Cucurbits depicted in Byzantine mosaics from Israel, 350–600 ce

Background and Aims

Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region.

Results and Conclusions

Twenty-three mosaics dating from 350–600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round–pyriform and probably used as vessels.     

Lipid Trafficking in Plant Cells

Plant cells contain unique organelles such as chloroplasts with an extensive photosynthetic membrane. In addition, specialized epidermal cells produce an extracellular cuticle composed primarily of lipids, and storage cells accumulate large amounts of storage lipids. As lipid assembly is associated only with discrete membranes or organelles, there is a need for extensive lipid trafficking within plant cells, more so in specialized cells and sometimes also in response to changing environmental conditions such as phosphate deprivation. Because of the complexity of plant lipid metabolism and the inherent recalcitrance of membrane lipid transporters, the mechanisms of lipid transport within plant cells are not yet fully understood. Recently, several new proteins have been implicated in different aspects of plant lipid trafficking. While these proteins provide only first insights into limited aspects of lipid transport phenomena in plant cells, they represent exciting opportunities for further studies.      

核盘菌侵染对拟南芥表皮蜡质结构及化学组成的影响

以野生型拟南芥与蜡质突变体cer1、cer4为试验材料,通过研究核盘菌胁迫对拟南芥茎表皮蜡质结构及组分含量的影响,揭示核盘菌侵染与表皮蜡质的关系。扫描电镜结果显示,野生型拟南芥蜡质晶体以垂直于表面的杆状、块状结构为主;突变体cer1晶体类型以水平的松针状、块状结构为主;突变体cer4蜡质晶体以垂直片层结构为主。核盘菌胁迫下,拟南芥蜡质晶体结构及分布形态发生变化。蜡质层结构在核盘菌胁迫下表现为:杆状、松针状蜡质晶体减少—蜡质晶体熔融—表皮"囊状凸起"—表皮膜层破裂。这些结构变化有利于病菌突破角质层屏障而侵入到植株体内。色质谱分析结果显示:与野生型相比,cer1突变体烷、次级醇、酮类显著减少;cer4突变体表现为一级醇含量减少。接种核盘菌后,野生型拟南芥与蜡质突变体一级醇类显著增加(cer1增加不显著);烷类、次级醇类、酮类含量与蜡质总量均显著减少,表明蜡质前体物质在受到核盘菌胁迫后更多地通过酰基还原途径生成一级醇,从而减少了由脱羰基途径所生成的蜡质组分。核盘菌通过改变表皮蜡质晶体结构与化学组分分泌量来促进侵染。     

南洋臀纹粉蚧雌成虫主要器官及其蜡泌物的扫描电镜观察

为明确南洋臀纹粉蚧Planococcus lilacinus(Cockerell)雌成虫及其蜡泌物的结构特征,利用扫描电镜观察该虫体表主要器官、蜡质及泌蜡腺体的超微结构.结果表明:南洋臀纹粉蚧雌成虫外覆白色粉状厚蜡被,体缘具18对蜡棒,触角8节、口器和足发达且分布有不同长度的毛形和刺形感受器,眼为单眼,腹脐和背孔唇形、发达;体表蜡质包含带状蜡丝、空心管状蜡丝和月牙形蜡丝,由三格腺和刺孔群分泌的带状蜡丝大量分布于整个虫体,由管状腺分泌的空心管状蜡丝主要分布于虫体腹部腹面和体缘,由多格腺分泌的月牙形蜡丝主要分布于虫体腹部腹面.研究结果初步揭示了南洋臀纹粉蚧雌成虫体表主要器官、蜡质及泌蜡腺体的超微结构特征,可为研究该虫搜索寄主、寻找配偶、群集为害、抵御逆境和传播扩散等行为活动提供支持.     

