Wood decay fungi and their bacterial interaction partners in the built environment – A systematic review on fungal bacteria interactions in dead wood and timber

Microbial biodeterioration of timber and woody material in buildings can cause costly restoration procedures. Here, we focus on Serpula lacrymans (commonly known as dry-rot) the fungus causing the most severe damages to buildings in Europe. Although its morphology, lifestyle, and dispersal have been intensively studied, research on microorganisms sharing the same habitat and interacting with the dry-rot fungus is not as comprehensive. Bacteria have long been known to inhabit dead wood, and several studies have shown their association to fungi. However, their identity, ecology, and putative interactions with co-existing fungi in dead wood remains largely underexplored. The interactions of bacterial and fungi have considerable impact on all partners involved covering the full spectrum between antagonistic and beneficial. Fungi are highly capable of manipulating the microbial community in their surroundings (e.g. via pH manipulation) and bacteria, in turn, can influence fungi by affecting the outcomes of (antagonistic) interactions or preventing fungal feedback inhibition via consumption of breakdown products. Associated bacteria on the other side could play an essential role for the fungus as bacteria can exert significant influence on fungal physiology and behaviour. This minireview summarizes the current knowledge on bacterial-fungal interactions in dead wood with a special focus on dry-rot and proposes possible bacterial-fungal interaction (BFI) mechanisms based on examples from soil or decomposing wood from forests.     

常见水稻病虫害胁迫对转cry1C基因抗虫水稻Bt蛋白表达量的影响

【目的】明确转Bt基因抗虫水稻在病虫害胁迫下对Bt蛋白表达量的影响。【方法】以Bt水稻T1C-19(表达Cry1C蛋白)为研究对象,探究褐飞虱、白叶枯病等6种水稻常见病虫害胁迫下其体内Bt蛋白的表达量变化。【结果】褐飞虱取食引起T1C-19水稻叶片中Bt蛋白含量降低,而黑尾叶蝉取食显著降低了T1C-19水稻叶鞘中的Bt蛋白含量,白叶枯病侵染导致Bt水稻叶鞘中的Bt蛋白含量显著上升。二化螟、水稻普通矮缩病、稻瘟病的胁迫对转基因水稻T1C-19叶片和叶鞘中的Bt蛋白含量均无显著影响。【结论】病虫害胁迫因种类不同对Bt水稻中Bt蛋白表达量的影响有所不同。这将为Bt水稻的抗虫效果评价提供数据基础,同时为Bt水稻病虫害综合治理提供科学依据。     

Effects of ribosome inactivating proteins on insect development —differences between Lepidoptera and Coleoptera

Ricin and saporin represent two different classes of ribosome inactivating proteins (RIPs), or cytotoxins, present in plant seeds. The toxicity of these substances to several eukaryotic organisms is widely known, as is their intracellular mode of inhibitory action on the ribosomes. However virtually nothing is known of the effects of these substances on insects. In this paper we report on systematic studies which indicate that RIPs can be extremely toxic to insects although the effects are variable with different insect orders. Specifically, two Coleopteran species were extremely susceptible to the effects of both RIP's with average LD₅₀ values of less than 10^-2% (dry weight). The studies also indicate that resistance to the toxic effects, exhibited by Lepidopteran insects, may be due in part to the protease complements of the insect guts which are capable of hydrolysing the RIPs, thus eliminating them before they are absorbed and can exert their effects within the insects cells.

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Résumé La ricine et la saporine des graines de plantes représentent deux classes différentes de protéines inactivant les ribosomes (RIPs), ou cytotoxines. La toxicité de ces substances pour plusieurs eucaryotes est bien connue, de même que le processus intracellulaire de leur activité inhibitrice des ribosomes. Cependant, on ne connaît pratiquement rien de leurs effets sur les insectes. Dans cet article, nour relatons des travaux systématiques qui montrent que les RIPs peuvent être extrêmement toxiques pour les insectes, bien que leurs effects varient suivant les ordres d'insectes.Particulièrement, deux espèces de coléoptères sont extrêmement sensibles aux effets des deux RIPs avec des DL₅₀ inférieures à `0^-2% du poids sec. Ces travaux indiquent aussi que la résistance des lépidoptères à ces effets toxiques peut être due en partie à la présence dans leur intestin de protéases susceptibles d'hydrolyser les RIPs, et de les éliminer ainsi avant leur absorption et avant qu'elles ne puissent exercer leurs effets dans les cellules des insectes.

     

新入侵害虫葡萄花翅小卷蛾的生物学特性

【目的】掌握新入侵我国的进境植物检疫性害虫葡萄花翅小卷蛾在吐鲁番市的生物学特性及种群周年发生规律,为其综合防治提供理论依据。【方法】在田间以性引诱剂定点监测、野外网室笼罩饲养以及室内人工饲养相结合的方法,观察葡萄花翅小卷蛾生活习性及其种群发生规律。【结果】该虫在我国新疆吐鲁番市1 a发生5代,以蛹在葡萄藤皮下越冬。越冬蛹翌年3月底—4月初（葡萄开墩）开始羽化,4月上旬为羽化高峰期（清明节前后）,中旬为羽化末期。越冬代成虫将卵产于花芽上,4月中旬第1代幼虫开始孵化;第1代成虫于5月中旬开始羽化,5月下旬羽化结束;第2代成虫于6月下旬开始出现,7月上旬为羽化高峰期;第3代成虫于7月底开始羽化,8月上旬为羽化高峰期;第4代成虫于8月底开始羽化,9月上旬为羽化高峰期;越冬代幼虫10月上旬开始化蛹越冬,大部分幼虫更趋向于在老树的藤皮下化蛹。成虫的飞行、取食、交配、产卵等行为多发生在黄昏。越冬代成虫将卵产于葡萄花序萼片以及花蕾上;第1~3代成虫将卵产于葡萄果实表面,第4代成虫将卵产于葡萄二次开的花絮上,卵单产,单雌产卵量为20~40粒左右。第1代幼虫取食葡萄花絮,第2~4代幼虫危害葡萄果实,并有自相残杀的习性,糖醋液（红糖：醋：酒：水=6：3：1：10）对成虫有一定的诱杀效果。【结论】该虫在吐鲁番1 a发生5代,各世代划分明显,越冬代发生数量最大,无世代重叠现象,随温度升高各世代和虫态的发育历期缩短,幼虫在葡萄整个生长季节均造成危害,第3、4代幼虫危害成熟果实,引起果实大量腐烂并造成严重经济损失。     

