马铃薯品种对软腐欧氏杆菌皮孔侵染的抗性机制

 抗病品种的薯块单位面积上皮孔数目少,表皮角质层厚,周皮细胞层数多,皮孔组织角质化程度高。抗性不同的10个马铃薯品种自然带菌的薯块在人工诱发时,抗病品种的腐烂率显著低于来自同一田块的感病品种。9个品种的薯块用皮孔浸渍法进行人工接种后,抗病品种皮孔内细菌数量迅速减少或缓慢增多,而感病品种内则迅速增多。扫描电镜观察表明,抗病品种Murlur的薯块皮孔内的细菌畸形,皮孔内有大量颗粒状或块状填充物质,感病品种晋薯二号薯块皮孔内的细菌形态正常,皮孔內无填充物质。

MECHANISM OF RESISTANCE OF POTATO VARIETIES TO LENTICEL INFECTION BY SOFT ROT ERWINIAS

Resistant varieties have less lenticels per surface area unit,thicher cuti cle in epidermis, more layers of cells in periderm and intensive culicularization in lenticel tissues. When natually contaminated tubers of 10 varieties are induced for soft rot, the rotting rate of tubers of resistant varieties is significantly lower than that in susceptible varieties from the same field. After inoculation by dipping tubers of 9 varieties in bacterial suspension, population of bacteria in lenticels of resistant tubers are sharply decreased or slightly raised, while that in susceptible ones increased. A lots of deformed bacteria and particulate or tuberous filling substances (FS)are observed in lenticels of resistant varieties by scanning electron microscopy(SEM).Contrastly, the pathogen in lenticles of susceptible varieties is regular and no FS is found in such lenticels.