Studies on Neospora caninum DNA detection in the oocytes and embryos collected from infected cows

Neosporosis is a major cause of abortion in cattle over the world. One of the methods of preventing vertical transmission within the herd is to avoid breeding replacement heifers from infected dams. Another procedure suggested and recommended by the International Embryo Transfer Society (IETS) is embryo transfer (ET) from infected dams into uninfected recipients. Oocytes and embryos taken from seropositive cows were examined for the presence of Neospora caninum DNA. A modified PCR protocol using Np21 and Np6 primers was applied to detect parasite DNA in the samples. The expected 328 bp product was not obtained in oocytes and/or embryos collected from seropositive dams. The results confirmed that transfer of the embryos from seropositive donors into seronegative recipients is an appropriate method to eliminate vertical transmission of neosporosis in a herd. The present study demonstrated that oocytes and embryos are not exposed to N. caninum in the uterine cavity of seropositive dams.     

辣椒的离体培养与遗传转化

综述了辣椒离体培养和遗传转化的研究进展。通过幼苗外植体培养、原生质体培养和花药培养三条途径建立辣椒离体再生系统。通过根癌农杆菌的Ti质粒和电激法，成功地介导子叶和原生质作进行遗传转化，获得转基因植株。还讨论了辣椒离休培养和遗传转化中存在的主要问题。     

光照强度对石斛生长与代谢的影响

在石斛分蘖期 ,于 2 5℃下分别设 80、 16 0、 32 0、 6 4 0 μmol·m- 2 ·s- 1光照处理 ,研究其对石斛生长与代谢的影响。结果表明 :低光照强度有利于株高和可溶性蛋白质含量的增加 ,但增重少 ,繁殖率低 ,代谢较弱 ;随光照强度的提高 ,光合能力递增 ,但呼吸消耗也随之加大 ;6 4 0 μmol·m- 2 ·s- 1的强光照破坏了叶绿素的形成 ,叶绿素含量较 16 0 μmol·m- 2 ·s- 1处理降低 17.7% ,可溶性蛋白质与总糖含量显著下降 ,分别比 32 0 μmol·m- 2 ·s- 1处理低 2 7%和15% ;CAT活性明显降低 ,MDA含量与POD活性则显著提高 ,表明出现光抑制。因此 ,石斛生长的光照强度以 32 0 μmol·m- 2 ·s- 1为宜。     

Effect of wx genes on amylose content,physicochemical properties of wheat starch,and the suitability of waxy genotype for producing Chinese crisp sticks

The effect of wx genes on amylose content, physicochemical properties of wheat starches, and the quality of Chinese crisp stick were investigated using near-isogenic lines (NILs) with null wx alleles in Yangmai 17 and Yangmai 01-2 backgrounds. wx genes showed significant effects on amylose content and other traits. The triple-null genotype had the lowest amylose content among eight genotypes, followed by double-null, single-null, and wild-type genotypes. The triple-null also showed lower flour yield, higher percentage of type B-granules on a volume basis and higher crystallinity than non-waxy genotypes, and showed significant differences in all pasting and thermal transition parameters compared to non-waxy genotypes, except for degree of retrogradation at day 14. For the quality of Chinese crisp stick, the hardness, crispness, fracturability, and specific volume of waxy genotype were 3.91 kg, 11.0, 1.85 mm and 104.4 ml, whereas the corresponding ranges for non-waxy genotypes were 5.39–5.70 kg, 0.5–0.9, 0.69–0.86 mm and 49.5–57.6 ml, respectively, in Yangmai 17 background. This indicates that waxy genotypes showed significantly better crisp stick quality than non-waxy genotypes. A similar trend was also observed in Yangmai 01-2 background. This indicated the potential utilization of waxy wheat for producing traditional products.     