不同产地白蜡虫(Ericerus pela Chavannes)产卵期天敌的种类及其群落结构研究

白蜡虫雌虫产卵期是白蜡种虫生产的关键时期,在我国白蜡主产地区,选择有代表性的4个种虫产地,2个白蜡产地和4个虫蜡混产地,调查群落中白蜡虫天敌的物种组成和数量变化,并进行聚类分析和排序,在10个白蜡主产地内,共收集到各种天敌15种,分属于6科11属,各群落的物种组成变化较小,优势种为白蜡虫花翅跳小蜂Microterys ericeri Ishii、中华花翅跳小蜂M.sinicus Jiang、白蜡虫啮小蜂Tetrastichus kodaikanalensis Saraswat、白蜡蚧长角象Anthribus la-jievorus Chao和黑缘红瓢虫Chilocorus rubidus Hope。群落的优势集中指数较小,多样性指数和均匀性指数较高,群落相似性系数最高达97.46%,最低为75.92%。影响群落相似性的主要因子为白蜡产区不同、生态环境差异和优势种天敌的数量变化,根据聚类分析和排序,将10个不同产地白蜡虫天敌群落分为3类;第1类为种虫产地,优势种天敌发生和危害较轻;第2类为白蜡产地,白蜡虫天敌发生和危害极为严重,其种群数量为第1类的3.36倍,第3类虫蜡皆产,其天敌数量介于第1、2类之间,中华花翅跳小蜂种群数量在第1、3类群落中大致相等,第2类发生较较重,白蜡虫天敌的严重危害是造成蜡区不产种虫的主要原因之一。     

花椒种籽油的含蜡量测定与脱蜡

花椒种籽油的含蜡量测定与脱蜡是长期困扰花椒种籽油处理的一项关键技术,本研究通过分析混合压榨制备的花椒种籽油,花椒籽种壳油及种仁油的含蜡量,研究了5种脱蜡方法脱除花椒籽油中蜡质的脱蜡效果,确定了脱除花椒籽油中蜡质的有效方法,研究结果表明,花椒籽油的含蜡量在15－20％,左右,而这些蜡质基本上都含在种壳油内一即种壳上,种仁油基本不含蜡质,脱除花椒籽油中蜡质的合理方法应是：（1）含蜡量相对较低的精制粗油可选用表面活性剂法脱蜡;（2）当含蜡量相对较高时,为降低脱蜡过程中油的耗损率可选用分步脱蜡法脱蜡;（3）需进行碱炼的油,可在碱炼过程中将蜡质与游离脂肪酸一半除去。     

Collected and self‐secreted building materials and their contributions to compression and tension structures

Animals that build structures have only two ways of obtaining their building materials: collecting them from the environment or secreting them. We identify a clear pattern among invertebrates: collected materials dominate in structures that bear loads predominantly in compression, whereas self‐secreted materials dominate in structures that bear loads in tension. Among vertebrates, by contrast, structures in tension are much less common and may make use of either self‐secreted or collected materials. Two possible explanations are examined for the difference between invertebrates and vertebrates. It may be that there has been evolutionary constraint on bodily secretions of vertebrates. Alternatively, the cost‐effectiveness of self‐secreted building materials diminishes with the load they bear in tension, and most vertebrates, because of their characteristically greater weight compared with invertebrates, exceed the viability threshold. Invertebrates have adapted biochemically varied secretions from a variety of glands to perform specialized mechanical roles. However, vertebrates have secretions with the potential to become building materials, in particular keratin, but only mucus‐like secretions have evolved as building materials. The cost of suspended structures is predicted to become relatively greater with increased weight, whilst it will also become more difficult to find supports rigid enough to resist the forces they impose. This conforms to the relatively small size and small number of vertebrate structures in tension. The much larger, heavier suspended structures built by some social insects demonstrate that ecological factors may have important effects on the determination of weight thresholds. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 625–639.     

