杂草稻nrDNA ITS片段的PCR扩增条件优化及测定

对杂草稻的nrDNA ITS片段的PCR扩增条件进行了优化并测定,建立的PCR最优体系为：20μL反应体系含1μL模板DNA,0．125mmoL／L dNTPs,0．5μmol／L正反向引物,1U Taq酶,2．0μL 10×Taq PCR Bufter;退火温度为57℃。这样的条件下充分保证了ITS PCR产物的质量和纯度要求,直接测序结果为600bp左右,与网上结果十分类似,表明结果准确可靠。这些ITS片段的系统学信息将为杂草稻的起源进化提供有力的分子水平证据。     

两种兼用型牛BoLA-DRA*exon2多态性及其与乳房炎的关联分析

利用PCR-SSCP技术,分析了牛主要组织相容性复合物DRA基因外显子2的多态性在236头中国西门塔尔牛、三河牛中的基因型分布及其多态性与乳房炎的关系。结果表明:经χ2独立性检验,发现该多态片段6种基因型在感染乳房炎牛和健康牛之间分布不一致(p<0.01)。在感染乳房炎牛中CC基因型频率最高,在健康牛中BC基因型频率最高。据此推测,CC基因型可能与这两种牛的乳房炎易感性有关,而BC基因型可能与这两种牛的乳房炎抗性有关。     

Transcriptional search to identify and assess reference genes for expression analysis in Solanumlycopersicum under stress and hormone treatment conditions

Tomato(Solanum lycopersicum) is a model plant for research on fruit development and stress response, in which gene expression analysis is frequently conducted. Quantitative PCR(qPCR) is a widely used technique for gene expression analysis, and the selection of reference genes may affect the accuracy of results and even conclusions. Although there have been some frequently used reference genes in tomato, it has been shown that the expressions of some of these genes are not constant in different t...     

Change of synapsins in hippocampal formation during spacial learning and memory in rats

AIM and METHODS: The immunohistochemical method was used to study the on synapsin express in hippocampal formation during spatial learning and memory in rats.RESULTS: (1) In control group there are diffuse brown granules without any obvious granular product in hippocampal formation and in model group there are synapsin products in the hippocampal formation ,especially in the subregion CA3 , CA4 and the dentate gyrus after water maze trained for one week. After two weeks water maze trained the hippocampal formation appear the same distribution of the product granules with darker staining. (2) The light dendity of synapsin products between the model and the control groups showed significant differences, that in the model group was highter than that in the control group (P＜0.05). The light dendity of synapsin products increased with the training time from the first week to the second week in the model group. And there is no increase with the training time from the second week to the third week . The light dendity is higher in the CA3, CA4 subregion and the dentate gyrus than the CA1 and CA2 subregion (P＜0.05).CONCLUSIONS: (1) As mentioned above, it is believed that the new synapes are formed in the hippocampal formation of the rat by spacial learning and memory training. (2) The CA3, CA4 subregion and the dentate gyrus are correlated with the spacial learning and memory.     

白足蚜小蜂对桃蚜的取食和寄生功能反应及搜寻效应

为评估白足蚜小蜂Aphelinus albipodus对桃蚜Myzus persicae的防控效果,在室内测定了白足蚜小蜂对不同发育阶段桃蚜的功能反应和搜寻效应,并对种内干扰和分摊竞争强度进行了比较。结果表明:白足蚜小蜂对不同发育阶段桃蚜的取食量和寄生量均随着蚜虫密度增加而增加,取食量和寄生功能反应均符合HollingⅡ模型。白足蚜小蜂对桃蚜的理论最大取食量2.809头,瞬时攻击率0.218,处理时间0.023 d;白足蚜小蜂对3～4日龄桃蚜寄生量最大,为47.62头,寄生瞬时攻击率0.723,处理时间0.021 d。搜寻效应均随蚜虫密度的增加而下降,且与蚜虫密度呈负相关。白足蚜小蜂个体之间存在种内干扰作用,随着自身密度增加,单头寄生率相对下降,分摊竞争强度增大,干扰效应符合Hassell-varley模型。由功能反应、种内干扰等指标可见白足蚜小蜂对桃蚜具有较好的防控作用。     

