协优57优质高产制种技术

系统探讨了杂交水稻协优５７的优质高产制种的规律,建立了协优５７高产制种的技术模型,同时为协青早Ａ系列组合的制种提供了技术参考。     

Identification of recombinants carrying stripe rust resistance gene Yr57 and adult plant stem rust resistance gene Sr2 through marker‐assisted selection

Many stem rust resistance genes have been formally named in wheat. Adult plant stem rust resistance gene Sr2 was mapped in the short‐arm of chromosome 3B. Stripe rust resistance gene Yr57, identified in Aus91463, was mapped about 5 cM away from Sr2 based on its linkage with Sr2‐linked marker gwm533. The objective of this study was to combine Sr2 and Yr57 in a single genotype. A mapping population containing 107 recombinant inbred lines was developed from a cross between Aus91463‐Yr57 and Hartog‐Sr2. This population was tested at the seedling stage in the glasshouse for variation in stripe rust response, and high temperature induced Sr2‐linked seedling chlorosis. The RIL population was screened for Sr2‐linked pseudo black chaff phenotype at the adult plant stage in field. Five recombinants carrying Sr2 and Yr57 in coupling were detected using phenotypic and marker data. Four recombinants also carried leaf rust resistance gene Lr23 from Aus91463. These recombinants are being used as triple rust resistance source in the Australian Cereal Rust Control Program.     

Compounds inhibitory to rat liver 5α-reductase from tropical commercial wood species: resveratrol trimers from melapi (Shorea sp.) heartwood

5-Reductase inhibitory activity of methanol extracts of the heartwood of 13 tropical wood species were examined. Strong 5-reductase inhibitory activity was observed withShorea species. From melapi (Shorea sp.), two known resveratrol trimers, vaticanol A and ampelopsin C, and two novel trimers were isolated as active compounds. The structures of the two novel resveratrol trimers were elucidated by one- and two-dimensional nuclear magnetic resonance spectroscopic analyses, including¹H-¹HCOSY, HMQC, and HMBC. The compounds were named melapinol A and melapinol B. There were no significant differences among the 5-reductase inhibitory activities of the four resveratrol trimers, which were significantly stronger than those of-linolenic acid and epigallocatechin gallate, known 5-reductase inhibitors.     

C57BL/6J小鼠亚慢性镉中毒模型的建立

为了建立小鼠亚慢性镉中毒模型,本研究将20只C57BL/6J雄性小鼠随机分为4个剂量组和溶剂对照组,每组隔天分别腹腔注射含0.25、0.5、1和2 mg/kg剂量的氯化镉溶液和等量去离子水(溶剂),共染毒4周,观察不同剂量的镉离子对雄性小鼠肝脏、肾脏、睾丸的损伤情况.结果各处理组小鼠体质量增长要比对照组慢,脏器系数与对照组相比也有显著差异,处理组小鼠肝脏、肾脏、睾丸中镉含量显著高于对照组.病理组织切片结果表明,各处理组中小鼠的肝脏、肾脏、睾丸组织均出现不同程度的损伤.氯化镉可以显著地抑制小鼠体质量增长,并对小鼠的脏器系数产生影响,腹腔注射后在肝脏、肾脏、睾丸组织中产生蓄积,并对其造成一定损伤.隔天腹腔注射2 mg/kg剂量的氯化镉,4周可建立较理想的小鼠镉中毒模型.     

KMC57F1小鼠卵丘细胞核的注射及其成功率观察

本文用在自制简易三维显微操作仪上,对KMC57F1小鼠卵丘细胞的核注射方法进行了研究,并对其注射成功率进行观察与分析.     

联合收割机后视障碍智能测试仪设计

分析了超声波测距系统的基本设计原理,较详细地介绍了超声波测距系统的软硬件设计。设计采用国内生产厂家的通用元件,成本低,性能可靠,有利于推广。     

New multilocus genotypes of <Emphasis Type="Italic">Phytophthora infestans</Emphasis> in Japan

Twelve isolates of Japanese Phytophthora infestans, which differed from the major genotypes US-1, JP-1, JP-2, and JP-3, were analyzed for RG57 fingerprints, mtDNA haplotypes, two allozyme genotypes, and mating types. Genotypes JP-1.1, JP-2.1, JP-2.2, JP-3.1, and JP-4 were newly defined. JP-1.1 and JP-2.1 were isolated discontinuously from potato fields in several years, and JP-1.1 was found in Hokkaido and Kagoshima. These results show that some minor genotypes can overwinter and disperse from their original site.     

短短芽孢杆菌A57菌株对棉花主要病原真菌的拮抗作用及其最佳液体发酵条件

研究了分离自棉花根际土壤的短短芽孢杆菌A57菌株对棉花立枯病菌、枯萎病菌和黄萎病菌的拮抗作用,在PDA平板上对峙培养,平均抑制率分别是33.5%、39.5%、29.5%。通过显微镜观察,发现拮抗细菌的主要拮抗机理是通过产生拮抗物质能够造成病原真菌菌丝体断裂、扭曲、畸形,抑制分生孢子的萌发,造成孢子畸形。以枯萎病菌为指示菌,研究了该菌株表现最佳拮抗活性时的菌液发酵条件,结果表明,A57适宜培养基为LB培养基,pH8,好气条件下抑菌活性最好。用硫酸铵沉淀法提取A57菌株的粗提蛋白,对供试的病原菌仍具有较高的拮抗活性,70%浓度时其拮抗活性最大,A57粗提蛋白对枯萎病原菌的最大抑制率为23.7%,同时该菌经硫酸铵沉淀后获得的粗体蛋白的上清液对病原指示菌仍具有一定的拮抗活性,说明A57拮抗细菌起拮抗作用的不仅有大分子蛋白类物质还有小分子拮抗物质。     

5种不同商品化的饲料对C57BL/6J和KM小鼠生长和繁殖的影响

研究市场上常见的5种饲料对C57BL/6J小鼠及KM小鼠生长和繁殖的影响,为实验小鼠生产中合理使用饲料提供科学依据.实验选取3周龄C57BL/6J小鼠和KM小鼠各250只,每种鼠随机分为5组,每组50只,雌雄各半,饲喂A,B,C,D,E共5种不同厂家的实验动物维持饲料,测定小鼠4～8周龄的体质量和脏器系数.另选取C57BL/6J小鼠及KM小鼠性成熟小鼠各150只,雌雄各半,每种鼠随机分为5组,每组15对,饲喂A,B,C,D,E共5种不同厂家的实验动物繁殖饲料,测定母鼠的产仔数、连胎率.结果表明:①5种维持饲料均能满足小鼠的生长需求, C饲料和E饲料更符合小鼠生长的营养需求.②5种饲料饲喂的小鼠器官指数正常.③5种繁殖饲料饲喂的母鼠第1,2胎的产仔数差异不具有统计学意义(p0.05),说明产仔数更多取决于遗传因素,本次调查的几种饲料对其影响较小.合理选择实验小鼠所需饲料,利于实验数据的稳定.     

高脂饲料诱发C57BL/6J小鼠非酒精性脂肪肝相关指标的动态观察

观察高脂饲料诱发的C57BL/6J小鼠血脂、转氨酶和肝脏脂质的动态变化.C57BL/6J分成基础饲料组和高脂饲料组,在给予高脂饲料后5、7、9、11周采血检测血脂、转氨酶,并制成10%肝匀浆检测肝脏脂质.取肝脏HE染色、油红O染色作病理学检查.结果表明,给予高脂饲料5周小鼠血脂TC和ALT显著升高,7～9周稳定,11周...