菜用豌豆尖专用品种云豌1号的选育

云豌1号是以食荚90-17(无须蔓生品种)为母本,以食荚大菜豌(矮生品种)为父本进行杂交,经系统选育而成的矮生无须菜用豌豆新品种。植株直立矮生,株高50～60 cm,复叶无须(即卷须退化),营养体发达,叶片肥厚,嫩梢纤维少,幼苗质地柔软,食用品质佳,VC含量34.9 mg · kg~(-1),总黄酮含量3?290 mg · kg~(-1)。一般每667 m~2可产嫩尖850～1?200 kg,适宜云南省海拔1?100～2?400 m的豌豆产区或南方生境相似的秋播豌豆产区种植。     

温室茄子氮、磷、钾素最大利润施用量研究

为了研究温室茄子氮、磷、钾素最大利润施用量,为茄子合理施肥和安全生产提供参考,在甘肃省张掖市甘州区党寨镇温室内,采用田间小区试验方法,进行了温室茄子氮、磷、钾素最大利润施用量研究。结果表明:随着氮、磷、钾素施用量梯度的增大,茄子产量逐渐增加,边际产量、边际产值和边际利润均呈递减趋势,其中边际利润最终出现负值。根据最大利润施用量计算公式求得茄子氮、磷、钾素最大利润施用量分别为0.62、0.41、0.29 t/hm~2,进而得出最大利润施用量的理论产量分别为95.58、96.04、95.35 t/hm~2。     

安徽省作物养分供需分析及化肥减施潜力研究

有机-无机相结合的农田养分管理模式是现阶段中国发展绿色农业的必由之路,因而开展有机、无机养分和作物养分需求的比较研究对促进养分资源的合理分配和施用具有重要的参考价值。本文采用文献调查和统计分析的方法,评估了安徽省16市2010—2016年主要有机肥(包括秸秆、粪便、绿肥和饼肥)的养分资源,明晰了安徽省农业生产中有机、无机养分投入现状,并根据农业种植结构开展了有机、无机养分和作物养分需求的差异和关系研究,最后探索了安徽省的化肥减施潜力。结果表明:安徽省2010—2016年平均有机肥养分资源为287.70万t,N、P_2O_5和K_2O分别为104.49万t、39.60万t和143.61万t,可基本满足作物的养分需求;但有机肥的当季利用率低,N、P_2O_5和K_2O的当季利用率分别为21.44%、19.91%和52.61%,有机肥N、P_2O_5和K_2O实际还田量仅占作物养分需求的20.74%、25.38%和63.61%,占农田养分总投入的比重分别为11.87%、10.27%和51.35%。全省N、P_2O_5、K_2O养分实际投入量(包括有机肥和化肥)是作物养分需求的1.75倍、2.47倍和1.24倍,有7个市的N和13个市的P_2O_5养分施用量超过作物需求的2倍,存在较高的环境污染风险。通过控制农业总养分输入,安徽省的化肥减施潜力为35.12%,N、P_2O和K_2O的减施潜力分别为21.28%、23.97%和78.61%。提高有机肥的当季利用率和发展冬季绿肥资源可进一步促进化肥减施。本研究可为安徽省化肥零增长和农牧业的绿色可持续发展提供数据参考。     

Assessing vulnerability of New Zealand lakes to loss of conservation value from invasive fish impacts

1. Predictions of invasion risk for seven non‐indigenous fish species, ecological impact scores for individual species, and lake conservation rankings were linked to develop Invasion Risk Impact (IRI) and Lake Vulnerability (LV) indices that help identify New Zealand lakes most at risk of loss of conservation value from potential multi‐species invasions.
2. Species‐specific IRI scores (the product of predicted invasion risk and species impact) highlighted Eurasian perch (Perca fluviatilis) and the brown bullhead (Ameiurus nebulosus), as the species most likely to spread and cause ecological harm in lakes. For 3431 lakes >1 ha throughout New Zealand, total IRI tended to be highest for lowland riverine and dune lakes most of which are already colonized by multiple invasive fish species.
3. The LV index indicated that lakes most at risk of loss of conservation value from invasive fish impacts were predominantly (i) in the northern half of the North Island where several uncommon lake types occur, and (ii) along the west coast of the South Island where conservation value is often greater, largely because of low catchment modification.
4. The IRI and LV indices can be used to assist with setting priorities for surveillance monitoring, advocacy, and response planning targeted at preventing the establishment of invasive fish in moderate‐to‐high value lakes most susceptible to ecological impacts. Both indices can be adapted to accommodate alternative impact and conservation scoring systems, providing a flexible tool for local‐ and national‐scale assessments of lake vulnerability to fish invasion impacts.

