马尾松叶表微生物多样性

为发掘对林木生长发育有利的优良微生物资源,并筛选适合叶表微生物的收集方法,以马尾松针叶为试验材料,分别用悬摇法和超声波法收集马尾松叶表微生物,用扩增子高通量测序技术、MUSCLE和Qiime软件研究马尾松叶表微生物的多样性。结果表明:扫描电镜观测结果显示,马尾松针叶表面定殖有大量微生物,包括真菌(菌丝及孢子)和细菌。扩增子高通量测序结果表明,马尾松叶表微生物物种丰富,包含细菌运算分类单位(OTUs)490个,真菌OTUs 1273个。马尾松叶表细菌以未分类的蓝细菌属(unidentified_Cyanobacteria)(36.53%)、未分类的拜叶林克氏菌属(unidentified_Beijerinckia)(28.60%)、鞘氨醇单胞菌属(Sphingomonas)(2.35%)为优势属;叶表真菌以枝孢属(Cladosporium)(2.45%)、拟盘多毛孢属(Pestalotiopsis)(0.92%)、无头孢菌属(Capnobotryella)(0.91%)为优势属。针对叶表细菌多样性的研究表明,悬摇法和超声波法均有较高的物种检出度;在叶表真菌多样性的研究中超声波法优于悬摇法,但超声波法样品间数据变异性较大,测定结果不稳定。     

Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.     

The Phytotoxicity of Various Graminicides in Durum Wheat in Greece

The effect of three herbicides, diclofop-methyl (DM), imazamethabenz-methyl (IM) and fenoxaprop-ethyl (FE), was investigated at the recommended rate (×) and double the recommended rate (2×) in a durum wheat crop. FE had the smallest effect on root system characteristics, while IM had the greatest effect. For all herbicides, the double rate treatment gave a greater statistical reduction than the single rate for root system characteristics. FE had the smallest effect on the activity of aerobic microorganisms, while DM gave the greatest reduction, 10 days after application, and all three herbicides reduced earthworm abundance. DM gave the smallest reduction in the number of tillers and in plant height, while the double rate of IM gave the greatest reduction. For all three herbicides, double the recommended rate resulted in a significant reduction in the weight of 1000 seeds, while no statistically significant deviations were noted at the recommended rate. Finally, the use of all three herbicides resulted in significantly lower statistical yields compared to the sample (control plot), although there were no significant statistical differences among them, for either recommended or double recommended rates.     

苹果试管苗不定根起源及其发育状况的研究

利用光学和扫描电子显微镜观察结果表明,经琼脂生根培养基诱导产生的长富—2苹果 (Malus pumila Mill.) 试管苗的不定根起源于维管形成层。这种不定根发育不良,根表面缺乏根毛,内部解剖构造为典型的初生结构。为避免因不定根吸收、运输能力差而影响试管苗移栽成活,宜采用通透性良好的基质进行瓶内或瓶外生根,可诱导出优质不定根。     

不同的施肥方式对剑麻施肥区域土壤微生物类群的影响

研究不同的施肥方式对剑麻施肥区域土壤微生物类群产生的影响。结果表明，不同施肥方式下土壤微生物总量各有差异，在总体数量上以细菌为主，真菌次之，再其次是放线茵，特殊生理类群是解磷茵居多，纤维素分解茵次之，固氮茵最少；但从土壤微生物多样性指数来看，则表现为土壤中主要微生物类群多样性指数是施肥点的土壤高于附近的土壤，而土壤中特殊生理微生物多样性指数则无此变化趋势，即微生物总数高的土壤，其多样性指数不一定高。因此评价土壤生物多样性应将二者结合起来。     

Horizontal transmission and host-virulence attenuation of totivirus in violet root rot fungus Helicobasidium mompa

