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。     

Screening and identification of soybean varieties with high phosphorus efficiency at seedling stage

In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X₁),relative value of root P utilization efficiency(X₂),and root volume(X₃)under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X₁t 0.320X₂t 0.007X₃-0.664(P=0.000,R²=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.     

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.     

Dynamics of Cotton Rhizosphere Bacterial Community Structure in Cotton Continuous Cropping Field Soil

[Objective] The aim of this study is to understand the dynamics of cotton rhizosphere bacterial community structure in cotton continuous cropping field soil. [Method] 16S rDNA genes were sequenced by high-throughput sequencing technology to determine the community structure of cotton rhizosphere bacteria in different developmental stages using an upland cotton cultivar (Gossypium hirsutum cv. TM-1). [Result] Four dominant phyla were found in the cotton rhizosphere bacterial community including Proteobacteria, Acidobacteria, Planctomycetes, and Bacteroidetes. The four dominant phyla and Firmicutes were largely influenced by cotton root. The relative abundances of Acidobacteria, Planctomycetes, Bacteroidetes were promoted, and Proteobacteria and Firmicutes were inhibited, by cotton root. There were significant differences in community structure, but not species richness or α-diversity among different developmental stages of the cotton rhizosphere bacterial community; the differences between the flowering stage and the budding stage were greater than the differences between the budding stage and the seedling stage. The diversity of the rhizosphere bacterial community in cotton continuous cropping field soil was significantly higher than that of the bulk soil; the β-diversity values of both the rhizosphere and bulk soil bacterial communities were highest in the flowering stage. [Conclusion] The structure and dynamics of the cotton rhizosphere bacterial community in cotton continuous cropping field soil was defined by high-throughput sequencing. The effect of cotton on the rhizosphere bacterial community structure was most significant in the flowering stage.     

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。     

朝鲜黄杨种源试验苗期效果初报

利用引进的锦州、沈阳、大连、鞍山4个产地朝鲜黄杨(Buxus microphylla var.koreana)种源进行播种试验,对幼苗出苗率、保存率、苗高、地径、分枝数、冠幅调查测量。结果表明:4个种源的出苗率、当年苗高、分枝数、冠幅均存在显著差异,地径差异不显著。沈阳种源播种出苗率最高,为75.48%;沈阳、大连种源当年苗高14.53 cm、14.08 cm,分枝数9.43条、9.21条,冠幅12.02 cm、10.00 cm,显著高于鞍山、锦州种源;苗木越冬保存率均在90%以上。沈阳种源表现最好。鞍山和锦州种源表现较差。     

优质水稻新品种芽期耐冷性鉴定

对来自不同地区的多个水稻品种进行芽期耐冷性试验,结果表明:15份优质水稻品种发芽期14℃、7 d处理,耐冷性均表现为极弱;14℃、14 d处理,龙稻18、通禾66耐冷性表现为极强,九稻68、吉粳511耐冷性表现为强。在芽期试验中,所有品种芽期耐冷性为强。