防治苦瓜枯萎病的拮抗放线菌分离筛选及鉴定

以苦瓜枯萎病菌为靶标菌,通过对峙培养试验和发酵滤液抑菌试验对分离自苦瓜根际土壤的放线菌进行筛选。候选菌株0250具有广谱抗真菌活性,根据培养特征、生理生化特性以及与同源性相近的菌株进行平均核苷酸一致性分析,被鉴定为Streptomyces rhizosphaericus,并评估了该菌株在温室和田间对苦瓜的促生长和防治枯萎病效果。结果表明: 链霉菌菌株0250对苦瓜枯萎病菌的平板抑制率为69.2%,对17种植物病原真菌的平板抑制率达64.3%~85.6%;该菌株的菌悬液处理能促进盆栽和田间苦瓜植株根、茎生长发育,提升产量,对苦瓜枯萎病的防病效果分别为66.9%和61.5%。预先用菌株0250菌悬液处理土壤再接种病原菌,对土壤尖镰孢菌数量抑制率达62.1%,显著提高了苦瓜幼苗苯丙氨酸解氨酶、过氧化物酶和β-1,3-葡聚糖酶活性以及根系活力。总之,菌株0250是一株对苦瓜枯萎病具有巨大生防潜力的放线菌资源。     

The importance of leaf surface wax as short-range attractant and oviposition stimulant in a generalist Lepidoptera

Green gram, Vigna radiata (L.) Wilczek, is an important pulse crop of Asia. Severe attack by the larvae of Spilosoma obliqua Walker (Lepidoptera: Arctiidae) causes defoliation of green gram and reduces seed yield. Females lay eggs on the leaf surface, and therefore, surface wax plays an important role as short-range attractant and oviposition stimulant. So, we have attempted to find out whether leaf surface wax compounds (alkanes and free fatty acids) from three green gram cultivars (PDM 54, PUSA BAISAKHI and SAMRAT) could act as short-range attractant and oviposition stimulant in females. The TLC, GC-MS and GC-FID analyses of n-hexane extracts revealed 20 n-alkanes from n-C₁₅ to n-C₃₆ and 13 free fatty acids from C12:0 to C21:0, whilst linoleic acid was unique in SAMRAT. Pentacosane was the predominant amongst n-alkanes in the leaf surface waxes of three cultivars. Heneicosanoic acid and palmitoleic acid were the predominant free fatty acids in the leaf surface waxes of PDM 54, and PUSA BAISAKHI and SAMRAT, respectively. Females were attracted towards one leaf equivalent surface wax of three green gram cultivars against solvent controls (n-hexane) in Y-tube olfactometer bioassays. A synthetic blend of pentacosane, heptacosane, nonacosane, hexatriacontane, palmitoleic acid, linolenic acid and stearic acid, a synthetic blend of pentacosane, hexatriacontane and stearic acid, and a synthetic blend of hexatriacontane, linolenic acid and stearic acid resembling in amounts present in one leaf equivalent surface wax of PDM 54, PUSA BAISAKHI and SAMRAT, respectively, served as short-range attractant and oviposition stimulant in females. Females showed equal preference for egg laying towards the above three synthetic blends when these blends were tested against each other, and hence, these blends could be employed in development of baited traps in pest management strategies.     

13CNMR Spectra of β-diketones from waxes of the gramineae

The ¹³CNMR spectra of six β-diketones and seven oxygenated β-diketones have been measured. The β-dicarbonyl grouping has the following effects on the chemical shifts of the neighbouring carbons: α-, + 8.72; β-, ? 3.98; γ-, ?0.42; δ-, ?0.33; ?-,?0.20; ζ-,?0.09; η-, ?0.05; θ-, ?0.03 ppm. The effects indicate the position of the grouping up to the 10,12-position. The positions of hydroxyl and oxo groups, up to the eighth carbon from the end of the chain, are also shown by long-range effects. The relative positions of a β-diketone grouping and another oxygen-containing group can be established from the ¹³CNMR spectrum with little ambiguity when they are separated by six or fewer methylene groups. For these structures NMR spectroscopy is more reliable than mass spectroscopy, which gives results which are difficult to interpret when groups are close together.Components of mixtures of hydroxy β-diketones, from grass waxes, are identified and proportions indicated by the NMR spectra.