川榛遗传资源分类、分布及其研究利用现状分析

利用图书馆和网络数据库检索工具,通过对包含"川榛"字段的各类书籍、文献的整理,对川榛遗传资源的分类地位、分布范围及其研究利用现状等内容进行了归纳总结,并通过对川榛分布区代表样点气象数据的统计,对其适生的生态条件进行了分析。结果表明:川榛(贵榛、黔榛)主要分布于中国102°06’~121°26’E,26°29’~36°58’N之间,年均温6.1~19.3℃的广大区域,覆盖全国15个行政省区、直辖市,自然分布以山坡地为主,跨越温带、暖温带和亚热带,具有广泛的生态适应性;分布范围、生态习性、植物学性状、孢粉学和遗传关系等方面的资料表明,川榛与平榛存在明显的差别,两者应为独立的种;川榛具有较高的经济价值和育种价值,但其开发利用进展缓慢;川榛遗传资源的调查与保护、种群多样性及杂交利用等研究工作亟待开展。此研究可为今后开展川榛遗传资源的调查、收集和评价工作提供依据。     

Early nut development as a resistance factor to the attacks of Curculio nucum (Coleoptera: Curculionidae)

The nut weevil Curculio nucum (Coleoptera: Curculionidae) is responsible for high yield losses in several hazelnut‐growing areas of Europe and Turkey, if not regularly controlled using pesticides. The resistance of hazelnut varieties to the nut weevil is known but poorly investigated so far. Thus a 2‐year study was carried out to investigate factors affecting C. nucum attacks on two cultivars [Tonda Gentile delle Langhe (TGL), Ennis] and four selections (Daria, 101, B6, L35) in a 15‐year‐old orchard of northwestern Italy. Nut developmental stages and shell characteristics, such as hardness and thickness, were measured and correlated to the biological cycle of the nut weevil and to the damage by its larvae. During the 2‐year sampling, nut weevil adults were collected on all cultivars and selections, but in greater quantities on TGL and Daria, and in lower quantities on 101 and B6. In 2005, by female dissection, mature eggs were observed from late June, when the mean temperature exceeded 18°C. Differences between cultivars and selections were found in nut and kernel development, and in shell hardening; in particular, the kernel development was directly related with the shell hardness. At harvest, the damage varied on average from 2.57% in cultivar TGL to 51.84% in selection 101 of total nuts harvested, so independently of the numbers of the collected weevil adults. These two varieties were the earliest and the latest in kernel development and shell hardening, respectively. Therefore, the susceptibility to nut weevil attacks was strictly related to shell hardening; in fact, a rapid hardening of the shell can hamper the oviposition of C. nucum females. By contrast, no correlation was found between shell thickness and damage at harvest.     

围栏条件下花鼠找寻种子的途径和方式

2009年8月和2010年8月,在黑龙江省带岭区东方红林场半天然围栏内研究了花鼠(Eutamias sibiricus)对地表放置和埋藏种子的发现过程,摸清围栏条件下花鼠找寻种子信号的途径和方式.实验步骤如下:第1天在花鼠巢区对角每释放点地表放置1粒标记种子,共30粒;第2天在巢区对角每释放点埋藏1粒标记种子,共30粒...     

Identification of sheep ovary genes potentially associated with off-season reproduction

Off-season reproduction is a favorable economic trait for sheep industry.Hu sheep,an indigenous Chinese sheep breed,demonstrates a higher productivity of lambs and displays year-around oestrous behavior under proper nutrition and environment.The genetic basis behind these traits,however,is not well understood.In order to identify genes associated with the off-season reproduction,we constructed a suppression subtractive hybridization(SSH) cDNA library using pooled ovary mRNAs of 6 oestrous Hu females as a tester and the pooled ovary mRNAs of 6 non-oestrous Chinese Merino females as a driver.A total of 382 resulting positive clones were obtained after the SSH.We identified 114 differentially up-regulated genes in oestrous Hu sheep by using subsequent screening and DNA sequencing,of which 8 were previously known,93 were reported for the first time in sheep,and 13 were novel with no significant homology to any sequence in the DNA databases.Functions of the genes identified are related to cell division,signal transduction,structure,metabolism,or cell defense.To validate the results of SSH,6 genes(Ntrk2,Ppap2b,Htra1,Nid1,Serpine2 and Foxola) were selected for conformational analysis using quantitative real-time PCR(qRT-PCR),and two of them(Htral and Foxola) were verified by Northern blot.All of the 6 genes were differentially up-regulated in the ovary of oestrous Hu.It is obvious that off-season reproduction is a complex trait involving multiple genes in multiple organs.This study helps to provide a foundation for the final identification of functional genes involved in the sheep ovary.     