高压电场下不同位置处土豆片水分的变化规律

在20。~25℃,相对湿度40%±10%的室温环境下,对烫漂后的土豆试样进行了高压电场干燥实验。实验采用单针-盘(圆盘直径260mm)电极系统,交流电压V=(20±0.1)kV,电极间距离为60mm。同样的环境条件下也进行了土豆对比实验。结果表明:高压电场可使土豆的干燥速率明显加快,但由于针-盘电极形成电场不均匀性的影响,使电场中不同半径位置土豆试样的干燥速度不同,越靠近针电极正下方位置,土豆试样中水分干燥速度越快,而对比试样恰好相反,即越靠近中心位置水分干燥速度越慢。另外,针-盘电极电场存在有效的作用面积。     

不同基质对闭鞘姜生长发育和光合作用的影响

采用随机区组设计,研究不同配比的红壤、泥炭、椰糠和珍珠岩6种基质配方对闭鞘姜生长的影响。测定6种基质的物理和化学性质,观测萌芽率、叶片数、茎粗、株高、株幅、光合日变化、根茎鲜重和根茎干重。结果显示,基质S4（泥炭+椰糠+珍珠岩=1∶2∶2）的植株净光合速率（P_n）显著高于其他基质处理。在6种基质生长的植株叶片净光合速率曲线呈单峰或双峰变化,而蒸腾速率曲线呈单峰变化。最大株高、最大根茎鲜重和根茎干重也出现在基质S4种植的植株。从以上结果可知,基质S4比较适合闭鞘姜的生长和根状茎干物质积累。     

棉蚜对吡虫啉抗性的初步研究

用吡虫啉对棉蚜进行室内抗性筛选,用药处理25次后抗性是筛选前的20.03倍;2007年对田间棉蚜进行抗性调查,发现不同地区种群对吡虫啉的抗性差异显著,江苏南京种群最为敏感,河南安阳、山东泰安和北京地区棉蚜与之相比,抗性分别为2.21、7.63和9.53倍;抗、感品系解毒酶活力分析发现,抗性品系的谷胱甘肽S-转移酶活性增加很少(比活力1.12倍),但酯酶活力显著高于敏感品系(比活力1.71倍);增效试验结果表明,顺丁烯二酸二乙酯(DEM)在抗、感品系中对吡虫啉均没有明显的增效作用,而磷酸三苯酯(TPP)和增效醚(PBO)虽然在敏感品系中对吡虫啉的增效作用较小(SR 1.24和1.29),但在抗性品系中的增效作用显著增高(SR 2.13和1.74);此外还发现,吡虫啉处理可提高棉蚜群体的酯酶活力。由此认为,棉蚜至少具有对吡虫啉产生中等水平抗性的风险,其抗性可能是由于棉蚜的酯酶和P450单加氧酶的解毒能力提高所致。     

花生籽仁蔗糖含量多世代联合群体主基因+多基因遗传模型分析

花生是重要的油料和经济作物,在世界范围内广泛种植.甜味是与花生口感及风味高度相关的遗传性状,花生的甜味主要来源于花生籽仁中的蔗糖,蔗糖含量达到6％以上时,其口感及风味较好.因此,提高花生籽仁的蔗糖含量是改善花生口感及风味的关键因素之一.但迄今为止,对花生籽仁蔗糖含量的遗传分析未见报道.本研究以2组高、低花生籽仁蔗糖含量...     

化隆县林草地鼠虫害调查及防治

就化隆县林草地带鼠虫害发生及防治情况进行了总结,指出了存在的问题,并就今后防治情况提出了建议。