草原灌丛化入侵:过程、机制和效应

草原灌丛化已成为全球性问题,也是生态学、畜牧学研究的热点问题。紧扣草原灌丛化过程、发生机理及其生态学后效等关键问题,介绍了国内外的最新研究进展。灌木入侵途径包括有意识引进入侵和自然入侵2类,入侵过程分为传播到达、定居建群和扩散入侵3个阶段。放牧、火烧、温室气体增加,干旱以及降水格局改变等均可导致草本向木本的转化,且机制复杂,主要有影响草本,木本植物盖度、水分利用效率、化感作用等。木本植物入侵打破了草原生态系统的稳定,表现出沃岛效应,影响动植物的分布以及生态系统的功能和服务。阐明草原“草本-木本”群落演替机制,可为我国研究草原灌丛化和管理提供理论借鉴。     

The effect of maternal obesity on fatty acid transporter expression and lipid metabolism in the full‐term placenta of lean breed swine

This study was conducted to evaluate the influence of back‐fat thickness (BF), at mating of sows, on the maternal and newborn circulating lipids, expression of placental fatty acids (FA) transporters and lipid accumulation in placenta. Full‐term placentas were obtained by vaginal delivery from BFI (9–14 mm; n = 37), BFII (15–19 mm; n = 43) and BFIII (20–27 mm; n = 38) sows according to BF at mating, and frozen placental sections were analysed for fat accumulation. Blood samples were collected from the sows of day 105 pregnancy and from cord blood at delivery. mRNA and protein expression levels were evaluated with real‐time RT‐PCR and Western blotting. Our results demonstrated that BFII females had significantly increased litter weight and placental efficiency, decreased maternal triglyceride (TG) and non‐esterified fatty acids (NEFA) levels, decreased maternal IL‐6, TNFα and leptin levels compared to BFIII females (p < .05). BFIII sows were associated with significantly decreased newborn TG levels, increased newborn glucose, IL‐6 and TNFα levels compared to BFI or BFII sows (p < .05). BFI and BFII females had significantly decreased placental TG, NEFA and cholesterol (CHOL) contents compared to BFIII females (p < .05). Moreover, decreased CD36, FATP1, FABP4, and FABP1 mRNA and protein and FATP4 protein expression, and increased LPL activity were also observed in BFIII group compared with BFII group (p < .05). PPARγ mRNA and protein and lipogenic genes such as SREBP‐1c, ACSL1, ACCα, FAS and SCD mRNA expression were downregulated or upregulated, respectively, in the placentas of BFIII sows compared to BFI or BFII sows (p < .05). Overall, this study demonstrated that there is no advantage, in terms of litter live size, litter weight and placental FA transport and metabolism, in performing the mating of sows with BF>19 mm.     

旱、盐胁迫下黄芪种子萌发及其对水杨酸的响应

通过测定不同浓度聚乙二醇(PEG)和NaCl胁迫下膜荚黄芪(Astragalus membranaceus)和蒙古黄芪(A.membranaceus var.mongholicus)种子的最终发芽率、发芽势、简化活力指数、苗长、根长、苗干重、根干重等指标,以及不同施用方式和浓度的水杨酸(SA)对重度PEG和NaCl胁迫下两种黄芪种子最终发芽率的影响,旨在研究两种黄芪种子对PEG和NaCl胁迫响应方式的异同及SA对两种黄芪种子在重度PEG和NaCl胁迫下保护效果的差异。结果表明,低浓度PEG和NaCl只能促进膜荚黄芪种子萌发。在-0.5 MPa PEG和-0.7 MPa NaCl处理下,蒙古黄芪种子的活力指数显著优于膜荚黄芪种子(P0.05)。SA浸种能促进重度PEG和NaCl胁迫下两种黄芪种子的最终发芽率。蒙古黄芪种子的耐胁迫性高于膜荚黄芪种子。两种黄芪种子对SA的响应方式有区别。SA浸种处理优于拌种处理。     

