排序方式: 共有39条查询结果,搜索用时 31 毫秒
1.
Stefano Nones Camila Fernandes Lídia Duarte Leonor Cruz Edmundo Sousa 《Plant pathology》2022,71(4):966-979
In Portugal, the oak pinhole borer Platypus cylindrus and its mycobiota have been associated with cork oak (Quercus suber) death, but no knowledge exists regarding the associated bacterial community. However, it is known that some bacteria are important for ambrosia beetle symbiosis and play a role in oak tree health. To explore the bacteria associated with this beetle and its host, with the ultimate goal of highlighting potential roles in oak decline, this study used a culture-dependent approach for strain isolation and phylogenetic identification using 16S rRNA gene sequencing and multilocus sequence analysis (MLSA). The bored galleries of different cork oak trees from a cork stand in Alentejo, together with the body and mycangia of adult beetles, were investigated. The samples revealed a diverse community comprising 500 isolates with 64 distinct types of bacterial colonies. Sixty-eight strains were selected for sequencing and used for phylogenetic analysis, 40 from wood galleries and 28 from beetles. Thirty-two genera of bacteria were identified, 18 of which were described for the first time within oak–beetle interactions. Major taxonomic groups were Actinobacteria in beetles and Enterobacterales in wood galleries. Although specific oak bacterial pathogens were not detected, a group of distinct strains detected in wood galleries, potentially belonging to a new Pectobacteriaceae species, were able to produce mild symptoms on cork oak plantlets. This study reports for the first time the biodiversity of culturable bacteria associated with the Q. suber–P. cylindrus interaction, their relevance to both organisms and the possible contribution to oak decline. 相似文献
2.
3.
4.
5.
Host trees can modify their soil abiotic conditions through their leaf fall quality which in turn may influence the ectomycorrhizal (ECM) fungal community composition. We investigated this indirect interaction using a causal modelling approach. We identified ECM fungi on the roots of two coexisting oak species growing in two forests in southern Spain - Quercus suber (evergreen) and Quercus canariensis (winter deciduous)-using a PCR-based molecular method. We also analysed the leaf fall, litter and soil sampled beneath the tree canopies to determine the concentrations of key nutrients. The total mycorrhizal pool was comprised of 69 operational taxonomic units (OTUs). Tomentella and Russula were the most species-rich, frequent and abundant genera. ECM fungi with epigeous and resupinate fruiting bodies were found in 60% and 34% of the identified mycorrhizas, respectively. The calcium content of litter, which was significantly higher beneath the winter-deciduous oak species due to differences in leaf fall quality, was the most important variable for explaining ECM species distribution. The evaluation of alternative causal models by the d-sep method revealed that only those considering indirect leaf fall-mediated host effects statistically matched the observed covariation patterns between host, environment (litter, topsoil, subsoil) and fungal community variables. 相似文献
6.
软木及其主要产品的耐候性研究 总被引:1,自引:0,他引:1
采用紫外灯耐候试验箱模拟自然环境对软木原材料及其制品进行耐候性试验,通过对紫外灯耐候试验箱照射过的试件进行物理性能、力学性能的分析,对软木及其产品的耐候性进行客观评价。试验确定的试验参数为:辐照时间4和8h;黑暗时间4h;试验时间为80、160和240h。随着试验时间的增加,软木及其制品的密度、亨特白度、回弹率、断裂强度呈现下降趋势;压缩率呈现上升趋势。 相似文献
7.
8.
9.
Modelling cork oak production in Portugal 总被引:1,自引:0,他引:1
The layout of 32 permanent plots in the most important cork production regions of Portugal and the measurement of the most
representative tree parameters were performed for statistically sound cork weight modelling. The establishment of cork weight
equations is presented for the different cork oak study areas considered alone or grouped according to the most representative
tree parameters. For the presented cork weight models was chosen independent variable the total stripping surface (artmax). For the selection criteria five statistic were used, including PRESS, APRESS and Mallows's statistic. The crossvalidation
of the best classified models was performed and to discuss the importance of the “study area” factor, a regression analysis
with “dummy” variables was performed. 相似文献
10.
软木复合地板生产工艺及其发展前景 总被引:4,自引:1,他引:3
本文介绍了软木复合地板这一地面铺装材料新产品的性能、结构特点和生产工艺并论述了在我国生产软木复合地板的可能性及发展前景 相似文献