摘要
用透射电镜技术研究了柑桔褐腐疫霉(Phytophthora citrophthora)引起的橡胶树(Hevea brasiliensis Mull.Arg.)无性系 RRIM600条溃疡病,比较了正常树皮(即不施乙烯丰树皮)和施用乙烯丰(2—氯乙基磷酸,乙烯释放剂)树皮接种后菌丝的侵染和寄主细胞的反应。在正常树皮中,菌丝主要在寄主细胞间生长并引起细胞壁分解。菌丝也常常垂直穿透寄主细胞壁而在细胞内形成吸器和细胞内菌丝。当开始垂直穿透时,寄主细胞壁常常形成乳头状突起。吸器具有吸器外基质(extrahaustorial matrix),也常常具有领(collar)。施用乙烯丰的树皮病斑比正常树皮上的较早停止扩展而且病斑小得多,但是未发现菌丝侵染和寄主细胞反应的方式有明显差别。据用商品纤维素酶和果胶酶对树皮细胞壁试验,乙烯丰处理的树皮比正常树皮较能抵抗这些酶的分解。这些事实表明,乙烯丰诱导的寄主细胞的变化使菌丝侵染延迟,但并未杀伤病原,也没有完全阻止穿透。
Black stripe,the bark canker of clone RRIM600(Hevea brasitiensis Mull.Arg.) caused by Phytophthora citrophthora was studied by using transmission electron microscopy with the emphasis on comparing hypha infection and host cell response in normal bark with that in ethephon-treated bark.In normal bark the hyphae grow intercellularly in host tissue and cause dissolution of host cell walls.The hyphae oftentimes penetrate the host cell walls vertically,and form haustoria and intracellular hyphae in the cells.The papillae are often formed on host walls when the hyphae begin to penetrate the walls ventically.The haustoria possess extrahaustorial matrixes and sometimes collars.Compared with lesions of the disease in normal bark,the lesions stop spreading earlier and eventually become smaller in ethephon-treated bark. No significant differences were found in the manner of hypha infection and host cell response between normal and ethephon-treated barks.The cell wall degradation experiment by commercial pectinase and cellulase indicated that the cell walls in ethephon-treated bark are more resistant to enzyme degradation compared with cell walls in normal bark.These facts suggest that ethephon-induced changes in host cell merely retard the hypha infection and fail to kill or injure the pathogen,or to restrain complete penetration into the cells.
出处
《热带作物学报》
CSCD
1993年第1期15-19,T001,2,共7页
Chinese Journal of Tropical Crops
基金
国家自然科学基金
关键词
溃疡病
抗病性
乙烯丰
橡胶树
Hevea brasiliensis
canker
disease resistance
ethephon
ultrastructrue
