叶用芥菜叶缘裂刻性状的遗传与相关基因表达分析

以叶缘裂刻和叶缘锯齿的2种芥菜为试材,构建F_2和BC_1分离群体,对群体单株的裂刻性状进行调查,并对相关基因进行qRT-PCR分析,以期明确叶用芥菜叶缘裂刻性状的遗传规律,为芥菜育种提供参考依据。结果表明:芥菜叶缘裂刻性状由1对显性基因控制,将该基因命名为BjLB(Leaf-lobe in Brassica juncea);qRT-PCR分析结果表明,KNAT1基因在叶缘裂刻芥菜中的表达量高于叶缘锯齿芥菜的表达量,与预期结果一致,其它基因在2个亲本中表达差异不明显,推测KNAT1基因有可能是候选基因。     

Soil properties, grassland management, and landscape diversity drive the assembly of earthworm communities in temperate grasslands

Earthworms are widespread soil organisms that contribute to a wide range of ecosystem services. As such, it is important to improve our knowledge, still scanty, of the factors that drive the assembly of earthworm communities. The aim of the present study was to conjointly evaluate the effects on the assembly of earthworm communities of i) soil properties (texture, organic matter content, and pH), ii) grassland management (grassland age, livestock unit, and type of fertilization), iii) landscape diversity (richness, diversity of surrounding habitats, and grassland plant diversity), and iv) presence of hedgerows. The study was conducted in temperate grasslands of Brittany, France. Earthworms were sampled in 24 grasslands and, in three of these grasslands, they were sampled near a hedgerow or near a ditch (control without a hedgerow). Soil properties explained the larger portion of the variation in the earthworm community parameters compared to grassland management or landscape diversity. The increase in soil organic matter content and pH were the most favorable factors for earthworm abundance and biomass, in particular for endogeic species. Regarding grassland management, the increase in the livestock unit was the most damaging factor for earthworm communities, in particular for the anecic earthworm biomass and endogeic species richness. Surprisingly, landscape diversity negatively affected the total earthworm abundance and epigeic earthworm biomass, but it was related to an increase in the epi-anecic species. At a finer scale, we also demonstrated that the presence of hedgerows surrounding grasslands enhanced earthworm species richness, especially within the epigeic and anecic ecological categories. This study highlights that the earthworm ecological categories respond specifically to environmental filters; further studies need to be conducted to elucidate the factors that drive the assembly of earthworm communities at this ecological category level. We recommend that policymakers should act on landscape management to favor earthworm diversity in order to improve the ecosystem services they drive.     

我国食品制造业季度固定资产投资增量与主营业务利润率的变化研究

对我国食品制造业2004～2010年季度固定资产投资增量与行业主营业务利润率变动值进行了格兰杰因果检验,并建立了联立方程模型。结果显示,食品制造业固定资产投资增量变化主要受主营业务利润率变动值的当期值和前第5期值影响。     

The response of foraging bumblebees to successional change in newly created arable field margins

Agricultural intensification is likely to have been a major factor leading to serious declines in bumblebee abundance and diversity in the UK and elsewhere over recent decades. Opportunities to restore habitat for bumblebees on uncropped arable field margins are now available, although the methods by which this restoration can be achieved have not been fully investigated. We present the results of a three year study undertaken to investigate the response of foraging bumblebees to five different arable field margin treatments (sown and unsown), as part of a replicated field experiment on arable farmland in northern England (UK). Bumblebee abundance was closely linked to successional changes in availability of suitable forage plant species. Field margin treatments sown with a `grass and wildflower' mixture had the highest bumblebee abundance, and provided a consistent supply of forage species, with different components of the seed mixture flowering in each year. The unsown natural regeneration treatment attracted foraging bumblebees in only the second year due to the local abundance of thistles, so we consider this option to be both inconsistent in terms of forage provision and agronomically unacceptable. Our results are discussed in terms of developing suitable measures to achieve the restoration of habitats for bumblebees on arable farmland.     

Influence of plant traits on production costs and profitability of strawberry in southeast Queensland

