MAGNETIC RESONANCE IMAGING FEATURES OF MULTILOBULAR OSTEOCHONDROSARCOMA IN 3 DOGS

Three dogs with multilobular osteochondrosarcoma of the skull were evaluated using magnetic resonance (MR) imaging. Spin echo T1, T2, proton weighted and post contrast T1W images were obtained with a 1.5 Tesla magnet. The MR imaging findings were similar in all three dogs with mixed signal intensities in the T1W, T2W and proton weighted images and fairly large areas of contrast enhancement in the post contrast T1W images. The extent of brain and soft tissue involvement were well delineated and provided useful information concerning surgical planning. MR imaging provided a useful method of evaluating dogs with skull tumors.     

桑萎缩病病原类菌原体的提纯、致病性及抗血清制备研究

用0．3mol／L甘氨酸缓冲液从病桑嫩叶提取病原类菌原体（MLO）,提取液上清经硅藻土柱层析分离,其洗脱液用高速离心浓缩,制备成部分纯化的病原MLO提纯物。采用显微注射技术,将提纯病原注射到介体昆虫体内,使病原在昆虫体内繁殖,再将获毒虫放饲在健桑苗上传毒接种,获得表现典型萎缩病症状的病株。病柔韧皮部筛管细胞的超薄切片在电镜下观察到大量病原MLO粒子,证实提纯MLO具致病性。同时用提纯病原为免疫抗原制备兔抗血清,抗血清用健桑提取液吸收后,获得仅与病桑抗原产生反应的特异抗血清,免疫电泳测验、仅产生一条沉淀带。     

烟草丛枝病蚜虫传毒的超微结构研究

 于典型烟草丛枝病病株上采集的蚜虫,经布安氏固定液及戊二醛固定液固定,次甲兰染色或不染色。取其唾液腺,经常规戊二醛、锇酸双重固定,丙酮脱水,Epon812包埋,聚合,超薄切片,电子染色后,于电镜下观察。在蚜虫唾液腺细胞内观察到大量烟草丛枝病病原MLO的聚集。健康烟株上饲养的第2代蚜虫唾液腺细胞内未检测到类似病原。     

新疆柳树丛枝病类菌原体(MLO)的电镜观察

本文报道新疆柳树丛枝病病原在透射电镜下的观察结果,在病枝韧皮部薄壁细胞、叶脉韧皮部筛管和伴胞细胞中均观察到典型的类前原体,其形状为球形、长椭圆形和哑铃型,细胞膜为双层膜结构,大小比一般的类菌原体稍小。初步认为此病是类菌原体引起的病害。     

Identification and expression analysis of the Pbr MLO gene family in pear,and functional verification of PbrMLO23

Mildew resistance locus O(MLO) is a plant-specific gene family that plays an important role in the growth and development of plants and their interactions with the environment. However, the available information on this gene family in pear is limited. Here, 24 PbrMLO genes were identified and divided into five subfamilies(I, II, III, IV and V). Wholegenome duplication(WGD) and dispersed duplication contributed to the expansion of the PbrMLO family. In addition, gene expression analysis revealed that PbrMLO genes were distributed in various pear tissues, suggesting their diverse functions. We selected PbrMLO23 for further functional analysis. Expression profile analysis by qRT-PCR showed that PbrMLO23 was highly expressed in pollen. Subcellular localization analysis showed that PbrMLO23 was located on the plasma membrane. When the expression level of PbrMLO23 was knocked down by using antisense oligonucleotides, pollen tube lengths increased, indicating that PbrMLO23 plays a functional role in inhibiting pollen tube growth. In summary, these results provide evolutionary insight into PbrMLO and its functional characteristics and lay a foundation for further analysis of the functions of PbrMLO members in pear.     

泡桐属不同种和种源对丛枝病抗性调查

调查表明，泡桐属所有的种和无性系均感染丛枝病（Phytoplasma-MLO），但感染的程度不同。在调查中发现一种高抗类型，其特征是叶背毛密而高大，毛为具长柄的树状毛、具长柄大腺细胞的腺毛、长柄叉状毛和单枝毛，这类毛粘性很大。该类型泡桐抗病的主要机制是抗传毒的媒介昆虫之故。     

泡桐对丛枝病原MLO的抗性研究*

本试验通过试验林自然发病调查、病根苗抗病性测定及ＤＡＰＩ染色等方法，对不同无性系及杂交组合的泡桐试材抗病性进行了评估。结果表明，５－７年生泡桐自然感染ＭＬＯ后的地面部分发病现象可归纳为四种类型；丛枝型（ＷＢ）、黄化型（Ｙ）、丛枝黄化型（ＷＢ＋Ｙ）和丛枝花变叶型（ＷＢ＋Ｐ）。外部发病差异与其韧皮部筛管中ＭＬＯ的含量有直接联系。一般情况下，ＭＬＯ的浓度高低依次为花变叶部位、丛枝部位、黄化部位、无症或健     

泡桐丛枝病类菌原体(MLO)病原传染长春花研究初报

菟丝子(Cuscuta spp.)是一种寄生植物,利用菟丝子为介体可以将植物病毒或类菌原体(mycoplasma like organism)从一株植物传染到另一株植物上。杨一朗陈景耀分别用大豆菟丝子和南方菟丝子为媒介成功地将甘薯丛枝病从甘薯传到长春花上,产生花器叶化、侧枝丛生病状。     

槟榔黄化病的病原的研究初报

槟榔黄化病的病原的研究初报金开璇，孙福生（中国林业科学研究院森林保护研究所北京１０００９１）陈慕容，罗大全（华南热带作物科学研究院植物保护研究所儋州市５７１５３７）蔡希灼（美国佛罗里达州立大学）关键词黄化病，槟榔，类菌原体，类细菌摈榔（Ａｒ。ｃａｏａ...