青藏高原垂穗披碱草种质资源遗传多样性的SSR分析

采用SSR分子标记技术,对采自青藏高原的30份野生垂穗披碱草(Elymus nutans)种质进行遗传多样性分析。结果表明,1)筛选出的16对引物共获得了116个等位基因位点,92个多态性位点,多态性位点率(PPB)为79.75%,多态性信息(PIC)含量为0.063~0.325,平均值为0.188,材料间遗传相似系数(GS)介于0.692~0.976,平均值为0.828。2)聚类分析表明,在遗传相似系数0.804处,30份供试材料可聚为四大类,单独聚为一类的09-214表现出与其他材料较远的亲缘关系,主成分分析结果与UPGMA结果基本一致。群体遗传结构分析显示,大部分材料的遗传背景较为单一,群体划分的结果与聚类分析的结果部分保持一致。研究显示,供试种质材料间存在较大的差异,部分材料表现出相对独立的特性,遗传多样性较丰富,可为垂穗披碱草的保护利用、新品种的选育及优良基因的挖掘提供参考依据。     

羊种布鲁氏菌疫苗株PCR-RFLP鉴定方法的建立

为建立一种羊种布鲁氏菌Rev.1疫苗株PCR-RFLP鉴定方法,利用羊种布鲁氏菌Rev.1具有链霉素抗性的特性,选取与链霉素抗性相关编码核糖体蛋白S12的rps L基因为模板设计引物,经PCR扩增后,将产物进行Nci I酶切,发现羊种布鲁氏菌疫苗株Rev.1出现约500 bp条带,而不具有链霉素抗性的羊种布鲁氏菌株16M则出现384 bp条带。结果表明,PCR-RFLP方法能够用于羊种布鲁氏菌Rev.1疫苗株的鉴定,这为今后区分羊种布鲁氏菌疫苗株Rev.1免疫与野株感染提供了基础。     

Effect of Luteolin on Blood Indexes,Liver and Kidney in Mice with Acute Mercury Poisoning

To study the effect of luteolin on blood indexes,liver and kidney in mice with acute mercury poisoning,28 mice were randomly divided into four groups:Control group (intraperitoneal injection 0.9% saline),luteolin group (lavage 100 mg/kg luteolin),mercuric chloride group (intraperitoneal injection 4 mg/kg mercury chloride) and mercury chloride+luteolin group (intraperitoneal injection 4 mg/kg mercuric chloride,lavage 100 mg/kg luteolin).The activities of ALT in serum,AST,CREA and BUN contents,blood WBC,RBC,HGB content and GSH and MDA contents of liver tissue were detected.Morphological changes of liver and kidney tissues were observed.The results showed that compared with the control group,the activities of ALT and AST of mercuric chloride group were extremely significantly increased (P < 0.01),serum CREA,BUN,blood WBC and liver tissue MDA contents were significantly increased (P < 0.05) while blood RBC,HGB and liver tissue GSH contents were significantly decreased (P < 0.05).Liver,kidney pathological changes were obviously.Compared with mercuric chloride group,the activities of ALT,AST in serum,CREA,BUN,blood WBC and liver tissue MDA contents of mercuric chloride+luteolin group were significantly decreased (P < 0.05),while blood RBC,HGB and liver tissue GSH contents were significantly elevated (P < 0.05).Liver,kidney pathological changes were attenuated obviously.The poisoning were characterized by inflammation and the occurrence of anemia when acute mercury poisoning occurred,liver and kidney showed different degrees of injury in mice.Luteolin could reduce the toxic effects of acute mercury poisoning on blood,liver and kidney.     

豫南地区野生地被植物资源现状调查与研究

豫南地区野生地被植物资源丰富,为了在城市绿化中引入新的具有利用价值的种类,对以信阳为中心的河南省南部具有典型立地条件的区域的野生地被植物资源进行了调查。结果表明:筛选统计出野生地被植物56科,359属,822种,其中具有较大开发利用价值的50种。通过对50种野生地被植物中的15种进行利用价值研究得出,随着植物的生态适应性的增强,该种植物同时观赏价值、经济价值也相对增高,在园林应用中可利用价值也越大。     

Research Progress on Influence Factors of Mutton Quality

Meat quality means the characteristics such as appearance is related to palatability in fresh meat or manufactured meat, it includes meat color, meat structure, hardness, marbling, water holding capacity and so on.The physical characteristics of mutton quality determines the consumer acceptability of meat and there is a close relationship between chemical composition of mutton quality and nutrient substance.With the improvement of living standards, consumers are increasingly high demand for mutton.From quantitative to qualitative change, we need to continuously improve mutton quality.At present, the production of high quality animal products has become a hot topic.This paper is a summary of the effects of breed, gender, age, environment and feed nutrition on mutton quality, and aims to provide a scientific basis for improving of mutton quality with nutritional regulation measures.     

The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.