响应面优化早花忍冬组培苗增殖培养条件

本试验以早花忍冬组培苗的茎段为试验材料,采用Box-Behnken响应面设计法优化早花忍冬茎段继代培养的条件,为早花忍冬组培离体快繁体系建立提供了参考依据.通过单因素试验法确定激素的添加范围,通过响应面优化得到最佳的增殖培养基.结果表明:激素种类对早花忍冬组培苗茎段继代培养的影响顺序依次为:6-BA＞IAA＞IBA,并且在6-BA浓度为1.9 mg/L、IBA浓度为0.76 mg/L、IAA浓度为0.27 mg/L时,茎段继代培养的增殖系数为7.66,与方程预测值相接近.     

羊支原体性肺炎两标准株对抗菌药物敏感性的研究

本实验测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰勒菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰勒菌素对Y-goat和四环素与氧氟沙星、泰勒菌素对Y98的联合药敏作用。对羊肺炎支原体两个标准株对抗菌药物的敏感性进行了分析。     

黄淮夏大豆主要农艺性状的遗传分析

利用黄淮地区的12个高产夏大豆品种(系),通过NCⅡ交配设计,对12个主要农艺性状的遗传进行了分析。结果表明,所有性状的加性方差大于显性方差。主茎节数、株高、每簇荚数和主茎荚数的加性成分占绝对优势,遗传力较高。分枝荚数、单株粒数和单株粒重的显性成分比例大,遗传力较低,其中单株粒重趋于完全显性。主茎节数的显性成分很少,其它性状均为部分显性。建立了单株产量与产量因子之间的逐步回归方程。     

中国葡萄野生种对葡萄根癌病的抗性

通过田间接种鉴定，系统研究了中国葡萄属１３个种和变种的２６个株系对葡萄根癌病的抗性，筛选出高抗株系１０个。其中燕山葡萄（♀）因扦插容易生根，可用自根苗作为抗葡萄根癌病砧木进行嫁接试验，其余可用作抗葡萄根癌病的育种资源     

Comparison of morphology, viability, and function between blood and milk neutrophils from peak lactating goats

The morphological features of blood and milk neutrophils from peak lactating goats were compared using light microscopy, scanning electron microscopy and flow cytometry in order to investigate the cytological changes of neutrophils after migration into the mammary gland. The kinetics of reactive oxygen intermediates (ROI) generation and gelatinase release of blood and milk neutrophils, with or without stimulation of phorbol 12-myristate, 13-acetate ester (PMA), were used to characterize their responses to inflammatory stimuli. Neutrophils isolated from goat milk were highly segmented and contained multi-lobed nuclei. Ultrastructurally, milk neutrophils were more ruffled on the surface compared to blood neutrophils. Approximately 30% of milk neutrophils were undergoing cell death, either necrosis or apoptosis, in contrast to 8% of blood neutrophils. The ROI production of activated milk neutrophils peaked earlier than blood neutrophils, but the duration and the intensity were much less. Neutrophils from both sources augmented the release of gelatinase in response to PMA (1 ng/mL). However, the amount of gelatinase released from milk neutrophils was lower (P < 0.05) than that of blood neutrophils. In summary, more neutrophils become apoptotic and necrotic in the mammary gland, presumably due to spontaneous aging, the process of diapedesis, and the interaction with milk components. Milk neutrophils have impaired functionalities in comparison with blood neutrophils. The information is relevant when studying mammary gland immunity and related diseases, such as mastitis.     

