Response of snails and slugs to fragmentation of lowland forests in NW Germany

Habitat fragmentation is a major cause for species loss, but its effect on invertebrates with low active dispersal power, like terrestrial gastropods, has rarely been studied. Such species can not cross a hostile habitat matrix, for which the predictions of island theory, such as positive relations between species richness and patch size, should apply. In order to test this prediction, we studied gastropod species diversity by assessing gastropod assemblage characteristics from 35 sites in 19 fragments of deciduous old-growth forests in the Lower Rhine Embayment, Germany. Assemblages differed between larger (≥700 ha) and smaller forests (<400 ha), those of large forests held a higher percentage of forest species. Although α-diversity was similar between the two forest size classes, small forests often comprised matrix species, resulting in a higher β-diversity. Edge effects on the species richness of matrix species were noticeable up to 250 m into the forest. Hierarchical partitioning revealed that distance to disturbances (external edge, internal edges like roads) explained most assemblage variables, whereas forest size and woodland cover within a 1 km radius from the sites explained only a few assemblage variables. Densities of two forest-associated species, Discus rotundatus and Arion fuscus, decreased with forest size. Yet, forest size was positively correlated with richness of typical forest species and densities of Limax cinereoniger. The latter species seems to need forests of >1,000 ha, i.e., well above the size of most fragments. In conclusion, the prediction is valid only for forest species. The response to fragmentation is species specific and seems to depend on habitat specialization and macroclimatic conditions. Jean-Pierre Maelfait: Deceased.     

Greenhouse biofumigation with <Emphasis Type="Italic">Melia azedarach</Emphasis> controls <Emphasis Type="Italic">Meloidogyne</Emphasis> spp. and enhances soil biological activity

The need for environmentally friendly agricultural practices has led to the development of plant-based nematicides for root-knot nematode control. The efficacy of these botanicals has been tested primarily under laboratory and rarely under actual field conditions. Moreover, any side effects on non-target soil organisms that support soil biological activity are usually ignored. Herein, we evaluate the efficacy of Melia azedarach preparations against Meloidogyne spp. in a tomato greenhouse, by root gall examination and soil J2 enumeration. We also assessed side effects on soil microbes through PLFA analysis and microbivorous nematodes, and we quantified several plant growth parameters (e.g., fruit number and weight, root weight). Different treatments within the greenhouse included M. azedarach ripe fruit powder (MFP), ripe fruit water extract (MWE) and furfural, one of the principal active ingredients of M. azedarach and previously known to exhibit fumigant nematicidal activity. Results were compared to those obtained with the commercial nematicide oxamyl (Vydate^® 10 SL) and an untreated control. All treatments were repeated every 20 days throughout the cultivation period. MFP and MWE suppressed Meloidogyne spp. often at the same levels obtained by furfural and oxamyl treatments and enhanced soil biological activity, as indicated by the proliferation of soil microbes and microbial feeding nematodes. Furfural and oxamyl adversely affected the soil community, especially the free-living nematodes. Moreover, furfural was phytotoxic to tomato plants in spite of its natural origin.     

Analysis of combining ability of two-types of male sterile and four restorer lines of <Emphasis Type="Italic">Zinnia elegans</Emphasis>

Eight cross combinations of Zinnia elegans were made using two recessive nuclear male sterile lines crossed with four restorers using the North Carolina Design II statistical method. Heterosis, combining ability and heritability was analysed using 12 horticultural traits and these demonstrated the advantage of heterosis in hybrid breeding of Zinnia elegans. Heterosis served to increase the number of whorls of ray florets across capitulum and the number of branches, and also decreased plant height, crown size, pedicel length and length of node. Thus, six horticultural traits were improved over mid parent and best parent status to fulfill major breeding goals of this herbaceous flower. The traits of plant height, number of whorls of ray florets across capitulum and pedicel length were primarily controlled by paternal additive effects, whereas crown size was mainly controlled by non-additive effects. Number of branches and length of node were affected both by paternal additive effects and non-additive effects. The ratio of general combining ability to specific combining ability indicated the importance of additive genes in the expression of these traits. Among the parental lines, AH003A and restorer A3 were chosen as primary female and male combiners, respectively. AH001A and restorer S5 were chosen as secondary combiners. The cross AH003A × A3 was determined as the most promising combination for producing potted plant characteristics, and AH001A × S5 was the best hybrid obtained in this study for cut flower traits. The analysis of combining ability for the parental lines showed that there was no causal relationship between general combining ability and specific combining ability effects.     

The seasonal activity of flea beetles in Bulgaria

Using allyl-isothiocyanate-baited traps, we recorded six species of flea beetles in cabbage and horseradish crops in the region of Sofia, Bulgaria in 2006 and 2007. The most abundant species in the traps was Ph. cruciferae (92–96%) followed by Ph. vittula, Ph. undulata and Ph. nigripes. The overwintering adults of these species emerge before the beginning of April and are active to the end of May–beginning of June. Catches of adults of the new generation occurred from the end of June–beginning of July to the second half of October–beginning of November. In 2006, air temperature and humidity strongly influenced the catches of the flea beetles. Investigations of the reproductive status of field collected females of Ph. cruciferae showed that this species develops one generation per year in the region. The results of this study can be used in integrated pest management approach to flea beetles control.     