黄河三角洲贝壳堤岛3种灌木光合生理特征研究

以黄河三角洲贝壳堤岛5年生的酸枣、杠柳及柽柳为材料,采用CIRAS-2型光合测定系统测定它们叶片的光合、蒸腾、水分利用效率等生理参数及其光响应过程,探讨3种灌木在当地自然生境下的光合生理特征.结果表明:柽柳和酸枣的光响应曲线符合非直角双曲线模型(R2>0.98),杠柳光响应曲线符合二次多项式模型(R2=0.95); 3种灌木的净光合速率、表观量子效率、暗呼吸速率、羧化效率、光饱和点、蒸腾速率及水分利用效率在树种间差异显著(P<0.05);酸枣的净光合速率分别是柽柳和杠柳的1.30和1.23倍,柽柳和酸枣弱光下羧化效率要高于杠柳,柽柳暗呼吸速率最大且生理活性最高; 3种灌木的蒸腾耗水能力表现为柽柳>酸枣>杠柳,且在高光强下均具有通过降低蒸腾作用来提高水分利用效率的生理特性,杠柳的水分利用效率分别是酸枣、柽柳的1.26和1.71倍;3种灌木具有较强的向阳喜光特性,但酸枣对弱光的利用能力要好于杠柳和柽柳.研究发现,3种灌木在贝壳堤岛相同自然生境下表现出不同的光合行为, 而酸枣和杠柳具有高光合、低蒸腾及高水分利用效率的生理特性,酸枣具有较宽的光照生态幅,它们适宜于该区域大面积人工栽植.     

Isolation and characterisation of phytase from dormant Corylus avellana seeds

Phytase (myo-inositol-1,2,3,4,5,6-hexakisphosphate phosphohydrolase, EC 3.1.3.26), which catalyses the step-wise hydrolysis of phytic acid, was purified from cotyledons of dormant Corylus avellana L. seeds. The enzyme was separated from the major soluble acid phosphatase by successive (NH4)(2)SO(4) precipitation, gel filtration and cation exchange chromatography resulting in a 300-fold purification and yield of 7.5%. The native enzyme positively interacted with Concanavalin A suggesting that it is putatively glycosylated. After size exclusion chromatography and SDS-PAGE it was found to be a monomeric protein with molecular mass 72+/-2.5 kDa. The hazel enzyme exhibited optimum activity for phytic acid hydrolysis at pH 5 and, like other phytases, had broad substrate specificity. It exhibited the lowest Km (162 microM) and highest specificity constant (V(max)/Km) for phytic acid, indicating that this is the preferred in vivo substrate. It required no metal ion as a co-factor, while inorganic phosphate and fluoride competitively inhibited enzymic activity (Ki=407 microM and Ki=205 microM, respectively).     

Development and Validation of Nomograms for Predicting Overall and Breast Cancer–Specific Survival in Young Women with Breast Cancer: A Population-Based Study

INTRODUCTION: The objective of current study was to develop and validate comprehensive nomograms for predicting the survival of young women with breast cancer. METHODS: Women aged <40 years diagnosed with invasive breast cancer between 1990 and 2010 were selected from the Surveillance, Epidemiology, and End Results database and randomly divided into training (n = 12,465) and validation (n = 12,424) cohorts. A competing-risks model was used to estimate the probability of breast cancer–specific survival (BCSS). We identified and integrated significant prognostic factors for overall survival (OS) and BCSS to construct nomograms. The performance of the nomograms was assessed with respect to calibration, discrimination, and risk group stratification. RESULTS: The entire cohort comprised 24,889 patients. The 5- and 10-year probabilities of breast cancer–specific mortality were 11.6% and 20.5%, respectively. Eight independent prognostic factors for both OS and BCSS were identified and integrated for the construction of the nomograms. The calibration curves showed optimal agreement between the predicted and observed probabilities. The C-indexes of the nomograms in the training cohort were higher than those of the TNM staging system for predicting OS (0.724 vs 0.694; P < .001) and BCSS (0.733 vs 0.702; P < .001). Additionally, significant differences in survival were observed in patients stratified into different risk groups within respective TNM categories. CONCLUSIONS: We developed and validated novel nomograms that can accurately predict OS and BCSS in young women with breast cancer. These nomograms may help clinicians in making decisions on an individualized basis.