猕猴桃品种‘金桃’采收指标与果实软熟品质相关性研究

分别对河南省27个果园的中华猕猴桃（Actinidia chinensis Planch.）品种‘金桃’果实的5项采收生理指标及果实软熟时的8项品质性状进行测定,采用主成分分析法对果实软熟时的品质指标进行综合评分,并对果实的采收生理指标、果实软熟品质指标及综合分值间进行相关性分析。结果显示,采收时的生理指标（干物质、色度角、硬度和可溶性固形物）均与果实软熟品质综合分值间呈极显著相关,其中干物质相关系数最高,为0.437。干物质与体现果实软熟品质的关键指标（可溶性固形物、总糖和糖酸比）均呈极显著性相关。研究结果表明‘金桃’果实采收时,干物质含量是果实软熟时品质的重要评价指标,而可溶性固形物和色度角是评判采收期的辅助指标。     

Liverwort genomes display extensive structural variations

PIKE, L. M., HU, A., RENZAGLIA, K. S. & MUSICH, P. R., 1992. Liverwort genomes display extensive structural variations. Analyses of the total genomic DNA of eight species of liverworts and two species of green algae by thermal denaturation and CsCl buoyant density gradient centrifugation reveal a high degree of structural complexity and interspecific heterogeneity. The hepatic taxa exhibit two or more DNA components of varying base composition. Average G4-C contents of total cellular DNA calculated from melting profiles are similarly variable, ranging from 38% to 53% G + C. The green alga Chara , a member of the ancestral line to land plants, shows similarities with liverworts in possessing multiple DNA components of comparable complexity, whereas Hydrodiciyon DNA displays a single component. Detailed hybridization analyses of individual density gradient fractions using α-tubulin, rRNA and ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene probes were performed to locate the low-copy number and moderately repetitive nuclear genes, and the chloroplast chromosome, respectively. The location of each gene within the density gradient is highly variable among the organisms examined; a-tubulin occurs in fractions ranging from 44–64% G + C, rDNA in 50–64% G + C fractions, and the RbcL gene is located in fractions from 30–59% G + C. For a given species, the two nuclear genes normally overlap in their distributions within the gradient. In most instances, neither gene occurs in the major DNA components, indicating that these components may contain repetitive DNAs. The observed variation in the density of the rbcL gene implies substantial reorganization of the chloroplast genome. The overall differences in the genomic components within and between taxa provide insight into the dynamics of DNA structure that have occurred during the extended evolutionary history of these organisms.     

二甲基苯并蒽对肺肿瘤细胞P1-450基因表达的调节

人肺肿瘤细胞(ChaGo)经二甲基苯并蒽(DMBA)处理,刺激了p 1-450基因的高水平表达,用亚致死剂量内的DMBA 处理细胞,检出了p 1-450基因的mRNA 水平随DMBA浓度和处理时间而增加;p 1-450基因的主要编码区和3’末端区“—CCGG—”序列的甲基化型式不受DMBA 处理的影响,但DMBA 处理细胞影响到基因5’末端和侧翼区的“—CC-GG—”中“—C—”残基的位点特异的低甲基化效应,这种低甲基化效应,可能关系到p 1-450基因的异常高水平表达,也可能同时存在着别的分子调节机制。     

多效唑连用其它植物激素对水稻试管苗生长的影响

本实验采用继代多年的花培体细胞无性系Hu18再生绿芽(0.5mm)为起始材料,研究多效唑(MET)与其它激素配合使用对试管苗的调控作用,结果指出:(1)单独使用MET对绿芽生长有毒害作用,除2,4-D、GA,外,MET与适宜浓度的其它激素配合使用才能发挥增苗、壮苗作用,其中以MET与BA配合使用的培养效果最好,MET与NAA,C_2H_4配合使用的效果次之;(2)MET与其他激素配合使用不但能降低植株高度,促进根系发育,而且可以延长试管苗的保存时间;(3)MET与乙烯利配合使用能加速绿芽成苗速度,而与其他激素配合使则延缓绿芽成苗速度,如与2,4-D配合使用则延缓2,4-D对绿芽的脱分化进程;(4)在本实验条件下,以MET 2.5mg/L+BA 2mg/L+NAA 0.2mg/L配合使用有利根芽的协调生长。本文还从植株干物质累积,叶细胞结构,细胞活力等方面进行了探讨。     