优质高产香型杂交水稻新组合宜香2292

宜香2292系四川省宜宾市农业科学研究所用浓香型优质不育系宜香1A与优质恢复系宜恢2292组配而成的中籼迟熟香型优质杂交水稻新组合,其农艺性状优、香味浓、产量高、品质优、适应性广。2002年荣获四川省第三届“稻香杯”优质米称号,2004年通过国家和江西省品种审定。     

烟草青枯病生防菌的筛选及其田间防效评价

为筛选出对烟草青枯病有效防治的生防菌,通过稀释涂布法从烟株根际土壤分离到一株具有明显拮抗作用的菌株69-1,经16S rDNA鉴定该菌株为壮观链霉菌(Streptomyces spectabilis),并用该菌株进行烟草青枯病田间防治试验。结果表明,与对照相比,经菌株69-1处理烟株茎围、有效叶片数、最大叶宽、最大叶长、上中下部烟叶单叶干重、最大叶面积、产量均显著增加,且对烟草青枯病的相对防效达60.42%,同时对不同处理组的初烤烟叶进行化学成分的检测分析,发现菌株69-1处理相对于对照组烟叶品质更佳。该菌株菌剂处理不仅可以提高烟株对烟草青枯病的防效,而且还提高烟叶品质和产量,可为烟草青枯病生物防治提供一定参考。     

辽宁省近53年冬季气温变化特征分析

为准确预测辽宁冬季气候,进而达到对冬季设施农业等方面服务的目的,根据辽宁省53个气象观测站1961—2014年逐月的平均气温资料,利用滑动T检验方法、Mann-Kendall检验方法、最大熵谱方法以及Morlet小波分析等方法,分析了1961—2013年辽宁省冬季平均气温的变化特征。结果表明：近53年辽宁省冬季平均气温时间序列呈显著的线性递增趋势,与全球气候变暖趋势相一致。但值得注意的是,近几年辽宁出现了气温偏低的情况;辽宁省冬季平均气温在1985—1986年前后发生了1次明显突变,之前气温以偏低为主,之后开始显著增温。辽宁省冬季平均气温的主要周期为准3~5年周期和17年周期。采用新资料得到的辽宁冬季气温变化特征与采用旧资料的情况略有差异。     

Investigation of the Potential Health Benefits as Lipase Inhibitor and Antioxidant of <Emphasis Type="Italic">Leopoldia comosa</Emphasis> (L.) Parl.: Variability of Chemical Composition of Wild and Cultivated Bulbs

There is a great interest in the nutritional value of vegetables and fruits and how the habitat affects nutritive and biological properties. In vitro studies here reported were performed to evaluate the inhibitory activity of formulations from edible plant on pancreatic lipase. The aim of this study was also to evaluate the biovariability of L. comosa (L.) Parl. bulbs from Italy. The wild bulbs were compared with the same cultivated species that are commonly commercialized to identify samples with the best quality for a potential therapeutic application. Hydroalcoholic extract and polar fraction of wild bulbs showed a very important pancreatic lipase inhibitory activity, with IC₅₀ values of 0.166 ± 0.005 and 0.153 ± 0.005 mg/mL, respectively. In order to characterize the extracts, gas chromatography associated with mass spectrometry (GC/MS) analysis was performed, revealing the predominance of palmitic acid. Phenolic and flavonoid composition was also evaluated. L. comosa extract obtained from wild bulbs demonstrated both antioxidant and anti-obesity activities that might be attributed to a wide range of present phenolic compounds.     

优质早籼新品种中优早13号的特征特性及栽培技术

中优早13号系中国水稻研究所选育的早稻新品种,多年多点试验示范,表现高产稳产,抗逆、抗病虫能力较强。本文总结了其特征特性和产量表现,并归纳了其栽培技术要点。     

Grassland songbird occurrence on remnant prairie patches is primarily determined by landscape characteristics

Context

North American grassland songbird populations have declined significantly due to habitat loss and fragmentation. Understanding the influence of the surrounding landscape on prairie fragment occupancy is vital for predicting the fate of grassland birds in these heavily altered landscapes.

Objectives

We examined the relative importance of local and landscape variables on grassland bird occupancy of prairie fragments using a focal-patch study. We also investigated the spatial scale at which landscape variables were most influential.

Methods

We surveyed birds on 29 unplowed prairie fragments in western Minnesota and eastern North and South Dakota. We quantified local habitat on the fragment using vegetation surveys and aerial photographs and the landscape surrounding the fragment out to 4 km using aerial photographs. We analyzed occupancy using multi-model approaches applied to multiple logistic regression.

Results

Of 38 species encountered, nine were neither too rare nor too abundant to be analyzed. Predictors of patch occupancy were unique for each bird species, yet general patterns emerged. For eight species, landscape variables were more important than local variables. Mostly, those landscape variables measured configuration (e.g., edge density) and not composition (e.g., percent cover of a particular matrix element). Landscape effects were mostly from variables measured at the greatest extents from the prairie fragment.

Conclusions

Using a focal-patch study design we demonstrated the importance of the surrounding landscape, often out to 4 km from the fragment edge, on prairie occupancy by grassland birds. Effective management of grassland songbirds will require attention to the landscape context of prairie fragments.