The disease complex Beet necrotic yellow vein virus and Beet soil borne mosaic virus on Beta vulgaris , Analysis of viral molecular biology, interactions and resistance stability in Beta vulgaris (Molecular Benyvirus-Interactions and Evolution in Sugarbee

甜菜坏死黄脉病毒(BNYVV)和甜菜土传花叶病毒(BSBMV)属于本尼病毒属，序列同源性较高。这两个物种都能引起甜菜病毒病，并表现出不同的症状表达和组织特异性定殖。BNYVV引起根瘤病，而BSBMV引起叶花叶症状。与仅限于根的BNYVV不同，BSBMV能系统侵染甜菜。虽然BNYVV是由自然抗性基因控制的，但尚未发现类似的性状对BSBMV起作用。这一现象的分子基础尚不清楚。天然BNYVV来源的耐久性有限，因为出现了抗药性破坏的变种。在自然条件下，这两种病毒都会在甜菜中混合感染。关于可能的对抗性相互作用的知识相当有限。到目前为止，还没有关于常见的定植组织或排斥、重组体的形成以及重组体的信息，这有望对病毒的进化产生影响。在前期工作中，这两种病毒的荧光标记感染性克隆的建立，现在第一次允许进行分子病毒学实验来回答这些问题。首先应利用病毒突变体和荧光标记病毒，在显微镜下研究甜菜病毒症状表达、寄主专化性长距离移动和系统定殖的分子原因。此外，还将分析两个物种在混合感染中的相互作用。这包括对组织特异性定植的调查，对可能的协同作用、拮抗或交叉保护的检测，以及对可能形成的种间重组体和重组体的分析。此外，它的目的是建立一个更好的理解寄主-病原菌相互作用依赖于病毒种类和植物抗性特性。我们计划破译物种特有的叶和根症状的分子原因，以及通过自然抗性机制对BNYVV的特异性控制。在BNYVV抗性的自然抗性稳定性领域，应开发量化病毒群体选择压力的方法，以选择抗性打破分离物。所获得的结果将有助于对本尼病毒的病原学、进化和相互作用产生基本和深入的了解，并从长期角度来看，将允许有重点和改进的耐药性管理。

Beet necrotic yellow vein virus (BNYVV) and Beet soil borne mosaic virus (BSBMV) are members of the genus Benyvirus with relatively high sequence homology. Both species induce virus diseases in sugar beet (Beta vulgaris) with variable symptom expression and tissue specific colonization. BNYVV induces rhizomania, whereas BSBMV produces leaf mosaic symptoms. In contrast to BNYVV that is limited to roots, BSBMV is able to infect sugar beet systemically. Whereas BNYVV is controlled by natural resistance genes, no similar traits are known to act against BSBMV. The molecular basis for this remains unknown. Natural BNYVV sources have limited durability due to the occurrence of resistance breaking variants. Under natural conditions, both viruses occur in sugar beet in mixed infections. Knowledge about possible antagonistic interactions is quite limited. So far, no information is available about commonly colonized tissue or exclusion, the formation of reassortants as well as recombinants, which is expected to have an influence on virus evolution. The establishment of fluorescently labeled infectious clones of both viruses during preliminary work now permits for the first time to perform molecular virological experiments answering these questions. At first the molecular causes for viral symptom expression, host specific long distance movement and systemic colonization in sugar beet shall be revealed in microscopical studies by use of virus mutants and fluorescently labeled viruses. More the interaction of both species in mixed infections will be analysed. This includes investigations of tissue-specific colonization, detection of a possible synergism, antagonism or cross protection as well the analysis of putatively formed interspecies reassortants and recombinants. In addition it is aimed to establish a better understanding of the host-pathogen interaction depending on virus species and plant resistance traits. We plan to decipher the molecular causes of species specific leaf and root symptoms as well as the specific control of BNYVV by natural resistance mechanisms. In the field of BNYVV resistance stability of natural resistance, methods to quantify the selection pressure on the virus population to select resistance breaking isolates shall be developed. The results obtained will help to generate a fundamental and deepened understanding of viral etiology, evolution and interaction of Benyviruses and on a long term perspective will permit a focused and improved resistance management.