In Queensland the subtropical strawberry (Fragaria × ananassa) breeding program aims to combine traits into novel genotypes that increase production efficiency. The contribution of individual plant traits to cost and income under subtropical Queensland conditions was investigated, with the overall goal of improving the profitability of the industry through the release of new strawberry cultivars. The study involved specifying the production and marketing system using three cultivars of strawberry that are currently widely grown annually in southeast Queensland, developing methods to assess the economic impact of changes to the system, and identifying plant traits that influence outcomes from the system.From May through September P (price; $ punnet⁻¹), V (monthly mass; tonne of fruit on the market) and M (calendar month; i.e. May = 5) were found to be related (r² = 0.92) by the function (±SE) P = 4.741(±0.469) − 0.001630(±0.0005)V − 0.226(±0.102)M using data from 2006 to 2010 for the Brisbane central market. Both income and cost elements in the gross margin were subject to sensitivity analysis.‘Harvesting’ and ‘Handling/Packing’ ‘Groups’ of ‘Activities’ were the major contributors to variable costs (each >20%) in the gross margin analysis. Within the ‘Harvesting Group’, the ‘Picking Activity’ contributed most (>80%) with the trait ‘display of fruit’ having the greatest (33%) influence on the cost of the ‘Picking Activity’. Within the ‘Handling/Packing Group’, the ‘Packing Activity’ contributed 50% of costs with the traits ‘fruit shape’, ‘fruit size variation’ and ‘resistance to bruising’ having the greatest (12-62%) influence on the cost of the ‘Packing Activity’. Non-plant items (e.g. carton purchases) made up the other 50% of the costs within the ‘Handling/Packing Group’. When any of the individual traits in the ‘Harvesting’ and ‘Handling/Packing’ groups were changed by one unit (on a 1-9 scale) the gross margin changed by up to 1%. Increasing yield increased the gross margin to a maximum (15% above present) at 1320 g plant⁻¹ (94% above present). A 10% redistribution of total yield from September to May increased the gross margin by 23%. Increasing fruit size increased gross margin: a 75% increase in fruit size (to ≈30 g) produced a 22% increase in the gross margin.The modified gross margin analysis developed in this study allowed simultaneous estimation of the gross margin for the producer and gross value of the industry. These parameters sometimes move in opposite directions.     

The impact of landscape structure and sown grass margin strips on weed assemblages in arable crops and their boundaries

A paired-field study was made in southern England in arable fields, each with or without sown 6-m wide grass margin strips. Seven field pairs were located in each of small, intermediate and open landscapes, which were based on mean field size. Ground cover, plant species diversity and assemblages were assessed in crop centres, crop edges and non-crop field boundaries. The data were used to test for effects of sown grass margins, differences in field location, impacts on rare weed species and for landscape effects on weed assemblages. Significantly higher plant species diversity was found in boundaries protected by buffer strips. Annual weeds associated with field edges, notably Anisantha sterilis , were found at lower cover where perennial grass strips were present. Sown grass strips enhanced boundary plant diversity, particularly by increasing polycarpic species. Margin strips had a small influence on the weed flora of the crop edge, possibly reducing weed cover, but had no influence on floras of field centres. Field size and landscape context did not affect weed assemblages, which show marked field-to-field variability, though crop type was an important influence. Grass margins did not enhance rare arable weed species and may be a threat to them, if margins are sited where such species are known to occur in the seedbank. With this exception, grass strips are a positive influence on boundary flora diversity and reduce margin weeds in arable landscapes.     

高速公路边坡滑动失稳机理分析与加固研究

分析了内蒙古呼和浩特——老爷庙高速公路K453 200~K453 800段的滑动失稳破坏,该段以路堑形式通过,在雨季后期,岩土体突然发生滑动失稳变形,通过对边坡岩土体物理、力学性能的试验研究,得到了产生边坡失稳的主要原因是:边坡下部存在泥岩夹层,该泥岩遇水膨胀,随着含水量的增加残余强度明显衰减为20.8%,当坡体较大范围内土层强度衰减至残余强度时坡体必然发生滑动失稳而破坏。采用了抗滑桩和预应力钢筋砼框架结构等加固措施,收到了较好的效果。     

兔生后舌和食管发育的组织学研究

对18只法比兔生后舌和食管进行组织学观察的结果表明,免出生时舌背侧粘膜上皮未角化,并含有大量丝状乳头（平均高为135.7μm）和少量菌状乳头。固有膜不发达。舌肌为纵向、横向及垂直方向排列的横纹肌。舌腹侧粘膜表面平滑。15日龄以后,舌背侧菌状乳头高为200～521μm,其顶部直径为93～221μm。1日龄时,兔食管粘膜上皮只有4～5层细胞（平均厚28.5μm）。60日龄时,已达30层左右（平均厚164.3μm)。固有膜与粘膜下层分界不清。肌层由内纵、中环、外纵3层组成。肌层随年龄增长而逐渐增厚,1日龄时平均厚度121.4μm,60日龄时平均厚度达750μm。     

DISTAL PHALANX FRACTURES IN HORSES

The case records of 274 horses with fractures of the distal phalanx were reviewed. Fifty-two horses had bilateral forelimb fractures, for a total of 326 distal phalanx fractures. The fractures were classified into one of five previously described types, based on the radiographic anatomic configuration of the fracture. Solar margin fractures, which have been briefly described in other reports and previously classified as type V fractures, were identified in 132 horses. This type of fracture is distinct from other distal phalanx fractures. Due to the high incidence of solar margin fractures, these fractures were classified as a separate type (type VI). Follow-up radiographic examinations to assess fracture healing were available for 36 horses. Twenty-two horses with distal phalanx fractures (three type I, nine type II, two type III, one type IV, one type V, and six type VI) had radiographic evidence of complete bony union of the fracture at a mean of 11 months after injury. Eight horses with complete type II fractures involving the articular surface had bony union of the body and solar margin, but not the subchondral bone at the articular surface, a mean of 11 months after injury. Six horses (four type II and two type IV) had little radiographic evidence of bony healing during the follow-up period. All fractures that eventually healed had evidence of progression toward bony union by 6 months after injury.