马铃薯茎溃疡病原菌毒素的鉴定及其作用机理研究

马铃薯茎溃疡的病原菌是立枯丝核菌（Rhizoctonia solani)，分泌毒素是其致病的主要原因。连作加剧了马铃薯茎溃疡的发生。我们的前期研究表明，病原菌粗毒素对马铃薯的根系形态与生理以及叶片和根系细胞的膜质过氧化造成了显著影响，并引起植株茎基部隘缩而导致植株死亡，但其作用机理尚不清楚。本研究拟采用高效液相色谱（HPLC）和气质联用（GC-MS）等手段分离和鉴定病原菌毒素的活性成分，同时用毒素处理马铃薯茎基部，综合采用植物病理学、生理学和细胞生物学等多学科的方法，在细胞和生理生化水平上，从膜伤害机制、抗逆生理与细胞的显微和超微结构病理学变化等角度揭示病原菌毒素对马铃薯茎溃疡的致病机理，以丰富毒素理论，为更有效地防治马铃薯茎溃疡病提供理论依据。

Rhizoctonia solani is the pathogen which causes black scurf and stem canker of potatoes, the mycotoxin produced by the pathogen is the most severe pathogenic factors. Continous potato monocropping has been deteriorating the disease. Our previous study indicated that the toxins resulted in the significant changes in morphological and physiological characteristics of root system of potato, caused lipid peroxidation of leaf and root, and let the inward contraction and canker of stem base of potato until plant death; however, little was known about the mechanisms. In this proposal, HPLC and GC-MS techniques are used to separate and identify the ingredients of the toxin. In addition, the stem base of potato plant is inoculated with the toxin, and cell membrane injury and physiological characteristics of stress-resistance as well as microstructure and ultra-structure of cells are studied by means of phytophysiology, phytopathology and cell biology methods. The aims of this study are to reveal the pathogenesis mechanisms of toxin produced by R. solani, to provide the theoretical basis for enrich the mycotoxin theory and the control of potato stem canker.