皖西白鹅淋巴器官的解剖观察

对４０只成年的和１００只性成熟前不同发育阶段的皖西白鹅（公母各半）,放血致死,标本用１０％福尔马林溶液固定１个月后,通过肉眼和放大镜观察了其淋巴器官（包括胸腺、法氏囊、脾脏、颈胸淋巴结和腰淋巴结）的解剖位置、形态特征,测量了各淋巴器官的大小和重量。     

Monoclonal antibodies against the aster yellows agent

Hybridoma clones secreting specific monoclonal antibodies against the aster yellows agent, a mycoplasma-like organism, were produced by using partially purified salivary gland preparations from infected leafhopper vectors as the immunogen. After 3947 hybridomas from 20 independent fusions were screened for specific antibody against the aster yellows agent, two table clones were obtained. With these monoclonal antibodies the aster yellows agent in diseased lettuce, periwinkles, and inoculative insects was specifically identified by enzyme-linked immunosorbent assay. The aster yellows agent was serologically differentiated from the mycoplasma-like organisms associated with ash yellows, loofah witches'-broom, paulownia witches'-broom, sweet potato witches'-broom, peanut rosette, maize bushy stunt, and elm phloem necrosis.     

Colonization of Bacillus cereus NJSZ-13,a species with nematicidal activity in Masson pine(Pinus massoniana Lamb.)

Bacillus cereus NJSZ-13,an endophytic bacterium with nematicidal activity,was isolated from stems of healthy Pinus elliottii Engelm.Colonization of P.massoniana Lamb.by endophytic B.cereus was studied using scanning electron microscopy and confocal laser scanning microscopy.After the plasmid p GFP78 containing the green fluorescent protein(GFP)gene was transformed into the NJSZ-13 strain,the NJSZ-13:gfp showed the same nematicidal activity and growth curve as the wild-type strain,and the plasmid p GFP78 was stably maintained in strain NJSZ-13 for at least 96 h of bacterial cultivation on medium without antibiotics.After inoculation into Masson pine roots,colonization of the NJSZ-13:gfp strain in plant roots and stems was visualized using confocal laser scanning and the strain was enumerated in inoculated roots and stems.These results suggest that NJSZ-13:gfp is an efficient colonizer of Masson pine and can transfer vertically from roots to stems.     

Natural infectious behavior of the urediniospores of Melampsora larici-populina on poplar leaves

The uredinial stage in the life cycle of Melampsora larici-populina on poplar leaves is the most important pathogenic phase. We captured partial phases of uredinial infection in the wild, aiming to reconstruct the process of uredinial ontogeny by using scanning and transmission electron microscope. At the initial infection stage, germ tubes germinated from the echinulate urediniospores. Germ tubes were frequently seen to merge with the leaf surface and cuticle breakage was observed, indicating direct hyphal penetration. Stomata penetration occurred commonly, sometimes with more than one germ tube penetrating the same stoma. Melampsora larici-populina did not form appressoria in the infection process,implying that infectious behavior of this pathogen may differ from the other rust pathogens. In general, germ tubes branched randomly, and no distinct evidence indicated that stoma could induce or orient germ tube branches. However, oriented germ tube growth has been occasionally observed in other studies. The urediniospores collapsed and finally wizened when they became nutrient stressed. At the last stage of infection, the uredinia erupted from the leaf epidermis and appeared as orange pustules on the leaf surface.     

GC02球虫病疫苗对鸡腔上囊发育的影响

将80只1日龄健康雏鸡随机分为GC02球虫病疫苗组（试验组）和对照组（n=40）。试验组鸡于7日龄和14日龄分别口服含8000个孢子化卵囊的GC02球虫病疫苗，对照组鸡口服生理盐水。于21、28、35和42日龄每组随机选取10只鸡，空腹称量体重，颈动、静脉放血致死，立即解剖取腔上囊称重并制作石蜡切片，光学显微镜下观察与拍照，研究了GC02球虫病疫苗对鸡腔上囊发育的影响。结果，试验组鸡腔上囊器官指数低于同日龄对照组，其中28-42日龄鸡的腔上囊器官指数显著或极显著低于对照组（P〈0．05或P〈0．01）。与对照组同日龄鸡相比，试验组鸡免疫GC02球虫病疫苗后，各日龄鸡腔上囊均表现出不同程度的病理组织学变化。试验组雏鸡腔上囊组织结构出现轻微损伤，GC02球虫病疫苗刺激了机体的免疫系统，增加了免疫效果。试验结果提示，GC02球虫病疫苗对雏鸡腔上囊发育有一定的抑制作用，对其组织结构有轻微损伤作用。     

采用甘蓝型油菜离体小孢子染色体加倍来提高双单倍体植株的生产效率

该文比较了甘蓝型油菜小孢子产生植株染色体加倍的三种方法；秋水仙碱处理小孢子再生植株，秋水仙碱处理小孢子诱导的胚和秋水仙碱处理离体小孢子。处理整株，有５３％的处理植株结实，但植株生长迟缓，结实率下降。用秋水仙碱处理小孢子诱导胚，植株加倍率为３２％。秋水仙碱直接处理离体小孢子可使７０％的植株整体加倍，同时还刺激了培养小孢子的胚胎发生，从而提高植株再生率。     

Synthesis and antityrosinase mechanism of benzaldehyde thiosemicarbazones: novel tyrosinase inhibitors

p-Hydroxybenzaldehyde thiosemicarbazone (HBT) and p-methoxybenzaldehyde thiosemicarbazone (MBT) were synthesized and established by (1)H NMR and mass spectra. Both compounds were evaluated for their inhibition activities on mushroom tyrosinase and free-cell tyrosinase and melanoma production from B(16) mouse melanoma cells. Results showed that both compounds exhibited significant inhibitory effects on the enzyme activities. HBT and MBT decreased the steady state of the monophenolase activity sharply, and the IC(50) values were estimated as 0.76 and 7.0 μM, respectively. MBT lengthened the lag time, but HBT could not. HBT and MBT inhibited diphenolase activity dose-dependently, and their IC(50) values were estimated as 3.80 and 2.62 μM, respectively. Kinetic analyses showed that inhibition type by both compounds was reversible and their mechanisms were mixed-type. Their inhibition constants were also determined and compared. The research may supply the basis for the development of new food preservatives and cosmetic additives.