张家界市蔬菜农药残留例行监测结果与分析

2012年对张家界市蔬菜农药残留进行例行监测,共定量检测蔬菜样本600份。通过数据分析表明:蔬菜样本中农药残留的检出率为16.50%,超标率为2.00%;不合格蔬菜样本主要为白菜类,各类蔬菜农药残留的检出率和超标率均具有显著差异性;引起农残蔬菜超标的农药主要是有机磷类农药。张家界市蔬菜农药残留合格率为98.00%,高于全国近年平均水平,能够保障市民和游客的蔬菜消费安全。     

Competitive enzyme-linked immunoassay for sialoglycoprotein of edible bird's nest in food and cosmetics

The proliferation of fake and inferior edible bird's nest (EBN) products has recently become an increasingly serious concern. To identify and classify EBN products, a competitive enzyme-linked immunoassay (ELISA) was developed to quantitate sialoglycoprotein in EBN used in food and cosmetic applications. The characteristic sialoglycoprotein in EBN was found, extracted, purified, and analyzed. Sialoglycoprotein, considered the main carrier of sialic acid in EBN, consisted of 106 and 128 kDa proteins. A monoclonal antibody that could recognize both proteins was prepared. The heat-treated process did not change the affinity of sialoglycoprotein with the antibody. An optimized ELISA method was established with a cross-reactivity of less than 0.1% and an IC(50) of 3.3 μg/mL. On the basis of different food and cosmetic samples, the limits of detection (LOD) were 10-18 μg/g. Recoveries of fortified samples at levels of 20 and 80 μg/g ranged from 81.5 to 96.5%, respectively. The coefficients of variation were less than 8.0%.     

Prevalence and risk factors associated with intestinal parasites in pigs in Chongqing, China

From 2007 to 2009, the prevalence of intestinal parasites was investigated in intensive and extensive pig farms in Chongqing, China. A total of 2971 samples from both sexes and five age categories (breeding boars, breeding sows, fatteners, growers and weaners) were evaluated by standard methods for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites. Of the 2971 pigs sampled, 362(12.18%) were infected with Ascaris suum, 301(10.13%) with Trichuris suis, 301(10.13%) with Oesophagostomum spp., 491(16.53%) with Eimeria spp., 149(5.02%) with Isopora suis, 677(22.79%) with Balantidium coli and 196(6.60%) with Cryptosporidium spp. Growers had the highest infection rate while breeding boars had the lowest among the five age categories. B. coli was the most common protozoan in all pig age groups. Pigs infected with multiple parasites were common. Risk factors such as management methods, seasons, ages, etc. can influence the infection rate to a certain degree. This investigation provides relevant data about risk factors for pig farmers, thus allowing them to make more appropriate antiparasitic treatments according to farm conditions and local climate in Chongqing.     

Isolation and characterization of emerging subgroup J avian leukosis virus associated with hemangioma in egg-type chickens

Subgroup J avian leukosis virus (ALV-J), first isolated in 1989, predominantly causes myeloid leukosis (ML) in meat-type or egg-type chicken. Since 2006, the clinical cases of hemangioma rather than ML in commercial layer flocks associated with ALV-J have been reported, but it was still not clear whether the novel oncogenic ALV-J had emerged. We characterized SCAU-HN06 isolate of ALV-J from hemangioma in commercial Roman layers through animal experiment and full-length proviral genome sequence analysis. The SPF white leghorn egg-type chickens infected with SCAU-HN06 in ovo at day 11 of incubation showed an overall incidence of 56% hemangioma and 8% renal tumor throughout the 22-week trial, the mortality rate was 16%. Most genes of SCAU-HN06 isolate showed high nucleotide sequence identity to JS09GY6 which was isolated from Hy-Line Variety Brown layers suffering hemangioma. The 19-bp insertion in leader sequence and one key deletion in E element were the common features of SCAU-HN06 and JS09GY6. SCAU-HN06 and those ALV-Js associated with hemangioma, possibly recombinants of ALV-J and other avian retrovirus, may share the same ancestor.     

四川种业的现状分析及发展对策

农业的发展状况与民生休戚相关,尤其是种子行业肩负着粮食安全的重任。然而,众多资料显示,与国外种业巨头相比,我国种业在研发、生产、加工、市场销售、售后服务等产业链各环节中,都处于明显落后的状态。四川是农业大省,面对种业市场的激烈竞争,四川种业必须审时度势,构建自己的核心竞争力,     

大豆种籽含油量的半姊妹轮回选择和测交组合评价

本文旨在研究半姊妹轮回选择对提高大豆种籽含量的效果；评价测交系油分含量对选择的响应；评价种籽含油量的测交组合杂种优势和自交退化。本文设计了一个大豆半姊妹轮回选择群体，分别采用高油和低油测交系对群体的含油量进行了7轮和3轮的选择。