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71.
家蚕胚胎滞育的生理生化研究概述   总被引:1,自引:0,他引:1  
在蛹期由咽下神经节合成和分泌的大量滞育激素(dH)作用于卵巢,引起系列生理生化变化,主要包括H2O2水平降低、山梨醇积累、葡萄糖减少、呼吸耗氧量下降等,最终导致家蚕胚胎进入滞育。本文综述了家蚕胚胎滞育的生理生化研究概况,以期为家蚕胚胎滞育机理研究提供借鉴和参考。  相似文献   
72.
旱、盐胁迫下黄芪种子萌发及其对水杨酸的响应   总被引:4,自引:0,他引:4  
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。  相似文献   
73.
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。  相似文献   
74.
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.  相似文献   
75.
76.
豫南地区野生地被植物资源现状调查与研究   总被引:1,自引:0,他引:1  
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。  相似文献   
77.
以6 个菱品种为试材,对花器形态特征、群体花期及单花开花动态、开花时间、柱头可授性、花粉活力、杂交指数 及传粉形式等进行观察测定。结果表明:菱花单生,两性,单花花期15 h,群体花期在5~10 月,盛花期在7~8 月;不同 品种在一天中的开花高峰期存在差异;柱头可授期主要在萼片开裂后2 h 内,结实率在50% 以上;花粉在自然授粉条件下活 力可保持7.5 h;以自花授粉为主,同时存在一定程度的无融合生殖和少量异花授粉。  相似文献   
78.
自助借还作为一种先进的图书馆管理设备,已在很多图书馆中使用。本文通过自助借还机在石河子大学的使用实践,分析了自助借还系统的优势和不足,并提出相应的改进措施。  相似文献   
79.
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.  相似文献   
80.
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.  相似文献   
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