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。     

油料作物油脂合成调控研究进展

植物油脂不仅是人类可食用油的主要来源,也是人类生产生活中重要的可再生原料。本文概述了植物油脂的生物合成途径,从母体效应、QTL、GWAS等多个方面总结了油料作物油脂合成的遗传学研究进展,同时探讨了已知的油脂合成调控相关基因的功能。本文综述了该领域的研究现状,为深入了解油料作物油脂合成调控网络提供了参考,也为油料作物的分子改良和遗传育种提供了理论基础。     

禁抗后仔猪细菌性腹泻的临床诊断与防治

为了促进食品安全和养猪业的健康发展，禁止在饲料中使用促生长抗生素势在必行。随着我国的饲料禁抗相关法规的推行，饲料企业被严格禁止在饲料生产过程中加入抗生素，这也导致了猪场疾病尤其是肠道疾病的高发，而仔猪肠道发育未完全，免疫系统未发育成熟，更容易发生严重的腹泻甚至死亡。文章对几种常见的仔猪细菌性腹泻疾病进行了回顾，病原包括大肠杆菌、沙门氏菌、魏氏梭菌，讨论了它们的临床症状与防控措施，为猪场在防控这些细菌性腹泻提供参考。     

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.     

SSCP Marker Development and Analysis of Candidate Restorer Gene Rf1 for Cotton Cytoplasmic Male Sterility

[Objective] Locating the cotton cytoplasmic male sterility (CMS) restorer gene Rf₁ is important for investigating restorer gene mechanisms and improving restorer lines. In our previous study, a gene cluster, with nine Pentatricopeptide repeat(PPR) genes and nine other genes, was found within the 160-kb Rf₁ target region in Scaffold 333. The objective here was to improve the density of Rf1-linked markers in the target region and determine the expression profiles of candidate genes. [Method] Using the sequences of the 18 genes, we designed 155 single-strand conformation polymorphism (SSCP) primers covering all of the gene sequences to identify the polymorphic SSCP markers between the fertile and sterile pools. Additionally, real-time polymerase chain reaction(PCR) was performed to analyze the expression profiles of eight candidate genes in the four developmental stages of buds of sterile, maintainer and restoring lines, respectively. [Result] In total, 15 polymorphic primers were identified. A genotype analysis of the F₂ population was conducted using the 15 primers and 3 other polymorphic simple sequence repeats (SSR) markers. The markers were distributed in a 4.8 cM range. In addition, owing to the influence of sterile cytoplasm or restorer genes, most of the genes showed different expression patterns in the four developmental stages of the three lines' buds. [Conclusion] SSCP markers tightly linked to Rf₁ were identified and the expression profiles of candidate genes were determined. This study provides a basis for the further fine mapping of restorer genes and for candidate gene screening.     

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。