云南高原香蕉产业低效益成因与对策

香蕉是四大水果之一,香蕉产业在云南热区占有重要的地位。通过对云南高原香蕉产业现状和低效益形成原因的分析,提出了相应对策以提高蕉农的经济效益,促进香蕉产业持续健康发展。     

Common dental disorders in the donkey

Normal dental anatomy and the range of dental disorders found in donkeys are largely similar to those described in horses. Recent studies have shown dental disease to have a high prevalence in donkeys. Some dental disorders, such as diastemata, displaced teeth and wave mouth can have serious clinical consequences by causing oral pain and weight loss and even predispose to colic. Many of these signs can be prevented by regular dental treatment that can slow down or even prevent the progression of these disorders.     

基于DNA的木材识别新技术发展与应用

介绍了基于DNA方法的木材识别新技术在国内外的研究进展,在分析现存技术问题的基础上,提出完善DNA方法在木材识别领域应用的建议.为开辟木材识别的新途径,保护木材资源、推进木材合法贸易提供技术支撑.     

Picea abies sapwood width: Variations within and between trees

Abstract

This study focused on the amount of sapwood and its variation by means of computed tomographic (CT) imaging. Twenty-four trees were selected from four Norway spruce [Picea abies (L.) Karst.] stands in north-eastern France, varying in age, density and fertility. In each stand, sampled trees represented the dominant, co-dominant and suppressed strata. The heartwood/sapwood boundary was detected from the CT images, and the heartwood and sapwood amount and their variations were then evaluated. At the within-tree level sapwood width was relatively constant along the tree stem above the butt swelling and below the living crown. The between-tree sapwood width variations were partially explained by the total cross-sectional area of living branches. This result opens up the possibility of investigating within-tree allometric relationships. Sapwood width was found to be highly correlated with tree slendemess (tree height/breast height diameter) and with the relative height of the crown. This suggests that sapwood width could be readily predicted from conventional forest inventory measurements. The number of sapwood rings within the stem was largely dependent on cambial age, and could be determined dynamically using the concept of mean lifetime of sapwood rings.     

甘蓝型油菜不同发育时期株高QTL的动态分析

利用新版SG遗传图谱和282个SG-DH株系在中国西安、杭州和德国哥廷根3个生长环境下8个发育时期测定的株高数据,运用WinQTLCart2.5复合区间作图法以及结合条件遗传分析方法对其进行静态和动态QTL分析。结果显示, 来自品种Gaoyou等位基因在PHA3和PHC6两个QTL上同时存在时,可降低株高约20 cm;而当植株整合来自冬性品种Sollux的PHA9、PHC1和来自半冬性品种Gaoyou的PHA1、PHA3、PHC6时,株高可相应下降40 cm;环境对株高QTL的作用机理影响不大,但不同QTL的基因表达模式不同,存在来自双亲之一的等位基因控制株高和双亲等位基因在不同生长时期交替控制株高两种情况;通常株高QTL在中后期才能被检测到,但基因多在生长最为旺盛的短时期内表达,符合基因表达在先,性状表现在后的规律。解析株高性状在不同发育时期基因的累加效应和特定时段内的净表达效应,对克隆油菜株高基因和指导生产实践都将提供富有价值的科学信息和理论依据。     

Biological and Chemical Approaches for the Detection and Identification of Illegal Estrogens in Water-based Solutions

The continuous introduction of new products used as growth promoters in animal husbandry, for sports doping and as products for body-building requires residue laboratories to initiate research on developing a strategy for the identification of ’unknown’ components. In this study, a strategy is presented for elucidating the identity, the structure and the possible effects of illegal estrogenic compounds in an unidentified water-based solution. To obtain complete information on the composition and activity of the unidentified product, a multidisciplinary approach was needed. A case-study is described with a ’solution X’ found during a raid. First, in vivo techniques (animal trials with mice, anatomical and histological research) were combined with in vitro techniques (the yeast estrogenic screen (YES)). In a later stage of the investigation, HPLC-fractionation, liquid chromatography–multiple mass spectrometry (LC-MS ⁿ and gas chromatography-multiple mass spectrometry (GC-MS ⁿ were used. Finally, the identity of ’solution X’ was confirmed in a very low concentration range (10 ng/L estrone and 400 ng/l ethinyloestradiol).     