用飞机喷洒有机磷超低容量制剂防治蝗虫

本文总结了1975—1980年在新疆巴里坤草原等地区进行的笼内药剂品种筛选试验、地面和飞机超低容量喷雾治蝗试验。结果表明:马拉松、马拉松与敌敌畏混剂、乐果、稻丰散和乙基稻丰散5种飞机超低容量制剂均可取代六六六粉剂防治各种蝗虫。每亩喷洒量为100—150克;每亩有效药量:马拉松、马拉松与敌敌畏混剂为25—45克;乐果为20—30克;稻丰散和乙基稻丰散为25—40克,蝗虫死亡率在90%以上。 使用飞机超低容量制剂治蝗具有防效好,功效高,成本低和环境污染少等优点。目前已在新疆、内蒙、青海和辽宁等省(自治区)大面积应用。累计防治面积达一千一百万亩,深受牧区群众欢迎。     

松梢蚧

松梢蚧又称松针蚧,是同翅目珠蚧科松蚧属专寄生在松树针叶上的害虫。由于它发生起始于松树梢头的新针叶,有些地区的群众称它为松梢蚧,表达了它发生的特点。松树受害严重的可使枝梢上的针叶大部脱落,影响松树生长。 在我国浙江早已发现中华松梢蚧(Matsucoccus sinensis Chen)。Ferris(1950)重新描述了在昆明云南松上采到的所谓中华松梢蚧。我们研究了从昆明采集的标本,发现它不是中华松梢蚧,而是一个新种。Ferris的鉴定和重新描述,很容易引起对中华松梢蚧的误解。     

马尾松干蚧的研究(一)

马尾松干蚧(Matsucoccus massonianae Y. & H.)是同翅目珠蚧科(Margarodidae)松蚧属(Matsucoccns)的一个种。1973年秋首先在宁波市郊和鄞县天童林场育王林区的马尾松林中发现。以后在台州、舟山等地的马尾松林中也相继发现。它以若虫寄生于松树树干或树冠下部大枝条的皮层缝隙内,吸食树液。被害的植株轻则树势衰弱、生长缓慢,严重者树冠下部枝条下垂,针叶枯黄,树皮翘裂,并引起小蠹虫(Blastophagus sp.)等次期害虫的侵袭,以致整株枯死。     

A global invasion by the thrip,Frankliniella occidentalis: Current virus vector status and its management

Western flower thrip, Frankliniella occidentalis (Pergande), is among the most economically important agricultural pests globally, attacking a wide range of vegetable and horticultural crops. In addition to causing extensive crop damage, the species is notorious for vectoring destructive plant viruses, mainly belonging to the genera Orthotospovirus, Ilarvirus, Alphacarmovirus and Machlomovirus. Once infected by orthotospoviruses, thrips can remain virulent throughout their lifespan and continue transmitting viruses to host plants when and wherever they feed. These irruptive viral outbreaks in crops will permanently disrupt functional integrated pest management systems, and typically require a remedial treatment involving insecticides, contributing to further development of insecticide resistance. To mitigate against this continuing cycle, the most effective management is early and comprehensive surveillance of the pest species and recognition of plant viruses in the field. This review provides information on the pest status of F. occidentalis, discusses the current global status of the viruses vectored by this thrip species, examines the mechanisms involved in transmitting virus‐induced diseases by thrips, and reviews different management strategies, highlighting the potential management tactics developed for various cropping systems. The early surveillance and the utilization of potential methods for control of both F. occidentalis and viruses are proposed.