Monokaryotic strains of Helicobasidium mompa were used as vectors of a mycovirus between various H. mompa isolates to examine the transmissibility of one of the mycoviruses, totivirus (HmTV1–17 virus) in the hypovirulent isolate V17 of H. mompa. The isolates that acquired HmTV1–17 virus were also examined for any alteration in the virulence. Twelve dikaryotic isolates of H. mompa, belonging to 11 mycelial compatibility groups (MCGs) and being mycelially incompatible with isolate V17, were used as recipients of HmTV1–17 virus. Two monokaryotic isolates that were mycelially incompatible with isolate V17 and all of the recipients were also used as vectors of HmTV1-17 virus between isolate V17 and the recipients. When isolate V17 and recipients were directly paired on plate media, HmTV1-17 virus was transmitted from isolate V17 into 2 of the 12 recipients (i.e., 2 of the 11 MCGs). Two monokaryotic strains were paired with isolate V17, and the monokaryotic strains that acquired HmTV1-17 virus were then used as new virus donors. When the monokaryotic strains containing HmTV1-17 virus were paired with the 12 recipients, HmTV1-17 virus was transmitted into 7 of the 12 recipients from the monokaryotic strains (i.e., 7 of 11 MCGs). Based on these results, we concluded that monokaryotic strains could act as vectors to transmit HmTV1-17 virus into H. mompa isolates. When four of the H. mompa isolates that acquired HmTV1-17 virus were used to inoculate apple rootstock Malus prunifolia, the virulence of all of the isolates was attenuated from that of their parental isolates. Moreover, because the DNA fingerprints of the fungal isolates that acquired HmTV1-17 virus were the same as those of their parental isolates, the infection with HmTV1-17 virus is considered the cause of virulence attenuation of H. mompa.     

反硝化聚磷一体化设备中微生物数量变化的研究

对反硝化聚磷除磷脱氮污水处理新工艺运行初期系统中的微生物数量进行了跟踪检测，并对细菌总数，霉菌，放线菌，硝化细菌，亚硝化细菌，反硝化细菌在不同日期的数量变化进行了研究。     

Fusarium oxysporum对苗期大豆根部的致病性和侵染规律

Fusarium oxysporum对苗期大豆具有较强的致病作用。病原菌自伤口或直接侵入大豆幼苗根部的皮层组织,随着病原菌的侵入和扩展,细胞出现坏死,组织发生崩解,根部组织表现红褐色病斑。环境因素对病原菌的侵染时期和在大豆体内潜育时间的长短有着明显的影响。侵染时期主要受病原菌侵入前自身所处状态和寄主的影响,侵入后潜育时间的长短则受植株状态的影响。土壤环境条件直接影响着病原菌的侵入和寄主的抗病性,间接影响着病原菌在大豆植株体内的扩展和病症的表现。     

The Effect of Detopping the Field Bean Plants (Vicia faba L. minor) and Lack of the Pod Setting on the Symbiosis with Root Nodule Bacteria

The plants of field bean var. Nadwiślaνski were detopped after about 1 month since the beginning of flowering and after that all flower buds were removed from some plants. The effect of a change in the trophic balance on the setting and subsequent growth of root nodules was studied.
The removal of pods had the greater effect on the increase in the weight of the remaining organs than the detopping of plants. Detopping retarded the ageing of the plants and delayed the phase of the greatest reduction of the number of pods. The detopping of plants revealed their considerable compensative possibilities in terms of production of the pod weight and the potential of leaves for biomass production. The data obtained indicate that plant detopping may disturb the root–bacteria exchange of signals, necessary to initiate the nodule development, while the further growth of nodules depends, above all, on the amount of available photosynthates.
A very high correlation between the dry weight of the whole plant to the dry weight of leaves ratio and the weight of nodules was observed. It proves the importance of the trophic balance of the plant for the root nodule weight production.     

洋葱挥发油的抗真菌作用及其机理

采用砂堡培养基液体稀释培养法和薄层色谱分析法研究了洋葱挥发油抗真菌效果及机理，以期发现天然抗真菌药物，开发洋葱资源．结果表明：洋葱挥发油提取物对酿酒酵母、白假丝酵母、新生隐球菌、黑曲霉、黄曲霉、红曲霉、青霉等真菌的生长有较强的抑制作用；其最低抑菌浓度酿酒酵母和白假丝酵母为0．25％，新生隐球菌为0．50％．薄层色谱分析表明：洋葱挥发油处理后的自假丝酵母的羊毛周醇、麦角固醇的古量降低。而角鲨烯的音量增高，说明洋葱挥发油可能抑制白假丝酵母麦角周醇的早期合成.