Copyright © 2016 John Wiley & Sons, Ltd.     

Breaking the ice: the introduction of biofouling organisms to Antarctica on vessel hulls

1. Few reports exist that describe marine non‐native species in the Southern Ocean and near‐shore waters around the Antarctic continent. Nevertheless, Antarctica's isolated marine communities, which show high levels of endemism, may be vulnerable to invasion by anthropogenically introduced species from outside Antarctica via vessel hull biofouling.
2. Hull surveys of the British Antarctic Survey's RRS James Clark Ross were undertaken between 2007 and 2014 at Rothera Research Station on the Antarctic Peninsula (Lat. 67°34'S; Long. 68°07'W) to investigate levels of biofouling. In each case, following transit through scouring sea‐ice, over 99% of the vessel hull was free of macroscopic fouling communities. However, in some surveys microbial/algal biofilms, balanomorph barnacles and live individuals of the cosmopolitan pelagic barnacle, Conchoderma auritum were found in the vicinity of intake ports, demonstrating the potential for non‐native species to be transported to Antarctica on vessel hulls.
3. Increasing ship traffic volumes and declining duration of sea ice in waters to the north and west of the Antarctic Peninsula mean the region may be at increased risk of non‐native species introductions. Locations at particular risk may include the waters around popular visitor sites, such as Goudier Island, Neko Harbour, Whalers Bay, Cuverville Island and Half Moon Island, and around northern peninsula research stations.
4. Simple and cost‐effective mitigation measures, such as intentionally moving transiting ships briefly through available offshore sea ice to scour off accessible biofouling communities, may substantially reduce hull‐borne propagule pressure to the region. Better quantification of the risk of marine non‐native species introductions posed by vessel hulls to both Arctic and Antarctic environments, as sea ice patterns and shipping traffic volumes change, will inform the development of appropriate regional and international management responses.

Copyright © 2016 The Authors. Published by Wiley Periodicals, Inc.     

Influence of climate and abundance on migration timing of adult Atlantic salmon (Salmo salar) among rivers in Newfoundland and Labrador

Evidence mounts for the influence of climate variability on temporal trends in the phenology of many organisms including various species of fish. Accordingly, we examined variation in adult Atlantic salmon Salmo salar run timing in thirteen Newfoundland and Labrador rivers where returns were monitored at fishways or fish‐counting fences. Run timing varied significantly among rivers with the median date of return differing by up to 5 weeks. Duration of runs was generally short with most adults returning over a period of three to 5 weeks. A mixed model analysis incorporating a first‐order autoregressive error structure was used to generalise changes in run timing among all monitored rivers. Results indicated that the median date of return has advanced by almost 12 days over a 35‐year interval from 1978 to 2012, while several individual rivers have advanced by almost 21 days. The influence of climate on median timing was evident when the simultaneous effects of both climate and salmon abundance were controlled. We found earlier runs associated with overall warmer climate conditions on the Newfoundland and Labrador Shelf. Results contrast with those from the north‐east Atlantic where Atlantic salmon are returning later in some rivers coincident with warming climate conditions.     

