核桃楸花粉活力测定方法比较

为建立核桃楸高效快速的花粉活力测定方法,分别采用了TCC染色法、I2-KI染色法和固体培养基萌发法对核桃楸花粉活力进行了测定比较。结果表明:采用TCC染色法和I2-KI染色法染色后花粉的不易辨识,测定结果偏低,不适合作为核桃楸花粉活力的测定方法;固体培养基萌发法辨识度高,萌发率高,适合作为核桃楸花粉活力的测定方法。     

平榛花粉活力测定方法比较

采用TCC染色法、I2-KI染色法和固体培养基萌发法等3种常见的花粉活力测定方法对新采集的平榛花粉进行活力测定,结果表明:采用TCC染色法和I2-KI染色法染色后花粉的辨识度低,影响对花粉活力的判断;固体培养基萌发法辨识度高,萌发率高,适合作为平榛花粉活力测定方法。     

利用CTC染色进行猪精子不同体外获能方法的比较

为了探讨不同方法对猪精子体外获能的影响,本试验以猪的新鲜精液为研究对象,分别经肝素上游法、钙离子载体诱导法和咖啡因诱导法进行精子不同获能时间的处理,并利用金霉素荧光染色法（chlortetracycline,CTC）对其获能效果进行检验。结果表明,采用肝素上游法孵育40 min处理后,精子的获能比例显著高于其他各处理组（P<0.05）,说明肝素上游法可以较好地诱发猪精子在体外获能。     

节节麦对铝的耐性评价

为了评价节节麦在普通小麦耐铝方面的应用价值,设置了pH4.50和pH4.50+50/μmol/L Al3+"以及pH4.50+100μmol/L Al3+3种水培营养液处理45份节节麦.结果表明,再生根伸长量以及耐铝指数在节节麦居群间存在较大的遗传变异.再生根伸长量以pH4.50的最长,pH4.50+100μmol/L Al3+的最短,pH 4.50+50μmol/L Al3+的居中.pH4.50+50μmol/L Al3+的耐铝指数变异范围为0.18～0.49,平均值为0.33.pH4.50+100μmol/L Al3+的耐铝指数变异范围为0.09～0.32,平均值为0.18;节节麦材料在50μmol/L Al3+的苏木精染色除As 65和As 88的染色程度相对较轻(为2级)外,其余染色均较深(为3级),而中国春的染色程度更轻(为1级);综合耐铝指数以及苏木精染色结果认为,所有节节麦都不耐铝,发现耐铝节节麦可能性较小.因此,节节麦可能不是小麦的耐铝抗源之-.     

Histopathological assessment of wheat seedling tissues infected by Fusarium pseudograminearum

Histopathological assessment of infection by the crown rot pathogen Fusarium pseudograminearum in wheat seedling tissues was performed using fluorescence microscopy. The coleoptiles and leaf sheaths of four host cultivars of differing susceptibility were examined. Leaf sheaths were most frequently penetrated via stomata, indicated by initial lesions forming at the guard cells. Internally, cell wall penetration was facilitated by penetration structures which appeared as hyphal swellings or septate foot‐shaped appressoria. Colonization of leaf sheaths resulted in the re‐emergence of hyphae from stomata on both surfaces of the sheath. These hyphae are hypothesized to have two major roles; first as exploratory hyphae for colonization of new tissues, and secondly as sites of profuse conidial production. The formation of conidia on the leaf sheath surface was only recorded on the most susceptible bread wheat genotype. No other major differences in host–pathogen interactions were observed among these cultivars. Almost all cell types in the leaf sheath tissues were extensively colonized, except for the vascular bundles and silica cells. This investigation provides the first comprehensive assessment of F. pseudograminearum infection structures and growth patterns during the infection of wheat seedlings.     

Isolation and characterization of Streptomyces species from potato common scab lesions in Norway

The present survey was conducted to isolate and characterize Streptomyces species from common scab lesions of potato in Norway. Bacteria were isolated from scab lesions on tubers sampled in two consecutive years at different locations in Norway spanning ～1400 km from south to north. In total, 957 independent isolations from individual tubers were performed, with 223 putative pathogenic isolates obtained from 29 different potato cultivars and 130 different fields. Streptomyces europaeiscabiei was the most abundant species isolated from common scab lesions (69%), while 31% of the isolates obtained were S. turgidiscabies. Streptomyces scabies was not found. Pathogenicity of selected Streptomyces isolates was tested on potato. The ability of the bacterial isolates to infect potato was consistent with the presence of the txtAB operon. The results revealed no pattern in geographical distribution of S. europaeiscabiei and S. turgidiscabies; both could be found in the same field and even the same lesion. Four different pathogenicity island (PAI) genotypes were detected amongst the txtAB positive isolates: nec1+/tomA+, nec1–/tomA+, nec1+/tomA? and nec1?/tomA?. The current findings demonstrate that there is genetic variability within species and that the species are not spread solely by clonal expansion. This is thought to be the most comprehensive survey of Streptomyces species that cause common scab of potato in a European country.     

东方蝾螈、太行隆肛蛙、丽纹龙蜥心脏的比较组织学研究

采用H．E．染色、显微镜观察法对东方蝾螈、太行隆肛蛙、丽纹龙蜥的心脏进行研究．结果显示：东方蝾螈、太行隆肛蛙心脏结构基本相同,丽纹龙蜥的心脏与二者有一定差别．3种动物的心脏均为两心房一心室,但丽纹龙蜥的心室开始出现不完全分隔,为不完全的双循环系统;红细胞均为有核红细胞;心脏壁有内、中、外3层结构,分别为心内膜、心肌层及心外膜．心内膜位于心脏内层,表面是一层不规则的多角形内皮细胞,胞核为椭圆形．心肌层主要由心肌纤维构成,心肌纤维间充满结缔组织和血管．心肌纤维由心肌细胞组成,胞核呈圆形或椭圆形,位于细胞中央．心外膜位于外层,由结缔组织构成,内含较多弹性纤维．3种动物心脏结构的差别是两栖类、爬行类动物在进化过程中对环境不断适应的结果．     

土壤性质对入渗再分布影响的显色示踪试验研究

同时使用染色剂和碘离子作为示踪剂,染色剂用于示踪大孔隙通道,根据碘-淀粉显色反应确定实际流动模式。开展了6组试验,研究了土壤大孔隙特征和非均匀流动特性,比较了粉土和粘土2种土壤,入渗水量分别为20、40、60和80 mm以及不同流动边界条件下的土壤水和溶质再分布特性。实验资料显示,入渗水再分布主要受到湿润模式的影响。入渗水量较小的情况下,水流运动主要发生在大孔隙中,随着入渗水量增大,入渗模式与孔隙发育表现出显著的区别,随着入渗水量的增加,水流运动非均匀性表现出先增加,随后减小的趋势。溶质迁移非均匀性取决于水流非均匀流动特性,然而表现出更多的不确定性。     

花生种子发芽率快速测定法

用TTC氯化三苯四氮唑)染色法和红墨水染色法对35份花生品种进行种子生活力的测定,并与其发芽率比较,研究结果表明,TTC法和红墨水法测定的种子生活力和发芽率之间存在极显著的正相关关系。TTC染色法和红墨水法都可用于花生种子发芽率的快速测定,其中TTC染色法的测定结果可靠性高于红墨水染色法。