一株鹅副粘病毒分离株的增殖最佳条件及其致病性研究

为了探讨鹅副粘病毒在鸡胚中增殖的最佳条件及其致病性,将不同血凝滴度的鹅副粘病毒分别接种于9～11日龄鸡胚尿囊腔,收获孵化36、48、60、72和84 h的鸡胚尿囊液,测定血凝滴度。结果表明将血凝价为1∶64的鹅副粘病毒稀释50倍后,接种9日龄鸡胚,37℃培养48～72 h获得的尿囊液血凝价可达1∶256～1∶512,平均尿囊液量可达9.4 mL/胚。动物试验表明增殖获得的鸡胚尿囊液具有较强的致病性,将该尿囊液接种10日龄鸡胚和颈部皮下注射21日龄非免疫雏鹅,结果接种后鸡胚于30～48 h全部死亡。雏鹅平均死亡时间为62.6 h。特征性剖检病变为脾脏肿大,有灰白色坏死点;胰脏出血,有灰白色坏死点;肠道出血,溃疡;病料分离培养的病毒液HA价高达28,能凝集鸡红细胞,并出现解凝现象。     

Evaluation of the Ph‐3 gene‐specific marker developed for marker‐assisted selection of late blight‐resistant tomato

Late blight caused by Phytophthora infestans is one of the most destructive diseases of tomato (Solanum lycopersicum L.) that mainly occurs in cool and wet environments. With the spread of the A2 mating type and new clonal lineages, fewer fungicides provide effective control of the disease, which has increased its worldwide threat. Host resistance could contribute significantly to sustainable disease control. Ph‐3 is a race‐specific late blight resistance gene commonly used in commercial tomato breeding. Availability of precise and easy to use gene‐based markers would facilitate selection. In this study, a Ph‐3 on‐gene cleaved amplified polymorphic sequence (CAPS) marker, Ph3.gsm/HincII, was developed based on the published gene sequence of Ph‐3. The effectiveness of the marker was evaluated along with other published Ph‐3 markers using an F₉ recombinant inbred line (RIL) population derived from NC 23E‐2(93) × L3708. Markers Ph3.gsm/HincII and TG328/BstNI accurately genotyped the RIL population for Ph‐3. In addition, Ph3.gsm/HincII was able to differentiate variable susceptible alleles. This reliable codominant DNA marker would be very useful in marker‐assisted selection, particularly for resistance gene pyramiding.     

副猪嗜血杆菌中毒素蛋白基因hipA的生物信息学分析

为预测毒素蛋白HipA的二级结构和B细胞抗原表位,首先从GenBank中查找副猪嗜血杆菌毒素蛋白基因hipA的序列,应用生物信息学方法,对副猪嗜血杆菌毒素蛋白HipA的理化性质、二级结构和B细胞抗原表位进行预测。结果显示,HipA蛋白的理论等电点为7.23,前50个氨基酸为信号肽,二级结构的预测结果显示该酶主要以α螺旋、无规则卷曲和延伸链为主,只有少数的β转角;推测该蛋白有17个B细胞优势抗原表位区域。该研究为进一步研究分析副猪嗜血杆菌毒素蛋白HipA的功能奠定理论基础。     

Applications of polysaccharides (β-glucan) for physiological and biochemical parameters for evaluation rice tolerance under salinity stress at seedling stage

Salt stress is considered to be the most important abiotic stress and is the main problem in the interruption of the metabolic processes of plants, thereby limiting crop production. The present study was carried out to examine the effects of exogenously applied mushroom polysaccharides (β-glucan) on the growth of two rice varieties of Oryza sativa L. (MRQ74 and MR269) seedlings grown in vitro in 200 Mm sodium chloride (NaCl). Growth characteristics, including shoot and root height, and fresh and dry weight of salt-stressed rice seedlings were inhibited by sodium chloride treatment, the degree of which depends on the rice variety. The negative effects of salinity stress resulted in an imbalance of N, K⁺ Na⁺ and Na/K ratios and biochemical analysis activities a degradation of chlorophyll content in the plants. However, treatment with exogenously applied polysaccharides (β-glucan) ameliorated the stress generated by NaCl and improved the parameters mentioned above. The significance of the changes in growth and metabolism to salt stress tolerance in rice seedlings are discussed in the paper.     

甜菜黑色焦枯病毒经甘蓝油壶菌传播的研究

用甜菜黑色焦枯病毒（Ｂｅｅｔ Ｂｌａｃｋ Ｓｃｏｒｃｈ Ｖｉｒｕｓ,ＢＢＳＶ）直接接种甜菜根,ＢＢＳＶ轻度侵染甜菜;而将ＢＢＳＶ与某蓝油壶菌（Ｏｌｐｉｄｉｕｍ ｂｒａｓｓｉｃａｅ）游动孢子体外混合接种甜菜根,ＢＢＳＶ则严重侵染。结果表明,ＢＢＳＶ经由Ｏ．ｂｒａｓｓｉｃａｅ进行传播,传播方式属游动孢子体表带毒,另外,ＢＢＳＶ也可进行少量的机械传播。国内首次报道油壶菌传播植物病毒。     

光质对小苍兰茎尖试管培养的影响

以小苍兰茎尖为外植体，分别置于白光（４００～６９０ｎｍ）、红光（５９０～６９０ｎｍ）、黄光（５２０～６４０ｎｍ）、蓝光（４００～５３０ｎｍ）、绿光（５００～５９０ｎｍ）和黑暗下培养，研究不同光质对小苍兰茎尖试管培养的影响。结果表明：白光下愈伤组织及芽的分化速度最快，芽的分化率和生物量最高，试管苗叶片数多、生长良好，但愈伤组织诱导率及根分化受到明显的抑制；红光下根的分化速度最快，根分化率及综合培养力最高；蓝光对愈伤组织诱导率、叶绿素含量以及试管苗的干重／生物量有明显的促进；绿光和黑暗对茎尖的分化与生长均有不利影响，试管苗出现玻璃化现象。     

河北省沧洲市园林绿化树种调查与树种选择

二次赴重盐碱地城市沧州市进行绿化树种调查，共调查树木１３４７株，分属２１科４７属。分析调查结果，并据沧州市的自然概况，选择沧州市的基调树种和各类型绿地的骨干树种。     

断奶后放牧羔羊补饲瘤胃缓释尿素的试验

采用反刍动物最新非蛋白氮饲料－缓释尿素及尿素、豆粕３个处理补饲东北细毛羔羊，与单纯放牧的幼羊比较，均有明显的促增重效果。但３个处理间差异不显著（Ｐ〉０．０５）。由于瘤胃缓释尿素的单位成本低于豆粕，所以用其代替豆粕可降低育肥成本。     

樟子松种子败育与形态解剖的研究

1987～1989年对净月潭樟子松种子园种子败育进行形态解剖观察,确定了胚珠、雌配子体,胚败育的形态特征及发生时间和比重。与宏观调查比较研究,得知产生败育的主要原因是养分竞争和授粉不良。     

牦牛出血性败血症的病原分离与鉴定

巴氏杆菌病是由多杀性巴氏杆菌引起的一类多种动物共患的一种急性、热性传染病,急性病例以败血症和出血性炎症为主要特征。