Wheat Rht‐B1 Dwarfs Exhibit Better Photosynthetic Response to Water Deficit at Seedling Stage Compared to the Wild Type

Wheat reduced height (Rht) genes encode modified DELLA proteins, which are gibberellin insensitive, accumulate under stress, restrain growth and affect plant stress response. The seedling reaction to soil water deficit regarding leaf gas exchange and chlorophyll fluorescence was compared in near‐isogenic lines carrying the alleles Rht‐B1a (tall), Rht‐B1b (semi‐dwarfing) and Rht‐B1c (dwarfing) and was related to leaf water content and anatomy. Under drought, Rht‐B1c line was characterized by less decreased CO₂ assimilation, delayed non‐stomatal limitation of photosynthesis and higher instantaneous water use efficiency. The functional state of its photosynthetic apparatus was better preserved as evidenced by the less decreased actual quantum yield (Φ_PSII) and potential maximum quantum yield (F_v/F_m) of PSII, and the less increased quantum yield of non‐regulated energy dissipation (Φ_NO). Rht‐B1b line also tended to perform better than Rht‐B1a, but differences were less pronounced. Although the leaves of both dwarf lines were smaller, thicker and more pubescent, their water content was not higher in comparison with the tall line. Nevertheless, in Rht‐B1c, leaf thickness was less decreased and mesophyll cells were less shrunk under drought. The more effective performance of the photosynthetic machinery of dwarf lines under water deficit could be explained by a combination of morpho‐anatomical and metabolic characteristics.     

蒙古蒲公英休眠特性研究

蒙古蒲公英为我国药典和兽药典收录的基源植物,在我国广泛分布.实验发现,蒙古蒲公英存在休眠现象,本实验通过形态解剖、激素处理(IBA、NAA、6-BA、GA)来研究蒙古蒲公英休眠的原因以及打破休眠的方法,为提高蒙古蒲公英的发芽率提供可行依据.结果表明:室温条件培养1个月,蒙古蒲公英种子发芽率为1％左右;破种皮种子只有吸胀而无萌发;形态解剖发现蒙古蒲公英种子有形态后熟,1个月即可完成形态后熟;不同激素、不同浓度以及不同浸种时间对蒙古蒲公英的发芽率有不同影响,其中6-BA浓度50 mg/L浸种9d的处理效果最好,萌发率高达54％,但从种子萌发以及幼苗质量综合考虑,建议200 mg/L GA处理12d,效果最好.综上所述,蒙古蒲公英休眠主要由形态后熟以及生理休眠所导致,激素处理可以有效打破其休眠.     

乌鲁木齐河源区10种真藓属植物茎的解剖学分析

利用石蜡切片和电镜扫描技术,对乌鲁木齐河源区10种真藓属植物茎的结构做比较解剖学研究。结果表明:该属植物茎分为表皮、皮部、中轴3部分,表皮细胞小,细胞壁强烈加厚;皮部细胞壁由外向内逐渐变薄,细胞整齐或镶嵌排列;中轴所占面积较小,细胞壁角隅加厚。茎细胞壁上分布有不规则的小孔,相邻细胞的细胞壁厚,表面角质层纹饰多为鳞片状或颗粒状,这些可能是植物在长期恶劣环境下的生存策略,揭示了真藓属植物茎具有较强耐寒、耐旱结构的典型特征,虽然它们在外形和亲缘关系上均很接近,但每个种又各具不同的形态特征,为该属植物鉴定提供了分类学依据。     

我国北方旱作农田保护性耕作发展与展望

保护性耕作是旱地耕作制度的重要组成部分,我国自2002年开始在全国范围内大规模推广保护性耕作。通过少耕、免耕及秸秆还田等综合配套措施,减少农田土壤侵蚀,保护农田生态环境,达到生态、经济效益协调发展的目的。对我国北方旱作农田土壤耕作发展历程、保护性耕作主要成就进行了梳理,并对未来我国北方旱作农田保护性耕作面临的新任务进行了展望,为气候变化条件下旱作农田持续高效发展提供借鉴。