农杆菌介导的蝴蝶兰基因转化系统的建立

 针刺后的蝴蝶兰‘White Hikaru’的类原球茎(PLB)，与含绿色荧光蛋白基因( )和潮霉素磷酸转移酶基因(^p￡)的pCAMBIA 1300一SmGFP的根瘤农杆菌LBA4404 共培养，培育出了转基因的蝴蝶兰。经绿色荧光蛋白检测和Southern印迹，证实了再生植株中含cop基因和hpt基因。     

Comparative expression profile of microRNAs and piRNAs in three ruminant species testes using next‐generation sequencing

microRNA (miRNA) and piwi‐interacting RNA (piRNA) are two classes small non‐coding regulatory RNAs that play crucial roles in multiple biological processes such as spermatogenesis. However, there are no published studies on conjoint analysis of miRNA and piRNA profiles among cattle, yak and their interspecies (the dzo) using sequencing technology. Next‐generation sequencing technology was used to profile miRNAs and piRNAs among those three ruminants to elucidate their functions. A total of 119, 14 and six differentially expressed miRNAs were obtained in cattle vs. dzo, cattle vs. yak and yak vs. dzo comparison groups, while there were 873, 1,065 and 1,158 differentially expressed piRNAs in those three comparison groups. The expression of three miRNAs was validated in the three ruminants, and the results suggested that the miRNA expression profiles data could represent actual miRNA expression levels. Moreover, the putative targets of differentially expressed miRNAs were predicted by their own genome, it is worth to note that both the cattle and yak genome were used for dzo, then the targets were subjected to GO enrichment and KEGG pathway analysis, revealing the likely roles for these differentially expressed miRNAs in spermatogenesis. In conclusion, this study provided a useful resource for further elucidation of the miRNAs and piRNAs regulatory roles in spermatogenesis. It may also facilitate the development of therapeutic strategies for dzo reproduction research.     

苜蓿抗旱生理与分子机制

苜蓿(Medicago sativa)是我国乃至全世界最优质的豆科牧草之一,具有较高的经济价值、营养价值和生态价值。然而我国的苜蓿种植大多集中在干旱半干旱的西北、东北一带,水分是影响其产量的主要因素。本文通过对比光合呼吸系统、活性氧防御系统、渗透调节系统、脱落酸等在干旱胁迫下的变化分析了苜蓿抵御干旱胁迫的生理机制,同时对转录因子、蛋白酶基因和抗旱基因在苜蓿干旱胁迫下的应答过程进行了阐述,并对未来苜蓿应答干旱胁迫的研究重点进行了展望。     

玛曲高寒草甸放牧强度的遥感监测

为给玛曲县高寒草甸草-畜平衡和草地资源的可持续利用提供科学依据,本研究利用遥感技术,结合2016年地面实测数据和同时期的MODIS影像资料,分别建立了研究区草地地上生物量和植被指数(NDVI)、相对放牧强度间的回归模型以及不同相对放牧强度和NDVI值之间的幂回归模型。结果表明,6-9月调查点NDVI和地上生物量间存在较好的相关性,即随着NDVI值的增加生物量呈上升趋势,且9月份的拟合(R2=0.510 2)达到了极显著水平;实测地上生物量和相对放牧强度之间有很好的拟合关系(R2=0.965 1),随着放牧强度的增加地上生物量呈下降趋势;相对放牧强度和植被指数间相关性较好(R2=0.631),即随着NDVI值的变小,相对放牧强度逐渐增强,当相对放牧强度增强到一定程度时,NDVI对其响应不灵敏。     

猪β防御素研究进展

β防御素是猪体内分泌的一类抗菌肽，广泛分布于各个组织中，在抵抗病原入侵和免疫调节中发挥着重要作用。猪β防御素对细菌、真菌和病毒都有很强的杀灭作用，并且具有分子量小、热稳定性好、无残留等优点，是理想的抗生素替代品。研究表明，猪β防御素的表达与个体抗病力正相关，增加内源性防御素表达或直接摄入外源性防御素均能增强机体免疫力并促进生长。脂肪酸、氨基酸、维生素、益生菌、病原微生物等外源刺激皆可影响β防御素的表达。随着防御素相关研究的深入，将有望解决养猪生产中长期使用抗生素而导致的耐药性、药物残留及环境污染等问题。文章介绍了猪β防御素的结构特征、表达特异性及生物学功能，主要综述了外源刺激对β防御素表达的影响及其作用机制，初步说明外源β防御素作为饲料添加剂在仔猪生产中的效果，旨在为猪β防御素的深入研究及其在生猪健康养殖中的应用提供参考。