Molecular mapping and candidate gene analysis for fruit epidermal structure in cucumber

Firmness of skin is an important quality of processing cucumbers, which is a feature of the palisade epidermis in these types compared to flat epidermis in fresh cucumbers. This study was conducted to map the Pe (palisade epidermis) and analyse the candidate gene. Populations derived from the cross of two inbred lines, NCG122 with fruit flat epidermis and NCG121 with fruit palisade epidermis, were used to identify the inheritance of palisade epidermis and to map the gene involved in its development. The results showed that the palisade epidermis trait is controlled by a single gene, Pe, that is dominant over flat epidermis. Seven simple sequence repeat (SSR) and five insertion deletion (Indel) markers were identified to be linked to the Pe gene. It was mapped to cucumber chromosome 5 (Chr.5) between SSR14611 and Indelpe12 with genetic distances of 0.3 cM and 0.2 cM, respectively. The physical distance of the genomic region harbouring the gene was 227.5 kb with 26 predicted candidate genes. The accuracy of marker‐assisted selection using the molecular markers, Indelpe12 and SSR14611, was 68% and 88%, respectively.     

甘蓝耐裂球性与叶表面微形态及细胞组织结构的关系研究

从细胞学水平上探讨影响甘蓝裂球的原因,为甘蓝耐裂性材料的选育和新品种的育成提供理论依据,并为甘蓝耐裂性鉴定指标的制定提供依据.运用扫描电子显微镜对4份耐裂性不同的甘蓝叶表面微形态及细胞组织结构进行比较观察.结果表明:甘蓝球叶表皮细胞为无规则型,气孔为卵圆形或长椭圆形.材料间下表皮微形态存在较显著的差别:耐裂材料的垂周壁上有明显的波状嵴,平周壁上有加厚的条纹状角质层纹饰,保卫细胞四周角质层褶皱较多、起伏较大,表皮细胞上覆盖有大量的粉状或颗粒状蜡质.易裂材料的垂周壁呈沟槽状下陷,平周壁上角质层光滑,保卫细胞四周角质层较平坦.耐裂材料的叶肉细胞层数多,排列紧密,间隙小.易裂材料叶肉细胞层数少,排列松散,间隙大.耐裂材料与易裂材料在球叶表面微形态及细胞组织结构上表现显著差异.     

Rapid temperature‐dependent wound closure following adipose fin clipping of Atlantic salmon Salmo salar L

Three groups of Atlantic salmon were kept at a constant temperature of 4, 10 and 14 °C. The adipose fins were removed; six fish/group were sampled at 11 subsequent time points post‐clipping. Samples were prepared for histopathological examination to study the course of re‐epithelization. A score sheet was developed to assess the regeneration of epidermal and dermal cell types. Wounds were covered by a thin epidermal layer between 4 and 6 h post‐clipping at 10 and 14 °C. In contrast, wound closure was completed between 6 and 12 h in fish held at a constant temperature of 4 °C. By 18 h post‐clipping, superficial cells, cuboidal cells, prismatic basal cells and mucous cells were discernible in all temperature groups, rapidly progressing towards normal epidermal structure and thickness. Within the observation period, only minor regeneration was found in the dermal layers. A positive correlation between water temperature and healing rates was established for the epidermis. The rapid wound closure rate, epidermal normalization and the absence of inflammatory reaction signs suggest that adipose fin clipping under anaesthesia constitutes a minimally invasive method that may be used to mark large numbers of salmon presmolts without compromising fish welfare.     

Effects of dietary taurine levels on epidermal thickness and scale loss in red sea bream,Pagrus major

Taurine is often added to artificial fish diets to compensate for a reduction in fish meal (FM). However, the taurine content of FM‐based diets is typically lower than in diets consisting of raw fish, even in diets where FM is the only protein source. We evaluated the effects of dietary taurine in FM‐based diets on epidermal thickness and scale detachability in red sea bream Pagrus major. We compared the effect of diets containing 0% (control), 0.3% (Tau‐0.3%), 0.6% (Tau‐0.6%) and 1.0% (Tau‐1.0%) taurine. Red sea bream (average body weight, 39 g) were fed these diets for 7 weeks. Taurine supplementation had no effect on growth, feed intake, feeding efficiency, or survival. However, the epidermal thickness was higher in fish in the Tau‐0.6% and Tau‐1.0% groups than in the control and Tau‐0.3% groups. Similarly, scale loss was significantly higher in the control group than in the Tau‐0.6% and Tau‐1.0% groups. Our results suggest that supplementation with >0.6% taurine (1.0% in diet) improves skin condition.     

天南星科3属3种代表植物叶表皮形态研究

利用光学显微镜对天南星科马蹄莲属、海芋属、龟背竹属的3种代表植物的叶表皮形态进行观察,同时用显微分析技术对3种植物细胞大小进行了测量。结果显示,3种气孔类型变异较大,有平列型、胞环型及平列型和胞环型间的过渡类型,表皮细胞大小有一定差异,垂周壁平直或弧形。虽然气孔器类型对天南星科分类上的意义不大,但与表皮细胞垂周壁形状、副卫细胞数目等特征相结合对种间分类具有一定的意义。     

陕西14种小檗属植物的叶表皮微形态

应用光学显微镜对西北农林科技大学植物标本馆中分布于陕西省的14种小檗属(Berberis)植物的叶表皮微形态特征进行了研究。结果表明:14种小檗属植物叶表皮细胞形状有多边形和无规则形两种;垂周壁式样有平直-弓形、浅波形和深波形3种。叶表皮外均有不同程度加厚的角质层。气孔器只分布在所有研究的14种小檗属植物的下表皮,形状为椭圆形、长椭圆形、宽椭圆形;气孔器类型大多为无规则型。这些特征与它们具有的耐旱性有一定的相关性。对气孔指数、气孔密度、气孔长宽比的数据分析表明:陕西14种小檗属植物的气孔指数差异较大,可作为种间分类的依据;气孔密度在特定几种植物间的差异较明显,可作为部分种的分类依据。     

国产萝藦科牛奶菜族11属植物叶表皮形态研究

在光学显微镜和扫描电子显微镜下观察了国产萝藦科牛奶菜族11属28种植物叶表皮的外表面和内表面形态特征.该族植物叶片上表皮细胞通常呈多边形,垂周壁平直或近平直;角质层有条纹状、乳突状、粗条状和脊状皱褶等结构;气孔器有平列型和环列型2种类型:眼树莲属D ischidia、球兰属Hoya和扇叶藤属M icholitzia具有环列型气孔器,其他属均为平列型.结合形态学、细胞学和分子生物学资料,提出牛奶菜族的气孔器可能是从平列型向环列型进化的.