Estimation of irrigation requirements for drip-irrigated maize in a sub-humid climate

Drip-irrigation is increasingly applied in maize (Zea mays L.) production in sub-humid region. It is critical to quantify irrigation requirements during different growth stages under diverse climatic conditions. In this study, the Hybrid-Maize model was calibrated and applied in a sub-humid Heilongjiang Province in Northeast China to estimate irrigation requirements for drip-irrigated maize during different crop physiological development stages and under diverse agro-climatic conditions. Using dimensionless scales, the whole growing season of maize was divided into diverse development stages from planting to maturity. Drip-irrigation dates and irrigation amounts in each irrigation event were simulated and summarized in 30-year simulation from 1981 to 2010. The maize harvest area of Heilongjiang Province was divided into 10 agro-climatic zones based on growing degree days, arid index, and temperature seasonality. The simulated results indicated that seasonal irrigation requirements and water stress during different growth stages were highly related to initial soil water content and distribution of seasonal precipitation. In the experimental site, the average irrigation amounts and times ranged from 48 to 150 mm with initial soil water content decreasing from 100 to 20% of the maximum soil available water. Additionally, the earliest drip-irrigation event might occur during 3- to 8-leaf stage. The water stress could occur at any growth stages of maize, even in wet years with abundant total seasonal rainfall but poor distribution. And over 50% of grain yield loss could be caused by extended water stress during the kernel setting window and grain filling period. It is estimated that more than 94% of the maize harvested area in Heilongjiang Province needs to be irrigated although the yield increase varied (0 to 109%) in diverse agro-climatic zones. Consequently, at least 14% of more maize production could be achieved through drip-irrigation systems in Heilongjiang Province compared to rainfed conditions.     

Replication of neurovirulent equine herpesvirus type 1 (EHV-1) in CD172a+ monocytic cells

Equine herpesvirus type 1 (EHV-1) is responsible for respiratory disorders, abortion and myeloencephalopathy (EHM) in horses. Two pathotypes of EHV-1 strains are circulating in the field: neurovirulent (N) and non-neurovirulent (NN). For both strains, CD172a⁺ monocytic cells are one of the main carrier cells of EHV-1 during primary infection, allowing the virus to invade the horse’s body. Recently, we showed that EHV-1 NN strains showed a restricted and delayed replication in CD172a⁺ cells. Here we characterize the in vitro replication kinetics of two EHV-1 N strains in CD172a⁺ cells and investigate if the replication of these strains is similarly silenced as shown for EHV-1 NN strains. We found that EHV-1 N replication was restricted to 7–8% in CD172a⁺ cells compared to 100% in control RK-13 cells. EHV-1 N replication was not delayed in CD172a⁺ cells but virus production was significant lower (10^3.0 TCID₅₀/10⁵ inoculated cells) than in RK-13 cells (10^8.5 TCID₅₀/10⁵ inoculated cells). Approximately 0.04% of CD172a⁺ cells produced and transmitted infectious EHV-1 to neighbour cells compared to 65% of RK-13 cells. Unlike what we observed for the NN strain, pretreatment of CD172a⁺ cells with histone deacetylases inhibitors (HDACi) did not influence the replication of EHV-1 N strains in these cells. Overall, these results show that the EHV-1 replication of N strains in CD172a⁺ cells differs from that observed for NN strains, which may contribute to their different pathogeneses in vivo.     

Responses of glutamine synthetase activity and gene expression to nitrogen levels in winter wheat cultivars with different grain protein content

Glutamine synthetase (GS) plays a central role in plant nitrogen (N) metabolism, which improves crops grain protein content. A pot experiment in field condition was carried out to evaluate GS expression and activity, and grain protein content in high (Wanmai16) and low grain protein (Loumai24) wheat cultivars under two N levels (0.05 and 0.15 g N kg⁻¹ soil). High nitrogen (HN) resulted in significant increases in GS1 and GS2 expression at 10 days after anthesis (DAA), and higher GS activity during the entire grain filling stage. HN also significantly increased yield, grain protein content and protein fraction (except for glutenin of Luomai24) in two wheat cultivars, which indicated that it increased grain yield and protein content by improving nitrogen metabolism. Wanmai16 showed higher grain protein content, gliadin and glutenin content, and had higher expression level of GS2 both in flag leaves and grains at early grain filling stage. However, Luomai24 had greater yield and higher expression level of GS1. The difference expression of GS2 and GS1 genes indicates they had various contributions to the accumulation of protein and starch in wheat grains, respectively. The results suggest that GS2 would be serving as a potential breeding target for improving wheat quality.