天然植物生长调节剂芸苔素的生物活性及应用浅析

天然芸苔素属于甾体类植物内源生物活性物质,其骨架为甾醇,其中芸苔素内酯生物活性最强,被称为第六类植物激素,是高效、广谱、无毒的植物生长调节剂(PGR)。为更好地将芸苔素推广应用于农业生产,本文概括了芸苔素内酯的生物活性及在粮食、果蔬等作物上的应用。探讨了芸苔素内酯在提高种子活力,促进作物生长,大幅度促进产量提升以及品质改善,提升作物抗逆性,缓解农药对作物影响的研究概况及取得的进展,指出了芸苔素内酯的应用是作物增产增收的关键途径,同时,能够减少化肥、农药的施用量,减少作物种植成本与减轻环境污染,将带来显著的经济效益。     

Performance of pyrazosulfuron-ethyl in non-puddled transplanted rainy season rice and its residual effect on growth of the succeeding crop in rice-wheat cropping pattern

Abstract

A study was carried out in sandy clay loam textured soil of Mymensingh, Bangladesh to evaluate weed control efficiency of pre-emergence herbicide pyrazosulfuron-ethyl either alone or in sequential application with post-emergence herbicide in transplanted rainy season rice under non-puddled strip-tilled (NPST) field condition and also to examine the residual effect of those herbicides on germination and growth of the subsequently grown wheat crop. Five treatment combinations of pyrazosulfuron-ethyl were tested against one weedy check and one weed-free check. The study revealed that NPST rice field was mostly infested by grass and sedge weeds and herbicide treatments offered a wide range of control (above 50% to 95%) on all types of weeds. Application of pyrazosulfuron-ethyl followed by (fb) orthosulfamuron fb butachlor plus propanil provided the most effective and economic weed control over two years of the study. Moreover, micro-plot bioassay study claimed germination and growth of subsequently grown wheat were not adversely affected by herbicides that were applied in rice. Therefore, application of pyrazosulfuron-ethyl followed by post-emergence herbicide could be effective and economic to control weeds in NPST rice under rice-wheat system, but proper rate and time of application should strictly be followed.     

Bacteria and antibiotic resistance detection in fractures of wild birds from wildlife rehabilitation centres in Spain

Anatomic adaptations make birds more prone to open fractures with exposed bone parts losing vascularization. As a result of this exposure, fractures are colonized by different microorganisms, including different types of bacteria, both aerobic and anaerobic, causing osteomyelitis in many cases. For this reason, antibiotic treatment is common. However, carrying out antibiotic treatment without carrying out a previous antibiogram may contribute to increased resistance against antibiotics, especially in migratory wild birds. In this paper, bacterial counts regarding fracture type, bacterial identification and antibiotic resistance have been analysed in wild birds from wildlife rehabilitation centres in Spain. The results obtained showed that open fractures had higher bacterial counts (CFU/mL) than closed ones. Bacteria in family Enterobacteriaceae, identified were Escherichia spp., Enterobacter spp., Shigella spp., Hafnia alvei, Proteus mirabilis, Leclercia adecarboxylata and Pantoea agglomerans. Other bacteria present in wild birds’ fractures were Aeromonas spp., Enterococcus spp. Bacillus wiedmannii and Staphylococcus sciuri. All species found presented resistance to at least one of the antibiotics used. Wild birds can be implicated in the introduction, maintenance and global spreading of antibiotic resistant bacteria and represent an emerging public health concern. Results obtained in this paper support the idea that it is necessary to take this fact into account before antibiotic administration to wild animals, since it could increase the number of bacteria resistant to antibiotics.     