陆地棉纤维性状的遗传分析

利用生育期不同的陆地棉(G.hirsutum L.)亲本,配制了5个组合的 P_1,P_2,F_1,F_2,B_1,B_2各6个世代。应用多元分析法,对棉花纤维性状进行了遗传分析。结果表明:绒长整齐度、纤维宽度以加性效应为主;2.5%跨长、纤维细胞壁厚度由显性及上位效应控制;比强度以加性和显性和显性×显性效应为主;伸长率、麦克隆值、腔/壁和纤维素含量的遗体成份中,上位效应占有较比重。绒长整齐度和比强度、伸长率、麦克隆值、纤维宽度、纤维素含量间;比强度和伸长率,纤维素含量间;伸长率和麦克隆值、纤维素含量间;壁厚与纤维宽度间均呈极显著的正相关。整齐度与2.5%跨长间;麦克隆值与纤维素含量间;壁厚与腔壁/壁间均呈免相关或极显著的负相关。分析还表明:伸长率,整齐度和纤维素含量与比强度的关系最密切。     

药剂处理对苹果梨贮藏效果的影响

本试验在不同的贮藏条件下，采用仲丁胺１８号乳剂、仲丁胺２号片剂及氯化钙等药剂对苹果梨进行了贮藏试验。试验结果表明，采用单果包纸，并结合仲丁胺１８号乳剂和氯化钙处理，对控制平果梨贮藏过程中的损耗及腐烂有明显的效果。好果率提高４％－１０％，并能明显提高果实的品质，无药剂副作用。     

三倍体山杨苗期形态特征及生长节律的调查

通过对三倍体山扬苗期形态特征及生长节律的观测，发现该品种干形通直，分枝角度小，可提高林地生产力；其苗高、地径生长迅速，年均生长量分别为1．87m、1．77cm，是优良的山地造林树种；苗高、地径生长量的大小与气象因于密切相关，自6月中旬开始；随温度的升高，苗高生长逐渐增高，7月上旬达到高峰，之后随温度升高苗高生长呈下降趋势，地径生长较平稳；当8月上旬温度、降水达到高峰时，地径生长达到高峰，高生长缓慢，一些苗木受高温影响而封顶。     

北京市和浙江省设施西瓜蜜蜂授粉现状调查

为了解设施西瓜授粉的现状,加快蜜蜂授粉在西瓜生产中的推广,在我国南方与北方两个西瓜代表性产区-浙江、北京,通过调查问卷方式对农户进行了调查。内容主要包括设施西瓜栽培与蜜蜂授粉现状、农户对蜜蜂授粉认知、供需意愿及期望费用。结果表明,浙江与北京两地的农户对蜜蜂授粉的认知度高,但实际生产中蜜蜂授粉的应用比例仅占6%,限制西瓜蜜蜂授粉的因素主要是授粉费用偏高与组织推广缺乏。建议通过争取政府财政支持,加强农技推广,培育专业授粉蜂场来加快蜜蜂授粉的推广。     

三倍体山杨组培繁育技术的研究

通过对三倍体山杨组培繁殖的各主要技术环节及规模化育苗生产技术的研究,结果表明,取外植体休眠芽进行组织培养,以WPM 为基本培养基,附加不同量的细胞分裂素与生长素进行分化诱导,获得了丛状无根苗;以WPM 附加生长素诱导生根,或用ABT生根粉进行处理都能获得再生植株,简化了育苗程序。为了降低组培苗的成本,研究出了继代培养基二次再利用及用凉开水代替蒸馏水配制培养基技术;同时研究了试管苗的移植技术,使移植苗的成活率达到90% 。     

雷贝拉唑联合法莫替丁治疗胃食管反流病

目的:观察雷贝拉唑与法莫替丁联合治疗胃食管反流病(GERD)的疗效。方法:GERD患者89例随机分为治疗组(n=45)和对照组(n=44),两组每天早、晚餐前均服雷贝拉唑10mg,治疗组夜间睡前另加服法莫替丁20mg,疗程6周。治疗前及疗程结束后行胃镜检查,观察其胃镜表现及反流症状的改善程度。结果:治疗组45例中治愈31例,有效12例,无效2例,总有效率达95.6%(43/45),对照组44例中治愈22例,有效13例,无效9例,总有效率79.5%(35/44)。结论:雷贝拉唑与法莫替丁联合治疗GERD的疗效优于单用雷贝拉唑者。