Decline and potential recovery of Yellow-footed Antechinus in parts of south-eastern Australia: A perspective with implications for management

Summary   The extent and intensity of European-induced changes to ecosystems in south-eastern Australia mean that remaining habitats, despite being degraded, are of high conservation value. Given the extinction of several species of native mammals in the last 160 years in the area, and conservation concerns regarding others, it is important to provide conservation managers with sufficient information to prevent further extinctions and maintain evolutionary potential of the species. A native, carnivorous marsupial, the Yellow-footed Antechinus ( Antechinus flavipes ) exists within these massively altered landscapes. We present conceptual models, derived from the literature, of persistence of populations of Yellow-footed Antechinus both before European colonization and in the 21st century. We conclude that preservation of large trees, restoration of fallen-timber volumes, spring flooding of floodplains and presence of vegetation corridors between forests should be undertaken to prevent local extinctions of Yellow-footed Antechinus. From historic and current gene flow, we identify remnant woodland and forest groupings that we consider should be managed as coherent units.     

Specific diversity of plant populations at rainfed scale and crop protection: the example of banana production in the French West Indies

Banana is a major crop in the French West Indies, where it is subjected to strong parasite pressure, resulting in pesticide pollution. An increase in plant population diversity in the cultivated ecosystem is generated by changing cultural practices. This results in a decrease in parasite pressure and hence a decrease in pollutant pesticide loads. Agricultural sustainability is therefore reinforced for better coexistence of populated, cultivated and protected areas.     

Behavioural responses of Oryzaephilus surinamensis, Tribolium castaneum and Tribolium confusum to naturally and artificially damaged durum wheat kernels

Observations on behavioural activity involved in the host selection by secondary pests of stored grains, Oryzaephilus surinamensis (Linnaeus), Tribolium castaneum (Herbst) and Tribolium confusum J. du Val, with respect to intact and mechanically or naturally damaged kernels are reported. Our results indicate that the attraction of secondary pests is facilitated by broken grain kernels, which resulted from either mechanical damage during harvesting and/or binning procedures, or the feeding activity of primary insect pests. Insect damaged kernels were more attractive to O. surinamensis, T. castaneum and T. confusum than whole kernels; in addition insect damaged kernels elicit more attractiveness than mechanically split kernels. The damage caused by primary pests, such as Rhyzopertha dominica (Fabricius) and Sitophilus oryzae (Linnaeus), on whole kernels may facilitate colonization by secondary pests, which continue damaging the cereals. O. surinamensis, T. castaneum and T. confusum utilize the grain volatile odours to distinguish whether the grain kernels of the stored cereals are damaged mechanically or by insects.     

化学防治对不同类型棉田害虫和捕食性天敌群落多样性的影响

分析比较了化学防治对8种不同类型棉田害虫、捕食性天敌群落多样性的影响。研究结果表明,化学防治对棉田害虫、捕食性天敌群落的多样性指数、均匀性指数、丰富度及个体数的变化有较大的影响,尤其对捕食性天敌群落的影响显著。但这种作用依不同类型棉田或棉花不同生育阶段而异：化学防治对套作棉田害虫、捕食性天敌群落的影响较小,而对单作棉田和豆间棉棉田害虫、捕食性天敌群落的影响较大;晚播棉田害虫与捕食性天敌群落较早播棉田受化学防治的影响更大;化学防治对免耕棉田害虫、天敌群落的影响更大,非免耕棉田害虫、捕食性天敌群落受其干扰较小;春套棉边害虫、捕食性天敌群落与其它棉田类型相比,受化学防治的影响较少;棉花害虫在棉花生育前期对化学防治较棉花生育后期敏感,而捕食性天敌在棉花整个生育期均对化学防治敏感。     

多功能用材林周边大气SO2和NOx的变动规律研究

树木在生长过程中,通过光合作用和树体表面,一方面能有效地吸收、阻滞和吸附大气中的SO₂、NO_x等有害气体,另一方面,由于树体的截留作用,使得其在林内及周边的浓度提高。研究表明:大气中SO₂、NO_x浓度以枝叶生长期最高,分别为高径生长期的5.2倍和6.7倍;枝叶生长期大气SO₂存在明显的上午高、下午低的日变化特点,早晨的浓度要比下午高出1倍至4倍,并以林带内最低、林带外侧次之、林带外侧最高,大气NO_x浓度则以中午较低;高径生长期大气SO₂、NO_x浓度为上午高、下午低,其中林带内和林带外侧大气SO₂、NO_x浓度早晨比下午高3倍至5倍左右;生长减缓期大气SO₂、NO_x浓度日变动幅度小,SO₂浓度从早晨开始持续上升,NO_x浓度林带外侧上升较快、林带内和林带内侧变动很小。研究认为,高径生长高峰期的下午是休息、旅游、健身等活动的最适时间。