得分最高，分别为2.42和1.36。因此，生物菌肥能够提高土壤微生物活性、功能多样性、微生物对碳源的利用强度及养分含量，其中以生物菌肥300 kg·667m^-2处理效果最佳。