施用锌肥和遮阴互作对花生生长发育、抗病性及产量的影响

采用大田裂区试验，研究了施用锌肥和不同遮阴程度互作对花生生长发育、抗病性及产量的影响。结果表明，与不施锌肥相比，施用锌肥能提高花生不同部位锌含量、增加叶片SPAD值，提高花生叶片中可溶性糖、蛋白质和生长素含量，减少花生病害的发生，平均降低7.1个百分点，花生产量平均增加19.4%。相同施锌水平下，随着遮阴程度的增加，花生不同部位锌的含量和不同生育期叶片SPAD值以及花生叶片中可溶性糖、蛋白质和生长素含量呈增加趋势，花生的发病率比不遮阴对照增加4.8、10.2个百分点，花生产量平均降低16.5%、10.0%。在30%、70%的遮阴条件下，施用锌肥的花生产量比不施锌的分别提高21.1%、25.0%。本试验条件下，施用七水硫酸锌30 kg/hm2，使花生具有较强的抗低温寡照能力及抗病性能，增产显著，可在花生产区推广应用。     

10种除草剂及组合对芨芨草的防效评价

为筛选出对芨芨草具有高效防除作用的除草剂品种及组合,本研究采用茎叶喷雾法分别在芨芨草开花期和平茬(成株芨芨草离地面15 cm刈割)后第3天施药,测定了10种常用除草剂品种和6个除草剂组合对芨芨草的防除效果,获得了"花期茎叶喷施除草剂"和"平茬+喷施除草剂方式"清除芨芨草技术。1)开花期:18%草铵膦AS在有效剂量(下同)405 g/hm~2时,药后7 d见效,30 d鲜重防效达100%;41%草甘膦异丙胺盐AS剂量为922.5 g/hm~2时,药后5 d见效,30 d鲜重防效达87.18%;24%烯草酮EC剂量为216 g/hm~2时,药后15 d见效,30 d鲜重防效达77.03%;18%草铵膦AS 180 g/hm~2+10.8%高效氟吡甲禾灵EC 37.8 g/hm~2处理,药后5 d见效,30 d鲜重防效达91.30%。2)平茬后:18%草铵膦AS、41%草甘膦异丙胺盐AS均药后5 d见效,30 d鲜重防效均大于87%;30%苯唑草酮SC剂量为22.5 g/hm~2时,药后5 d见效,30 d鲜重防效达85.97%;24%烯草酮EC剂量为144 g/hm~2时,药后7 d见效,30 d鲜重防效达88.21%;15.8%精喹禾灵EC剂量135 g/hm~2时,药后7 d见效,30 d鲜重防效达85.26%;12.5%烯禾啶EC 112.5 g/hm~2+15.8%精喹禾灵EC 15.8 g/hm~2处理,药后5 d见效,30 d鲜重防效达97.97%。     

通过GbF3’H基因单独沉默及其与GbCHI和GbDFR基因共沉默研究其在海岛棉中抗枯萎病功能

【目的】通过沉默海岛棉GbF3’H基因及共沉默GbF3’H、GbCHI和Gb DFR基因,研究其在海岛棉抗枯萎病中的作用。【方法】以海岛棉抗病材料06-146为研究对象,GhCLA1基因为阳性对照,空载体为阴性对照,构建海岛棉TRV2-Gb F3’H沉默载体,协同课题组前期构建的TRV2-CHI和TRV2-DFR载体,利用病毒诱导的基因沉默技术(Virus-induced gene silencing,VIGS)分别进行Gb F3’H基因单独沉默以及GbF3’H、GbCHI和Gb DFR这3种基因共沉默试验。通过实时荧光定量聚合酶链式反应(Quantitative real time-polymerase chain reaction,q RT-PCR)分析各处理样品中基因沉默情况;设置室内接种枯萎病菌试验测定病情指数,分析各沉默材料对枯萎病的抗性差异。【结果】q RT-PCR结果显示,海岛棉GbF3’H基因沉默后其在海岛棉根、茎和叶中的表达量比空载体对照低,Gb F3’H、GbCHI和GbDFR这3种基因共沉默后其在海岛棉根、茎和叶中的表达量均比空载体对照低。病情指数调查结果显示,野生型<空载体对照相似文献